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ZI-_ - INTERNBTIONU BANK FOR RECONSmUCnON AND DlWELOPMENT

INTERNATIONAL DEVEXDPHEXT ASSOCIA'FIION

Phase I : Final Report

October, 1971

!fhe objectives of the Phase I study were, f i r s t t o survey the relevant emneer ing and economic l i t e r a t u r e to determine the s t a t e of exis%ing knowledge conctmri.ng the subs t i tu tabi l i ty of labor and equipment i n road construction, including the nature and extent of available empirical evidence, and siecond, t o p r e p e e detailed recommendations for further studies as r e q a e d .

The prel'iminary findings of the consulting team are t h a t t h q substitution of labor for equipment i s technically feasible for a wide range of construction ac t iv i t i e s for roads of various qual i t ies , but tha t almost a l l exidting engineering data are inappropriately structured or too poorly defined with respect t o specif ic environmental conditions t o permit a quantitative analysis of the dubstitution poss ib i l i t ies . Therefore a major pa r t of the Phase I study has focused on development of an appropriate disaggregation of construction ac t iv i t i e s a d delineation of the principal parameters which must be observed i n subsequent f i e l d studies i n order t o explain variations i n productivity rates.

Tne only general conclusion tha t can be ventured a t this stage of the study i s tha t specif ic environmental factors are so important tha t a case by oase analysis of subst i tut ion poss ib i l i t i e s may be required. Formulation of an appropriate computer model, u t i l i z ing existing programing routinesf, has been i n i t i a t e d i n the IBRD Economics Department and should permit removing a number of r e s t r i c t i v e assumptions tha t were employed i n the Phase I analySes t o ease the computational burden. Tne model wi l l be used i n i t i a l l y t o further ;define the data t o be collected i n the Phase IS studies. Arrangements have been made t o commence Phase I1 f i e l d studies i n India i n November, 1971.

This study has been prepared joint ly by a team from the IBRQ Economics Department bansportation and Public Ut i l i t i e s Division and four consulting firms which was f i r s t under the direct ion of Jan de Weille and subsequently of Clel l G. H a P r a1 .

Tne pressure of time deadlines has not permitted ,clearance of this d r a f t with the consulting firms so tha t they should not be held responsi61e for the analyses and conclusions given herein. Summary and Conclusions follow the Table of Contents.

Prepared b : C. G. Harral, B.P.M. Mitchell and E.P. Holland (IBRD); K,C,W. James and d ( S c o t t Wilson Kirkpatrick and partners, Ltd. ); P. Lombard and M. Testet ( ~ e a u Centr ale d l Etudes pour l e s Equipements d1 Outre-Mer ); M. Chervel and P. Trocme ( ~ s c i e t e dlEtudes pour l e Developpement Economique e"cocia1) ; J .W. Knowles and R.E.G. Smith (~conomist Intell igence U n i t , Ltd.)j M. Latimer ( ~ d i t o r i a l consultant),,

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!Cable of Contents

Summary amnB Conclusions

Chapter I: The hployment Problem and Choice of Construction Technologv

A. Introduction

Be The Choice of Socially Optimal Construction Technology

- In f l ex ib i l i t y of Available Road Construction Technology

- Price Distortions and the Divergence between .Make% an8 Social P ro f i t ab i l i t i e s

Chapter 11: lhgineering Analyses of the Substitution of Labour f o r Eauiment

A. Imtroduction

- Definitions of the Basic Inputs in Road Construction

Be Disaggregation of Construction Activi t ies

- L i s t of Basic Act ivi t ies

- Further Consideration of Basic Construction Act iv i t ies

C. Review of Available N i n e e r i n g Data and Evaluation of Alternative Sources

- Review of Available Data

- Evaluation of Alternative Sources of Information

- Conclusions Concerning Available Ehgineering Data

Dm Comparative Analyses of the Subs t i tu tab i l i ty of Labour i n Road Construction Activi t ies Based on Alternative Data Sources

- Analysis of Basic Act ivi t ies J

- Analyses of Interdependent Activities

An Introduction to Production Functions

Production hmctiona for Wad Constmction Activities I

E, Bnalyses of thet ica l Road Projects I

I

- Analyses of Production Functions fo r One ELome$re of Hypothetical. Roadworks i

Subbases and Bases I

Surf ace Dressings I

- Comparison of the Costs per Kilometre fo r Different Mixes of Equipment and Labour and Different Construction Qualities

Chapter 111: Qmlifications of tihe Engineering Analyses

A. Limitations of the Analyses

B. The Effect of the Environment on the Substitution I Problem I

I

- The Productivity of Labour , I

- The Productivity of Equipment I

- The Nature and Volume of Activities

C, Associated Ehgineering Problems

- The Problem of Scale

- T W g and Sequencing Problems

- Idle Time

- Compatibility of Equipment and Labour

- Mobilization and Other F'ixed Costs

- Problems in Comparbg Alternative Techniques

- The Aggregation Problem

Conclusions

ehagter IT: Organization and Management of Large labour Forces

A. Recsui-bent of Labour

B. Organization of the Labour Force

E. Labour Camps

F. Payment of Labour

G. Designing f o r Labour-Intensive Means

I. Social and Economic Consequences of Using More Labour

Conclusions

Chapter V: Potential Job Creation i n Road Construction

A. Calculation of the Scope and Economic Cost of Maximum Labour Substitution in the I#pothetical b a d Projects

€3. 'Phe National Promotion Scheme of Morocco: A Case Study i n Bnplogment Creation

- The Moroccan Economy

- The National Promotion Program

- The Road Construction Industry

- Additiondl Etnployment Potential i n Road Construction

C. Comparative Evaluation of the Scope f o r Labour Substitution i n Road Construction and Bther Industries

D. The Labour Surplus Problem in Less Developed Countries

Conclusions

INTERNATD3NILZI BANI5 FOR RECONSTRUCTIOW AND DEVELOPMENT

i n Road Constructbra

SlDMARY RND CONCLUSIONS

l, 61 review of the existing engineering l i tera ture has revealed an atraor-ary variation in the limitad amount of data that is available concerning productivfty rates in road constmction. Even productivity rates quoted for equiptent show a marked variation, though significantly less so than for labor. An evaluation of alternative sources of further data (including international and local contractors, supemimry consrsbting engineers and public w r k s deparhaents) has led to the conclusion that l i t t l e usef'ul information can be expected from these sources a d -that the only way to obtain rel iable information sufficiently detailed to p e d t study of the substitution problem is through direct f i e ld obsemations of ongoing mnstruc- tion projects (su plamnted by a lfmited interviewing program and further l i tera ture search 7 . 2. A major part of the study has t h e ~ f o r e focused on development of an appropriate disaggregation of constmction act ivi t ies and dellneation of the principal parameters which must be observed in subsequent f i e ld studies in order to explain variation in productivity rates. The parameters which were found to have a major effect on productivity rates and the substitut- ab i l i ty of labor encompass :

( i ) the physical environment (geology, climate, vegetation,length of h i s , height of l i f t s ) ;

( i i ) the size o r scale of the project, and the time available ta complete it;

( i i i ) the construction quality standard specified;

(iv) the social and inst i tut ional environment, including t h k prevailing att i tude toward manual labor, the organization of the work (particularly as it affects the incentives fo r productidty), and the health and nutritional standards of the labor force.

3 Despite the extremely wide variation in available, data, a series of grelirainary analyses of substitution possibilities have been atterapted in order to derive mch conclusions as may be possible and ta f o d a t e an initial

i c d approach ito the problem. In each of two paral lel analyses subet i tu t im possibi l i t ies were examined for a s e t of hypothetical road projects in different terrains fo r three typical types of paved roads. The two analyses diffemd in thei r solarces of data (one using English, the other French sourcee) and in the differ- judgements of the two erfag consultants (SWD and BcEOM). Production function isoquants were dete fo r each group

of mad mnstmction operations (earthvorlcs, subbass, b s e and surface trsabnent) eonbination s f metbods for each opera (for an assumed wage

led labor of US$l,OO per day) was dete d a d c ~ a r e d with t intensive anxi labor intensive a x t m s of" the productbn f~mction.

conelusions emerge from these e a p l e s o

feasible ta subs t i tub 1t3.bor for equkpent fo r dl bat about 10 to 20 percent of tatd mad mnstmction costs for %he higher quality construc%ion rsta&& considered hem, while relaxation of s t a d a d s to an inbmediab quaUty p e k t s labor substitution fo r on* an additbrad 5 to 8 percent of costs (iebr for a l l but about 2 to 15 prcenk of t o t a l costs).

(b) The economic feas ibi l i ty of h b o r substitution w i l l depnd, inter aUa, on the pmductivity rates of eqdpanmt m d labor and the wage

d to unskilled labor (ass a fixed se t 016 prices for nt , materials and fuel). -Be p a r a e l estimates for

one road type in rolling terrain u$%lizing ibrat ieal assmpttons eonceming wages =d prices, but e q b m g the &iff a s s ~ t i o n a concerning produsti.spity rates given by yield markedly dif femnt conclusions comcemhg th feasibil i ty of substitution. A t a wage of $1.60 per day the optimal comnbinatlon of methods would h m l n about 28 and 37 pe~cen t labor costs for the high aad btsmedia te quality cases, respectively, in the - estimates and only about 6 percent i n either case for the BCEOM analyses. The inst i tut ional framework is a major factor fn expl these differences: the BCEOM estimates reflect produc rates weighted toward experience deirived in public 'llaakeworkw projects, such as the National $romotionn in Morocco, where there is l i t t l e h c chielre eff3cient ut i l izat ion of labor, whereas the es are weighted laom by experience derived f r m dm pro th India which were oriented to sehieve m labor p r o ~ c t i v i t y .

(c) The feasibil i ty of using intermediate bchaaologies involving a mixture of modern equipment and manual methods appears gmmising and &odd be further hvestigated. For exwPe, accorWg to the estimates haradloadhg of detachable l o w slung t ra i l e r s pulled by tractors m a y be optbnab for moving earthworks and mabl ia ls over certain hadage a s t m c e s when wage rate8 for

&/ Design geometries ham not been vafied, i.e. are the same for both the intermediate and high quz98ty coastpuctiora stmdwd, Relaxation of &a%@ geolsetrics may in fact be warnantied to take better aamtage of labor intensive methods, but s s i n mnstmction costs w-i.l.3- ham $er be offset by the resulting h c in road user (vehicle opera tkg 1 costa, Andy-sss of this kind w i l l be investigated th the IBRD Highway Design Studyo See EconQnslfcs Departwent WorkFaPg P

m s l d l b d labor are in the range of DS$3.50 per day or less. Hawever, handloading of trucks muld never appeear sensible (except in isolated instances), since the cost of detaining ehe tmck e r while loading it greatly exceeds the s 3

in loa costs according to my eatinate,

h . A t this stage of the study no general mnclusions earn be B r a n in the fanor of simple cr i ter ia for d e b the optimal combination of equipent and labor intensive methods of cxnstruction. The only condusiow that can be ventured %a that specific physical, economic arad social mental, factors are so %-&at that a case by case analpsis may be re . ? h i l t 3 it Ss hoped &a% subsequent studies i g a c l u ~ g generation of an hpmved daaa base w i l l pdt a- siolplificatican of the probleaa, the smpe of the analyses still required for ea& project w i l l remain substantial. In the examples analyzed 3 ~ 3 tHs report,

s h p l i assumptions were made ta reduce the conputatqona.l burden cf and s fy the presentation. Hore adequate analyses mist distinguish inputs, separately account for local and foreign exchande cmponmks

and corporate tiam phasing and other b t e cies among Lhe a f f e r e n t activities. Thus, eonaputationally efficient al method8 should be developed for pm ject by g m jeet analysis, and fornub eomputer model of the choice of technology pmblen using existing l inear progr g routines is 4Llreaa underway Bn the Bank. The model w i l l be used hitidly to further define the necessary data fo r the Phase PI f ie ld studfea.

5 Inaslsueh as the number of environmental parameters and com@inations of parameters uhich have a major influence on pmdhmctivity rates is uery great, it w i l l m t be possible to collect infomation for more than a Umitbd sample of the t o t a l spectrum in the Phase 11 f ie ld study. However, this s t u w should help to further define the most important parameters, thus narrowing subsequent research, and w i l h in i t i a te a data bank which should be continuously extended as additional infomation becomes available from various sources. The establish- ment of a regular system for collecting this type of information from a l l future DRD highway projects is one possibility that should be considered seriously.

6 . Where labor substitution is not financially profitable, substitution may s t i l l be socially desirable where unemployment or underemployment exceeds the flfrictionalfl minimum. In these cases the ninefficiency costsff of substituting successively more labor intensive methods for equcipent can be c a l d a t e d . This cost m a y be viewed as the price of the additional jobs created, or the subsi* that w d d be r d %o compensate private contractors for treat* these jobs. Analyses of this nature were undertaken for road construction based on the SWKB a d BCEOH data, which indicate that the average cost per additional laan-day of ea~phymnt fn mad construction may range from about OS$O.49 t o 0.62, ~t

stage these, f i g m s can only be considered a9 educated guesses; they may w e l l vat-y by orders of magnitude in specific cases* An attempt was made to find comparable estimates for in-tdes other than road construction, but the l i terature search remaled no information of this nature.

7. An kvaluation of the employment creation potential of the road constmction industry revealed that while employment in road construction could be q ~ f l c b d to a great extent, particularly i f appropriate pollicy instruments (eegw mbeid3.e~ for labor o r taxes on equipment) wera vigolousw pursued, the additional employment crsated would constitute onlp a minor f saotion of that needed accordling to all available forecasts of labor force and erapEoym9nt growbh in ttPae forea~gable jruture. For example, i n the case of M[orocco it is e s t h t e d that ~ a a x h l ~ l ~ labor absorption in road ~ns t rmc t ion w i a l provide a t met about 3 percent of the jobs necessary to maintain the current ra t io s f ~ ~ l < P y m e m t over the next s yews l e t alone reduce it. However, many of the results of these an for mad comtl l l~t ion may be applicable t o other c iv i l construction act iv i t ies &A& e m p m ~ d 9 additional employment o ~ ~ t i e s e

The mloyment Problem and Choice of Construction Technology

A. Introduction

1. It i s a t r u i s m t h a t l e s s developed countries are characterized by a ckronic underutil ization of human resources. I n order t h provide improved standards of l i v ing for a r i s ing population, a l l resources available should be u t i l ized as f u l l y as possible. If, howev&r, technology i s inf lex ib le and resources are not available i n appropriate proportions, some factors may remain underutilized. When the surplus factor i s labour, those without work consider themselves denied an equitable share i n the product and are l i k e l y t o become d issa t i s f ied with the po l i t i ca l , economic, and soc ia l s t r u c t u ~ e s of their t o w t r i e s . Thus, clespite growth i n per capita income and r i s i n g productiViby leve ls i n most ccruntries, concern with what i s now called the employmen$ problem has beqnincreasing greatly. Nany people now believe employmbnt t o be the major qhallenge of development policy.

2. Despite the ava i lab i l i ty of abundant surplus labour iri many l e s s developed countries much of the construction and manufacturing i.n these economies i s highly mechanized. Some of the reasons for t h i s pr ofepence for capi ta l intensive methods can be summed up i n t e n s of (a) rlonavailability, or lack: of knowledge of, sui table labour intensive technology4 and (b) dis- tor t ions i n prices which tend t o overstate the cost of labour ar~d understate the co8t of equipment thus leading t o a divergence between so#isi~l p ro f i t ab i l i t y and pr jvate prof i tab i l i ty , which guides pr ivate firms1 choice of technique.

3 . This equipment b ias can be detected i n various industr ies . The present report i s concerned with the road construction industry and the poss ib i l i t i e s of substi tuting labour for equipment i n t h a t f i e ld ; i n

a addition, some of the r e su l t s of these analyses may be applicable t o other c i v i l construction. We f i r s t examine many al ternat ive method6 t o determine the economically e f f i c i en t method (or combination of methods) t o build a given road of specified quality. We then consider the incpkase i n economic costs tha t would be required t o employ successively more and more labour t o the point of displacing v i r tua l ly a l l equipment for the sa e of job f creation. The findings depend, of course, on what prices and wage pates are assumed; hence the e f fec ts of a l ternat ive wage ratesare ekplored.

4. The technical f e a s i b i l i t y and problems of subst i tut ing labour for equipment a re examined i n Chapters I1 and 111, while Chapter I V considers the problems of mobilizing and managing large labour forces and related issues. Chapter V examines the extent of job creation t h a t can be expected from the road c o n s ~ u c t i o n industry and calculates the costs thereof i n

t m m of the subsidies t h a t would be required t o compensate for the resul t ing inefficiencies. I n addition, the expe~ience of Morocco where the lfNational Pr omotion" cons ti tutes an important example of ~ o a d construction being used as a vehicle for employment creation i s reviewed. Finally, Chapter V I provides recommendations for f w t h e r studies.

B. The Choice of Socially Optimal Construction TeckUlology

5 m The forces of competition w i l l theoret ical ly r e su l t i n an e f f i c i en t choice of technology i n those industr ies where reasanably competitive conditions exis t . Those producers, or contractord, who u t i l i z e the most eff icient technology w i l l survive and those who do not w i l l uyltimately f a i l . I f the cost of labour i s low then contractors can be expected t o take advantage of the lower cost by using techniques tha t employ more labow and l e s s equipment. Yet the assertion i s repeatedly heard t h a t road contractors i n developing countries with large and persis tent labour surpluses are employing highly equipmen$ intensive technitlues . A t l e a s t two explanations f o ~ t h i s seeming contradiction are plgusible: First, construction technology may be so r ig id ly fixed tha t optimal methods are s t i l l highly equipment intensive desgite the presence of abundant cheap labour. Second, dis tor t ions i n mal'klet prices, the causes of which are discussed below, may tend t o overstate the t rue cost (k.e. scarci ty value) of labour i n the labour surplus ecqnomy, thus leading private contractors (and very possibly many public ag&nc:ies as well) -GO employ l e s s labour than they would i f the pr ices they confronted reflected true soc ia l costs. Let us consider these issues i n tilrn.

1. Inf l ex ib i l i ty of Available Road Construction Techliology ,-

6. The major developments of modern road construction technology have t&en place primarily i n the United States and Western Europe i n the l a s t 30 t o 40 years. I n these economies labour costs are high re la t ive t o capita$ SO tha t the major W u s t of technological development has been t o reduce the labour component by substituting machinery, much of which i s complicated and requires la rge capi ta l investments, but has high ovwal l productivity and part icular ly low labour input coefficients per llbnit of outputb Development of such equipment, of cousse, nas constituted a very favorable development for the labous-scakce developed economi$s permitting great reductions i n the costs of civ5.l construction and Pesseqing the Ittoil of man1! i n some very onerous physical work. However, this labour economizing technology i s not necessarily appropriate t o the labour abundant economy - although it may be financially profi table i f the improvement i n overall productivity i s great enough, as it certainly i s i n some road construction operations.

7 . It i s part icular ly unfortunate tha t there has been no major thrust i n world technological development toward a technology more suited t o the labous abundant economy. An ~in te rmed ia t e r f t echo logy offering improvement i n efficiency ovm f u l l y manual methods but more f l e x i b i l i t y to accommodate higher labour inputs would be highly desirable. EacHng

an appropriate intwmediate technology, f i e equipment intensive, labour miximizing technologies current i n t h e w e s t e ~ n countries, which have l i d t e d f l e x i b i l i t y for adaptation t o labour abundant s i tuat ions , have frequently been exported t o developing countries even where labour i s i n f a c t r e l a t i ve ly abundant.;/

2. Wice Distort ions and the Divergence between Market and Social prof i t a b i l i t i e s

8. Private (or f i nanc ia l ) costs are the costs ordinar i ly incwred in neeting the cap i t a l and operating costs of my o ~ g a d e a t i o n or undertaking. These a re costs as a businessman ole (often) gsvesrunent corporation would compute them, including taxes, t a r i f f s , l oca l empency value of any foreign exchange components a t o f f i c i a l ra tes , i n t e ~ e s t charges on cap i t a l investments, and the market p r ice (plus taxes end soc i a l secuasity contri- butions) paid for labour. It i s a basic tene t of %he competiCive economy t h a t r e l a t i ve pr ices of various f a c t s ~ s i n f inanc ia l cos-t terms should approximate r e l a t i v e soc ia l (or economic opportunity) costs so t h a t decisions based on than yield an e f f i c i e n t a l locat ion of Pesources which maximizes soc i a l welfare as defined i n economic theory.

9. However, it i s widely acknowledged t h a t %here are maqy instances i n developed as well a s developing countries i n which f inancial costs of production inputs may diverge from the i r soc ia l opportunity costs and the use of f inanc ia l costs i n economic planning i n general and the choice of construction technology i n par t icular would r e s u l t i n a non optimal use of resowces .z/ I n developing countries important examples include the pr ices of sk i l l ed and unskilled labor, capi ta l , inputs which u t , i l i ze foreign exchange, and inputs upon which sa l e s and o t h e taxes are imposed. For the e f f i c i e n t a l locat ion of t he countryls scarce resources, these inputs should be valued (~fshadow priced!! ) a t t he i r soc ia l opppr tun i ty costs, as d i s t i n c t from f inanc ia l costs . The soc i a l o p p o r t q t y cost of any input factor i n a given use i s the value of the output of the factor i n i t s next-best use which i s forgone because t h a t resource i l s employed i n one use rather than the other .3 / -

IJ' The preliminary engineering analyses for the hypotheticdl road pro jec t s given below suggests t h a t the technical f e a s i b i l i t y of mixing labour intensive and equipment intensive methods i n v a ~ i o u s acCivit ies should be investigated fur ther .

2 See Jan Tinbergen, The Design of Bevelspment, Economic Developnent - I n s t i t u t e s f the Internat ional Bank for Reconstruction and Development Q~altimor e: Johns Hopkins University Press, 1958 ) : A . Qayum, The Theory and Policy of Accounting Prices (Amsterdam: North Holland Publishing Co., 1960); and i n the more recent l i t e r a t m e , I,PP;,D, L i t t l e and J . A . Mirrlees, Manual of Project Analysis i n Developing Countries, Vol. I1 (Paris: omb,

Opportunity Cost of Lab~ur , rf 1 n t e ~ n a t i o n a l Labour Review ( ~ u n e 1971 ) .

31 Harberger, ib id . , and others have argued tha t the supply pr ice of marginal - w i t s of l a for given jobs i n give^ labour market areas i s a bettep measwe o f social. opportunity cost than +he fopgone product. 'This d i s t i nc t ion i s suggested pa r t l y because s f concep3;ual deficiencies i n national income accounts and pa r t l y because of p rac t ica l problems i n estimating forgone product, I

10 The market price of labour does not r e f l e c t i t s t rue social opportunity cost i n many developing counbies. There are three principal reasons why this i s so. F i rs t , government pol icies such as m i n i m u m wage leg is la t ion and social security taxes, intended to benefit the labour force, tend t o overstate the scarci ty value s f labow. Second, trade unions, where present and potent, have essent ial ly the same effect on the price of labour. n i r d , extended family ins t i tu t ions i n many countries d ic ta te t h a t the householder take i n and care for a b ~ o a d range of re la t ives regardless of what the i r contribution may be t o the f a ~ l l y farm or household industry. I n these cases the marginal product of the additional family members may f a l l below the going market wage OF even approach zero. If the marginal labour were removed, output would :remain constant or be reduced only marginally, and the social opportunity cost might be considerably l e s s than the market wage.

12. For equipment, the market pr ice w i l l often tend t o understate the sotcia1 opportunity costs, !This i s because road constructiop equipment i s qui'te t n i c a l l y an imported item and the loca l currency i s overvalued by the o f f i c i a l foreign exchange ra t e . T h i s problem may be aacentuated i n many cases by the avai labi l i ty of foreign loans for equipmant a t concesei'onary ra tes of i n t e r e s t provided by b i l a t e ra l and in te rmt iona l lending agencies.

12. Private contractors and many government agencies base the i r decisicpn concerning the choice of technology on market prices. 'l$us where the market price overstates the t rue cost of labour and upderstates the t rue cost of equipment, the resul t must be choice of a more equipment- intensive technology than i s economically ef f ic ient or socialLy desirable.

13. If i n f ac t subsequent studies provide proof tha t more labour intensive technologies would be ef f ic ient , or social ly desirauls even i f ineffic;ient, various policy measures may be considered i n order t o guide the chpice of technology along desired l ines . These include, in ter a l ia , taxes pn the purchase of equipment, subsidies on labour employe~d, and d i rec t force account work by public agencies employing labour 'intensive techniques. These policy irstruments are not treated i n the present report but w i l l be aonsidered i n subsequent studies.

- I Chapter 11. Engineering Analyses of the Substitution of Labor for Equipment

A. Introduction --

1. The basic inputs in road construction are labour, equipment and materials. Over recent years, the general trend has been to reduce the labour input by increasing the use of equipment and hence, in view of the higher productivity of the latter, to reduce the time needed for and the cost (in financial terms) of copstruction. The increasing use of equipment has led to a rise in the qwlity of the finished product since in many of the construction Dxocesses closer tolerances can be achieved than with hand labour. It has also encouraged the development of designs and methods which are particularly suited to equipment-intensive operations.

2. The principal question which the engineering studies are required to answer is:

"What, from a purely technical point of view, is the scope for substituting labour for equipment in road construction, taking into account a variety of physical (and economic ) environments. 'I

Before the advent of civil engineering equipment, there was no alternative but to build roads by hand labour assisted by simple hand tools. Hence, from a purely technical aspect, roads mdoubtedly can be built by hand labour, but not necessarily to the s a e design or to the same standards of quality as can be achieved by equipment.

30 Some of-the older forms of road pavement constructign, such as pitching and stone setting, are clearly not suited to mechanical construction. Waterbound macadam bases were originally de+ised for construction entirely by hand labour; however, while it id technically possible to manufacture and lay waterbound macadam by equipment, such bases have been largely replaced in the developqd countries by graded stone ('crusher-run1) bases which can be produced more easily by mechanical crushers. On the other hand, some modern forms of construction necessitate the use of eguipment; for example, an asphaltic concrete pavement can be laid normally only by machine.

4. Even with the most modern forms of construction, there are a few activities which have to be undertaken by labour. Furthermore, it is technically possible to carry out many activities associated with equipnent-intensive methods (such as production of local materials and their handling and transport) without reducing the overall standards of workmanship and quality. Hence, while the scope for labour substitution may be restricted by the desi=, it still exists to some degree even with the most modern equipment-orientated designs and techniques. This study attempts to measure the extent to which such substitution is possible for roads of various standards.

5 The quality of a finished road is dependent upon its geometric design, its riding performance and the period of time over which the latter is maintained. For a given design, the riding performance and durability are mainly governed by the standards achieved in construction where such activities as compaction and surface finishing are important. Other activities, such as haulage of materials, have no effect whatsoever on the quality of the finished road. In considering the scope for labour substitution, account needs to be taken of the quality levels reas onably attainable by labour/equipment in these cri ti- cal activities. Three levels of quality have been considered - high, intermediate and low - and have been defined in t e c ~ c a l terms for each of the critical activities. It should be noted that equipment intensive techniques do not necessarily imply a high quality factor; in certain activities (e .g. selection of excavated materials) hand labour can often do better than equipment.

6. The general approach to the engineering side of the study nas been to break down the road construction process into basic activities, and to assess the technical feasibility of labour substitution within each activity in relation to quality and environment. The relative importance of labour and equigment in road construction and the theoretical scope for labou substitution have been analysed without taking account of the constraints which w~n~la lirllit the extent to which this cauld be done in practice. 11 Productivity data for both labour and equipment have been a~stracted and reviewed. The effects of the environment on the substitution problem have been awlysed and the associated engineering problems have been evaluated.

Definitions of The Basic Inputs in Road Construction

7. m e study is concerned with assessing the possibility and practicabilikj of varying the mix of two of the basic inputs, labour and equipment, in road construction. For the results to be meaningful, it is essential that account bq taken of any consequential changes in the third input, materials. Th& substitution of labour for equipment necessarily entails the replacement of the skilled personnel engaged in equipment operation and maintenance by other (mainly unskilled or semi-skilled) labour ; the latter also save the materials consumed in operating the equipment.

8. In the context of this study, the meanings of the terms flequipmentn , tflabourll and Ifmaterials 11 have been widened to take account of these factors in such a way as to simplify the computational burden of the analyses and presentation sf the ~esults. These simplifications are not essential and would be relaxed for more advanced analyses than the examples given in the present report.

. .

1/ These constraints are described in Chapters I11 and IV. -

9 IlEquipmenttr i s taken t o mean e s sen t i a l l y powered machines t h a t replace ra ther than a id unskil led labour. It includes the trained. operators, operatorsf ass i s tan ts , maintenance mechanics and f a c i l i t i e s , s p m e pa r t s and other consumable mater ia ls such a s fue l , greases, tyres , etc., required for i t s operation.

10. With tlie exception of the operators and mechanics r e f erred t o i n paragraph 8, lllabourll consis ts of a l l categories of sk i l l ed , semi-sHlled and unskil led labour. It a l so includes the hand tools required t o car ry out the work together with elementary unpowered equipment such a s wheel barrows, hand-operated winches, pumps, handcarts, etc., whose main purpose i s e s sen t i a l l y t o increase the productivity or improve the qua l i t y of the work carr ied out by unskil led labom rather than t o replace it. It includes animal-drawn car ts .

11. W i t h the exception of the consumables requizled for equipment operation (which a r e defined as forming p a r t of 1requipmentlt) materials a r e divided i n t o t he following categories:

IfManufactured" - those materials which a re not produced a s p a r t of t he road construction operation and the labour/equipment input i n t h e i r manufacture i s beyond the control of the road construction author i t ies . Examples of materials i n t h i s category a r e cement, bitumen and s tee l . I n general, the quant i t i es required for a given operation a r e independent of the manner i n whikh the operations i s carr ied out; there a r e exceptions, such a s the possible need t o use a higher proportion of cement t o achieve a specified concrete s t rength when mixing by hand. An essen t ia l requirement of these materials i s t h a t they cannot be subst i tu ted for, e i ther i n p a r t or i n whole, by labour.

( i i ) "Localtt - those materials which can be produced as pa r t of the construction work. Common examples a r e crushed rock products, br icks and pre-cast concrete un i t s . These mater ia ls can be produced with varying combinations of labour and equipment and they a r e therefore t rea ted as par t of the cons tmct ion process.

12. It will be noted that there are materials which under different circumstances could be categorised as manufaatwed or local. For example, in certain areas timber for bridging, fomwork, etc., could be produced, by hand or by machine, as par* of the road construction and hence it would be categorised as a loaal material; on the other hand, it might be purchased as a manufactured product. Similar considerations could apply to other materials such as lime for stabilisation, crushed rock products, pre-cast condrete units,etc.

13. One material which falls into neither of the two categories is the explosive for blasting. This is manufactured but can be replaced entirely by hand labour. To avoid having a further category, explosive material is considered to be part of llequipme/ntll and dealt with in the same way as the consumables required for plant operation.

. Although the study is primarily concerned with t(he substitution of unskilled labour for equipment, it is clear that acclount must also be taken of the corresponding substitution of unskilled for skilled labour and the replacement of materials by labour.

B. Disaggregation of Construction Activtties

1. List of Basic Acti~ties

15. The first approach to defining the basic construction activities? centred on an analysis of a typical specification and bill of quantities for road construction. Many of the basic activities were found to be common to several "bill items1' and it was considered that a better approach would be to define the basic activities, grouping similar items together, and to build-up the "bill itemsB1 or processes from them. Varying d e ~ e e s of disaggregation were considered. To permit the full analysis of labour substitution possibilities, it was concluded that complete disaggregation was required to the state where an activity could be carried out either solely by labour or solely by equipment with no possibility of a mixture of the two inputs.

16. A n attempt has been made to minimize the number of basic . activities by grouping reasonably similar activities together; for instance, loading such items as soils, crushed rock and stabilised materials has been considered to be the same activity since the productivity rates and hence the trade-off between la'tJour and equipment would differ only marginally.

17- Sub-division of activities has been necessary %o allow for differing qualities of workmanship where these' would affect the quality of the finished road. However, in many of the activities this has not been necessary, since either there is no significant difference between the standards obtainable'by labour and equipment- intensive methods or the quality of the basic activity has a negligible effect on the quality of the finished road.

18. Further sub-division of activities has been necessary to allow for inherent variations in productivity rates due to environmental factors, since the optimum trade-off between labour and equipment could vary. This applies in the case of clearing and gruhhin~. where allowance has been made for the density of vege0ation; in excavation where the nature and condition of the soil has a pronounced effect on productivity; and in haulage where the distance involved is paramount in determining the technology.

19. While the scale of the work and the time available will, in practice, limit the extent to which labour substitution can be implemented, they have not generally been taken into account in identifying the basic activities since these factors can best be dealt with during the aggregation process. A n exception is the case of earthworks where a distinction has been made between excavating 'in small quantities and excavating in bulk, since the former is more suited to the use of labour.

20. In drawing up the list of basic construction activities certain works have been excluded. The most notable omission has been bridgeworks, which have been specifically excluded from the study (though culverts have been included ) . Other excluded works are fencing, pavement markings, signposting and other minor items which would have little significance in the overall asgects of labour substitution.

I

21. The basic construction activities are listed immediately following this section. Each activity has been categorised in the following terms:

(1 ) "EM denotes an activity which is essentiblly equipment- intensive and labour substitution is not technibally feasible.

(2) "Ll1 denotes an activity which is essentiglly labour- intensive and equipment substitution is not technically feasible . ( 3 ) "ELI1 denotes an activity which cari be carried out by either equipment or labour. I

22. The main criterion applied in assessing these cbtegories has been that of technical feasibility as distinct from thbt of technical possibility. While it could be argued, for instance, that crusher-run base material' (~ctivity 11.8 could be produced by ha+ labour, it is doubtful whether this would ever be done, since waterblound macadam would be better suited to a labour-intensive project.

23. The categorisation of activities indicates is technically feasible to substitute labour for from the practical constraints of scale, timing, labour, etc., that might apply in relation to a

taken into account. the effect on costs consequent on labour

I

I

24. If the substitution process leads to increases in equipment costs for a particular activity, then there is clear1 no benefit to be gained by so doing, irrespec'tive of the wage ra e for labour - this particularly applies in the loding activity whe i ein any savings in replacing loading equipment by hand labour could be more than offset by additional equipment charges for the increased waiting time of the vehicle being loaded. Labour substitution is cons4ide:red impracticable in such cases.

25. While the level of disaggregation has to some extent been governed by the need to allow for differing productivity rates due to environmental and other factors, this has been limited to those cases where productivity'is dependent primaglily on the nature of the work. Disaggregation has not been based on:

(i) Differing types of equipment which could be used for a particular activity and which would have differing productivity rates, unless the nature of the activity is essentially of a different character (e .g., mixing stabilised materials "in situ" or "not in situ").

(ii) Differences in the relative rates of pr~ductivity of equipment and labour due to environmental and gther factors (for example, a particular environment may lead to high productivity for equipment but low for labour). ,

26. These general principles have been applied to varying degrees in isolating the basic activities. The degree of disaggregation has been greatest in those cases where substitution of labour for equipment appears to have the best possibility technioaily.

27. In certain construction processes, disaggregation to such a detailed level is not meaningful. This particularly applies to earthmoving operat ions carried out by equipment. For example, a scraper operation combines the basic activities of exdavating, loading, transporting, unloading, spreading and part a ompac t ing ; excavating by shovels is invariably combined with the loading operation, and numerous other examples could be quote . Similarly, with labour-intensive methods, the excavating and loa d ing activities, and the unloading and spreading activities, are often carried out simultaneously. It is therefore clear that in additidn to considering each basic activity on its own, it will be necessary qo take into account combinations of certain associated activities.~

28. There is a further interaction between some seduential activities and this particularly applies in the load*, hauling, unloading and spreading activities. The method of haql, be it by head basket, wheel barrow, animal cart, tractor/trailqr, truck or scraper, givee rise to differing loading heights and corresponding loading rates. Similarly, the method of unloading influences the effort required for spreading. These factors have not been taken into account in drawing up the list of basic activities at this stage, but it is clear that further sub-division of the basic list will eventually be required. Further reference is made to this aspect in Section .

29. The trade-off between labour and equipment varies from activity to activity and is dependent on the relative costs (and productivities ) of the alternatives. Labour substitution could lead to increases in cost and, in practice, there would clearly be a limit to which this would be acceptable. For the purposes of this study, labour substitution has been deemed to be impracticable if the cost of carrying out an activity by equipment (at the assumed rates) is less than that of carrying it out by unskilled labour at a daily wage rate of ~~$0.20.

30. While the list of activities is thought to be comprehensive, further additions and greater disaggregation may become desirable as productivity data becomes available during the subsequent stages of the study. The areas in which this is most likely to occur are referred to in the next section of this Chapter.

%ble 11.1. List of Basic Construction Activi t ies

1. S i t e Preparation

1.1. Clearing and grubbing (1) l i g h t vegetation (2) medium vegetation (3) dense vegetation

1.2 Skipping topsoil

2. Excavatinst: Small Quantities

2.1 In so f t material 2.2 I n h a z d m a t e r i a l 2.3 I n r o c k

Category

3 Excavatiw i n Bulk

3.1 In s o f t material 3.2 In hazd material 3.3 In rock

4.1 Homogenous loose materials (e.g. s o i l , EL crushed rock, s tab i l i sed materidls, asphal t ic concrete, etc. )

4.2 Other so l id and packaged mater iTs EL (e.g. bagged cement, drummed biQxnen and petrol , lump rock, re inf orc+ent, etc.) I

I

4.3 Water I

EL I

4.4 Other bulk l iquids (e.g. bulk EL bitumen, fuel o i l , petrol , etc.~)

Table 11.1 (continued)

6.1 Homogenous loose materia Ls 6.2 Other solid and packaged materials 6.3 Water 6.4 Other bulk liquids

7 Spreading

7.1 Natural soils (for earthworks )

7.2 Unstabilised base and sub-base materials, quality factor

7.3 Stabilised base and sub-base materials, quality factor

7.4 Bitumen macadam and asphaltic concrete, quality factor

7.5 P.C. concrete for pavements, quality factor

7.6 ~ement/lime for stabilised bases, quality factor

(1) high (2 ) intermediate

7.7 Bitumen for surface dressing, penetration macada~, etc . , quality factor

high . intermediate

7.8 ~ravel/sand for surface dressing, penetration macadam EL

7.9 Water(forcompactionandcuring, EL limewater for stabilisation)


8. Mixing

8.1 N a t u r a l s o i l s i n s i t u ( f o r mechanical stabilisation, aeration, etc.), quality factor

(1) hi& (2 j intermediate (3) low

8.2 ~ement/ l imewithsoi l s ins i tu , quality factor

(1) hi& (2) intermediate (3) low

8.3 ~ement/lime with s o i l s not i n s i tu , quality factor

(1) hi& (2) intermediate

8.4 Cold bitumen w i t h so i l s i n sib, quality factor


8.5 Cold bitumen w i t h so i l s not i n s i tu , quality factor

(1) h i & (2) intermediate

8.6 Hot bitumen with so i l s not i n s i tu , qual4. t~ factor

(1) U3-h (2) intermediate

8.7 Bitumen macadam, quality factor


8.8 Asphaltic concrete E

8.9 P.C. concrete, quality factor

(1) hi@ (2) intermediate 3 low

9 Compac tin^ and Finishinq

9.1 Bulk materials i n earthworks, quality factor



9.2 Unstablisedbases andsub-bases, quality factor

10. Laying


9.3 Stabilised bases and sub-bases, quality factor

(1) high (2) intermediate

9.4 Bitumen macadam, quality factor


9.5 Asphaltic concrete

9.6 Surface dressings, quality factor


9.7 P.C. concrete for pavements, quality factor

(1) high (2 ) intermediate

10.1 Stone pitching 10.2 Brick soling 10.3 P.C. concrete linings (including

compacting and finishing ) 10.4 Masonry walling 10.5 Brick walling 10.6 Precast concrete products 10.7 Steel pipe culverts 10.8 P.C. concrete in foundations,

headwalls , etc . , (including compacting and finishing quality factor

(1) high (2) intermediate (3) low

1 1 . Production of Local Materials

1 1.1 Rock for pi tching/masonry EL 11.2 Coarse aggregate for waterbound EL

macadam 11.3 Crushed rock for bases and sub- E

bases (i.e. Crusher run) 11.4 Coarse aggregate for bitumen EL

macadam


11.5 Coaxse aggregate f0rP.C. concrete asphaltic concrete

1 1 .6 Coarse aggregate for quality factor

(1) hi& (2 { intermediate 3 low

11.7 Coarse aggregate (chippings) for surface dressing

11.8 Fine aggregate, quality factor

(1) (2) intermediate (3) low

11.9 Making bricks 11.10 Breaking bricks 11.11 Precast concrete units,

quality factor


Miscellaneous

12.1 Cutting, bending and fixing reinforcement

1 2.2 Formwork (including stripping) qualiw factor

hi& (=owt) intermediate (rough)

12.3 Laying, trimming and compacting EL topsoil

12.4 Sprigging with grass, etc. L

12.5 Seeding w i t h grass, etc. ' EL

12.6 Brooming and cleaning surfaces EL

-ent and Other

13.1 Site overheads, logistic support, etc.

13.2 Head office overheads and profit

1 3.3 Administration

1 3 .4 Mobilisation, including transport to site offices

Further Consideration of Basic Construction Activities

Site Preparation

31. Clearing and grubbing have been treated as a single activity though the two are occasionally carried out as separate operations. Productivity depends on the thiclmess of vegetation and t h i s has been allowed for by sub-division of the activity into three levels - light, medium and dense vegetation. No separate activities have been provided for demolition of buildings, structures, etc., which are seldom of significance in under-developed countries.

32. The activity for removing topsoil is confined to tliis operation alone. Loading, transporting, unloading, e tc . , when replacing topsoil is provided for under other activitiea.

Excavating in Small Quantities

Excavating in Bulk

3 . These two groups of activities are confined to the actual digging operation. The first group applies to tho excavation of small quantities in ditches, trenches, foundations, etc,, and it differs from the second group in that the excavation is invariably to precise lines and levels and hence it is more suited to hand labour. The second group includes bulk excavation in cuttings and borrow pits where tolerances are not ao strict and are of less significance in relation to the quantity of material moved.

3 . In both groups sub-divisions of the activity have been made to allow for the effect on productivity of the nature of the ground. The sub-divisions are defined:-

(1) "Softt1 - capable of being excavated by a spade or similar hand tool; or capable of being loaded by a tracked scraper without push assistance but becoming uneconomic to do so; or capable of being loaded by a wheeled scraper with push assistance.

(2) "Hard1' - requiring to be loosened by a pickaxe or crowbar before excavation by spade, etc., can take place; or capable of being loaded by scrapers with pre-ripping and push assistance.

( 3 ) Tiock" - requiring the use of &rills, plugs, feathers or wedges if excavated by hand, or mippable by earthmoving machines and requiring the use of

tools and/or blasting. I

35.. These are the broad contract defirlitiorls but they are clearly not adequate for precise identification of all materials. It is considered that, as the study proceeds, there will be such a .wide range of productivity rates dependent upon this factor that further sub-divisions will become essential.

36. To allow for the wide difference in rates of loading by hand labour and equipment and since transporting equipment is not productively employed during loading, this activity is defined as including the waiting time during the loading activity of any equipment for transport. Four sub-divisions of the activity are envisaged, depending on the nature of the materials being loaded.

37. No provision has been made for variations in the height through which materials are moved during the loading activity. This can have a marked effect on productivity, particulgrly when loading materials by hand labour, and may need to be taken into account during later stages of the study.

Hauling

38. Three sub-divisions of this activity have been provided, depending on the length of the haul, viz:

(1 ) up to 300 m - the practical limit of hand labour (though greater distances could be achieved using a relay systeln of carriers)

(2) up to 2 km - the practical limit of haulage by scrapers and animal-drawn carts

( 3 ) over 2 km - essentially a truck or tractor/txailer operation

These arbitrary sub-divisions might need to be amended in the light of further experience.

39 No differentiation has been made between loaded and unloaded trips since the former necessarily entails the latter and they can both be taken into account by averaging. The height to be gained or lost during haulage significantly affects the productivity of hand labour but that of equipment to a lesser extent; some further disaggregation of this activity might be shown to be desirable to allow for this factor. Similarly, the condition of haul routes would particularly affect equip-. ment productivity but this can be allowed for as an environmental factor.

Unloading

40. As with the loading activity, the waiting time of any equipment used for hauling is included. The same sub-division (by nature of the materials unloaded) of the activity has been adopted. It seems unlikely that further disaggregdtion to allow for variation in unloading heigfit will be required since this has little effect on productivity. However, account will probably need to be taken of the haulage method since, for example, the use of self- tipping vehicles would preclude the use of labour for unloading. (see also paragraph L3 )

4 The quality of worlananship in many of the activities in this group can have a pronounced effect on the quality of the finished road and it has been necessary to allow for this factor in the dis- aggremtion process. As previously stated, three general levels of quality have been chosen; these can be defined in terms of the degree of control exercised over the activity, permitted tolerances in the thickness of layer (or rate of spread) and permitted tolerances in the upper surfaze of thewlayer. Many of the activities are concerned with spreading high-cost materials such as bitumen and cement mixtures; it would not be appropriate to utilise low standards of quality with these materials (though this doubtless occurs at times j and hence the lower levels of quality have been omitted in these cases.

42. The qualitjr factors are defined as:

(1 j For bases and sub-bases (~ctivities 7.2, 7.3, '7.4 and 7,s)

High - Courses laid to precise levels with a substantial degree of compaction incorporated in the spreading process. Tight control. of thickness of layer on basis of direct measurement after compaction. Surfaces true to line and level with little or no reshaping required during or after compaction.

Intermediate - As above but no pre-compaction required during the spreading process and reshaping permitted during and after compaction.

Low - Thickness of layers controlled by average rates of spread of loose materials (e .g. measured by truck load ). Surface tolerances achieved primarily by shaping during the compaction process.

(2) Cement, Lime and Bitmen ( ~ c t i v i t i e s 7.6 and 7.7)

=gYL - P ~ e c l s e ~ o c i r o l of rstss and u r i f o m i t y of spread by r e g d m d i rec t measurement (by t ray t e s t s ) and frequent checking and cal ibrat ion cf spreading devices, becurate control of bitumen temseratwces .

Intermediate - Precise control of r a t e of spread by checking q u x t i t i e s i n re la t ion to areas covered but control of u~df ormi t y of spread by visual fnspse-Lion only, Fair ly wide margins on b i tmen temperatmes.

43. Some further disaggregation may be necessary t o takre account of the way i n which ma3erials t o be spread are ploaded. For .instance, materials carried by head basket can be unloaded so t h a t l i t t l e spreading i s required whereas those dumped f r m a kpck would en ta i l much more e f fo r t $0 spread,

Mixing. y,

u, As i n the previous g o u p of a ~ t i v i k i b e s ~ i t has been necessary t o take i n t o account the quality of workmanship. Again, although three general leve ls of quality a re used, the. lowest quality has been deemed not to be appropriate w i t h high-cost materials. In the case of asphal t ic concrete i t i s considered that only the highest quality would apply.

45, Tne quali%y .factors a re defined: - ( I ) Natural Soils i n S i t u ( Activity 8.1)

High - Involving pulverisation and intimate, uniform mixing of the s o i l s and W f o m moisture content; high degree of control by frequent t e s t ing of gradation amd moisture contents.

Intermediate - A s above but without pulverisation of the so i l s ; a high degree of control but s l ight ly lower standards of unif ormitg acceptable.

Low - A blending or " t m i n g overt8 of s o i l s rather than mixing; control exercised mainly b;y visual inspection. ( ~ e s a t i o n of s o i l s would f a l l i n t o t h i s category . )

(2) ~ement /~ ime w i t h So i l s (Act iv i t ies 8.2 and 8.3)

High - Involving p 'dver isa t ion and int imate, uniform mixing of the cement/lime with the s o i l and uniform moisture content; weigh batching f o r "not i n si.&uf' process; high degree of control by frequent t e s t i n g f o r cement/lime and water content.

Intermediate - A s above but without pulverisat ion of the s o i l s ; volumetric batching f o r "not i n s i tuIP process; a high degree of control but s l i g h t l y lower standards of uniformity acceptable.

Low - Blending of the cement/lime with the s o i l by " t u n i n g over" ra the r than mixing; control exercised mainly by v isual inspection.

(3) Cold Bitumen with So i l s (Act iv i t ies 8.14 asld 8.5)

High - IwvoPving p d v e r i s a t i o n and int imate, un i fom mixing of the bitumen with the s o i l ; weigh batching f o r "not i n s i t u " process; high degree of control by frequent t e s t i n g f o r bitumen content.

Intermediate - A s above without pulverisat ion of the s o i l ; volumetric batching f o r "not i n s i t u " process; a high degree of control but s l i g h t l y lower standards of uniformity acceptable.

(4) Hot Bitumen with So i l s ( ~ c t i v i t y 8.6)

A s (3) but with addi t ional requirements f o r control of bitumen temperatures.

High - Involving int imate and uniform mixing with weigh batching of ingredients; precise control of temperature of ingredients and f i n a l mixture; high degree of control by frequent test i r lg f o r gradation and bitumen content.

Intermediate - Sl igh t ly lower standards of uniformity acceptable and volumetric batching of ingredients ; no precise temperature control ; control mainly by v isual inspection.

(6) l , .C . concrete (Activi ty 8.9)

High - Weigh batching of a l l ingredients with precise control of moisture content of aggregates, proportions of ingredients , mixing time, workability and strength; normally required t o produce high strength (above 30 MN/m2) c s i c r s t e , I

Intermediate - Volumetric batching of a l l ingredients with s l igh t ly lower standards. of control; to produce concrete strengths within the range 1 5- 30MN/m2.

Low - Volumetric batching of sol id ingredients with control of workability, water content and workability mainly by visual inspection; low concrete strengths ( l e s s than 15 MN/1112).

NOTE: Wherever weigh batching i s specified, calibrated adjustable volumetric devices providing the same standards of accuracy would be acceptable fo r continuous mixing processes.

~ompacting and Finishing

46. Although compacting and finishing are separate ac t iv i t i es , requiring dif fer ing types of hand tools or equipment, they ase essent ia l ly undertaken as a joint operation. Ekperience may show that they should be deal t with separately, but it i s believed that f u l l disaggregation i s not necessary i n t h i s case.

47. Disaggregation of the individual ac t i v i t i e s h&s again been based on quali ty following a similar procedure adopted t o that i n the spreading and mixing groups. In the case of earthworks, some further disaggregation by s o i l type w i l l certainly be required since the e f fo r t required tomeeta given level of compaction varies between wide extremes depending on the s o i l type; the desirable range of compaction i s similasly dependent on the type of soil/material .

48 m e quali ty factors are defined below:-

(1) Bulk Materials i n Wthworks

High - Greater than 9% B.S. (Proctor") compaction with a high degree of control of moisture content and f i na l density by frequent testing.

Intermediate - Between 90 and 95% B.S. (Proctor) compaction with a moderate degree of control possibly by a method specification ( e . g . by a cer ta in number of passes of a specified type and s ize of r o l l e r a t a specified moisture content).

Low - ~ e t w e e n 85 and 9% B.S. (Proctor) compaction w i t h control mainly by visual inspection and moisture content testing.

(2) Unstabilised Bases and Sub-bases

High - Greater than 98% B.S. (Proctor) compaction with a high degree of control of moisture content and final density by frequent testing.

Intermediate - Between 95 and 98% B.S. (PPoctor) compaction with a moderate degree of con-trol, possibly by a method specification.

Low - Between 90 and 95% B.S. (Proctor j compac.tion, control mainly by visual inspection and moisture content testing.

(3) Stabilised Bases and Sub-bases

High - Greater than 97% B.S. (Proctor) compaction with a high degree of control by frequent density testing.

Intermediate - Between 94 and 97% B.S. (~rroctor) compaction with a moderate degree of control, possibly by a method specification and (where applicable) moisture content testing.

(4) Bitumen Macadam

High - Bulk density greater than 95% of the maximum density for the material when compacted in a suitable mould using unlimited compactive effort.

Intermediate - Bulk density between 90 and 95% of the above maximum dens'ty.

(5) SurfaceDressings t

High - Rolling by heavy pneumatic-tyred rollers which facilitates the penetration of the chipping into the underlying material without crushing.

Intermediate - Rolling by other equipment which causes some crushing of the chippings and/or lack of penetration into the underlying material.

High - Compacted by mechanically operated vibrating beams.

Intermediate - Compacted by hand tamping supplemented by vibrators.

49. The foregoing principles define the quality standards relat ing to the s ta te of compaction. They aze coupled to requirements for surface finish which are given below i n terms of maximum tolerances:-

High - Within 10 mm of required levels; when tested with a 3 m straight edge placed a t right angles or pazallel to the carriageway, no depression to exceed 10 mm.

Intermediate - Within 20 mm of required levels when tested with a 3 m straight edge placed a t r ight angles or parallel to the carriageway, no depression to exceed 20 mm.

Low - No precise requirement relat ing to required levels; when tested with a 3 m straight edge placed a, t r ight angles or parallel to the carriageway, no depression to exceed 30 mm.

While i t would be possible to combine differing levels of qptlity for compaction with those for finishing, the same levels are, i n general, compatible with each other.

Laying

50. Further additions to this group of act iv i t ies may be required to cover construction techniques peculiar to specific countries, together with some further disaggregation (e.g. differentiation between dry-stone masonry and that la id i n mortar).

51. In the items for concrete linings and concrete i n foundations, headwalls, etc., the separate basic act iv i t ies of placing, compacting and finishing have been aggregated since these act iv i t ies form such a small part of the construction operation and are carried out essentially as part of the same operation. The quality factors for concrete i n foundations, etc., are:-

High - Thin reinforced concrete sections requiring close tolerances of finish and trowelled/floated surfaces.

Intermediate - Mass concrete sections requiring close tolerances of finish and trowelled/floated surfaces.

Low - Mass concrete with screaded surfaces.

Production of Local Materials

52. The a c t i v i t i e s i n this group r e l a t e only t o the actual production processes and other a c t i v i t i e s , previously defined, m e required t o cover the f u l l operation of producing a loca l material. The intent ion i s tha t the processes required f o r the production of loca l materials should be f u l l y disaggregated. Examples are:-

( 1 ) The a c t i v i t i e s f o r producing coarse aggregates ( 11.2 through 11.7) cover only the crushing operation. Supplementary a c t i v i t i e s that might be required t o cover the f u l l processes are excavating i n rock, loading, transporting, unloading, e tc .

(2) Activity 11.8, f i n e aggregate, covers the cq~shing , washing, blending and grading operations only. Supplementary a c t i v i t i e s would include the excavation of the sand, loading, e tc . , and the supply of water fo r washing.

( 3 ) Activity 11.9, making bricks, covers only t l ~ g forming and burning of the bricks. Supplementary ab$iv i t ies t h a t might be required t o cover the f u l l prboess axe excavation of brick clay, loading, transporiti.ng, unloading, etc.

(4) Activity 11.11 precast concrete units , includes erection and str ipping of moulds and the plac,ing, compacting and f inishing of the concrete. Local materials f o r and the mixing of the concrete would be covered under other a c t i v i t i e s .

53. The qual i ty fac tors a r e defined:

Coarse Aggregate for- P.C. concrete ( ~ c t i v i t y 11.6)

High - A homogeneous precisely graded clean mi:rture achieved by blending fract ions of d i f ferent s i zes together; washed i f necessary.

Intermediate - A well graded mixture with wider tolerances than above, achievable by modern crushing plant without blending.

Low - A stone mixture with unspecified grading except f o r l imitat ions on the m a x i m u m stone size.

(2) Fine Aggregate (Activity 1.8)

High - Washed, with precisely defined grading characteristics which may require blending of two or more materials or other processing.

Intermediate - Washed, but with no grading requirements.

Low - Unwashed, with no grading requirements. NOTE: The lowest level of quality seldom applies since such

aggregate can normally be obtained by the excavating activity alone. However, it is included here since in some sand-deficient areas fine aggregate is produced by crushing rock

( 3 ) Precast Concrete Units (Activity 11.14

High - Spun or hydraulically pressed units. Intermediate - With concrete compacted by tarnping

or vibration.

Miscellaneous

54 Again, the intention is that activities within this soup should be fully disaggregated. Other associated activities required for the full processes would be considered separately.

Management and Other

55. Theseitemshavebeenlistedseparatelysince theyforman integral part of any road construction project. They are not (in the true sense) activities and labour substitution can apply in only a few isolated instances (such as partly in the erection of construction camps). However, it is essential that they be distinguished from the construction activities and their proportion of the total cost of a project be recognised. They are related, in one way or another, to the feasibility of labour substitution and the trade-off between labour and equipment. For instance, in some areas, it may be less costly to mobilise labour than equipment; a larger site staff may be required to supervise labour-intensive projects; it may be argued that a labour-intensive project involves greater risk to a contractor, owing to the possible incidence of strikes, difficulties of enforcing discipline, and greater management problems, etc. and hence higher profits might be justified.

C. Review of Available Engineering Data and Evaluation of Alternative Sources

56. This section describes the sources of engineering data found i n the survey of exis t ing l i t e ra tu re , and evaluates the adequacy of these data and the problems i n collecting more adequate information.

1. Review of Available Data

57. Data recording the productivity of equipment and labor has been extracted during a study of the l i t e r a t u r e described i n Appendix A and referenced i n the engineering bibliography. The data sources have taken three main forms - records of projects and experiments, interviews with contractors, and estimating handbooks. An attempt has been made t o assess the adequacy of the data a s either good or poor and it can only be concluded t h a t the available data a re highly inadequate and i r su f f i c i en t ly detailed t o permit study of the subst i tut ion problem. The two main reasons for this assessment are:

(1) Lack of disaggregation of basic a c t i v i t i e s t o the leve l required for the study.

(2) While precise output f igures have been recorded, the conditions and environment under which these outputs have been achieved (or are possible ) have seldom been described.

A notable exception t o the foregoing i s the 1963 ILO publication, "en Who Move mountains^^,

58 A review of the data reveals an extraordinarily wide range of productivity ra tes , par t icu lar ly of labour, i n d i f fe r ing environments. While cer tain of the published figures could be r e l i ed upon t o be represen- t a t ive of Itaveragell conditions, it would be impossible t o quantify the e f f ec t of environment ( in i t s widest sense) on productivity by any siinple ra t ing system.

59 An important example of the extremely wide variat ion i n labour productivity r a t e s i s given i n Table 11.2 for the case of bulk excavation. m e r e applicable, the source figures have been modified to correspond with the working day of 8 hours assumed for the analyses.

60. The data given i n Table 11.2 are drawn from a wide range of environments and they range for a single s o i l categorization ( ~ o r d i n a r y ~ ~ ) from 0.13 to 8.00, or a var iat ion of more than six thousand per cent. A t l e a s t two factors may be offered t o explain this extraordinary variation. First, a more specific geotechnical ident i f ica t ion of s o i l types w i l l be required; moisture content i s only one important parameter which has been l e f t undefined.

Table 11.2 Labour Intensive Methods Input Coefficients

Ekcavating i n Bulk and Loading Into Wheelbarrows

Source, Year (~e fe rence No.)

EClhFE ear ly 1960's (SW 11, Philippines ECAFE ear ly 19601s (SW l ) , Japan

ear ly 19601s (SW I ) , Burma ECAFE ear ly 1960's (SW l ) , India Boon llEconomic Choice of Human and

Physical Factors, 11 1964 (BC 20) HIQ Wen Who Move Mountains, 11 (SW 2),

India-Maliabari Bri t ish Army (SW 4 ) Cameroon 1945 (BC contractor s documents 1 Price Davies, 1932 (SW 40) IU), 1963 (BC 2), India other than

Maliabar i E g o l e t R.A.L.L., 1970 (BC 5) Cameroon, 1945 (BC contractor 1 s documents) Spence Geddes, 1948 (SW 16) Galabru T%quipement General (BC 8 ) Analysis of Poi t iers Crossing, 1850 (BC 3) Bigolet R.A.L.L., 1970 (BC 5 ) French Army Handbooks (BC 6 and 7) Galabru "Equipement Gener a l " (BC 8) ILO, 1963 (BC 2, p. 53), Ceylon France, 1961 ( BC contractor s documents j Madagascar Estimating Handbook, 1930 (BC 4) Analysis of Poi t ie rs Crossing, 1850 (BC 3) Cameroon 1945 (BC contractor s documents) Galabru 1TEquipement General" (BC 8 ) Madagascar Estimating Handbook, 1930 (BC 4) Madagascar Estimating Handbook, 1930 (BC 4) French Army Handbooks (BC 6 and 7) French Army Handbooks (BC 6 and 7 ) Abidjan, 1952 (BC contractor 's documents)

Labour Hours Soi l Type per m3

or dinar y ordinary ordinary ordinary

or dinar y

or dinar y or dinar y sandy or dinar y

ordinary sandy clayey or dinar y sandy sandy clayey sandy ordinary ordinary unspecified sandy hard hard clayey ordinary clayey ordinary clayey or dinar y

Reference number preceded by BC refers t o BCECM engineering bibliography; SW refers t o SWKP engineering bibliography. , ,

Second, these coefficients were observed i n physical, economic and social environments as different , for example, a s France i n 1850 and India i n the 1960's and a whole host of environmental parameters which bear importantly on the productivity r a t e s a re unspecified. Possibly among the most important are the social acceptabili ty of and ind iddua l a t t i tudes toward manual labor and the ins t i tu t iona l and managerial frameworks i n which manual labor takes place.

61. A l l of these factors, which a re elaborated upon i n Chapter 111, w i l l bear importantly upon the choice of construction technology i n any given situation.

2. Evaluation of Alternative Sources of ~ n f o r m t i o n

62. International contractors. I n an attempt t o locate sources of re l iab le productivity data, discussions were held with several c i v i l engineering contractors having experience of worldng i n underdeveloped countries. Such records are maintained by these organis ations but invariably i n financial terms and essent ial ly for the purpose of f inancial control. The contractors seldom attempt ta make use of these records i n preparing tenders since the f u l l enkLronmenta1 conditions are not recorded and, even i f they were, it would be d i f f i c u l t t o properly compare the varying effects of differ ing envi- r onment s . 53. It is considered t h a t l i t t l e useful information could be obtained from a study of contractorsf records of past projects since :

a. Operations are seldom disaggregated in ta basic ac t iv i t ies .

b. Records are related t o the costs of items l i s t e d i n the Bills of Quantities which, however, do nbt represent the actual work carried out but rather define the f inancial basis of payment.

c. Contractors might not be will ing t o disclose the f u l l extent of the information required, part icular ly the elements of overheads and profi t .

d. It i s unlikely tha t there would be adequate knowledge or detailed descriPtions of the conditions under which the work was performed.

e. The personnel who were actually engaged on the construction of the project and who could supple- ment the recorded data by personal knowledge are unlikely t o be available t o a s s i s t i n the research. llhis aspect i s part icular ly pertinent since contractors would probably be l e s s willing t o disclose f u l l par t iculars of the more recently completed projects.

f . Data obtained from l e s s recent projects nigfit not be applicable to current construction techniques, part icular ly equipment operations.

g. I n recent years very few labour-intensive projects have been carried out by large contractors and such data as might be available would be largely confined t o equipment-orientated techniques and methods.

Certain of these disadvantages could be overcome by enl is t ing the active support of contractors (and supervisory personnel ) on current projects.

64. Local contractors. The foregoing applies mainly t o the large llinternationalll type contractor. The smaller lfpettyff contractor common t o most developing countries i s unlikely to maintain records of t h i s type. However, i t i s f e l t t ha t much useful information re la t ing to the performance of labour could be obtained by interviewing small contractors and works department personnel ( a t the overseer l eve l ) engaged on road maintenance operations by force account methods.

65. Supervising agencies. Further possible sources of productivity data include the agencies responsible for and consulting engineers engaged i n supervising highway construction. No approach has been made t o highway authori t ies to ascertain whether their records could provide f u l l y documented productivity data. However, the experience of engineers who have worked on highway construction and maintenance as government employees i n many of the former B i t i s h colonies i n Africa and the Far East indicates tha t such information 14ould be t o t a l l y lacking. Nevertheless, it i s believed tha t thme i s scooe for drawing on the knowledge and experience of personnel engaged i n d i rec t ly supervising force account work i n the developing countries by an in te r- viewing procedure.

66. The records maintained by international consulting engineers supervising highway construction contracts a re not designed t o record productivity data i n the form required for the study and while an examination of records of past projects i n combination with those of the contractor might produce some data, it i s unlikely tha t the necessary degree of disaggregation would ex i s t and the accuracy would be open t o doubt. However, as previously s tated, the active supp.ort of such consultants on current projects would provide a useful source of information.

47. The UK Road Research Laboratory is currently collecting equipment productivity data on two road construction contracts i n Uganda and on a further contract in Liberia. The data i s i n raw form but it i s understood t h a t it could be made available t o the study a t some future date.

3. - Conclusions Concerning Available Engineering Data

68. Unfortunately a t t h i s stage of the study there appear t o be few easy generalizationswhich would permit formulation of simple c r i t e r i a fo r the determination of road construction technology. The available data permit few conclusions except, perhapqthat physical, economic and soc ia l environmental factors may be so i r t a n t i n each instance tha t a case by case approach w i l l be required.- It is hoped tha t further study involving f i e l d generation of new data w i l l t o some extent relax this finding, permitting some generalization and simplification of the problem.

69. It has been concluded from the review of available data t h a t the data needed i n order t o determine the production functions and t o r e l a t e productivity r a t e s t o the environment must be ob$ained primarily by d i r ec t f i e l d observation of current projects, supplemented by an interviewing programme w i t h personnel engaged i n d i r ec t ly supervising construction work. Never theless, it i s believed thdt fur ther studies of existing l i t e r a t u r e and documentation could projide some additional information of value.

70. Some thought has been given t o the poss ib i l i t y of aol lect ing productivity data by postal questionnaire. Although it is l i k e l y tha t data so collected would be sketchy, unreliable and slow t o arrive, a method which couples the completion of questionnaires with a visit might overcome these objections.

71 Many of the basic a c t i v i t i e s i n road construction a re common t o other f i e l d s of c i v i l engineering (e.g. dam construction and i r r iga t ion work) and fu ture f i e l d work w i l l be arranged t o observe these a c t i v i t i e s t o the extent tha t time permits.

1/ The reader should bear this i n mind i n considering the example - analyses given i n the remainder of t h i s Chapter and Chapter V. The opposed conclusions of SWKP and BCEOM may each be val id i n appropriate circumstances. -

72. Despite the extremely wide range of data avai lable i n the l i t e r a t u r e , a s e r i e s of analyses of road construction a c t i v i t i e s have been prepared separate ly by t h e two engineering consultants, SWKP and BCEObl, i n order t o gain some measure of t he technical scope fo r the subs t i tu t ion of labor f o r equipment i n road construction. Four s e r i e s of analyses have been undertaken :

i. the calcula t ion of t h e t rade off between labor and equipment a t the l e v e l of t h e basic construction a c t i v i t i e s expressed i n terms of breakeven wage ra tes ;

ii. tne aggregation of c e r t a in basic a c t i v i t i e s which a r e interdependent a t the l e v e l of a production function isoquant fo r a specif ied group of a c t i v i t i e s (e.g. excavation of 1000 m3 of s o f t earth, loading, hauling a specif ied distance, unloading and spreading );

and i n sec t ion 3 below for a s e r i e s of hypothetical road projects :

iii. t h e aggregation of groups of s imi la r operations (earthworks , sub-base, base, and pavement ) i n t he quan t i t i e s required fo r t he construction of one kilometr e of hypothetical roadworks according t o various designs and t e r r a i n .

i v . analyses of the cos t s required i n t h e complete construction of one kilometer of the hypothetical roadworks by equipment in tens ive methods, by labour in tensive methods and by an optimal combination of methods.

73 I n these analyses t he construction operations have been d i s - aggregated i n t o basic construction a c t i v i t i e s . Estimates of the time required t o ca r ry out each a c t i v i t y have been prepared based on data contained i n estimating handbooks and other sources (as documented i n Appendices A and B) f i r s t fo r t he optimal combination of methods ( for an assumed wage r a t e for unskil led labour of US$1.00 per day) and then fo r the equipment in tensive and labour in tens ive extremes of the production functions. These estimates have been converted i n t o monetary terms using

the same s e t of p r ices fo r equipment and labour i n both the SWKP and BCEOM analyses, so t h a t d i f ferences Setween the two estimates r e f l e c t differences i n t he product ivi ty coef f ic ien t s adopted.

74. Construction standards fo r a given geometric design have been varied between high and intermediate q u a l i t i e s a s defined i n sec t ion 1 I . B above. !Che geometric standards have been kept the same though, i n pract ice , some changes would be made t o accommodate labour- intensive methods.

75 It i s noteworthy t h a t the product ivi ty coef f ic ien t s judged most applicable by t h e two engineering consultants d i f f e r by extra- ord inar i ly wide margins, r e f l e c t i ng presumably d i f f e r en t experience and d i f f e r en t engineering judgment a s well a s the inadequacy of ex i s t ing data sources. Thenever avai lable the est imates of the two consultants have been juxtaposed and the bas i s and source fo r each givsn.

1. Analysis of Basic Act iv i t i es

76. The r e s u l t s of the f i r s t s e r i e s of analyses are presented i n Table 11.3 i n the form of t he break-even wage r a t e s . Equipment and mater ia l p r i ce s and product ivi ty r a t e s on which these analyses are based a re given i n Appendices A and By respectively. For t he i n t e r - dependent group ol" a c t i v i t i a s excavating, loading, h a u l i ~ g , unloading, and spreadins, SkjKP a r b i t r a r i l y divided the time of the road scraper and bulldozer i n t o t h e individual a c t i v i t i e s based on the time cycle of the operation. BCECEI eschewed such calcula t ions , so Lha t correspond5ng coeff ic ients a re not avai lable i n Table 11.3 fo r these separate a c t i v i t i e s .

77 o The break-even d a i l y wage r a t e , %, i s defined for a ,?ivsn set, of' equipment p r ices a s t h a t wage r a t e ( for unskil led labour) s t which the cos t of carrying out an a c t i v i t y by labour i s i den t i ca l x-it!i t h a t of equipment. 3% i s equal t o the marginal r a t e of subs t i tu t ion under these assumptions. Its val2e i s given by the followTng expression:

E - E W = 1 2

l2 - 1 1

wnere El and E2 represent the equipment cos t s f o r eq-dipnent-intensive :ind labour- intensive methods, ?espectively, and 1 and 1 a re the unskil led labour inpu t i n days fo r t he equipment and la&our -in%ensive nethods, respectively. The greater the value' of W, the !nore advantageous i s subst i tu t ion. A negative value ind ica tes t h a t more oquiprntx~t i s required for the labour - intensive method and subs t i t u t i o r i is t i e r efor s impracticable. For the purpose of t h i s study, subs t i t u t i on i s ~ l s o deemed t o be impracticable if the break-even da i l y wage r a t e i s l e s s than U.S.$G.20 (See para. 29 ).

TABLE 11.3: Break-Even Wage Rates (W) by Basic Activity

No.

(W i n US $ per man day) - I muipment Labour

Activity Intensive Intensive W W Description

' Method Method BCEOM SWgP

S i t e Preparation I Clearing and grubbing medium vegetation D8 Hand 0.66 3.56 - Stripping topsoil 10 cm thick ~8 Hand 0.72 0.33

Excavating i n Small Quantities

Ditches i n s o f t material Hand 0 .,51 1.17 ' -

Or ass roots for sprigging Or ade r Hand NllV 0.73 - Ditches i n rock Compressor , Hand 0.06 1.87

d r i l l s and explosives

Excavating i n Bulk I Earthworks i n so f t material I D8

Hand NAV 3.82

Gravel for sub-base I D8 Hand NAV 3.82

Gravel for base D8 Hand NAY 3.82

Rock i n earthworks Compressor , Hand NAV 0.90 I d r i l l s and

I explosives

Rock for bases I Compressor, Hand N AV 0.34 d r i l l s and explosives

Rock for chippings Compressor , Hand N AV 0.50 d r i l l s and explosives

Loading Homogeneous loose materials

Homogeneous loose materials


Tr axc avator Hand i n t o -0.61 -0.24 in to truck truck Tr axc avator Hand i n t o i n t o truck t r a i l e r 0.00 5.48 Tr axcavator Hand i n t o NAV 4.90 i n t o truck bullock

NAV = Not available ~

TABLE 11.3 continued W W

BCEOM SwXP - I Loadirq (continued) I Homogeneous loose materials Tr axcavator Hand i n t o NAV ;r -56

i n to truck wheelbar r aw

4 -1 1 Homogeneous loose materials I Traxcavator Hand i n t o NAV U.04





Rock from earthworks






Rock from earhlworks



Water

C i n t o truck basket ; - Traxcavator Handinto N AV Lr .06 in to t r a i l e r t r a i l e r

Traxcavator Hand i n t o NAV 3 72 i n t o t r a i l e r bullock calrt

Traxcavator - Hand in to NAV 5 72 i n t o t r a i l e r wheelbarrow

Traxcavator Hand i n t o NAV 0.36 i n t o t r a i l e r basket

I Traxcavator Hand i n t o N AV 1.. 68 i n t o truck truck

Tr axcavator Hand i n t o NAV i? .46 in to truck t r a i l e r

Traxcavator Hand i n t o N AV 6-54 in to truck bullock cakt

I Traxcavator Hand in to N AV 10.10 in to truck wheelbarrow

Traxcavator Handinto in to truck basket N AV lb.72 -

I Traxcavator Hand in to in to t r a i l e r t r a i l e r N AV 5=54

Traxcavator Hand in to NST 4.. 95 i n to t r a i l e r bullock c a r t

T r axc ava tor Hand i n t o NAV 7.56 i n to t r a i l e r wheelbarrow

Traxcavator Handinto , N AV 11.. 15 i n to t r a i l e r basket

P

Pump i n t o Hand in to N AV -0.10 bowser t r a i l e r

Pump in to Hand i n t o NAV 0.25 bowser bullock

c a r t - I

NAV = not available I


BCEOM SWKP Hauling

Excavated s o i l 100 m I Duck Wheelbarrow NAV 0.22

Excavated s o i l 100 m Truck Baskets NAV 0.14

Excavated s o i l 100 m Tractor and Wheelbarrok NAV 0.50 t r a i l e r

Excavated s o i l 100 m

Ekcavated s o i l 200 m I Truck Wheelbarrow IfAV 0.12

Tractor and Baskets NAV 0.30 t r a i l e r -

Excavated s o i l 200 m Truck Bullock NAV 0.24 c a r t

Excavated s o i l 200 m I Tractor and Bullock NAV 0.44 t r a i l e r c a r t

Excavated s o i l 200 m Truck Basket NAV 0.10 -

Ekcavated s o i l 200 m

Excavated s o i l 400 m I Duck Bullock NAV 0.19 c a r t

Tractor and Wheelbarrow NAV 0.24 t r a i l e r



Gravel 1 lan

Tractor and Basket NAV 0.20 t r a i l e r -

Gravel 1 kn

Gravel 2 km

I Tractor and ~ u l l o c k N AV 0.44

I t r a i l e r c a r t

Truck Bullock N AV 0.15 c a r t

Tractor and Bullock N AV 0.27 t r a i l e r c a r t -

I puck

Bullock NAV 0.12 c a r t

Gravel 2 km 1 Tractor and Bullock NAV 0.2h

Water 2 km t r a i l e r c a r t Bows er BuLlock NAV 0 .r

I c a r t

Loose materials 10 ky I p u c k Bullock NAV 0.10

Water 2 km

c a r t Loose materials 10 km I Tractor and Bullock NAV

Tractor and Bullock NAP 0.21 t r a i l e r c a r t

7

I --

t r a i l e r c a r t I

I


BCEOlI SWKP - 1 I

Homogeneous loose materials Tipping Hand from NAV 17.2,h truck t r a i l e r

6.1 1 Homogeneous loose materials Tipping Hand from NAV 0.90 I truck bullock c a r t

Homogeneous loose materials 1 Tipping Hand from NAV 8.46


truck baskets

Tipping Handfrom NAV 6.30 truck wheelbarrow

1 Spreading


Natural s o i l s

Tipping Hand.from NAV 17.18 truck t r a i l e r -

Natural s o i l s

Natural so i l s

Natural s o i l s

Natural s o i l s

Natur a1 s o i l s

Natural s o i l s

Natur a1 s o i l s

Gravel bases and sub-bases intermediate qual i ty

Grader from Hand from 0.16 0 . 50 truck/ truck/ t r a i l e r t r a i l e r

Grader from Hand from 0.16 20.56 truck/ bullock tr a i l e r c a r t

Grader from Hand from 0.81 0.91. truck/ wheelbarrow t r a i l e r

Grader from Hand from NAV 20.56 truck/ basket t r a i l e r - Grader from Hand from (3.16 0.24 wheelbarrow t ractor /

t r a i l e r

Grader from Hand from 0.16 10.28 wheelbarr ori bullock

c a r t

Grader from Hand from (3.81 0.46 wheelbarrow wheelbarrow

I ~ r a d e s from Hand from NAY 10.28 wheelbarrow basket

I D8 with Hand from NAV 6.96 spreader box truck/

t r a i l e r 7.2.2 Gravel bases and sub-bases I IIand from NAV 278.80

intermediate qual i ty spreader box bullock I I c a r t I -

I

NAV = Not available I

I

Table 11.3 continued

Spreading (continued) I Chippings for surf ace dressing

I Compacting and Wlishing I

Truck with Hand from 0.13 1.1.1 chipping truck/ spreader t r a i l e r -

7.9

Gravel bases and sub-bases intermediate qual i ty

Water

9.1.1

Macadam and crushed rock base, intermediate qual i ty

Bows er Handfrom NAV 3 CIS t r a i l e r / c a r t

Natural so i l s I Gr ader and Hand 0.22 0.2!4 intermediate quality r o l l e r -

Surface dressing, intermediate qual i ty

Gr ader and Hand 2.25 1.06 ro l l e r

Gr ader and Hand E1.65* 1.07 ro l l e r - Roller and Hand -296.8 1.58 broom

Production of loca l Materials

Crusher Hand 0.57 0.52 -

11.2.1 Coarse aggregate for macadam

Chippings for macadam dressing

. 11.7.1

Gr anula tor Hand 0.57 1.56

I Miscellaneous

Chippings for surface dressing

Granulator Hand bJAV 1.26

Roller Hand 3-53 0 .Sir -

12.3.1 Laying, trimming and compacting tops o i l

The BCEQ4 coeff ic ient for compacting and finishing gravel base has been calculated from pp. 15, 90 of the Appendix t o the BCECrM Report, but i s i n disagreemept with the W coefficient, 0.15, given on p. 28 of the i r Report. Source: SWKP Report!, pp. 29-33. I

BCEOM Report, pp. 26-30 and Appendix. 1

12.6.1

- Eirooming and cleaning surf aces

Tractor with Hand 1.. 21 I.. 78 broom

78. The l i s t of a c t i v i t i e s given i n Table 11.3 has excluded the following :

(1) Act ivi t ies i n categories 'Ef and 'Lf since, by , definit ion, subst i tut ion by labour and equipment,

respectively, i s not possible.

(2) Operations which essent ia l ly combine several a c t i v i t i e s together (e.g . , earthmoving by scraper). These a c t i v i t i e s a re t reated i n paras. 93 f f . below.

Furthermore, these break-even wage r a t e s would not necessarily apply t o a l l the a c t i v i t i e s i n road projects. For example, the output from equipment excavating rock i n a quarry would be greater than when excavating it piecemeal within roadway excavation. While such factors are excluded here, they have been taken i n t o account i n the subsequent analyses.

79. The wide range i n values of the subst i tut ion coeff ic ients and break-even wage r a t e s given i n Table 11.3 w i l l be n o w pom a few with negative values t o qui te large values for some of the spreading operations. There i s a wide variety of a c t i v i t i e s for h i c n substitu t ion would be f inancial ly advantageous a t a dai ly wagerate of U.S.$2.00. These include a c t i v i t i e s i n the excavating, loading, unloading and spreading groups of operations but not i n /Ule hauling group. Loading homogeneous loose materials i n to trucks bnd water in to bowsers by hand give negative values and indicate t h a t these subst i tut ion poss ib i l i t i e s should possibly be rejected fkom further consideration as being impracticable,

80. Act ivi t ies for which the break-even wage r a t e i s between zero and $0.20 per day are confined t o the haulage goup of operations. I n themselves, the figures indicate t h a t the following mpthods of haulage would be impracticable:

(1) By basket for distances of 100 m. or more. (2) By wheelbarrow for distances of 200 m. or more. (3) By bullock c a r t for distances of 400 m. or bore.

However, the haulage method cam& be considered on i t s own, but only i n combination with other related ac t iv i t i e s .

81. Many of the basic ac t iv i t i e s a re inter-dependant i n tha t the method adopted for one ac t iv i ty can a f fec t t h a t preceding and tha t following it. This i s part icular ly so i n the excavating, loading, hauling, unloading and spreading groups of sequential ac t iv i t i e s .

To determine the most advantageous cambinations of the various possible ways of carrlfing out these interdependent ac t iv i t i e s , the corresponding substitution coefficients (and break-even wage ra t e s ) cannot be added or averaged and i t i s necessary t o aggregate the equipment and labour contents of each possible cmbinatian of the basic ac t iv i t i e s . The concept of production function isaquants has been used i n the aggregation process and the procedure is explained i n the following section.

2. Analyses of Interdependent Activities

a. An Introduction t o Production Functions

82. I n the subsequent analyses production functions are presented graphically i n the form of two dimensional isoquants. For those unfamiliar with production function concepts, this section constitutes an introduction t o the graphical representation and interpretat ion of isoquants. Those readers familiar with production functions may proceed d i rec t ly to the analyses which commence i n section b.

83. A re la t ion between the quantity of output produced from any ac t iv i ty and the associated inputs of equipment and labour can be plotted i n two dimensional space. !The ver t ica l axis represents, i n some unit, the equipment input for a specific ac t iv i ty or operation while the (unskilled) labour input is shown horizontally. For a given output, a se r i e s of points may be plotted defining the equipment/labour function, or isoquant . This relationship w i l l have as parameters the specif ic environment, the scale of the undertaking, length of construction period and the qual i ty l eve l t o be achieved.

84. Production relat ions for some a c t i v i t i e s i n road construction, such a s excavation, a re not affected by qual i ty considerations, while others, such as compacting and finishing, a re heavily dependent on the level of quality specified. It should be noted t h a t a given isoquant depicts al ternat ive combinations of inputs which can produce a given quantity of output of ident ical quality. A given qual i ty may be achieved by d i f ferent methods and design e.g. a square meter of pavement with a specified bearing strength and longevity index might be achieved by such al ternat ive designs as penetration macadam of one thickness or s ingle surface treatment over base and subbase courses of different materials and thicknesses, e tc . Just as for a given quality, other quantity (or output) leve ls would re su l t i n further isoquants, for a given quantity different leve ls of qual i ty would often require d i f ferent isoquants of inputs. I n the analyses below we expl ic i t ly consider the e f fec t on the required inputs of varying the qual i ty l eve l specified for various road construction ac t iv i t i e s .

85. Some common un i t of measuring differ ing types of equipment and labour i s required so tha t differ ing types can be combined together for a two dimensional graphical representation. There are various poss ib i l i t i e s :

(1) Equipment could be measured i n t e r m of i t s horse- power; while this would take some account of the materials consumed i n operating the equipment, the sk i l led and semi-skilled labour involved i n its. operation could not be so measured.

(2) Labour could be measured i n terms of time units with appropriate weighting between the various categories.

( 3 Labour, equipment and materials could be measured i n monetary terms.

For various reasons monetary cost (excluding mobilisation, overheads, p r o f i t , i d l e time, e tc . ) has been taken a s the unit fo r equipment and time fo r labour i n t he following presentation.

86. For a basic construction a c t i v i t y of category 'El, the production function would theore t ica l ly consis t of a s ingle point on t he v e r t i c a l axis, representing the cost of carrying out t h a t a c t i v i t y . Similarly, a category IL' a c t i v i t y would be represented by a s ing le point on the labour axis and a category 'ELf a c t i v i t y would be defined by two points one on each axis. I n the l a t t e r case, it i s assumed (though t h i s may not be s t r i c t l y accurate) the two points could be joined by a s t r a i g h t l i n e since any p a r t of the work could be carr ied out e i ther by equipment or labour. The e f f e c t of some unskil led labour content i n an equipment-intensive a c t i v i t y or of some equipment content i n a labour- intensive 'EL1 category a c t i v i t y Would be t o o f f s e t these points from the axes, but i n t he same way they could s t i l l be joined by a s t r a i g h t l i ne .

87. With equipment costs measured i n U.S.$ and labour time i n days, the slope of such a basic production function i s equal t o W, the break-even wage r a t e defined i n t h e previous section. The greater the value of W and hence the steeper t he slope of the l i n e , the greater i s the sco~pe f o r subst i tu t ion. Where the slope of the l i n e i s greater than the assumed wage r a t e for unski l led labour, there i s f inanc ia l advantage i n subdti tuting. The l i m i t of pract icable subs t i tu t ion has been taken a s the l i n e represented by a da i l y wage r a t e of $0.20 per day.

88. I n drawing up the production functions fo r individual or groups of a l l i e d operations, i t i s assumed t h a t subs t i tu t ion would taKe place i n the order of cos t advantage. To take a simple example, consider an operation consist ing of three basic a c t i v i t i e s which can be car r ied ou t e i ther so le ly by equipment or labour with the inputs given below:-

Act ivi ty W

The production function would be defined by s t r a i g h t l i n e s coluiecting the following sequential points : -

( 1 ) A wholly equipment - intensive operation with co-ordinates E = 200, 1 = 0. I

( 2 ) The subs t i tu t ion for a c t i v i t y 2, co-ordinates E = 100, 1 = 50.

(3) The fur ther subs t i tu t ion for a c t i v i t y 1, co-ordinates E = 50, 1 = 100.

(4) The fur ther subs t i tu t ion for a c t i v i t y 3, co-ordinates E = 0, 1 = 200.

89. Mathematically, i f there are In1 basi.c a c t i v i t i e s making up an operation, each of which can be carr ied out i n one of two ways, the number of possible combinations i s two raised t o the power of I n . For example, an operation zequiring the excavation of s o i l from cutt ings and i t s placing and compaction i n embankments would require the following ac t iv i t i es :-

Excavating Loading Hauling Unloading Spreading Compacting and f inishing

and t h i s l i s t excludes the addit ional a c t i v i t i e s required fo r Me adjustment of the natural moisture content t o the l eve l appropriate for compaction.

90 Ekclcding any sub-division of the a c t i v i t i e s t o allo* for type of material being excavated, d i f fe r ing loading r a t e s and cos t s due t o var ia t ions i n the type of haulage vehicle being loaded, the type of haulage vehicle, d i f f e r ing unloading r a t e s due to vehicle type, and differ ing l eve l s of qua l i ty fo r spreading and compacting and f inishing, the theore t ica l number of possible combinations of the basic a c t i v i t i e s i s 64. I n pract ice , t h i s number can be reduced. For example, it would not be l og ica l t o load a scraper by hand nor t o load head baskets by machine.

91. Reverting t o the simple example of para. 88 it has been assumed t h a t labour subst i tut ion can take place i n any ac t iv i ty , indepehdently of the others. The production function i s defined by 4 points whereas there a r e e i ~ h t possible combinations. The production function is i l l u s t r a t e d i n Figure 11.1 and i s defined by the l i n e a-c-g-h. The other points, b,d,e, qnd S , are possible combinations of equipment and labour but represent l eds e f f i c i en t ways of carrying out the subs t i tu t ion process.

92 This procedure has been followed i n aggregating the 'various sequences of interdependent a c t i v i t i e s t o es tab l i sh the most advantageoud ways of combining the respective basic construction a c t i v i t i e s so t h a t the optimum trade-off functions between labour and equipment could be established.

Labour days

AN EXAMPLE OF A SIMPLE PRQDdCTlON FUNCTION

Production Functions for Road Construction Act ivi t ies

93. The complete grouping of i n t e r dependent sequential a c t i v i t i e s i n to production functions is:

(1) Bulk Excavation i n Roadworks: excavating i n bulk i n s o f t material, loading, hauling (various distances), unloading and spreading.

( 2 ) Rock Excavation i n Roadworks: excavating i n bulk i n rock, loading, hauling (various distances) and unloading.

( 3 ) Rock Bcava t i on i n Quarry (for crushing) : excavating i n bulk i n rock, loading, hauling and unloading.

(4) Gravel Sub-base: excavating i n bulk i n hard material, loading, hauling, unloading and spreading ( a t two l eve l s of qual i ty) .

(5) Gravel Base: as above ( 5 ) Macadam Base (from crusher t o s i t e ) : loading,

hauling, unloading and spreading ( a t two leve ls of qual i ty) .

( 7 ) Crushed Rock Base (from crusher t o s i t e ) : loading, hauling, unloading and spreading.

(8) Water Distribution: loading, hauling, unloading and spreading .

( 9 ) Chippings for Surface Dressings (from crusher to s i t e ) : loading, hauling, unloading and spr4ading.

(10 ) Bitumen Distribution: loading, hauling, unloading and spr eading (including heating).

94. For purposes of i l l u s t r a t i o n and because of i t s impoktance we examine the case of bulk excavation i n roadworks i n the following sect ion for both the SWKP and BCEW data. Production functions for the other a c t i v i t i e s a t unit l eve l s of output a r e given i n Agpendix A; while production functions for various a c t i v i t i e s a t the quantity l eve l s required for one kilometre of various hypothetical roadways are given i n section' E below. The data from which the production functions have been plot ted a re contained i n Appendix A.

( 1 ) Bulk Excavation i n Roadworks

95. Table 1I.b shows the various combinations of methods considered for carrying out each ac t iv i ty . The l i s t does not cover a l l technically pos- s ib l e combinations and for s implici ty it has been assumed t h a t the excavating and loading operations would be carr ied out e i ther both by equipment or both by labour.

95. Figure I1 2 shows the corresponding e uipment and labour inputs 9 for these various methods of carrying out 1000 m of bulk earthworks i n f l a t t e r r a in where the average length of haul i s assumed t o be 100 m. The heavy black dots represent the estimates of SWKP while the crosses represent tthe estimates by BCEOM.

Table 11.4 Construction 1.1.1cthods foil Bu1.k m:cavation j.n Xoadt~orlrs .---WI------r-----.----- -̂IIII.̂---.LL---I---- -.-a

Operat,icn ConstrucLj.on I.Ie!:.hocl for Act ivi ty ----"--L7--,*---- ---I---- -."..--.---.---, ...

Method --- x a v a t l n g Loacli.ng Kaul.ing --"-- ------ - Uriloadj n r -..-.-O- Splgead?i.ng --". - A Scrzper Scr ape* Scrzper Scr apsr Scraper

B ~8 dozer Shovel i n t o Truck Tipped frorn Grader t ruck t ruck

G ~8 dozer Shove:[. i n t o Tzlucl: Tipped from Labour t? uck t ~ u c k

D DO dozer Shovel i n t o Tractor and ~ i p p e d from . Grader t r a i l e r t r a i l e r t r3a i le r

E D8 dozer Shovel i n t o Tractor and Tipped from Labour t r a i l e r trai1e.r t r a i l e r

F Labour Labour in-to Bas!:e-L T i ~ e d f r ~ m L~bou.r. basket basket

G Labom L:ibo~l~ i n t o tJineelbarr ow Tipped from Labour wheelbsrz: 0r.j w ' r :~eelb~~~ro?c

H Labour Labour i n t o \4'r~celbar1*ox Tipped from Gi:adcr d1eslbaid1:oiir \.rhoclbariio:.r

J Labour Labour il l t lo Bull-ock c a r t Labour Labour bull.oc!c c a;? t

K Labour Labow i n t o Tfac tor and. ,-I- llppcd f r o n LaI)wx tl7 ai1.cr trai l .er t r a i l . el7

L Labour: IA~IOU?: ir i -L .3 ac.'[)r a-rlcj Tipped f r o m C:radcr t r 2 i lc r tlr ai l . el: tr ai . ler

11 I,c?I~our Lsbou? i n t o T ~ u c k Tiprjcd f 1' GUI L:!k~r)t.:~ t r u c k tltvclr

N Labom3 La3our i n t o l?luck TTy!gecl f 1:c;:a c.,: T,. ,=LC - .i I .;:: I t ruck tiii!(.rk

PRODUCTION FUNCTION FOR 1000 M~ OF BULK EXCAVATION IN ROADWORKS -

FLAT TERRAIN (HAULAGE DISTANCE 100 M) - INTERMEDIATE QUALITY

I

LABOR MANDAYS

Figure 11.2

97 SWKP estimates: The scraper operation, ident if ied as point A, i s the mo-ay of carrying out the operation wholly by equipment. Of the labour-intensive methods, point G i s the most e f f ic ient , with haulage by wheelbarrow. However, the s t ra ight l i n e A-G does not represent the production function for t h i s operation since some of the other points l i e beneath t h i s l ine . Point L which represents excavating and loading by labour, hauling by t rac tor / t ra i le r and spreading by grader, i s an intermediate substitution poss ib i l i ty and it must l i e on the production function which follows the l i n e A-I,-H-G. Hence, while the slope of the l i n e A-G gives the break-even wage r a t e ($1.70) for the whole operation, substitution along the slope A-L would be more advantageous with a break-even wage ra te of $3.35 but along L-H-G the overall slope would drop to $0.73. With an actual wage ra te between these two figures, substitution would be advantageous only up to point L. BCEOM estimates: Estimates only for methods A, G, and H are available from the BCEaM report, and they depict radical ly different input requirements for labour intensive methods. Between methods A, G and H, A i s ef f ic ient a t unskilled wage ra tes above $0.30 per day, method G i s the eff icient method a t wage rates below $0.30 per day, and method H wbuld never be used, i .e . it l i e s off the production function.

95. Figure 11.3 depicts a similar production function for earthworks i n h i l l y t e r ra in where the average length'of haul i s assumed to be 200 m. SWKP estimates: I n th i s case Method J, hauling by bullock car t , i s the most e f f ic ient of the labour-intensive methods. Points L and K, both u t i l iz ing tractor/ t r a i l e r units for hauling, are intermediate substitution poss ib i l i t ies , and the production function follows the l i n e A-L-K-J. The break-even dai ly wage r a t e for the overall operation i s $1.12 while the slopes of A-L and L-K-J a re 3.80 and 0.49 respectively. BCEOM estimates: Estimates only f o ~ methods A, G and H are available for the 200 m. haul and the conclusions are qui te similar t o the case of the 100 m. haul: method -4is the ef f ic ient method a t a wage above $0.25 per day, method G i s e f f i c i en t a t a lower wage ra te , and method H l i e s off the production function.

99. I n rol l ing t e r ra in the average length of haul has been taken as 400 m and th i s condition is represented i n Figure 11.4. SWKP estimates: Methods F, G and H (hauling by basket and wheelbarrow) have been excluded i n view of the length of haul. Again, the production function follows the l i n e A-L-K-J. The average substitution slope for the o v e ~ a l l operation is $0.92 per day while the slopes for A-L and L-K-J are 3.27 and 0.47 respectively. BCEW estimates: For the 400 m. haul estimates are available from the BCECM report for methods A, J, K, L, My N. However, only two points A and J l i e on the production function, a l l other points being grossly ineff icient , with methods M and N having negative breakeven wage ra tes . The substitution slope or breakeven wage between methods A and J i s $0.39 per day; a t a higher wage per day method A would be ef f ic ient and a t a lower wage method J would be eff icient .

100. SWKP conclusions: These three examples demonstrate tha t the most e f f i c i en t equipment-intensive method for bulk earthworks i s by serapes but substitution for more than half of the equipment input is f inancial ly advantageous w i t h wage ra tes l e s s than about $3.25 per day by using tracto.r/trailer units for hauling and carrying out the other ac t iv i t i e s by hand.

PRODUCTION FUNCTION FOR 1000 M OF BULK EXCAVATION IN ROADWORKS -

ROLLING TERRAIN (HAULAGE DISTANCE 400M) - INTERMEDIATE QUALITY

L (BCEOM)

0 K (BCEOM)

0 100 300 400 500 A 600 700 800 900 1,oOO 1,100 1,200

LABOR MAN-DAYS

IBRD - 621 7

BCECM. conclusions: The scraper operation i s the most e f f ic ient for a l l cases a t wages above about $0.45 per day. Hauling by tractor t r a i l e r units is not a feasible method a t any s e t of prices, and only- i f wages drop below $O.h5 per day would manual excavation with hauling by bullock ca r t s or wheelbarrows become feasible, Thus according t o the BCEm analyses the e las t i c i ty of substitution of labor for equipment i n earthworks would appear t o be qui te low.

E. Analyses of m o t h e t i c a l Road Projects - 101. To gain further measure of the technical scope for the substitution of labour for equipment i n road construction and the extent of employment generated thereby, a se r i e s of hypothetical road projects has been considered. The basic specification i s given below:

i. ii .

iii . Width of surfacing - 7.00~1. Width of upper surface of base - 7.50m. Width of shoulders - 1.2sm.

iv. Width of formation - 10.00m. v. Side slopes - 1:2

v i . Thickness of sub-base - 15cm. vii. Thickness of base - 1Scm.

102. For simplicity, construction work has been assumed t o be l imited t o the following operations:

i. Clearing and grubbing ii. Stripping and stacking topsoil iii. Drainage excavation iv . Roadway and borrow excavation v. Ebbankments

v i . Sub-bases and bases vii . Bi tminous surf acing

viii . Topsoiling and grassing

(The only major operation excluded from th i s l i s t i s culver tihg. )

103. Flat , ro l l ing and h i l l y terrains have been simulate4 by varying the quanti t ies of excavation, f i l l i n g , so i l ing and grassing, land the proportion of rock i n excavation. Average haul distances f o r excavated materials have a lso been varied according t o topography. assume differing geometric designs t o accommodate the topova variation i n design t o accommodate differing construction undoubtedly be done i n actual practice).

104. Three types of road pavement, t o simulate differ in4 geological conditions, have been considered:

Type A: Gravel sub-base, gravel base, s ingle surfa~ce dressing. Type B: Gravel sub-base, penetration macadam base.^ Type C: Gravel sub-base, crushed rock base, single; surface

dressing.

Haulage distances and quanti t ies of water required for compac~tion have been varied i n re la t ion t o the nature of the pavement material.

105. Full. de ta i l s of the methods of analysis are contained i n Appendix A.

1. Analyses of Production Functions for one Kilometre of Hypothetical Roadworks

106. Bie basic construction ac t iv i t i e s have been aggregated i n the quantit ies required for the construction of one kilometre of hypothetical roadworks according t o the following groups :

a. Ear thworlcs ( f l a t , ro l l ing and h i l l y terrains b. Sub-bases (gravel) and bases (gravel,

crushed rock, macadam) c. Surface dressings (on different bases).

107. For individual independent a c t i v i t i e s the construction methods assumed are as l i s t e d i n Table 11.3, whereas for the groups of in t e r- dependent a c t i v i t i e s those shown t o l i e on the production functions have been adopted. For interdependent ac t iv i t i e s , the two consultants, SWKP and BCEQN, adopted s l igh t ly different approaches, varying primarily i n the number of al ternat ive methods considered. BCEOM derived Qroduction functions (isoquants) from a l e s s extensive range of al ternat ive construction methods (often jus t two - an equipment intensive and labour intensive al ternat ive) which limited the extent of intermediate (mixed labour and equipment) subst i tut ion poss ib i l i t ies . SWXP considered a wide r w g e of alternative methods i n developing the production functions introduced i n section D (and elaborated i n Upendix A) t o examine the scope for various combinations of labour and equipment. I n the following sect ior~s a, b, and c both the SWKP and BCXOM analyses are treated concurrently, excbpt t h a t isoquant relat ions for earthworks i n f l a t and h i l l y t e r ra in ( able 11 .S ) are not available from the BCEOM Report.

a. Earthworks

108. Tables 11.5 (for f l a t and h i l l y te r ra in) and 11.6 ( ro l l ing t e r ra in ) l is t the operations and ac t iv i t i e s considered under this heading and define the corresponding substitution slopes and break-even wage ra tes for the intermediate quality. mese have been combined together i n the manner described i n para. . t o form the production functions i l lu s t r a t ed i n Figure 11.5.

109. - SFKP. I n the case of earthworks, intermediate substitution i s possible, as has been shown i n section D, Figures 11.2, 11.3, and 11.4. Taking the case of h i l l y t e r ra in i l lu s t r a t ed i n figwe 11.3, opeaation e.1 i n Table 11.5 corresponds to the intermediate substitution AL, whereas operation e.2 corresponds to substitution LJ. similarly, i n rock excavation for earthworks, the over a l l subst i tut ion i s subdivided in to three segments represented by l ines ED, D J and J K i n Figwe A.L of Appendix A. ( ~ a b l e s 11.4 and A.S indicate the construction methods which these l e t t e r s represent). Each of these segments has been incorporated in to the production functions i n decreasing order of Yne break-even wage ra te . I n to ta l l ing the column a t the foot of Table 11.5 to determine the values of E and 1 a t the extremities of the functions, only the values representing the overall subst i tut ion slopes (e.g. AJ i n Figure 11.3) are included.

110, Total subst i tut ion for a l l a c t i v i t i e s i s possible a t the intermediate leve l of qual i ty and the overall slopes of the functions are:

Terrain

F la t Rolling B l l y

Haul length U.S.$ pek day

Hence the overall benefits of t o t a l subst i tut ion reduce as the length of haul increases.

111. It w i l l be noted tha t the order of substitution varies s l igh t ly depending on the nature of the t e r ra in but the general shapes of the three functions are similar. W i t h a wage r a t e of $2.00 per day, the proportions of the t o t a l equipment contents for which it would be f inancial ly advantageous t o subst i tute are given below:

Terrain Equipment content i n u.s.$ Substitute

Total with W = 2

F la t 3,486 2,7L9 8 0 Rolling 7,306 4,409 60 Hil ly 10,509 6,873 65

The limiting values of W a t which these substitutions are adv#tegeous are 3.35, 3.27 and 3.56 with increasing d i f f i cu l ty of te r ra in .

112. The main substitution within these figures are handSloaded t rac tor / t ra i le r units (including hand excavation) for scraper$, and labour for dozers i n the clearing and grubbing ac t iv i ty . Thesaine substitutions would be possible a t the high level of quali* though the proportion of equipnant substituted would be marginally l e s s ?wing t o the increased equipment content of the spreading and compacting aGtivities.

113. BCEOM. ( ~ o l l i n g Terrain) . Total subst i tut ion i n earthworks - i s possible for the intermediate qual i ty but would be p ro f i t a t l e only a t low wage rates, the overall breakeven wage s a t e being $0,47, A t a wage r a t e of $1.00 per day, only the loading, transporting, laying4 trimming and compacting of topsoil ac t iv i ty which constitutes s l igh t ly under 13 per cent of t o t a l equipment costs i n the equipment intensive Approach, could be substituted for profitably.

r1r - - TZE OZT LT*T CC - 6E 081 - I 2:: o o c - - OOT cooc $r

782 - - oOOT 000 '51 I I 2 2 T T I i YI T 3 T a ~l.zr?mo

b. Sub-bases and Bases

114. The operations and ac t iv i t i e s considered for the gravel sub-base are l i s t e d i n Table 11.7 while those for the gravel, the macadam and crushed rock bases are contained i n Tables 11.8, 11.9, and I1 .lo, respectively. The production functions are i l lu s t r a t ed i n Figure 11.6.

115. SWKP. For the gravel sub-base and base t o t a l subst i tut ion i s - possible apart from the loading, hauling, unloading and spreading of water operation, and the overall break-even wage ra t e s a re $0.95 and 0.56 per day respectively. The differences are mainly due t o the varying haul distances assumed.

116. For macadam base, substitution i s impracticable for loading, hauling, unloading and spreading water. The long haulage distance also r e s t r i c t s subst i tut ion poss ib i l i t ies . The average slope of the production function i s $0.65 per day. Similar considerations apply t o the crushed rock base and, i n addition, crushing of the rock i s assumed t o be a category IE1 act ivi ty. The average substitution slope i s $0.64 per day.

117. With a wage r a t e of $2.00 per day, the proportions of the total equipment content for rJfiich it would be f inancial ly advantageous t o subst i tute are given below:

Equipment content i n U.S.$ Substitute

%

Total with TIJ = 2

Gravel sub-base Gravel base Macadam base Crushed rock base

The limiting values of W a t which these subs t i tu t io l~s are advantageous are 4.94, 3.98, 4.36 and L.36 respectively.

118. The substitutions within the above figures are:

(1) Gravel sub-base and base: the substitution for a f u l l y equipment-in tensive operation for excavating , loading, hauling (by truck ) , unloading and spreading gravel by a labour-intensive operation using t ractor/ t r a i l e r uni ts for hauling.

( 2 ) Macadam and crushed rock basest spreading base course materials by hand instead of by equipment, loading excavated rock by hand i n the quarry ( into t r a i l e r s ) instead of by shovel.

119. Subst i tu t ion p o s s i b i l i t i e s would be l e s s a t the higher l e v e l of qua l i t y s ince i n this case spreading (and compacting) the basecourse mater ia ls a r e category 'El a c t i v i t i e s .

120. BCEM. For the gravel subbase and base t o t a l subs t i t u t i on i s p o s s i ~ x c e p t fo r the watering operation, and the over a l l break- even wage r a t e s a r e 0.74 and 0.27, respectively. It may be noted t h a t fo r the excavating loading and hauling ( 1 kilometre) of gravel f o r the

.

subbase BCEOM hypothesized a dozer a s s i s t ed scraper operation fo r the equipment in tens ive solut ion, with a r e su l t i ng high cost . A s can be seen from a comparison with the gravel base operation, t l e scSaper i s highly i n e f f i c i e n t and t h i s method would not i n f a c t l i e on the production function. llhe BCEOM breakeven wage r a t e s fo r the dompacting and f in ishing of gravel subbases and bases, $5.78 and $2.09, Pespectively, consider ably exceed the corresponding est imates of SWKP, $1.04 for both operations . 121. For t he macadam base, subs t i tu t ion i s p rac t icab le i n the quarrying of stone, production of materials , loading, and sprgading of materials a c t i v i t i e s fo r which t he breakeven wages range from $6.77 ( fo r the handloading of a t r a i l e r as opposed t o mechanical loading of trucks)l / t o 0.05 ( for unloading of stones a t t he crusher s i t g ) . The overal l subs t i t u t i on s lope fo r the macadam base i s 0.30. Essen t ia l ly the same conclusions a p p i ~ f o r the crushed rock base, w i t h t he subs t i tu t ion slopes ranging from 5.78- t o 0.06 fo r the same a c t i v i t i e s , and t he overa l l subs t i t u t i on slope i s 0.16.

122 With a wage r a t e of $1 .OO per day, no substir;ulion wohld be p rof i t ab le , s ince the only a c t i v i t y with a higher breakeven wege i s the loading i n quarry ac t i v i t y , which i s interdependent with the hauling and unloading operations and for which t he overal l breakeven wage i s well below 2.00 (viz. 0.23 and 0.15 fo r aacadam and crushed rock ryspectively). According t o t he BCEOM data, wage r a t e s wouldhave t o drop t o $0.50 and 0.52 for crushed rock and macadam respect ively before any sub$t i tu t ion would become yrof i t ab le .

1/ It should be understood t h a t the BCEOM a c t i v i t i e s a.1, a. 2, and a.3 are - interdependent so t h a t they must be considered only a s a group. The overa l l subs t i t u t i on slopes (breakeven wage) for t h i s group a r e 0.23 fo r macadam and 0.14 for crushed rock quarrying.

Tabb 11.71 Ruductbn Functions For One ~ o m t & ~ o f the Hypthetlwl b a d Pmjects

Gravel Sub-Base , Intermediate Qualltp

Operation or Activity

No. Description U n i t QuantiLty

a.1 Excavating, loading 3 m3 1,700 a.2 hauling, unloading and spreading m 1,700 a.3 gram1 d 1.700

b Loabing, haul*, unloading a d spreading water Id 100

c Compacting and finishing 3 11,201)

Totals

(Units: E l , E2, d - US$; 4, I, - man days) I

suw ~s t imate I 0 m n ~stirmatc I ' .

b t e s : * Substitution impracticable. W i s i n US $ per day.

For SWK?: Bows a.1, a.2 and a.3 are the intcaaediate substitution slopes fo r the interdep docit activities j the i i w e s in brackets a m coneeauentb excluied from the totals.

For BCEOHI Row a.1 exclubs spmading and Apre;mta hauling by t r a i l e r p a d by traator. Row a.2 is spreading.

Sowcesr Sm- RepoFt,p, 65, BCEM Report, p. 55.

For SWKP

a.1 comsponis to PB i n Figure A.6. a.2 BH A.6. a.) HK r.6. Table A.7 &scribes the aonstmctbn m t b d s mpm8mted.

92'0 TRSE LLtl 6 CCET €2'0 9 - 52.0 QCLZ - (S6T) (OC9) mzeT T~AWS C*a OT'O !!?6:;) (WZ) 86.C (561) (0C9) (OC) ( 6 ~ 2 ~ ) ~ Z ' T $ xu??eads pm l u ~ ~ o m e % m c l z0* 09'0 (126) (CLz) (628) 96.9 (Or) ( 6 8 2 ~ ) - Q6fT mZeT ~m B u p e o ~ rZtqqe~e~x3: -

LZ'O %9C 155 LT OTST 95'0 86LZ CC - S6ST SPqOL

. . TABU II.10: h d u c t l o n Functions f o r One Kilometre of the Hyl!~~theticib Road R o b c t s . .

Cmshed Rock Base, Intermdlate Qualitx . .-- (Units: El,E2, WmUS$; 1 1 , 1 2 - . a n d a y s )

r

Operation or Activity SWI(P Estimate , BCEOlI Estdmata -

b. Ibscrlption U n i t Quantity E 1 1. U B 1 E E2 l 2

U 1 1 2 1 1 2

3 a.1 Xxcavatlng, loading, hauling, m 1035 2 ("1 (86) ?:b I ( 61) (62W ( 32&0) 0.10 a.2 and unloading mck 3 1,200 (667) (86) (502) (Us) - - ( 67) 6.78- a.3 in w r g 3 1,200 ($02) (US) - 1935 0.33 1201) ( 6) - (3806) 0.06

b M c M o n of base course material m3 1,200 1 810 - 810 - * 875 12

c.1 Loading, hauling, un- 3 1,200 1865 - 1656 30 6.96 ( 298) - (298 - * c.2 loading and spreading (252) - ( 1153) - * C.3 base course nnterial ( 18) - 1 k 5 ) 0 . 6 Q

1697 18 l&51 &2S 0.60

d Loading, hauling unloading and spreading water m3 70 1 3 3 ' - 33 - * I 37 1 37 1 it

e Compacting and finishing m2 ' ~ J W 61, - - 60 1.07 &b & &b & t

Totals 3OY 7555. 0.16

Notes: w W does m t agree because of rolllld5.q errors. * Substitution impracticable.

Fbr SWKP: b u s a.1, a.2, and a.3 represent the i n t e w d i a t e subsututlon possibiLltLes for tha - Intardepanaent a c t i d t i - tka l lguraa lnbrackkts-ara maeqmntlJC axahuk& f m t h e totals,

For B M M : Rows a.1, a.2 and 0.3 refer, respecJd.vely, to the excavating of stones; loading of stones; and hauling by t ra i l e r pulled by t r a c k and unloading a t the cmshar site. Rows c.1, c.2, and c.3 refer, respectimly, loading, hauling and spreading of base ~urbrials.

Sourceat SdKP Report, p. 66. BCEOH Beport, p. 63.

msponds to BD Frr Pigure A.5.

Table A,& Qecrlboa the conatmourn

PRODUCTION FUNCTIONS FOR SUB - BASE AND BASES FOR ONE KILOMETER OF

THE HYPOTHETICAL ROAD PROJECTS - INTERMEDIATE QUALITY.

LABOR MAN-DAYS

Figure 11.6

c. Sufface Dressings

123 The a c t i v i t i e s considered for bituminous surface &%$sing of the various types of base are l i s t e d i n Tables 11.11 and 11.12. The surface dressing for a macadam base d i f f e r s from the others i n tha t the bitumen is applied i n a single coat and the chipping s i z e i s larger . Figure 11.7 shows the corresponding production functions.

124. SWKP. Apart from the loading, hauling, unloading and spreading - of chippings and bitumen (where p a r t i a l subst i tut ion is possible), a l l a c t i v i t i e s can be carried out by labour. The overall br+akeven wage r a t e s for the macadam surface dressing i s $1.5h per day and s l ight ly lower a t $1.23 per day for the other types.

125. A t a wage r a t e of $2.00 per day, substitution for nobe of the ac t iv i t i e s i s f inancial ly advantageous but a t a wage of $1.& per day, subst i tut ion would be profi table for a l l a c t i v i t i e s except al. 2 (hand excavating and hauling of stones i n quarry by bullock c a r t 1.1

126. For high qual i ty work, category 'El a c t i v i t i e s would be required for spreading bitumen and compacting and hence the scope f o r substitution would be reduced. ,

127. BCEW. For theBCEOMestimates, subst i tut ionposs i~ i l i t i e s are 1imitea"to the loading, hauling, and spreading of chippipgs and t o the brooming and cleaning of macadam surfaces. range from 0.22 for loading, hauling, unloading and t o 1.78 for broorning and cleaning macadam surfaces.

gravel or crushed rock base, O.U. t i t u t i o n slope for surface treatment for macadam

I

9L'T ZOT OL f

PRODUCTION FUNCTIONS FOR SURFACE DRESSING FOR ONE KILOMETER OF THE HYPOTHETICAL ROAD PROJECTS - INTERMEDIATE QUALITY

LABOR MAN-DAYS

IBRD - 6220

Figure 11.7

2. Comparison of the Costs per Road Kilometer for Different Mixes of Equipment and -Labow and Different Construction Qualities

128. I n order t o examine the impact of d i f ferent mixes of equipment and labour methods on construction costs per road kilometer, and the effect of the construction qual i ty specified on the f e a s i b i l i t y of substituting labour intensive methods, a f i n a l ser ies of analyses were performed for the hypothetical road projects. I n these analyses for both high qual i ty and intemediate quality specifications the optimal combination of equipment and labour methods for an assumed wage of US$1.00 per day was f i r s t determined and the costs of the various operations (earthworks, subbase, base, and surf acing) were added together t o yield a f igure applymat ing the t o t a l basic cost for the hypothetical road kilometre.- A further calculation was then made, substituting step-by-step more labour intensive techniques for each ac t iv i ty for which subst i tut ion i s technically feasible, so tha t the llinef ficienc y cos tslt of employing successively more labour could be calculated.

129. We give herebelow the resul ts of the f i r s t calculations which refer to the case of a Type A road i n ro l l ing terrain. The stepwise analysis of the costs of employing more labour i s presented i n Chapter V. Supple- mentary analyses prepared by SWKP of the costs using ei ther fu l ly equipment intensive or f u l l y labor intensive techniques for a l l three road types i n f l a t and h i l l y as well as ro l l ing t e r ra in are given i n Appendix A (part b) .

130. Table 11.13 presents the estimate of costs of the Type A road (gravel subbase, gravel base, and two coat surface dressing) i n ro l l ing te r ra in for intermediate and high qual i ty for the equipment intensive solution, the optimal combination of methods (when the wage Pate for unskilled labour i s $1.00 per day) and the maximum labour soluticn for both the SWKP and EEU4 data. The optimal combination of methods has been found from the equipment intensive solution (as given i n Tables 11.6 - 11.12) by substituting labour for equipment i n a l l those operations for which the breakeven wage ra t e s exceeds (or equals) $1.00, the pr ice of labour assumed i n this exercise. The more detailed tables l i s t i n g the separate ac t iv i t i e s fram which Table 11.13 has been drawn are given i n Appendix A (part 5 ) .

131. A comparison of the cost figures derived from the S W and BCEOK data reveal major differences as expected, with the BCEOM figures being much higher i n every case. However, the SWKP and BCECM estimates are re la t ive ly clos er for the equipment intensive solution than for the optimal

1/ Excluding structures, mobilization, engineering supervision, administrati~re - and miscellaneous costs.

Table 11.138

(U.S. Dollars)

SWI[P BeE014 . ; Equipmnt Gbor %d~-t Labor

Intensive Solution Optimal Mix Intensive Solution Intensive Solution O p t i d PUx Intensive Solutbn El Ll Eo Ia 62 L2 E l Ll Eo Ia E2 12

Earth-arks

Gravel Subbaae

A. Int?irmdiate Quality

7 ,306 10 2,736 1,387 - 7,236 l l j825 119 10,313 2,380 19 r8W 91316 b.123 u& zA2!!!t 22,180

2 - 562 361 lil 3.4 2,887 2,177 2,931 35 1,552 1,883 rn e22 2,224 a 2.922 M

Total Costs per Kilomtm, Y

In*arre.iiate Quality 1l,880 i&L - - - - - 17 ,LO1 - =!Y -

- 235 508 Gram1 Subbase 2 ,181 1,023 n,lel 21601

Gravel Bass 1 ,6k9 - 989 ' 166 k57 u.55 M

pa b a t Surfaca h e s i n g 900 1 535 276 k70 901 8 l l !xi

S l ; b b t d Q u i p n t h b o u r 12 ~ 1 0 k ll 5 ,379 2 j a k 1,572 12 ,190 17 jk8O Wo 2k,o& Total Cost per gilomstm ,lf 12,1l5 M U,?62 - - - a ILla C d t Y - 7

1/ Lxclrding structures, englmesing supervision, mpbFUzatlon, a b i n i s t r a t i w ard mhcellaneeus costs. z/ S h e them i s greater technical scope Per (inefficLent) substitution of labour for equlpiant in the ildermsdiate quaUtg than the high quaUQ Lve l , the cost of tbs intermdiate quality e x w e b tbat ef tb high qunllty for the d l a u m labour srrlution.

combination and labour intensive solutions as can be seen from the following tab1 e :

Table 11.14: Ratio of BCEOM and SWKP Estimates of Total Costs per Road Kilometer, Type A Road - Rolling Terrain

Equipment Labour Intensive Optimal Intensive

Method Mix Method

Intermediate Quality High Qual i ty

This i s simply another evidence of the greater f e a s i b i l i t y fo r labour subst i tut ion inherent i n the SWKP estimates, as was seen previously i n Figures 11.5, 11.6, and 11.7. For the optimal combinatioa of methods SWKP shows considerable savings over the equipment intensive method, while BCEOH shows very l i t t l e change i n method and costs betveen the two cases. For the labour intensive solution, the estimates ba$ed on BCEOM data are much higher than the S W estimates since t h e d a t a adopted by BCEDM show much greater labour inputs necessary t o of fse t withdrawal of equipment; t h i s implies of course t h a t deliberate manuali a t ion of construction technology beyond the optimal combination w i l l k r ea t e more jobsl~ccording t o the BCEOH estimates, but a t greater inefficiency cost per job.- I

m e Effect of Quality Standards on the Subs t i tu tab i l i ty of Lhbour and Equipment (High Quality versus Intermediate Quality)

132. The relaxing of construction qual i ty standards from bigh t o in t e r- mediate leve ls is shown t o have l i t t l e overall e f f ec t on th$ t o t a l costs of the projects and st i l l smaller e f fec t on the optima$ combination of methods for e i ther the SWKP or BCEOM estimates, as can b$ seen from a comparison of the percentage of equipment i n costs f o r the various cases i s given i n Table 11.15. According to the SWKP estima !5 e fo r the optimal method, equipment consti tutes approximately 72.3 percent of t o t a l costs for the high qual i ty case and 63.5 percent for the low qual i ty case. The corresponding f igures far BCEOH are 94.4 and 94.2 1 percent

1\ See Chapter V, p a r t A below. -

respectively. Thus, i n the SWKP case the additional labour employment made profi table ( a t wage = $1 per day) when qual i ty standards are relaxed i s only about 11 percent of t o t a l costs (or an increase i n labour days of 17 percent) while according t o the BCECM data there i s essent ial ly no change i n the optimal mix. I n ei ther case the s+='

additional employment generated is small, suggesting tha t relaxation of construction qual i ty standards may be a poor way t o create additional 8mployment Depending on the benefits deriving from the higher qual i ty s tandards ,g t may be more e f f i c i en t to maintain high qual i ty and subsidize the employment of more labour.

133. Again, it must be emphasized t h a t geometric design standards have not been varied here except t o accommodate t e r ra in t o some extent, i . e . the geometrics are the same for both the hfgh and intermediate qual i ty construction standards. I n actual practice, it may be profi table t o relax geometric standards t o some extent t o take bet ter advantage of labour intensive methods of construction. For example, equipment involved i n earthworks i n the optimal solution s t i l l const i tptes 38 percent and 63 percent of t o t a l costs i n the SWRP and BCEOM estimates, respectively, and relaxation of geometric standards t o permit reductions i n the quan- t i t i e s and cost of earthworks might be profitable, but these savings w i l l have t o be compared with the resul t ing increase i n user costa (vehicle operating costs ) . Such analyses have not been possible i n the present study due t o the l imitat ion of available data and time but ape being investigated i n subsequent studies i n conjunction with the TBhiIP Highway Design Study

x- -% -%

Conclusions of the Engineering Analyses appear a t the end of Chapter 111.

1/ See the followine ~ a r a e r a ~ h and footnote.

Chapter 111

thq Ehgineel*ing Analyses . a -

A. LIMITATIONS OF THE ANALYSES

1 . I It is emphasised that the foregoing analyses are for -the purposes of illustrating the problems and effects of substituting labour for equipment and they do not represent the actual costs of carrying out the work. Firstly, they have been based on arbitrarily assumed rates for the costs of equipment and labour whereas, in practice, actual costs (financial or economic ) might be considerably different. Secondly, it has been necessFry to utilise several different sources of labour and equipmerit productivity data and some distortion is consequently inevitable.

2. While an attempt has been made to simulate some of the effects of the environment on the nature and volume of activities by relating earthwork quantities, haul distances, etc. to the nature of the terrain, in practice the effects would be much more complex and they could differ substantially from the simple assumptibns made. For example, a new road in flat terrain passing through kice paddy would involve more extensive earthworks and much longer fiaul distances than those assumed to be representative of flak terrain.

3. No account has been taken of the effect of the enyironment on productivity rates, either on or between differing tries of equipment, or on the relative productivity rates of equibment and labour.

4. The geometric design standards have been assumed to vary in accordance with the terrain but not to accommodate labom-intensive techniques though some allowances in the latter respect would almost invariably be made in practice.

5. No account has been taken other than in a general way of the engineering problems that would be associated with laboui. su1,stitu- tion, such as:-

(1) scale - the size of the project and the rate at which construction has to be carried out;

(2) the timing and sequencing of activities making up the project ;

( 3 ) idle time of equipment and labour;

(4) the compatibility of labour- and equipment-intensive techniques on the same site;

( 5 ) mobilisation and other fixed costs as they differ between the two techniques, including supervision, overheads, administration, logistic support, etc.;

(6) differences in the nature and volume of activities due primarily to the difference in techniques, such as temporary works, etc., and

(7) the practical difficulties of aggregating basic production functions beyond the simple grouped operation level in that substitution for one activity could influence other activities in a varietb of ways.

6 These limitations and their effects are discussed in this chapter, while the organizational aspects of labour substitution are described in Chapter IV,

B. THE EFFI;TTS OF THE ENVIRONMENT ON THE SUBSTITUTION PROBLFN

7. The physical environment can be defined in terms of climate, vegetation, topography, geology and soils, and these ape all inter-related in a geographical sense. The social environment is determined by such things as conditions and standards pf living and many other factors. To some extent they are related tb the physical environment.

8. Consideration of the wide range of possible combination of these factors has led to the general conclusion that none can effect the technical feasibility of labour substitution in any of the basic road construction activities, but will b e a mJor influmce on the profitability of such substitution.

9. The environment influences the scope for substit+tion in three main ways, by: I

(1 ) its effect on the productivity of labour; )

(2) its effect on the productivity of equipment, and

( 3 ) determining the nature and volume of activities which make up a project.

10, The environment affects the productiv5ty of equipment and labour in differing ways and its impact varies with th< nature of of the activity. Conditions conducive to high plant p?oductivity may be far from ideal for labour, and vice versa. Again, clonditions favouring a particular activity may not favour others. A detailed understanding of the specific environment is therefore essential to determine the true scope for labour substitution.

THE PRODUCTIVITY OF LABOUR

11. In general, the factors affecting the productivity of labour may be divided into two broad groups; those affecting the capacity of labour (i.e. possible rate of output) and those which affect the performance of labour (i.e. actual output). The scope for increasing productivity by modifying the capacity factors is largely restricted to long-term measures. Unfortunately, perfopuance invariably falls below capacity but there is scope for narrowing the gap since many of these factors are within the control of the employing agency and/or the government of the country, and short - term measures can often show immediate benefit.

12. Factors commonly affecting capacity, listed generally in descending order of importance, are:-

Standards of nutrition; . . Standards of health; Tra2itional skills, methods and tools; Effective working times; Climate - particularly temperature and humidity; Adaptability.

13. The report of an ILO study in India ("Men Who Move Mountains") identifies the main reason for the consistently higher output rates of members of the Malabari tribes engaged on earthworks sls being the higher nutritional standards enjoyed by them. The un- or underemployed unskilled workers in the labour-surplus developing countries often exist on a near-starvation diet and the effects of years of under-nourishment cannot be overcome in a short period. Nutritional problems are closely allied to those of health. Malaria, filaria, intestinal parasites and other debilitating tropidal dis4ases are endemic in many of these countries. They are due in par3 to the lack of pure water, poor or non-existent medical faciliti,es, bad hygiene and absence of sanitation. Although certain of these factors can be partially overcome in the organisation of large grioups of labour in camps, the effects of these diseases extend well beyond the removal of the cause and are often permanent.

14. Traditional skills, allied to methods and hand tools, can be particularly important to productivity in certain activitxes. In many countries there are tribes or social groups who by long standing custom apply themselves to particular types of work and t@e work will not be undertaken by other people; high rates of prbductivity are common and use for these particular skills can often be found in road and bridgeworks. It is sometimes customary for who19 families to be engaged with a traditional division of tasks betweed adult males, adult females and children. Traditional methods okten appear inefficient to foreigners and a t t e w to change rather t W to adapt them are met with resistance and often lower productivityd Traditional tools, particularly in earthmoving, have been developed over the centuries to perform specific functions often ofan agricultural nature and they may well not be suited to cadrying out the basic activities in road construction. Changes to moqe efficient hand tools are essentially a long-term measure - they are invariably difficult to adapt to and may involve the building up of a completely different set of muscles. To these difficulties must be added the natural resistance to change inherent in under-developed and rural areas.

15. The capacity of labour, in terns of productive hours worked per day and productive days per year, can have a major effect on output. Daily working hours are often governed by custom yr decree; productivity throughout the year is affected by the climate

(particularly rainfall and its consequent effects), absenteeism for various causes, and traditional and religious holidays. In Moslem countries output is significantly reduced during the annual fasting period.

16. The effect of climate on capacity has been given sl low ranking in that indigenous people are accustomed to working in their normal climatic conditions. However, it is recogqised that there are particular combinations of temperature and huniidity which are conducive to efficient working although acclimatisation goes some way towards reducing these effects. The effeqt of climate (and altitude) on capacity would be much more pr)onounced if labour was required to work in unfamiliar climatic conditions.

17. The adaptability of labour and its ability to learn new techniques has been ranked as of least importance ir- the context of substituting (unskilled ) labour for equipment. The $as t majority of labour that could be employed to replace equipmeat would require little skill to master the use of the him@ $ooBs involved and they would invariably have some ingrained Enowledge, if not skill, gained in other fields of many of the baailc construction activities. I

18. The factors commonly affecting perf ozmance are lris~ted below, again generally in descending order of importance:-

Management and organisational skill; Incentives to work; Consequences of unemployment; Social attitudes; Organisation of labour; Living conditions.

19. Management and organisational skill is ranked as the most important of these factors and its effects are significGt at all levels; from the ganger or overseer ensuring that laboa is productively employed and has the right tools and materi&ls to do the work, to the higher levels of management integratirgthe work of large bodies of labour. The relationship between m&r&gernent, at all levels, and those who actually do the work, is of great importance. A particular type of management skill is re~uired for labour-intensive work which differs significantly fron; that required for equipment-intensive work, the former requiring pronohced leadership qualities.

20. The main incentive for labour to work is the wages structure, not only in absolute terms of what can be bought with the cash received, but the rate in relation to that which other workers receive. To control the performance of large bodies of labour it is essential to relate output to wages, either by a task or a piecework system. Taskwork is simpler to operate but the benefit to the workers is solely in terms of time saved and this may not

be of great value to them. Piecework is more complicated to administer but has the advantage that both labour and management share in the benefits from increased production, in terms of higher wages or reduced unit rates; the nature of road construction generally means that it mst be applied on a group basis. Whichever the system adopted, it is essential that tasks or norms of production be properly assessed taking into account the full circumstances of each case. While task work is frequently common on force account projects, piecework is seldom used lergely because of administrative difficulties and thb possibilities of abuse.

21. The consequences of unemployment have a bearing on discipline and hence the performance of labour. In circmstances where unskilled work is not freely available, i.e. where there is an unemployment problem, the ultimate disciplinary deterrant of dismissal can,if effected, lead in some countries to gtarvation for the worker and his family. In other countries, notably those with surplus land, social customs ensure that the unemployed are looked after by other more fortunate members of Weir tribal group. These traditions are more pronounced in rural areas and the effect is of less significance in the urban areaswhere the unemployment problems are invariably greater. This fqctor is likely to be of greater importance on small projects dsing locally recruited personnel who are less dependent on employment income tha.11 on large projects drawing labour from a wider area (or using mobile labour) whose dismissal could lead to deprivation.

22. Social and political attitudes towards m u d work vary considerably from country to country. There is sometimes a social barrier between skilled and unskilled workers, and manuaP work is accepted only as a last resort. Increasing educatiopal sLandards tend to make manual labour unacceptable and, on occasions, the use of equipment-intensive methods is dictated by national pride. Under these circumstances it is not unusual tlo find %hat labour engaged on manual operations is poorly paid and regarded as inferior; there is consequently very little pride in kork and productivity suffers accordingly. At the other extremb, where %'he virtues of hand labour are extolled at all levels, thepe is recognition of achievement within the community and productivity is increased accordingly. While the latter cannot be achieved overnight, it is clear that the substitution of labour for equipment must be encouraged at the highest levels for it to be successful, and must never be regarded as a retrograde step.

23. Productivity can often be restricted by the attitudes of trade unions and other labour organisations that are concerned with improving the standards of living of their members. Where labour is well organised in this fashion, it is essential that their views be taken into account by management not only in the

day-to-day running of a project but in the orerall administration and organisation. With proper consultation, a good union can be of considerable assistance. On large projects, the incidence of strikes can be minimised and both the reliability and productivity of labour cam be improved.

24. The importance of good living conditions for labour varies considerably. On small projects dependent on locally recruited labour, there is little that can or need be done. On large projects imported labour might be entirely dependent on the employer for food and shelter. Good conditions lead to good productivitybutthe extent to which it is economic to provide them is largely a matter of scale. On a very large project, labour canps could include accommodation, proper water supplies, sanitation, health, feeding and recreational facilities, together with the specialist staff required for their operation. While it might be economic to provide facilities on such a scale for a large project such as a dam, they could seldom be considered for road projects which of necessity cover a wider area. Flowever, simple measures such as bulk purchase of feedstuffs w d the provision of elementary health and sanitation facilities can be of considerable assistance in improving relations with and the productivity of labour.

25. A wide range of factors affect the capacity and performance of labour, and wide variations in productivity are therefore to be expected. Rates of output can vary considerably under normal conditions and may be unacceptably low in very difficult environments. The trade-off between labour'and equipment would remain constant if the environment affected both labour and equipment productivity to the same extent, but this is seldom so in practice and the scope for labour substitution depends to some degree on this fact.

THE PRODUCTIVITY OF EQUIPMENT

26, The factors affecting labour described in the previous section have similar effects on the performance of equipment in that they influence the capacity and performance of the skilled personnel operating and maintaining the equipment. Their impact varies in accordance with the nature of the activity. Ehvironmental factors also have a direct effect on the equipment.

27. The skill and adaptability of labour and, in particular, its inherent mechanical aptitudes are probably the most important of the factors affecting the capacity of the operators and mechanics. Familiarity with lorries and similar hauling equipmenf; and their maintenance is common in most countries but more sophisticated equipment such as heavy earthmoving plant is not so well known. Labour skilled in the operation and mainCenance of

such plant is often not available and there is no alternative but to train the most suitable labour obtainable. Apart from the time required for initial training, skill can be developed only by practical experience over a lengthy period and the full benefits of training are often not realised until some years later.

28, The performance of equipment is directly related t o that of the operators and mechanics. For a given output, the number of personnel involved is far less than for a labour-intensive project. The management and organisation of the labour involved is still of prime importance since it is esbential to keep machines operat- to their full capacity to attain m a x i m benefit. The low labour content per unit of work, both in time and cost, offers the opportunity to provide substantial incentive to improve performance while achieving ovekall reductions in cost.

29. Apart from these factors directly related to the labour required for equipment operations and maintenance, there are other factors affecting the capacity and performance of th$ equipment itself. Equipment is often required to perform ope~ations for which it was not specifically designed. It is impr cticable to i provide a full range of specialised equipment (asswng it exists) for each basic activity; to a large extent the cost of aobilising equipment and its availability in relation to the vol/ume of each activity governs the choice. Certain types of equi6ment are more adaptable than others, and the overall requirements qf a project may lead to the selection of such equipment in prefedence to plant of a more specialised nature.

30. The age and condition of equipment affect prodtlctivity, mainly due to reduction in util-isation caused by incrieased incidence of breakdowns and difficulties of maintenanbe. EQuipment on road construction in many of the developing countriies is often used for periods well in excess of its normal economic life and this places greater strain on the available maintenanbe facilities. The effective productivity of such equipment can be very low.

31. Of prime importance to productivity are the maintenance facilities, both those provided on site as part of the project and others in the area which can be relied upon for svpport. The availability of spare parts in terms of the time elapding between ordering and receipt can have a major influence on equipment utilisation. Where time for an operation is critical, it may be necessary to provide spare units to allow for these factors.

32. On very small projects it is seldom economic to provide other than the simplest routine maintenance facilities. On the other hand, major projects could justify comprehensive workshops

and large stocks of spare parts, and there would be no need to rely on external agencies for immediate support. However, such an ideal environment can seldom be justified in road construction. To obtain maximum utilisation of equipment, large stocks of spare parts must be held on site, particularly where these are not immediately available from other adjacent sources. Consequently, the utilisation that can be expected from equipment ihcreases with the size of the project.

33. Of the climatic factors, rainfall is normally the most significant. It is particularly important in earthmoving operations where it can restrict work by its effects on the engineering properties (and subsequent uses) of the s~ils being moved and, in certain circumstances, can dictate the type of equipment to be used. Of equal importance is the ti$e wh.ich must elapse after rainfall before equipment can be used withopt causing excessive damage. This is frequently much longer t* the rainfall period. Extreme climatic conditions invariqbly increase the wear and tear of equipment and place greater d e d d s on maintenance.

34. The accessibility of the site can restrict the size and type of equipment and necessitate the use of smaller, less efficient, units. The topography and condition of site haul routes affect productivity in the hauling activities and it may well be economic to undertake substantial temporary wc)rks to achieve greater output. These factors can also influence the choice of haulage equipment.

35. There is usually a need to maintain traffic while construction is in progress and it is difficult to assess the effeat of this on productivity. Effects are related to the traffic volume and clearly are of more significance in the higher type of road, particularly in difficult terrain. In the United ~i&dom, it is often said that the cost of dualling an existing road is greater than that of building a new dual facility, but such extremes will seldom apply in the developing countries.

36. The bad effects of factors influencing the productivity of equipment can be partially offset by good management and proper organisation. With the high capital investment involved high unit costs prevail with idle or inefficiently used plat. In many of the developing countries carrying out road construction by force account methods, it is not normal to debit the project with realistic hire charges for equipment. This invariably leads to low productivity since the true cost of the work is not immediately apparent.

THE NA'CTTRF: AND VOLUME OF ACTIVITIES

37. For a given road, defined in terms of cross-sectional geometrics, traffic loading and quality, the physical environment influences the nature and volume of the basic activities in many ways. The trade-off between labour and equipment w d the scope for labour substitiution varies with activity and hence must be dependent, to some degree, on the environment.

38, Of the climatic factors, rainfall generally has the most influence on the nature and volume of activities; it determines the type and frequency of drainage structures, side drains etc. and the construction activities associated with these items will clearly be more significant in areas subjected to hi$h or intense '

rainfall. High rainfall favours the use of those materials, such as rock and non-plastic soils, which can be handled and placed at higher natural moisture contents. Conversely, low rainfall coupled with absence of readily available natural water supplies, could favour such types of construction as stabilisation by bitumen in preference to cement. The pattern of rainfall throughout the year, together with other climatic faators, affects the natural moisture content of local materials and governs the volumes of the activities needed to adjust the moistyre to the optimum state. The extent to which earthwork slopes, drainage channels, etc. need to be protected is also related to the rainfall. Prevailing temperatures and humidities cah have similar, though less marked, effects. The direction of the pkevailing wind and its velocity in areas of sand dunes can be the pr$me factor in fixing the profile of a road, with its resultant effebt on earthwork quantities. Road location and design canalso be influenced by snow, fog and exposure to high winds.

39. The density and type of vegetation affect activities concerned with clearing, grubbing and removal of topsbil. It also has an indirect effect on the retention of moisture-ih the ground and this, in turn, affects excavation and compaction activities. The vegetation covering has a direct bearing on the egtabliskent of vegetation on shoulders and earthwork slopes. Fojc example, where vegetation is abundant, natural processes can often be relied upon to provide protection without the prior necessity for topsoiling.

40. Topography is particularly important in relation to earthmoving although its effects can be offset by reducing design standards in difficult terrain. Earthwork quati ties increase as the terrain becomes more difficult but frequently there are compensating effects in that the engineering qualities of the soils tend to improve leading to greater usability of excavated soils in embankment and steeper pemissible side slopes in cutting-s. It is also often found that local materials suitable forpavement

construction are more readily available in areas of pronounced relief. Drainage works are usually more frequent in hilly areas than in flatter country and steeper gradients lead to a greater need for protective linings in drainage channels. Access problems are often increased but haulage distances may be reduced.

bl . The topography of an area is related to the geology. Geology has an obvious effect on all earthwork o p e r m influencing the difficulty or otherwise of excavation, n a m e of the available materials and haul distance. The nature of the soils similarly affects the type and size of the basic activities. Some soils may have to be excavated, discarded and replaced with others of a better quality; processing of soils to reduce their natural moisture content may be necessary, and moisture contents may have to be increased to achieve satisfactory compaction.

42. All these factors combine variously in n a m e to produce a wide spectrum of physical environments which often vary continually with time. The factors and their effects are taken - into account in the selection of the alignment for a road and in the design and specification processes which define the nature and volumes of the basic activities required for construction.

Some allowance has been made in the hypothetic41 road projects for the effectsof the environment on the na4re and volume of activities. However, it is emphasised that these would be far more complex in practice and they could vary bttween wide extremes. ,

44. Quipment intensive methods favor wider safety margins and overbuilding, whereas labour intensive methods favor very close tolerance limits and staged construction.

C. ASSOCIATED ENGINEEXING PROBLENS

THE PROBLEM OF SCALE

4 . The hypothetical road projects may be used to illustrate the problems of scale. Quantities per kilometre for excavating in bulk in soft material (including loadillg, hauling and unloading) are :-

Terrain Flat Rolling Hilly

Excavating 5 , 000 9,800 14,250 mJ

Average haul 100 4.00 200 m

To achieve an average weekly output of one kilometre of road, and assuming that earthworks could not be possible during 4 months of the year, average weekly outputs during the construction season would need to be:-

Terrain Flat Rolling ~i$.ly

'7,500 14,700 91,375 m5

46. For a labour-intensive project, the high outputs and increased haulage distances would be achieved by usin@ more labour. If the physical conditions of the site imposed a limitation on the numbers who could be usefully employed in a given are+, the required rate of output could normally be achieved by spreadi4 the work over a greater area. However, there would be no economieq of scale; in fact, there might be some marginal reduction in output due to a lower degree of control. The unit cost of carrying qut the work would remain much the same, apart from the effect of jncreasing the haulage distance . 47. On the other hand, higker output on an equipqent-intensive project can be achieved either by using more equipment (subject to any site limitations) or by using larger units. The leffect of equipment size on unit rates is illustrated in Table *I-1 which is based on productivity rates quoted by Spence Geddes abd UK Plant Hire Rates.

Assuming a 60-hour working week for scrapers during the construction season, the hourly output rates and the corresponding theoretical numbers of scraper units required are shown in Table 111-2 based on an average weekly output of one kilometre of road.

Table 111-7 :Outputs and Unit Rates for Tractor-Drawn Scrapers Excavating Soft Soil

Source: SWKP Estimates

Table 111-2:Tractor-Scraper Units Required for Construction of Hy-pothetical Road Projects

Hourly Output Required

Source: SWKP Estimates I

!

49, In practice, it would not be wise to use a large number of small scrapers since supervision and administration is more difficult and unit costs are high. Similarly, a small number of large scrapers could also be unwise, since a breakdown of one unit could seriously interrupt the programme of work. In the above emple, flat terrain would tend to favour the use of the smaller units, while rolling and hilly terrain would favour units even larger than those considered.

3 3 50, Comparing the use of the 6 yd scrapers (US $0 3l/m ) with a labour-intensive wheelbarrow operation (US $0.5 1/d at $2.00/ day) in flat terrain, the break-even wage rate would be US $1.21/day. In hilly terrain, using 12 yd3 scrapdrs, the corresponding break-even wage rate would be US $0.64/day.

1 Similar analyses could be carried out covering other operations and activities. On a recent project in India, it was shown that hand loading of vehicles was cheaper than using a small powered shovel but that labour could not compete witq larger loading equipment. It may be concluded that the scoFe for labour substitution is greater on the smaller projects wherel, for one reason or another, the size of equipment is restricteid.

TIMING AND SEQUENCING PROBLENS

52, Labour-intensive projects invariably take longer to complete than those using equipment (provided that an adequate supply of spare parts and competent mechanics are available). The longer construction period is due to the lower rate of laboup productivity when compared with that of equipment. Theoretically\ the use of a larger labour force would overcome this problem but constraints in practice would include:- I

( 1 ) the non-availability of labour, particula~ly during the planting and harvesting seasonb;

I

(2) the practical difficulties involved in mobilising and administering large bodies of labour ;

( 3 ) the lack of skilled supervisory staff and^ shortage of training facilities, and

(4) the physical limitations of the site restricting the amount of labour that can usefully be employed.

5'3. Lengthening of the construction period could have undesirable effects in that it could delay other projects dependent on the road

and the benefits arising from investment in the highway constnzc- tion could be deferred. At the same time some of the costs would be deferred. All these factors would have to be taken into account in assessing the extent to which labour substitution could take place. Optimal timing of costs and benefits could be attempted by planned stage-construction; completing the road to motorable standards in the first season (bridges and drainage works and partial earthworks) ; and completing earthworks b d laying the pavement subsequently. This practice is not uncommon in many of the developing countries.

While this may go some way towards overcoming the overall problem, other timing problems might still occur within a construction season. These could include the need to complete certain works before the onset of the rainy season t~ preclude subsequent damage, which may necessitate the use of equipment with its higher rates of productivity. However, these ppoblems are not solely restricted to labour-intensive methods and mi~ht be of even greater significance where additional equipment cannot be mobilised rapidly to offset shortfalls in planned productivity'.

55. Coupled with the timing problem is that of seqpencing, the arrangement of activities in their correct order. Apart from straightforward requirements, such as the need to complete earthworks before laying the pavement, there are invariabJy others more complex. For instance, it may be necessary to complete some earthworks or structures before access to a borrow area c@ be achieved. Such constraints may be of equal or even greater sieificance with equipment-intensive methods.

56. Sequencing requirements can affect the overall timing and programming for a project and may dictate that certain activities must be carried out by equipment-intensive methods. It can consequently affect the nature and amount of equipment required and its utilisation rate.

57. A work programme suited to a labour-intensive qethod might not be applicable to equipment-intensive methods and thei-e is a wide range of possible programmes for work involving partial substitution. In assessing the scope for labour substitution, work programmes must take account of many factors, including:-

(1 ) constraints on the availability of equip&ent and labour which might differ in time;

(2) the effect of the environment on productivity as it varies with time (e.g. some earthmoving equipment is largely unproductive during and for some time after heavy rainfall whereas

other types are not so affected by climatic changes) ;

(3) the optimum starting date for a project might be dependent on the equipment/ labour mix, and

. (4) the relative flexibility of equipment and labour.

58. Where the time to complete a project is of importance, the scope for substitution may be largely confined to those activities which are not on the critical path of the flow network of activities.

59. Sequencing problems can lead to enforced substitution; even though it may not be economic to do a particular activfty by labour, to do so may lead to higher overall productiviky. Conversely, the need to keep equipment fully utilised q ~ y lead to its use on activities for which it is less suited than labour.

IDLE TIME

60. Idle time of equipment or labour on a road construction project can normally be attributed to:-

(1) climatic effects, particularly rainfall; ~ ( 2) mechanical breakdowns of equipment ;

(3) difficulties in sequencing operations, and 1 (4) lack of proper organisation.

I

I

These factors vary with the nature of the work and wikh the type of equipment.

61 Rainfall has a noticeable effect on many earthmoSing operations since excessive moisture content can restridt the use of the material in embankments unless it is dried out. Scraper operations are particularly affected since a larger area of excavation is opened up at one time. On the other hdd, excavation by shovels (or hand labour) can be so arranged to minihse the harmful effects of rainfall. I

62. It is often necessary to restrict the movement od earthmoving plant during and immediately after heavy rain to avoid damage to haul roads and partially completed works. Static plant and equipment handling materials unaffected by rain (e.g. rock products) are affected to a much lesser extent.

63. The effects of rainfall can be most significant in the United Kingdom where the utilisation rate for scrapers can be as low as 4%, even though work is available. In countries where seasonal effects are pronounced, it is common to suspend all earthmoving operations at certain times of the year and equipment is idle during these periods. ,

64. Rainfall also affects the utilisation of labour but generally to a lesser extent. Labour is more flexible than equipqent and can be used in work not affected by rain. laid-off and some of the cost of idle time particularly that due to seasonal effects. I

65. Some idle time of equipment is due to mechanical bkeakdown. The incidence of break-downs is a function of the age an& condition of the plant, the skill of the operators and qintenance staff, and the conditions under which it is working. The availability of spare parts and repair facilities and thb skill of the maintenance staff determine the time required to effbct repairs. It is good practice to adopt preventative systems of maihtenance at the expense of losing part of the productive time of the equipment.

66, Sequencing difficulties can lead to under-utilisatlion of equipment. At one extremg particular operations may need the use C of a crane for short terms at isolated intervals and the e may be no other work on which it can be utilised during the intervening periods. Equipment such as bitumen distributors may W e capacity in excess of the overall construction rate and it may b$ utilised on average for only 2 or 3 days a week. With longer tyan average hauls, loading equipment (or labour) may be idle waitiq the return of vehicles; conversely, with shorter hauls, vehicles may be idle awaiting their turn for loading. Some of the idle tim$ due to sequencing difficulties is unavoidable since the nature of the work varies from day to day.

I

67. A breakdown of one piece of equipment can lead to the stoppage of a whole operation (and have adverse effects on other not always possible to use the associated equipment on The balance between capacities of loading and hauling eguipment is particularly critical. I

68. All these factors can be aggravated by lack of prdper organisation - inadequate supplies of spare parts and mdterials, lack of forethought in planning the day-ts-day activities in advance and of flexibility in planning to overcome expected andunexpected difficulties. The specialised nature of road-building equipment means that much of it cannot be directed to other work when climatic and other factors preclude activities being carried out in their normal planned sequence. These problems can be partially

overcome by the careful selection of equipment, both in relation to size and type, so as to retain the maximum possible degree of flexibility. On the other hand, labour is inherently more flexible and, while some idle time is often unavoida$le, high rates of utilisation can be achieved with proper mawgement.

69. The unit rates for equipment costs used in theanalyses of the hypothetical road projects contain some allotrancb for idle time due to climatic effect and for breakdowns/mainjenance since

1 8 the rates are for daywork. I

70. To illustrate the effect of idle time on the c~sts of owning and operating equipment, a typical case of ascraper has been taken, and the utilisation rate has been assumed to vary from 1,000 to 2,500 hours per year. The calculatio~s, which are based on average operating conditions, are shown in Table 111-3 Taking 2,000 hours utilisation per year as a standard, the effect on hourly costs is:-

Utilisation Rate Effect on Houri$ Cost

A utilisation rate of 2,000 ho~rs/~ear is near optim& for this type of equipment under the conditions (and costs) assumed and unit costs increase rapidly with under-utilisation. ~

71. The hourly output of such a scraper excavating in soft material, loading, hauling 100 m, unloading and spregding would be about 76 cubic metres. Comparing this with a lapour-intensive operation (hauling by wheelbarrow) where 0.256 man dhys are required for one cubic metre, the effect on the break-even wage rate is given below:-

Utilisation Rate Cost by Break-even wage of Scraper Rate for Ungkilled Labour ~ours/~ear $/by

72. It should be noted that no allowances have been made for mobilisation costs, profit, supervision, etc. in these figures.

I / The plant hire contractor charges only for the time that the equipment is fulu available for use, and bears the cost of maintenance and repairs himself. These, of course, fie expects to recover from the rates charged.

Table 111-3:Typical Owning and Operating Costs of a Scraper

DEPRM: SAT ION

Delivered price Less value of Amount to be depreciated

Average yearly investment % of purchase price Anaount per year

Yearly charges (1% of average yearly

Hourly charges

Tyre life, hours Total tyre replacement

'Pyre repair cost,

Fuel and lubricants,

Notes (1) Operatorrs costs at $1.35 per hour

(2) Idle time of operator charged

(3) Allowance made for overtime.

Source: SWKP Estimata

COMPATIBILITY OF EQUIPMEWl" AND LABOUR

73. Apart from the very simple roads, some equipment will invariably be needed in road construction and, in practice, partial substitution of labour for equipment will ofteri be the best solution. Consideration is therefore given to the difficulties that may arise in mixing the two methods on the same site and the ways in which they may be overcome.

74. One of the main difficulties in integrating equipment- and labour-intensive methods is that of sequencing, due to the wide disparity in their relative rates of productivity. Shortfalls in labour output, of little significance in themselves, can lead to under-utilisation of expensive equipment with consequent increases in cost.

75. This difficulty can be overcome by good advance planning and programming, starting the labour-intensive activities at a sufficiently early date to allow some slack to cater for (unfore- seen) contingencies. Ekamples are keeping clearing a d grubbing operations (by hand) well ahead of earthwork operations using equipment; opening borrow pits and gaining base-course and other local materials in advance of their requirements.

76. Some unskilled labour working with equipment can increase the productivity of the latter by undertaking that part of the activity for which equipment is not particularly suited (e. g. trimming excavations). The extent to which this is a$vantageous depends on the relative cost; in the United States the proportion of unskilled labour employed on a road project is very low, whereas quite large numbers of unskilled labour can be usefully employed on equipment-intensive projects in other countries where labour costs are lower. However, there can be danger in using too q c h unskilled labour on a confined site.

77. Hand labour coupled with equipment can often improve the quality of workmanship, particularly in the finishing operations and in confined areas where equipment cannot operate efficiently.

78. The size of equipmentis also of importance and it mayaf tenbe appropriate to sacrifice some of the economies of scale inherent in the large units to match the lower rates of output of hand labour. It is uneconomic to load large vehicles by hand in view of the lengthy waiting time during loading. ~ractor/trailer uni ts are more compatible with hand loading; with several trailers to each tractor, the more expenstve tractor can be fully utilised.

79. Similarly, a tractor is a multi-purpose vehicle which can be used for a variety of tasks such as towing water bowsers, bitumen boilers, rollers, etc. It can serve as the motive power for a variety of unpowered equipment and its flexibility helps overcome the sequencing problems referred to earlier. $eductions in the variety of equipment types also eases the maintendmce and spare parts problem.

80. In general, the problems of compatibility are not serious and can be overcome by the judicious choice of equipment types and sizes, and by adequate planning,

MOBILISATION AND OTHER FMED COSTS

81. In the list of basic construction activities these costs were identified in terms of:-

Activity 13.1 Site overheads, logistic support, ktc.

1 Head office overheads and profit

1 3.3 Administration

1 . Mobilisation, including transport 'to site offices.

None of these costs were taken into account in the analyses of the hypothetical road projects.

82. Under Activity 1 3.1 would be included such items 9s :-

(1) site offices, stores and general workshops; ~ (2) facilities for maintaining equipment and ailequate

supplies of spare parts;

( 3 ) provision of and facilities for maintaining tools;

(4) materials testing laboratory;

(5) site transport;

( 6 ) insurance of the work and compliance with o~ther conditions of the contract, and

(7) accommodation for supervisory staff, labour! camps and health and welfare facilities.

These costs arise partly from the provision of the facilities initially and, thereafter, from their operation and maintenance.

83. Site overheads (activity 13.1 in Table 11-1 ), vary greatly from job t o job. There is no clear-cut definition of what constitutee a s i t e overhead and practices differ. Certain of these costs are sbnetimes treated as labour or equipment charges by marking-up the unit rates accordingly; on other occasions, separate provision is made by the insertion of corresponding bill items in the contract. In amount, they are primarily related to the size of the labour force/amount of equipment used, and hence to the required rate of progress rather than to the size of the project. The construction period determines the recurrent costs of maintenance and operation but they are normally of less importance than the initial costs.

84. Of particular significance is the cost of spare parts for equipment. On an equipment-intensive project in Nigeria completed some 10 years ago, where there was little local support for equipment, the value of spares held on site by the contractor was about $250,000, some 15 '$ of the contract price. In such circumstances the value of s es on the s i t e could be as much as 15% ta 20%

. of the original cost o 4" the project.

85. Generally speaking, the site-overheads for an equipment- intensive project would be greater than those for a labour- intensive project. However, this advantage could be mqre than outweighed if large labour camps and associated facilities were required.

86. For contract work, allowance has to be made in the rates for head off ice overheads and profit (activity 1 3.2 in Table 11-1 ) . Ws would include such items as:-

(1 ) general supervision and visits to site;

(2) financingof the project;

( 3 ) general running costs of the head office, and

(4) profit.

On force account work these costs, except profit, would still be incurred but it is seldom customary to debit them againdt the project. There would not be a great deal of difference betweerr

labour- and equipment-intensive projects in this respect.

v 87. Administration and supervision comprises the salaries, allowances and other costs of administrative and supervisory staff, including engineers, inspectors of works, overseers, clerks, storekeepers and timekeepers, together with administrative costs of running the project. In general, these are likely to be greater on a project employing large bodies of unskilled labour.

88, The mobilisation (and demobilisation) costs of equipment 2/ depend on the location of the site and ease of access to it. They are of significance only where small quantities of work are involved. Taking the case illustrated in TableIII-3,a mobilisation cost of US $1 ,000 would increase the hourly owning and operating costs of a scraper (assuming one year's work on site) by between US $0.75 and 0.40, depending on the utilisation rate. The effect on unit rates would not be great except where small quantities of work and low utilisation rates are involved.

89, It is impossible to generalise on the mobilisation costs of unskilled labour since these would need to take into accbunt the distance to the site from the place of recruitment, the inode of transport, the conditions of employment, the availabiliti of labour and other similar factors. However, experience has show that mobilisation costs in many of the labour-surplus developing countries can be extremely low.

S)O, An analysis of a recently co Jeted highway contract in the B United Kingdom showed that on-costs were about 25% of the tender price, i.e. a mark-up rate of 33%. The breakdown of the on-costs is given below:-

Provision of site buildings Maintenance of site buildings Site transport Supervisory staff salaries Staff facilities

Total site overheads Head office overheads Project financing Mobilisation Profit

Total

Apart from this on-cost applied to all bill rates, provision was made in the labour rates used for costing bill items for holiday pay, labour taxes, hand tools, sickness benefits, and other associated payroll costs.

1 / Activity 13.3 in Table 11-1 2/ Activity 13.4 in Table 11-1 3/ Broadly equivalent to the t o t a l lWanagement and Other n section 13 in Table 11-1 I

91. It is difficult to draw any firm conclusions on the effects that these factors would have on the scope for labour substitution but it seems that the total on-costs might be higher on a labour- intensive project. However, it is clear that these coslts are important and that they must be clearly identified and +&en into account in determining the trade-off between labour and equipment.

PROBLEfJIS IN COMPARING ALTERMATIVE TECHNIQUES

92, Attention has already been drawn to one of the hiportant limitations in the analyses of the hypothetical road prdject in that the geometric design standards have been kept the dame though in practice some changes would undoubtedly be made to aucommodate labour-intensive methods. To assess the true scope fo$ labour substitution in a particular environment, it is not sufficient to compare labour-intensive and equipment-intensive techniques for a road adapted to that environment. The designs themselies would need to be orientated towards the particular technique yhile at the same time providing the same levels of quality and servqce. For example, a crushed stone base (equipment-orientated) shquld be compared with an equivalent thickness of macadam base (qabour- orientated) rather than comparing labour- and equipment-intensive methods of crushed stone base construction. A furtherexample is the roadside ditch, where the traditional trapezoidal shaped section (which cannot be excavated efficiently by machirje ) has been largely replaced by the grader-dug vee-ditch; it $s difficult to construct (and maintain) the latter by hand labour.

93. In some cases differing alignments should be compared (making due allowance for variations in vehicle operating and rdad maintenance costs) since modern route location pract e has been influenced by the greater productivity of equipment* f?

94. Civil engineering works are commonly defined by 3 list of items in a bill of quantities. However, the bill items do not define the volume or full extent of the work to be carried out and are devised solely as a basis for payment. Many of the basic activities are unlisted and their cost is "deemed to be included in the tendered rates and prices". Some of the unlisted Activities are common to both labour- and equipment-intensive techriiques, whereas others may differ in both nature and volume depending on the technique or type of equipment used. An example of the former case is the bulking of soil and rock on excavation where for purposes of payment, no allowance (or one on an arbitrary basis) is provided

I / See Ughway Design Study, Phase I Model: IHRD Economics Department Number 96.

in the bill but a prccisc estimate would bc necessary to determine thc volmcs of the exc:~va.ting, loading, flriuling, unloading, spreading and compacting activities.

s, The volume of a basic activity is often dependent on the way in which it is carried out. For example, the excavhtion of a foundation by equipment invariably entails greater quanttties of excavating (also backfilling and possibly foundation concrete) since hand labour can work to closer tolerance in these circumstances. hrthermore different equipment gives different volumes.

96. The nature of activities may differ, particularly in respect of unlisted temporary works which are commonly not a item. The need for haulage routes is minimised on a labour-intbnsive project ; tractor-drawn scrapers can operate over less wbll- maintained routes than pneumatic-tired equipment. ~on4~rsel~, labour-intensive methods may lead to additional works sdch as timbering on excavations. The use of labour may result in less efficient use of materials to produce an equivalent end-broduct.

97. The technical scope for substitution of labour id earthmoving and other similar operations is largely dependen? on the length of haul. In the analyses of the hypothetical road proj~ect the substitution possibilities were assessed on the basis haul. In practice, this would not be adequate and have to be made to a detailed mass-haul design to the scope.

THE AGGREGATION PROBLEN

98, The production functions prepared in the analyses of the hypothetical road projects are of limited value in that they do not take into account the effects of the environment on productivity, both in place and in time, the relative efficiencies of differing types of equipment performing the same activity, scali9, timing and other similar problems.

99, Environmental effects could be eliminated from the functions by defining a 'standardt environment and other environments could be related to the standard by a simple rating system. 'However, the relationship between environment and productivity varies with activity and the environment varies with time, and separate ratings for each aztivity would be required on a time scale.

lo(), Differing types of equipment carrying out the same activity would give differing trade-offs and substitution slopes in the basic production functions and, in effect, there would be a separate basic production function for each type of equipment suited to each activity.

An added complication is that certain types of equipment (particularly that used in earthworka) essentially combine several basic activities as one operation and corresponding additional functions would be required. It becomes apparent that the number of basic production functions would greatly exceed the liumber of basic activities.

101. The problem of scale could be overcome in the ba$ic production functions by using rates of output rather th$n quantities of work. However, this would introduce comglexities in grouping basic functions to be representative of opeiations or groups of operations.

102. There are also problems in combining the basic fkctions to the operation or group level. Assuming that the basicfunctions are representative of the most efficient ways of carryi out the basic activities by equipment- and labour-intensive met t ods, their combination would not necessarily represent the most efficient way of carrying out the operation. While account can, to be taken of this problem in the aggregation of a few ac the problem becomes complex at the stage where the oper2ttions are grouped together.

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103. Taking the simple case of a grader which can be $sed to greater or 12ss effect in the following activities:-

(1) Light clearing, or assisting other equipme$t in more dense vegetation; I

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( 2) Excavating drainage ditches ;

(3) Maintaining haul routes;

(4) Spreading materials;

(5) Finishing.

Under particular circumstances, it might appear economidally advantageous to substitute for one or more of these activities. But doing so would affect the utilisation rate of the equipment; mobilisation charges would have to be spread over a lesser volume of work and, consequenCly, the effective trade-off between labour anfi equipment in the other activities would be changed, most probablyto the advantage of labour.

104. AS a further example, the analyses of individual operations might indicate advantages in using scrapers for medium-haul earthworks ant tractor/trailer units for long hauls of earthworks and base course materials. However, to obtainmfnimum costs f a r the two operations on the same site, and taking into account

the problems of scale, etc., it might be best to use other methods for medium-haul earthworks. The possible combinations of this nature are innumerable.

0 , It is clear that the aggregation process is most Complex and optimisation on an activity basis will seldom be com~atible with that on a project basis. In addition, it would need to take account of various other constraints that might be applibd in practice in assessing the scope for substitution, such a$ minimising financial or resource cost, minimising foreign exchange @ost, varying the construction period and timing, taking account of the relative availability, type and mobilisation costs of equipment and labour, varying the quality of the finished road, and so on. These factors could vary from country to country and eve@ within a country.

106, The complexity of these proble~na leads us to believe that the aggregation process can best be carried out by a computerised mathematical model simulating the highway construction pkocess and incorporating optimising procedures.

107, The input to such a model would be a definition o'f the project, possibly in terms of a normal bill of quantities, together with a flow network relating bill items in their construction slequence and breaking down each bill item into individual sequential activities. Other input data would define the environmental conditiops (in relation to time), the required objectives (such as maxisnising labour substitution, etc. ) and external constraints (e.g. budgetary or time considerations) together with costing data in tl2e required form. I

108, The model would draw on 'standard' productivity data and adjust it in the light of the environmental conditiqns, as varied by time. The flow network would be analysed to optimise the project as a whole in accordance with the imposed constdaints and objectives. Such a model could handle a sub-division of the basic activities at a detailed level, allowing for differing 3ypes of equipment, soil types and a wide range of environments. The standard productivity data would be in the form of basie production functions and the aggregation process would optimise the equipment/ labour mix from these levels without attempting to optinhise individual operations. The data bank could be updated kontinuous- ly as more productivity data becomes available (to allow for new types of equipment, methods of construction, etc. ) and Corrected to suit conditions in particular countries. Its scope could eventually be widened to deal with other civil engineering works such as airfields, dams and irrigation works.

109, In view of the wide range of productivity data and variability in its quality, it would be advisable to incorporate into the model a procedure for dealing with probability. Many of the variables can be considered as stochastic.

110, The output from such a model could take many formg, such as a detailed programme of work with equipment, labour abd materials requirements, together with estimates of cost, all in accordance with the imposed constraints. There are varkous refinements which could be added to the programing process, such as eveningiout equipment and labour requirements and the combined effects of various constraints could be studied.

111. Ebquiries have been made as to whether such a mode already exists or is being developed, While similar models incllSding optimisation and stochastic techniques have been developed in other fields of engineering including W d - construction, no direc$ research into this problem appears to have been undertaken. The Road Research Laboratory, as the UK member of the International Road Rtpsearch Documentation scheme, has been unable to trace any record of this type of research.

Conclusions of the Engineering Analyses

( i 1 Examination of the l i s t of basic ac t iv i t i e s and of the categories assigned t o each leads t o the general conclusion tha t it i s technically feasible t o carry out a large proportion of the basic construction ac t iv i t i e s i n road construction by labour and tha t the technical scope for substitution increases only t o a limited extent as quality standards are relaxed. I n the example analyses given above, it was found tha t labour could be subs- t i tu t ed for a l l but about 18 t o 20 percent of t o t a l road constduction costs for the higher qual i ty construction standards, while relaxation of standards&/ t o an intermediate qual i ty permits labor substitution for only an additional 5 t o 8 percent of costs ( i . e. for a l l but about 2 t o 15 percent of t o t a l costs).

( i i ) The economic feas ib i l i ty of labor substitution w i l l depend, i n t e r a l i a , on the productivity ra tes of equipnent and labor and the wage assigned to unskilled labor. The example analyses for Road !Type A i n ro l l ing t e r ra in u t i l iz ing ident ical assumptions concerning wages and prices, bQt employing the differ ing data and assumptions concerning productivity r a t e s given by SWKP and BCEaM, yield markedly d i f ferent conclusions concerning the economic f e a s i b i l i t y of substitution. A t a wage of $1.00 per day the obtimal combination of methods would involve about 28 and 37 percent labor costs for the high and intermediate qual i ty cases, respectively, i n the SWKP estimates and only about 6 percent i n either case for the XE& analyses.

( i i i ) The ins t i tu t ional framework i s a major factor i n explaining these differences: the BCEM estimates r e f l e c t productivity r a t e s wkighted toward experience derived i n public rfmakework~l projects, such a s the Bational Promotion i n Morocco, where there i s l i t t l e incentive t o achieye ef f ic ient u t i l i za t ion of labor, whereas the SWKP estimates are weighted more by experience derived from dam projects i n South India which were oriented t o achieve maximum labor productivity.

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( iv ) As an o v a a l l conclusion, the greatest scope for substitution occurs i n the interdependent ac t iv i t i e s of excavating i n bulk, loading, hauling, unloading and spreading. O f these, only the l a s t acqivity is affected by the l eve l of quality. Reliable productivity data f o r these ac t iv i t i e s are consequently of greater importance than for thd other l e s s s ignif icant ac t iv i t ies .

1/ Design geometrics have not been varied, i.e. are the sanie for both the - intermediate and high qual i ty construction standard. Rdlaxation of design geometrics may i n f ac t be warranted to take bet ter advantage of labor intensive methods, but savings i n construction costs w i l l have t o be offset by the resulting increase i n road us- (vehicle operating) costs. Analyses of t h i s kind w i l l be investigated i n subsequent studies i n conjunction with the IRIUI Highway Design Study. See Highway Design Study Phase I: B e Model, Economics Department Working Paper No. 96 (January, 1Y'EL).

(v) The f e a s i b i l i t y of using intermediate technolcgies involving a mixture of modern equipment and manual methods appears promising and should be fur ther investigated. For example, according t o the SWKP estimates handloading of detachable low slung t r a i l e r s pulled by t r a c t o r s may be optimal f o r moving earthworks and mater ia ls over ce r t a in haulage dis tances when wage r a t e s f o r unskil led labor a r e i n t h e range of US$3.SO per day or l e s s . However, handloading of buciks would never appear sensible (except i n i so l a t ed ins tances) , s ince the cos t of detaining the t ruck longer while loading it grea t ly exceeds t he savings i n loading costs according t o any estimate.

) Other conclusions r e l a t i n g t o the methods used i n the analyses are:

(1) To permit the f u l l analysis of labour subs t i tu t i4n p o s s i b i l i t i e s , disaggregation should be carr ied c$ut t o such a degree t h a t an a c t i v i t y could be car r ied out e i ther so le ly by labour or so l e ly by equipmeht.

(2) The l i s t of basic construction a c t i v i t i e s needs t o be fur ther sub-divided t o allow for d i f f e r ing , types of equipment, haulage methods, a greater range of s o i l types, loading heights, e tc .

( v i i ) The cos t of supervision is an important fac tor fo r thk comparison between the equipment and the labour a l te rna t ives . Research i 6 needed t o quant i fy t h i s cost , and a l so the cos t of mobilization.

( v i i i ) I f the subs t i tu t ion of labour fo r equipment i s t o be successful, it must be encouraged a t the highest possible l eve ls and no t be confined so le ly t o t h e highway construction industry. It must a l so 5 e s o c i a l l y acceptable t o the people of the country.

Chapter N

Organization and Management of Large Labour Forces

INTRODUCTION

I . The main conclusion of the engineering studies is that there is considerable technical scope for the substitution of labour for equipment in road construction. This chapter is concerned with the practical problems of labour substitution and whether these might impose a further constraint on substitution possibilities.

RECRUITMENT OF LABOUR

2. The analysis of the hypothetical road projects assuming labour-intensive methods at intermediate levels of quality indicates that the unskilled labour content per kilometre Could range from some 7,657 man days for a type A road in flat terrah to about 14,945 man days for a type B road in hilly terrairg. Making some allowance for idle time, work-free days and exdluded activities (culverts, bridges etc.), a labour force of betwem 2,550 and 4,980 would be required to achieve a construction rate of 1 km. of road per week. Seasonal effects could increase these figures by some 50 per cent suring the months most favourable to construction.

3 • In addition to these basic elements of the work force, there would be a need for engineers and administrators skdled in the management of labour-intensive work, junior engineei-s and assistants, overseers, surveyors, artisans, clerks, storekbepers and other miscellaneous subordinate staff, the majority of whom would need to be skilled in their particular field of work,

4. To have the maxim impact on local underemployment problems, and to reduce need for camp facilities, labour should be recruited locally as far as possible. Certainly, the unskilled workers, the lower supervisory levels, and the more common varieties of artisans are usually recruited as closely as possible, whether by a contractor or a public authority. The success of recruitment may depend on wages offered, the difficulty of the work, its timing, the extent of the pove'rty of those being recruited, the need for them to travel, either daily to sites, or over a long distance to the site, in which case accommodation requirements enter as a further variable. If sufficient or certain types of men are not available locally, or are not attracted by the work, or do not hear of it, it may be necessary to send recruiting officers to areas with hown labour surpluses and use the services of labour exchanges.

5 In the construction of a large dam in Nysore, India, by labour-intensive means, on which up to 20,000 people worked, persons had to be recruited from up to 1,000 kilometres aww. Most 97 these returned to their home villages for seasonal work. Recruiting can be eased by taking advantage of units or groups already in existence, such as villages, families or the groups of the petty contractors.

6. In some less developed countries labour expects to move from job to job using such transport as is available. In some cases it may be necessary to pay a travelling allowanqe to attract labour. Only where the sites are in areas which a m completely undeveloped or without transport should it be necessary to offer transport.

With the increasing standa,rds of education common to most developing countries, there should be no seat difficxilty in obtaining adequate numbers of subordinate personnel tho* they may need some additional training before they become Wly effective. However, there could be a problem in recruit* senior staff of the right calibre.

ORGIANISAllION OF THE LABOUR FORCE

8. It is difficult to define an ideal organisation for sd labour-intensive road construction project since much depe$ds on the nature and volume of the activities. The basic u t is the gang, of some 10 to 20 unskilled labourers, under the control of a ganger or headman. The latter is normally a working member of the soup and is often elected by the group either because of natural leadership qualities or on traditional Essentially his function is to enforce discipline and to e Pads* ure that productivity targets are obtained. For most activities, no special training or knowledge is required, he need not be I literate and his rate of pay is normally only marginally @eater than that of an unskilled labourer.

9 , Gangs are pouped and each group is supervised by an overseer. Generally a group is given a particular type ok task to perform, such as cleazing and grubbing, forming cuttings and embankments, quarrying and breaking stone, laying base courses, etc. The size of the group is a function of the nature of the work and the area over which it is spread. For a large cutting or embankment, a single overseer could control up to about 200 men, while for other

1 / "Men Who Move Mountains If, ILO Management Development add Productivity Mission to India, New Delhi, 1 963. ,

more specialised operations, the number might not exceed 30 or 40. The function of the overseer is to control and organise the work for his group. He is responsible for:

- ensuring proper standards of workmanship and productivity;

- keeping records of hours worked and work done; and - maintaining an adequate supply of materials and

tools.

He is usually assisted by a timekeeper and, where appropriate, checkers to record production. The overseers and their assistants would have to be literate and possess a reasonable degree of intelligence.

10. Working parallel with the funskilledf groups are 'specialistf groups who would undertake more skilled operations such as surface dressing, and culvert constructioq. These groups would contain trained artisans and their number$ would be dependant on the nature of the work.

11. The overseers of the funskilledf groups are generally chosen from the gangers showing the greatest intelligence and leadership. They may be considered to be of much the same status as a fully-trained artisan. For the 'skilled! group+, overseers would need to have specialised knowledge and they would normally be selected from amongst the artisan grades.

12. In some of the lesser developed countries where labour intensive methods are currently employed, the labour gangs &d their overseers are supplied by petty contractors and a similar pattern of orgavsisation is followed. In these casea, the overall management of the project is carried out by the employing agency which accepts responsibility for the co-ordiination of the work of the various petty contractors.

13. Above the overseer is the inspector of works. Numbers of these are related to the type of work, but one inspector to (Lt to 6 overseers is a common ratio where close control of quality is unnecessary. In the more critical operations there may be one inspector to each overseer. Generally on a large project there is at least one inspector for each of the main operations subh as earthworks, drainage and pavements. Large individual wokcks, such as bridges or major earthworks may justify their own site inspector. While the inspectors are responsible for the control of all workmen assigned to them, they are essentially concerned with the technical side of the work. They are generally selected from the overseer grade and, lacking formal engineering training, tend to specialise in one or other of the basic road construction operations.

1 . The numbers of engineers required to properly gupenrise a labour-intensive project depends not only on the size and nature of the work but also on the quality, experience and effectiveness of their subordinates. Quite large projects have been satisfactorily completed under the supervision of a single engineer with a well-trained and experienced labour force. However, there would generally be a need for at least 3 or 4 engineers to supervise road construction at an acceptiable rate of say 1 km per week.

15. Ap& from their general duties of administering and controlling the work, specific tasks which would normally be undertaken by the engineering staff would include:

(1) setting out the work;

(2) planning and sequencing of operations;

(3) measurement of work, p&f cularly where a petty contract system is operated;

(4) materials control, both quantitively and qualit at ively ; and

(5) control of workmanship.

16. In carrying out these functions, the engineers would be assisted by various subordinate staff and provision within $he project organisation, would have to be made for the followidg:

(1 ) general administration, including payment of staff and the keeping of records;

(2) maintenance of equipment, since some would undoubtedly be required except on the simplest .of projects;

(3) ordering, receipt and issuing of tools and materials ;

(4) maintenance of hand tools;

(5) soils and materials testing facilities, and

(6) camp maintenance and operation, including sanitation, health, water and food supplies, welfare facilities etc.

17. It is clear that the successful management of a large labour force entails a fairly complex organisation. However, the use of a petty contract system can simplify these requirements at the lower levels to some degree, particularly where this procedure has been established by custom and petty contractors are efficient and competitive. Where this cannot be done however, and where natural discipline tends to be deficient, a militaristic or para-militaristic organisation on thc lines described may be desirable. I

18. The foregoing comments are confined to the organisation required on site. The headquarters organisation, either the Public works/HighwaYs Department or that of a main contractor, is equally important in providing the necessary support in terms of facilitating supplies and providing assistance when difficulties are encountered. The degree to which authority should be delegated to the site supervisory staff must vary with circumstances but on force account works government regulations often place a severe burden on the site staff and reduce their efficiency. Problems arise since force account work is frequently not investigated nor planned to the same degree of detail as work carried out by contract.

19. Where large bodies of unskilled labour are employed, it is normal to restrict the activities carried out by each group. While this reduces the flexibility of labour to some degree, it eases the effort required for, and the cost of, training. The time that can, or has to be, devoted to training is related to the complexity of the operation and volume of work to be carried out. Clearly more effort can be devoted to training, particularly in the semi-skilled operations (such as surface dressing), if there is opportunity for continuity of employmeht in that operation, since this will reduce the need for and the cost of higher level supervision when the operation is carrieb out. However, while specialisation in this wa,y promotes productivity and reduces training requirements, it has the disadvantage that work can become dull. Allowing some variety removes this problem and allows the worker to use all his muscles relatively evenly.

20. Many of the basic activities do not require the use of particular skills which are unfamiliar to unskilled labour and such training as may be required can often be provided ton-the- job1 by the overseer through the headman. More formal tra- may be necessary for the semi-skilled operations and, for e-le, where unfamiliar types of hand tools are to be used.

21. Apart from the cases instanced above, there is usua,lly little need for the training of headmen who are normally selected for their leadership qualities.

22. Where overseers are not conversant with the methods and procedure in the more specialised activities such as compaction and finishing, mixing concrete, spreading bitumen and the like, formal training sessions are essential to attain adequte standards. The P.W.D. school in Northern Nigeria rara most

successful one-month courses for training road construction and maintenance overseers which included lectures on technical aspects, including reasons for required degrees of quality, demonstrations of the various activities performed by trained gdngs, practical carrying out of these activities by the course members with rotation of the leadership function, and demonstration of and instruction in administrative record keeping.

23. Where inspectors of works are promoted from the ranks; little further training is necessary, as the few required selected largely on the demonstrated basis of their howled@ and ability. Some less developed countries have excellent^ schools for training inspectors of works.

2h. Other staff required would include engineers, engineering assistants, surveyors, clerks and storekeepers. Generally, the construction technique chosen makes little difference tO the numbers required and their duties are only slightly affected by the technique. They are normally provided by the local education systems and little additional training is needed. Where adequate numbers of trained engineers are n ~ t available, they would have to be obtained from overseas until the local educational institutions could meet the needs.

25. The prime object in supervising labour-intensive work must be to keep the perfomce of labour as close as possible to its capacity. Mention has already been made of the most important factors affecting the productivity of labour. It is essential that management does its utmost to create an environment conducive to high productivity and recognises the activities where this ia most important. Particular skill is required on projects where equipment- and labour- intensive methods are mixed since shortfalls in labour productivity, of little significance in themselves, can lead to under-utilisation of expensive equipment with consequent high increases in cost.

26. In the developed countries there is a notable lack of experience of, and training facilities for, organising and managing large bodies of unskilled labour. Certain of the less developed countries, such as China, India and Pakistan, have ample current experience of these problems whereas othbrs are not so fortunate. It will be largely up to the develobixg countries to develop their own techniques, drawing on past experience elsewhere. The importance of good management cannot be over-emphasised and it may well be necessary to develop special facilities for the training of indigenous engineers.

27. Few engineers in modern societies have any experience of labour-intensive methods. The training of these engineers is orientated tom& equipment-intensive methods. Few are

likely to be pcticularly knowledgeable about the problems of large-scale man-management. Hence, it would seem desirable for engineers involved in labour-intensive techniques to be given some introduction to the problems likely to be encountered.

28. In terms of training and education, the need for additional and improved management training may be the most important implication of a switch to more labour-intensive methods of road construction. The management problems associated with a change of technique might be considerably eased by the use of critical path planning techniques. In addition, the o p p o w t y to study labour-intensive techniques already employed elsewhere would be of considerable value in familiarising maaapment pith the problems. Even so, it may be necessary to tolerate lebs efficient production and perhaps lower quality output for a period following a change of technique and expect part of the educational process to be achieved by the experience of learning by doing.

E. LABOUR CAMPS

29. Where local residents are employed, and the sites r*in close to their homes, there is no need for any camps to be 1 provided. Although men have been known to walk up to 20 1 kilometres each way each @y to the sites, this exertion their working efficiency. It is probably therefore as far as possible to transport the men to and from villages in trucks attached to the project as far as roads slow.

30. In Nigeria as recently as the 1950s it was not found) necessary, evea in sparsely settled areas, to provide accomodation for those who travelled to the sites from d i tant places. The contractor or public authority then had to p 5 vide nb more than a water supply and latrines. These workers hhould be discourag;ed as far as possible from bringing families. ( As living conditions rise, however, or it becomes necessary th attract workers out of cities, it may become necessary to $rovide c q s with reasonable facilities. I ,

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31. It is sometimes suggested that camps be soundly constructed for later permanent occupation as villages. This is a po4icy frequently followed with dam construction where new irriga$ion areas are to be opened up. A dam, however, is a single sYte and a- reasonably long-term activity, whereas a road, especially in easy agricultural country, can be expected to progress hway

1 / ILO Technical Meeting on Productivity and Eh~lopent in Arblic Works in African Countries, Lagos, 1 963.

2/ J. Iheller, "Labour Intensive Methods in Low-Cost Road Construction -- a Case Study;' International Labour Review, Geneva, ~ ~ r i t 1970, p. 359.

from the camp fairly quickly. In some newly opened up areas there may be scope for this, and some well sited c q s may be suitable for occupation by maintenance gangs.

32. Of necessity, highway construction workers must be pobile and, in the absence of reasonable alternative facilities, there is little inducement for labour to seek other than casual employment. While this might be acceptable for the unskilled labour element, provision would have to be made for the accommodation of permanent skilled staff in many cases, down to the level of overseers and artisans. Them is invariably a need for some camp facilities, if only to aclcommo- date offices, stores, and maintenance facilities.

33. The natme of the camps will vary depending on the intended length of occupation and the size and nature of the project . In some cases, they will consist of primitive shelters, built largely by the labour forces themselves yshg entirely local materials. On the other hand, a major bdidge being constructed over several yeam or a base camp coul? justify higher standards for some, if not all, of the bqld ings . For the more important needs there could be advantage iniusing specially pre-fabricated buildings which can be taken d o h and re-erected elsewhere as the work proceeds, or even mobil4 caravans. I

34. clean and adequate water supplies, at the camp and on the worksites, are very important. Care should be taken to ensure that camps are provided with washing facilities, incluctiqg those for clothes. Camps and worksites should be provided with latrines, which should be looked after by a responsible person, and properly closed down on the cessation of work. I

I 35. Medical facilities, at least of an elementary natuqe, would be required in all but the simplest of camps. The concentration of men on a site gives the public health aqthorities an excellent opportunity to check general health, and meqsure the effects of work as an aid to generally preseming hedlth in labour-intensive activities. The willingness to care fdr their health can e e ected to have beneficial psychological '1/ '"P on the men.

36. The provision of recreational facilities is impor t, especially as workers are likely to lose interest in tra 'tional * forms of entertainment. Such facilities as cinema, spo&sfield, canteen, areas set aside for religion, and the organisatj/on of entertainment and adul ducation can all assist in the maintenance of morale. BP 1/ J. Mueller, op. cit. 2/ U.N. Economic Commission for Asia and the Far East, I1-g by Manual Lamr and Machinesl', Bangkok, 1961.

37. Workers recruited local ly w i l l continue to provide t he i r own food. Recruits from dis tant places usually prepare t h e i r own food, perhaps jo int ly hi r ing a cook, depending on loca l tradit ions. Some petty contractors, however, do feed t he i r men, and provide the necessary f a c i l i t i e s and cooks, and consider t h i s 'keep1 t7 park Of ;' the wage. On the construction of the large dam in @more th i ls was shown t o have some advantage. The only worthwhile explanation fo r 80 t o 100% greater productivity from the Malabari workers was *at they had a bet ter d i e t (4500 calories with 130 grams of proteirq, compared with 2900 calories and 20 grams f o r the others). Such communal feeding may be very important i n building up the general physical condition of previously unemployed persons especially a s 3000 calor ies per day is needed f o r heavy physical work.$/

38. Even where contractors o r public authori t ies do not suppdy food etc. they o r the welfare authori t ies may f ind it useful to makd arrangements f o r supplies t o be transported from loca l markets, and even t o ensure an adequacy of supplies to preserve productivitg/ and to avoid the tendency f o r local r e t a i l e r s to increase t h e i r prqcesS/

39. Large camps might require some form of policing, e i ther h e r - na l ly or by arrangement with the loca l authori t ies, t o enforce t h e necessary degree of camp discipline and to avoid possible confqict with the loca l residents of the area.

Fe PAYMENT OF LABOUR

40. The wage ra tes paid need t o be no higher than is necessa* t o obtain the will ing services of the workers. A s previously disdpssed, t o a t t r a c t men to work, especially those with no immediate need( f o r additional income, these wa e levels need to be higher than lodal subsistence wages.l/ 2/ h/ % Over time, t h i s can $ expected to draw the normal r a t e f o r slack season labouring upwards. This m a y i n turn require adjustment t o the wages of the permanent workers + the area. Wages should be increased a s productivity r ises , t o pre erve ? just ice between the gangs and such increases must be no f a s t e r t h a n productivity increases. ~

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41 . Payment of wages on a piecewor pposed t o a provides a be t te r incentive ?/work, 'pJPbut dai ly complications of measurement. A compromise used Nigeria i s payment on a gang/task basis. This reduces adminis rat ion t costs (which can be high with labour-intensive techniques) and preserves the incentive t o the natural gang un i t which may havd been hired. The ra tes need t o be f a i r l y se t , agreed upon in advancd with the headmen, and will ingly changed should conditions prove mord d i f f i c u l t than expected. Any quali ty t e s t s needed should be s ' p le and unambiguous. f 1 / Wen Who Move Mountainsu, op. c i t e 2/ IIX), Lagos, ftPublic Worksff, ope c i t e 3/ J. Mueller, ope c i t e 4 S. S. Berry, llEconomic Development with Surplus Labour: Fu;rther Complications Suggested by Contemporary African Ekperiencen, W o r d Economic Paperg, July 1970, p. 275. 5/ J. We Thomas, llTtural Public Works and East Pakistan's Developmentn, k r v a r d University Center f o r International Affairs, Economic ~ Development Report No. 1 1 2, September 1 968. I

42. There is no reason why wa,ges should not be paid partly in food. Some developed countries with food surpluses sometimes hesitate to give this food away for fear that less developed

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countries will become dependent on gifts when it would be 'better' if they found a longer term solution to food shortages. Such countries might therefore be happier if they knew the food was to be used to finance developmental works. The inclusion of food in the wage, especially prepared food served conmluna$ly has the advantage that workers' diets can be controlled. -her, giving food in return for work removes the charity aspect associated with its distribution in the form of gifts .l/ Many rural dwellers, however, will already have adequate foob supplies (although perhaps not 'ideal' diets) and may not be attracted by payment in such form. For them the payment in food may be in the form of diet supplements, whereas for any urban dwellers, the payment can be in the form of very basic food. Where there are problems of transporting, storing, o* preserving the food, the additional costs may make it prefedble to pay in cashew

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DESIGNINCT AND P- FOR LABOUR-INTENSm MEANS

43. The design of a road may need to be modified to allow for labour-intensive techniques. It may be modified to avoid difficult terrain even if distance is increased, use steeper1 gradients, adopt local materials such as timber or stone for1 bridges, or allow for greater thichesses etc. to compensate^ for the inability of labour to perfom certain tasks to the dame high quality. Alternative designs can be evaluated in term$ of additional costs and the benefits of additional employment. ~ u. The scheduling of the construction of a road may also need to be modified. In particular, account must be taken Of the times when labour is scarce (for example in the planting1 and harvesting seasons), or when the weather may make work ~ intolerable or unproductive (eg. very wet or hot periods). ~ Such scheduling may require borrow-pits, for example, to be , opened up well in advance of actual construction. The econmic evaluation must consider the extent that this method of cons$ruction delays completion of the road compared with equipment- 1

intensive means. In this respect, alternative timing strategies should be considered. For instance, in one season it may bt$ possible to clear the route and form the road and in a second season to pave it. In fact, if the road is to or through a~ newly developing area, traffic can be expected to be very light at first, and improvements can be made as traffic grows. v s form of staged construction has been quite common in the developing countries and is well-suited to labour-intensive methods.

I / A. Ardant, "A Plan for Full Bmployment in Developing Countriesn, Internatii.na1 Labour re via^, Geneva, July 1 963, p. 1 5. F/ J. W. Thomas, op. cit.

bS. Particular care must be taken in scheduling works not to offend local practices connected with religion, food, fwly, oommerce etc. These matters should be known in advance, and taken into account in planning the work and hiring the labourers - eg. if necessary, all of one tribe should be paid off before any of another tribe are engaged, persons subordingte by tradition should not be placed in ~uperv~sory positions etb.

46, To some extent the problems involved in recruiting, providing the infra-structure for and training large bodies or unskilled labour can be reduced by matching the build-up rate at the commencement of a project to that of the staff engaged on administering and managing it. This seldom occurs since there is a natural tendency, invariably encouraged at all levels, once a project has been approved to get work started on the ground as quickly as possible. The physical problems can alsb be reduced to some extent by dividing a project into several smaller contracts or sections, though this often tends to the^ need for additional administrative effort and possibly to som* reduction in control.

47. The cost of mobilising, training and demobilising large groups of labour is not inconsiderable and can be minimised only by ensuring continuity of employment. While some fluctuation in the numbers employed is unavoidable, and indeed desirable, due to seasonal effects, there could be advantage I in offering permanent employment to at least the more highly 1 skilled staff. I

48. Permanent employment is not generally offered to labourers. Under surplus labour conditions, care should be taken to avoid any thought that there is entitlement to . continuity of work. To the extent, however, that petty I

contractors are able to find work for most of the time, some rural dwellers are almost certain to find moving from site to ~ site, with all its inconveniences, an attractive life,

I

especially if they can thereby earn higher income and the production on the family farm is not affected. Further, petty contractors will be keen to offer permanent employment to the^ more efficient men. In fact, the canal and railway construct tions in Britain in the nineteenth century attracted many men^ who adopted nawying work for long periods, which absorbed mubh of the surplus rural labour.

49. Higher-level staff should be offered permanent employmeht if possible. Good overseers can be transferred from job to job, or if they are unwilling to leave their home districts, placed on the maintenance staff as far as possible. Inspectors of works and technical assistants are, like engineers, usually

permanently employed. Artisans should be offered permanent employment only if they are in short supply, which is often the case.

50. If any programme designed to employ more people in road construction is to succeed, it must be persisted with. Contractors, even petty contractors, will not adjust their methods and organisations if they feel that the inducementsl offered to them to change their technique are to be short- lived. Further, as more people would be affected by fluct'uations in contracts awarded (apart from fluctuations in road work designed to accommodate other activities), it is desirable for works to be planned so that continuity can be offered for tbe permanent workers. The subsequent contracts need not nece/ssarily be in road work if the contractors are capable of organis- other labour-intensive works. The implication, however, is that1 Public Works should be planned over a longer term than may at present be the case. I

51. For the substitution of labour for equipment to be sqccess- ful, it is essential that the concept be fully supported add actively encouaged at the highest possible levels. It c h o t be successful as a short-term expedient and must form part of a general policy, not only in relation to highway constructi4n. It must also be socially acceptable to the people of the count/ry.

I

I. SOCIAL AND ECONOMIC CONSEQUENCES OF USING MORE LABOUR

52. Generally speaking, the employment of previously s q l u s labour may require expansion of certain parts of the econoniy, will result in increased consumption expenditure, and poss4bly consumption imports , probably slower growth (unless addit iqnal highly productive investment can now take place when it coqd not earlier), reduced imports of equipment, and to certain types of production. The size of industry, however, is such that some effects - production - may be very minor indeed, at the any rate. Other costs may result from slower completion c/f the project, or reduced durability of the assets created. ( ~ q the extent that the social opportunit cost of capital is high,^ this may be of little consequence^. Further, if market wage rates have, for legal or other reasons, to be paid to the dewly employed workers, the higher cost of roads will result in less road work being performed, or reductions in other areas of

1

government activity. To the extent that road standards hqve been too high, a lower standard of road may merely reflect [the high social opportunity cost of capital.

53. At the macro level, the wages paid to the newly employed road workers will in general represent a transfer from those at present employed, and capitalists, both at home and abroad, or if the employment is financed by inflationary means, will take from

the present high income earners. The reduction in the use of equipment could reduce borrowings (although it need not for investment can still occur in the work of the labourers) and hence returns to capitalists. Areas with large numbers of unemployed will benefit at the expense of areas where people are more fully employed for similar reasons.

54. The organisational adjustment necessaxy for the emploJPment of more labour has costs of its own until completely in effbct; a contractor may therefore perceive for some time costs eveh higher than the usual market prices. I

55. The educational budget should not be noticeably affected by the training requirements of labour-intensive methods of ~ building roads. Most training needed will be on the job, that of overseers will be carried out by the employers, and that 1 of artisans and engineers will in general be unaffected, a m 1 from initially introducing engineers to the problems. In Pact, the problem of training sufficient mechanics, fitters etc. 40 service equipment may be slightly eased by the change to ladour- intensive methods. ,

56- Large groups of itinerant workers, separated from theilr homes, may be subject to bouts of lawlessness, requiring adqtional policing. Discipline can be more easily enforced if the wqrkers are housed in properly organised camps. This would also aqsist in the control of hygiene. To the extent that while at honje, these workers are lawful and their hygiene acceptable, therd will be additional costs to the government, resulting from their /new employment . I

I

57. Although some research has been done into labour-intensive means of road construction, and a certain amount known from the past, there is still a very great need for research into alll aspects of the problem. This activity will almost certai.9 add to government expenditure, but in the social rather than public works section of the budget.

I

58. There are other less general and less direct economic effects which would enter any perfect calculation of social opportunity costs, but which are very difficult to value in i practice. For example, many of the forms of organisation and skills used in labour-intensive road construction should have direct transfer to other areas, such as clearing, cleaning ditches etc. Similarly, urban dwellers will have knowledge of methods which may be useful in construction generally. Certain men will have obtained leadership experience, and all will d v e gained something in work discipline. Many men, and whole families, will gain from better nutrition and health. Further, the additional rural income may permit improvements to farms and increases in rural productivity and perhaps even in farm employment. To the extent that all effects reduke the population

drift to the cities, they will save the social costs thought to be created by urban overcrowding and unemployment.

59, Labour-intensive methods increase the scope for local entrepreneurs, who can reasonably easily recruit men, even if they could not raise sufficient capital to buy equipment. This has the added benefit that the repatriation of profits overseas is reduced, easing the call on foreign exchange. The genera encouragement thus given to local enterprise and management development could have considerable benefits in other sectors of the economy. In Iran, for example, government policy results in almost all road contracts being awarded to lraniansel/

Ekpatriate consulting engineers are required to take lqcal partners and trainees as part of the same policy.

60. On the other hand, it has been argued that labour-inteqsive methods require such a large number of high quality supervisoqs that other types of activity are hindered. There would seem to be little basis for this contention, for the number of engineers, technical assistants and artisans is little affected by the ~ technique. In fact, the use of large numbers of men, with ~ promotion from among them to ganger, overseer, or inspector oft works, would seem to possess the advantage that the location df leadership talent is facilitated.

61. Two less desirable economic consequences could follow unless particular care is taken. First, if the previously unemployed, certain districts, or the community at large, comd to feel that productivity does not matter, haw could be done ~ to the growth of the econonqy. Second, if protected unions azje never made to feel the effects of competition, they may becomt vested interests or sources of corruption. The greater number of contractors likely to exist with labour-intensive methods , could lessen this problem, but the tendering system needs to b~e open and uncorruptible.

62. Most of the social effects of using more labour would be favourably regarded by the residents of less developed countries, on account of the redistributive effects among persbns and regions, the reduced dependence on expatriates, and the general improvement in human dignity and happiness as more people are employed. Traditional family life may be disruptetl to a degree, but less so than if people drift to cities; in a& case, traditional life will have to alter if any growth is to be achieved, and the very act of moving away from home will sometimes act as a spur to innovation and change. If governmBnts employ directives to induce extra employment, certain undesirable social effects could result; such directives are discussed fulky in the next chapter.

63. The general social desirability of the results should be reflected at the political level. A failure to provide work

1 / Economist ImtelBigence Unit files

is likely to be detrimental to the survival of any government. Promises of more work, and achievement of that goal, would be advantageous. In those countries which are not fully democratic, however, there could be some fear of the results of grouping large numbers of men together, on account of the opposition they can organize. This may in the long run be less of a problenh, however, than a revolt of highly dissatisfied unemployed. bn the other hand, successful creation of employment may add considerably to the res ect which people feel for their govew- P/ ments and institutions, and the evelopent of decision making can assist political If budgetary problems pdevent absorption of large numbers in public works, the politicians may prefer stable underemployment to unstable full employment, ad long as a reduction in general underemployment can be observed.

64. The main conclusions reached in this chapter are summzised below:-

(1) recruiting, organising and managing large labour forces in roadwork are possible, although the 1

adjustments and learning necessary have costs of their own;

(2) knowledge and experience of these techniques is largely confined to such countries as China, India, and Pakistan; ,

(3) the main training effort is required at the overseer level, with unskilled and semi-skilled workers being trained ton-the-job', but there should

1

be no cost to the educatiow budget;

(4) the need for additional and improved management training may be the most important implication of a change to more labour-intensive methods ;

(5) payment for unskilled and semi-skilleq work ~ is best made on a gang/task basis, partly m food if desired;

( 6 ) planning, designing and scheduling of road works should take account of the labour-intensive 1

methods to be adopted;

1 / R. V. Gilbert, "The Works Programme in East Pakistan", International Labour Review, Geneva, March 1964, p. 213.

2/ J. W. Thomas, op. cit.

(7) permanent employment should not be offered to unskilled workers, but planning should be such as will allow a continuity of work; all policies adopted should be persisted with;

(8) it is essential that the concept of labour substitution be actively supported as a general policy at the highest possible levels; it must also be socially acceptable to the people of the country, and

( 9 ) in most developing countries, the social and economic costs of organizing large grsups of labour are not f 3t to outweigh the advantages obtained.

11.2 Finally, it is concluded that the practical problems involved in labour substitution can be overcome W, in general, will not impose major constraints on the possibilities of substitution.

Chapter V

Potent ia l Job Creation i n Road Construction

1. I n t h i s chapter, an attempt i s made t o assess the scope fo r subs t i tu t ing equipment by labour i n road construction and t o quantify t o the extent possible i t s po t en t i a l impact on the unemployment problem i n l e s s developed countries. Scope or po ten t ia l of l abow subs t i tu t ion here thus means the nwnber of addi t ional labour day? required t o subs t i tu te a given input of equipment. Section A i s e s sen t i a l l y a t heo re t i ca l exercise: it i s based on the hypothet$cal road pro jec t s presented i n Chapter I1 and presents a method of evaluating a range of labour subs t i tu t ion p o s s i b i l i t i e s and calcplat ing t he i r economic costs . Section B by contras t draws on an importapt case -- the National Promotion program i n Morocco -- t o i l l u s t r a t e some pf t he p rac t i ca l problems and l imi ta t ions of employment creat ion i n pubFic works. Final ly Section C attempts t o compare i n a general fashipn the scope fo r , and cos t of, labor subs t i t u t i on i n road construction kith t h a t i n other indus t r ies , while Section D describes the nature apd extent of the labour surplus problem i n l e s s developed economies.

I I

I - - I

A. Calculation of the Scope and Economic Costs of ~ a x t m k Labo Subst i tu t ion i n the Hypothetical Road Projects . 4

2. The analysis presented below i s based on the SWKP and WEaM data fo r one of the nine hypothetical road projects . The data were analyzed i n terms of addi t ional labour/days created by adopting Jsuccessively more labour- intensive techniques i n the various construction phqses . The increases i n cos t t h a t would be associated with d i f f e r en t inputs of labour and equipment were evaluated. Comparing these costs with those ;of the optimal technique ( a t a given p r i ce of labour and equipment), i d i s possible t o es tab l i sh what might be cal led an Itinefficiency cost11 for prdviding addi t ional employment opportunit ies . I

3 . The case selected i s one kilometre of Road Type A (grauel subbase and base) of intermediate qual i ty , i n ro l l i ng t e r r a in . The optAmal solution, i . e . t h a t combination of equipment and labour inputs producing the road kilometre a t l e a s t cost on the assumption of a wage of $l/day fdr unskil led labour was determined from the relevant tables i n Chapter I1 and, Appendix A, f o r each of t he four construction groups - Earthworks (E) , Gravql Subbase (GSB), Gravel Base (GB) and Surface Dressing (SD) i n combination. A f h t h e r calculat ion was then made, subs ti tu t ing step-by-step more l a b o d intensive techniques i n each a c t i v i t y for which subs t i tu t ion was technical ly f ea s ib l e up t o the point where the production function has a slope equal t o a wage r a t e of $0.20 per day (which was defined a s the pract icable l i m i t of subs t i tu t ion) . The cost of each s t ep i n the successive subs t i tu t ion of more ladour in tensive methods a t a wage for unskil led labor of $l/day then exceeds thgt of the optimal solution by a calculable amount, which w i l l be the higher, the lower i s the breakeven wage r a t e for the subst i tu ted a c t i v i t y and vice versa, Table V - 1 below i l l u s t r a t e s the r e s u l t s of these calculat ions from the STaP data.

Table V-1; Comoarative Cost of O p t i d and X~dmum-Labor Solutions f o r 1 Km. of b a d Type A , iislli;?;: 'Perr.iin f o r ma;:c - $1/Day

1,ntarmadiatn 4u3lit.y

Estimates Based on SJKP b t a (U.S. m n 3 t s )

lkdrnum-Labor Activity Optimal Solution Solution Breakeven Wage

Eo Lo E2 L2 #

E a r t h o r k s

Clearing and grubbing - 2 8 1 - 281 + E2 Str-pprng topso i l 100 - - 300 0.33 E3 + & Excavating 13 bulk-soft

materials, loading, hauling, unloading, spreading 2,293 960 - 5,815 p.k7

H Coapacting and f in i sh ing 68 - - 281 0.2k ~6 Excavating in tulk wclr 302 Lk - 397 0.79 E7 Excavating ditches in soft

matsr lals - 25 - 25 + ~8 Excavating ditches i n rock - 56 - 56 + E9 Laying trimming, cowacting

toprai l m 2,763 1,387 - 7,236

Total Earthworks !hi22 u& (bawl Subbase

sB1-2 Excavating, loading, hauling, unloadiw, s p r e e d n ~ -1 % 277 - 1,093 0.28

(iSB3 had ing , hauling, unloading apruadinp water lil - lil - *

S B & Compacting and finishing - 84 - 8& + 562 361 47 2 4 7 7

TOM Gravel subbase 22.2 2,221r

Gram1 Base

OtU-& Excavating, loading 8 hauling, unloadtug, spreading g ram1 630 195 - 2,738 0.25

08 5 had ing , hauling, unloading, spreading water 33 - 33 -

GB 6 Compacting and fFnishing 60 - 60 + %3 255 33 2,790

Total Gravel Base 918 a Surface Dlessing

SD 1-3 Excavating, loading, hauling, unloading roc^ in quarry 65 6 - 135 0.50

SD 4 Pmduction of chlppirrgs - 210 - 210 + SD 5 Loading, hauling, heating,

unlading,spreading bitumen 77 IJJb 77 111, - SD6-8 Loading, hauling, unloading,

rpre*g cuppings 116 &2 U 6 k2 * SD 9 Compacting and f in i sh ing - 26 - 26 + SD 1 0 Brooming and cleaning surf ace - 17 - 17 1 +

258 US 193 5 b TOM Surface h a s s i n g 22 1U.

Subtotal rLabour/Equip n t & 2.lilS 2.u LLI% TOTAL COST PER K I U ) E T E R 6,664 131028 - - (Excluiing engineering superv l sbn , m b i l l r a t i o n , housing: administrative, and misceUanmus costs).

+ Labor intensint technique i s o p t i d . No poss ib i l i ty of f u r t b r subst i tut ion.

So, E2 C q u i w n t Cost Lo, 12 Labor Cost (alao labor days a t $l/day).

Eo - E2 u - -

Table V-2r Sequential Substitution o f More Labor-Intensive for More Equipment-Intensive Methods of Construction - Road Tyjm A, R o l l h p Terrain, f o r Wage = $/Day

Intermediate Quality

Estimates Based on SWKP Data

Mainnuo- Substitution f o r Activity ($ /, Km. ) Labor Solution

Cost . Lator/ Activity Days in $ ~6 a 1-3 E 3 + k E2 GSB1+2 oB 1-3 in $ ~5 Dap

Earthworks

Gravel Subbase

Gravel Base 255 918 > e , 2,831 2 a 8 3 2,798 I

Surface Dmssing US 617 - 737 '> 7 - .- 737 544

Totdl Cost - 6,661r 6,745 6,809 9,401 9,601 10,902 12,815 13 ,028 -

Total Labor Days 2 a4I.8 - 2,801 . 2,930 7,815 8&5 9,931 12~1r74 12,755 12,755

Additional Cost 81 61r 2 ,592 200 1,301 1 ,913 213

Marginal Costhabor Day 0.21 0050 0.53 0067 0.72 0.75 0.76

Average Cost/Labor Bay -- - -

4. SWKP: Table V-1 shows t h a t the re a re seven a c t i v i t i e s i n a l l , f o r w h i c h ~ s t i t u t i o n is pract icable , i. e. f o r which t he breakeven wage is$0.20 or higher. Four of these a c t i v i t i e s occur i n the $arthworks group and one each under Gravel Subbase, Gravel Base and Surfact% Dressing. If labor in tensive techniques were adopted fo r a l l seven a c t i v i t i e s , the cos t of the p ro jec t would increase from $6,664 t o $13,029 Qr by 95 percent, and the number of labor days would increase from 2,418 t o 12,755 or by 427.5 percent. I

5. Table V-1 fu r ther shows consider able di f ferences i n t he breakeven wage r a t e s fo r the seven Itsubstitutable" a c t i v i t i e s , ranging fr+m $0.79 f o r excavating bulk rock t o $0.24 fo r compacting and f in ishing. Thble V-2 below shows the r e s u l t of subs t i tu t ing labor sequent ia l ly s t a r t t n g with t h a t a c t i v i t y which has the highest breakeven wage r a t e fo r 1 K$. of Road Type A, Rolling Terrain, Intermediate Quality based on t he SdKP data.

I

5. The f i r s t a c t i v i t y t o be subst i tu ted i s t h a t with the 6ighest breakeven wage r a t e , ~ 6 . This w i l l c rea te 383 addi t ional labor days a t a cos t of $81, which i s equivalent t o a marginal cos t of $0.21 er labour/ ! day. By subs t i tu t ing a c t i v i t i e s GB-1-3 another small increase I n labour/ days (129) i s gained a t addi t ional cos t s of $64; t he marginal cos t per labour day however goes up sharply t o $0.50 per labour/day. It i s onlk with the t h i r d subs ti tu t i on (E 3+4) t h a t a subs tan t ia l increase i n labouf/days (+b885) i s e f fec ted and for a r e l a t i v e l y small fu r ther increase i n marginal cos t per labour/day: up from $0.50 t o $0.53. Total costs per Elm. r i s e t o $9,401 an increase of 41 percent over the optimal solution. ~ h b difference between t he t h i r d subs t i tu t ion and t he optimal so lu t ion ($9,401- $6,664=) $2,737 i s the inef f ic iency cos t fo r providing (7,815 - 2,418=) 5,397 labour/ days of addi t ional employment. This means a marginal cos t per Additional labour day a t this l e v e l of $0.51: subs t i tu t ion i s indicated i the shadow wage r a t e i s $0.50 per labour/day or l e s s . By carrying he exercise

or $0.62 per addi t ional labour/day.

t through four lnore sequential s teps , the maximum labour s o l u t i o n i s reached. This provides 10,337 addi t ional labour/days for a cos t increase 1 of $6,364

I

7. BCEaM: I n Tables V-3 and V-4 below, the exercise i s r e p e a t e d , based on BCE0b.I f igures . Tne remarks under 5 for Table V-2 apply equally t o t he i n t e rp re t a t i on of Tables V-3 and V-4. Since some o f t h e a c t i v i t i e s a r e aggregated d i f f e r en t l y i n the French estimates, there a re t k e e more subs t i tu t ion s teps . The successive subs t i tu t ion of more labour , in tensive for more equipment in tensive solutions r e s u l t s i n a cost i n c r e a ~ e from the optimal t o the maximtun labour solut ion of $9,807 or 61 percent, ( f o r an increase i n labour days from 929 t o a t o t a l of 20,160 or by a fbctor of 21.

Table V-3 Conparatin Cost of Optimal and P-?ximum-Labor .%lations l o r 1 Km. 01' iio id ;s;'c! A. t w l l i n i l'r.rr-u~~ fo r * . a l p - Sl./Uw

I ~ l t r r w d i ~ t e . u s l i t x

Es t lmtes Based on BCEOM Data

(u.$. Dollars) Wnaun-Labor Break

Activi ty O~tlmal Solution dolution E m Eo La E2 I L? dace r

El Clearing ard grubbing E2 Stripping topsoil E3 Excavating, loading, haublg, unloading Eb Spreading E5 ConpacUng and finishing E6 Excavation i n bulk rock E7 ErcavaUng s f t in small quantities E8 Excavating rock in small quantities t9 LPying, t r lm lng , compacting t o p w i l

Total E a r t b r k s

Gravel Subbase

GSB 1 Excavating, loading, hauling, unloading,grawl GSB2 Spreading QSB 3 laading, haulirg, unloaQng, spreading srater GSB k Conpacting and finishing

Total Gravel Subbase

Grarel Basa

OB 1-2 Excavating end bading 08 3 HauUneaard u d w d n ~ tw Sprea- GB 5 Loading, hauling, ploadlng , spreading w a t e r

i o m p a o q a m I I Z U ~ ~ ~

-are1 Basa

Roductbn stones Loading stones Hauling and unloading stones Production 10/l$ chipping9 Biturmn spreading loading chippings ) k1 (10 h.1 c h i ~ ~ i n g s Spread &ppings 1 Compacting and f i n i & b g )

Total Surface h asing

Subtotal Equlpmnt/labour

TOTAL COST PER KILOHCTilE - - (Excluding englmering, supervision, nobilloation, housing, adndntstrative, ard edsceLbneous oPsts.)

+ Labor intensive techrdqw i s optimal. No possibil i ty of Surther substitution.

Eo, E2 'Equipent Colt la, 12 h b o r Cost (also labor days a t bVday).

à able V-4s Sequential Substitution of &re Labour Intensive . for More ~quipm~t In%ensiw Methods of Construction - - Road Type A, Rolling Terrain, for Wage = $l./Day

Intermdiate Quality

Estimates based on BCM)M Data

O p t i m a l Solution Substitution fo r Activity ($be) mum Labor Solution . Labor Cost $ Labor/

Activitg Days in $ GSB-1 E-2 E-1 OB1 E-7 E-8 E-3 aSB-2 GBb E6 Days

Earthwork8

Gravel Subbase

Qravel Base

Surface M s s l n g

Total Cost

T o t a l tabor/~ays

Additional met/$

Additional Lab0 r/Daye

Merginal Coet/Labor Days

Average Cost/hbor Day

8. Even given the reservations about the figures arrived a t for the hypothetical road projects, a brief comment i s indicated on the differences between the two se ts of figures presented i n Tables V1-2 and ~ 3 - 4 . The optimal solution based on the BCEOM data has an unskilled labor tontent of only 40% t h a t of SWKP while the naximum labor solution arrived a t from the BCECM data provides 63% more man-days than SWKP estimates. These resul ts r e f l e c t the impact of the d i f ferent productivity ra tes - especially for unskilled labor - which the two engineering consultants derived from the i r data sources. Sone of these a re no doubt a re f lec t ion of the a f fe rences i n actual experience between R i t i s h and French contractors and Public Works Departments, but the differences highlight once again the crucial importance of specific productivity data for any given case: the impact on unemployment w i l l be very d i f ferent i f say, construction of 1 Km. of a cer tain type of road provides 20,199 or 12,755 days of unskilled employment.

9. I n order t o examine whether high quality standards would s ignif icant ly l imi t the scope for substituting equipment by labor, one f i n a l y e r c i s e was done, based on SGJKP figures, for the case of the High Quality Ro@dy Type A. The resul t s a re presented i n Table V-5 below. They would seem ko indicate that,contrary t o current engineer i~g thinking,even with high qua+ity construction standards the poss ib i l i t i e s for subst i tut ion a re i n f a c t only slightly reduced. Earthworks, which provide the bulk of the labor days i n the intermediate qual i ty examples, a re only affected by high qual i ty s t r i c tu res i n the cohpacting and finishing ac t iv i ty and s t i l l offer wide scope for substitution. For the gravel subbase and the gravel base, substitution i s res t r ic ted is the spreading as well a s the compacting + finishing a c t i v i t i e s but there i s s t i l l considerable subst i tut ion potential . The table thus shows t h a t the maximum p$acticable labour substitution even for the high qual i ty road s t i l l may profide 12,190 labor/days compared with 12,755 i n the intermediate qual i ty alte+native. m e average cost per additional labour day created is no higher than for the intermediate qual i ty example, i . e . , $0.62/labor day.

10. Table V-6 presents the resul t s from equivalent calculations based on BCEOM data. These again show, tha t high qual i ty standards d o n o t rule out extensive use of labour: there i s only one ac t iv i ty - compactink and finishing of earthworks - for which subst i tut ion i n the high qual i ty case i s on a slope of the production function equal t o a wage r a t e of l e s s than $O.l?O/day. Retaining the equipment intensive technique for t h i s ac t iv i ty rebul ts i n a t o t a l cost of the maximum labour solution per kilometre of high qual i ty road s l igh t ly l e s s than tha t for the intermediate qual i ty road. 1 (See footnote 2, Table I1 -13 for comment ) .

Table V-5; Sequential Substitution of %re Labour Intensive for Mom Equipment Intensive Methods o f Construction - Road Type A (Rolling Terrain) for Wage - $l/daz

Hi& QudLitx

Estimates based on SWKP Data

OptiLmal Solution Substd.tution f o r Activity ($1 Km. ) Miximum Labour Solution Labor Cost Cost i n $ Labor

Activltv Days i n $ E6 SD 1-3 E 3 + 4 E2 GSB 1+2 GB 1-3 Days

Gravel Subbase 235 1,258 .- - - - 2,601 2 ,601 2,093 I

Oravel Base

Surf ace Dmssing - Total Cost

Total Labour/Daya 2,06)) 2,447 2,576 7,461 7 ,761 9 ,619 12 ,190 12,190 . .

Additional Cost/$ . . 81 64 2,592 200 1,343 2,039

Additional Labor Days - 383 129 4,885 300 1,858 2 8571 - l4argi~l.d Cost/Labo~r D a y 0.21 0.50 t 0.53 0.67 0.72 0.79

Average Costhabour Day 0.62

Table 'v-6r Sequential substitution of More Labour Intensive. f o r Jbm Equipment Intensive Methods of Con~ltructLn - Road Type A, Rollin? - Terrain, - Uage f o r Unskilled Labor-$l/day

Estimates based 017 BCMlH Data

optimal Solution Substitution f o r Activity ($/F/Km.) I . q a . Labor Solution Labour Cost - - - - -&~a GBb Days -

Earthworks sb8 U , U ~ - ll,470 12,060 -> 12J91 12,260 18,150 -- 18,150 14,582

Gravel Subbase 50 3,075 3,204 - , - -> - .4 --> 3,628 3,628 1,979

Oravel Baee 20 1,585 - > - 18951 .-> j --> 2,262 1,355

Surf ace Dreeeing 3 3 968 -> *- > -5 9 > 968 313 I

- I-' Total Coet 6 16,876 17,227 178817 18,183 18,314 18383 24,273 24,697 258008 - IU 0\ Total Labor/Days 2 2 2,272 3,538 58268 6,189 6,457 6,587 17,227 17,815 18,229 18,229 1

Average Co~t/Labour Day 0.52

I

B. The National Promotion Scheme of Morocco: A Case Study i n Em~loment Creation.

11. Tne analysis carried out above i s one tool with which t o assess the theoret ical employment creation potent ial of road constructiop projects. But given the reservations spelled out i n the previous Chapters with regard t o the hypothetical road example projects, it is evid~ent tha t i n r e a l i t y a great number of constraints w i l l be influencing and b i t i n g actual employment creation through public works significantly. I@ an effort t o document some of these constraints, SEDES undertook an analysis of the Wational Promotionff program i n Morocco, one of the more important attempts made i n recent years to absorb unemployment i n road cons~truction.

The Moroccan Economy

12. To place the National Promotion program i n the context qf the Moroccan economy, a br ief overview of the economic s i tua t ion i s gresented f i r s t . Population and Employment: The present population of Morocco js about 15 million, 11 million of which l i v e i n r u r a l areas. Over the 1960-70 period, population has increased a t a r a t e of 3.15%; it i s hoped t h a t this r a t e w i l l go down to 2.7% for the 1970-1980 decade. The-active opulation (= 4.2 million men over age 15) i s increasing a t a r a t e of 3.39 nnually, 3 a s the demographic wave of the f i f t i e s reaches active age. I n onder t o maintain present levels of employment, the five-year plan for 1988-1972 c i t e s a figure of 140,000 additional jobs t o be created annually. Optimistically, the Plan foresees the creation of just under 100,000 jobs per anrim: 55,000 i n agriculture, 8,500 i n government, but no more than 5,400 for industry, craf ts and public works taken together, the remainder t o be provided i n 1othe.r f ie lds .

13 Although there are no o f f i c i a l s t a t i s t i c s on unemploymerit, a r a t e of between 182-208 for the urban are?? seems r e a l i s t i c . Rural udderemployment is also significant: i n 1944, fiano- cites the following figureis for the male and female active population combined: I

Urban employment de f i c i t : 500,000 jobs I

Rural employment def ic i t : 465 million maddays

For 1970 it i s estimated that , i n a l l , 9,000 new permanent jobs were created. Some of the pressure on the job-market was eased by continued emigration: i n the same year, there were 32,800 emigrants, 80% of whom went %o France.

Tne Overall Economic Picture: The level of industr ial izat ion i n Morocco i s qui te low and, given the current leve l of investments, i s unlilkely t o improve much i n the near future. I n contrast t o i ts neighbours iln the Maghreb, the country does not possess any major : 'o i l- f ields and earns i t s f o r e i g n exchange from three main resources: phosphate, tourism, and c i t rus f r u i t .

1/ A . Tiano: ItLe Maghreb entre lea m h e s t l , P.U.F., 1967. -

I n 1967 GDP per capita amounted to $190, w i t h an annual growth ate of about 0 -6%. . Income dispar%ies i n monetary terms are considwable, although consumlition of home production s l igh t ly moderates the disproportions between sectors. Industr ial wages can be up 30 times those earned by a labourer i l l agriculture (about DmO/year)g There are equally large dispadties between different social s t ra ta . A crucial feature of Moroccan public finance i s an imbalance between operhting and investment budget. I n contrast to most countries, it is t~he operating rather than the investment budget, which is curtailed during periods of auster i ty. The r e s u l t i s a deterioration i n the val~ue of investments due t o lack of upkeep. I n the f i e ld of Public ~ o r l i s , this leads t o a run-down of equipment because of lack of maintenancd, w i t h consequently low rates of equipment u t i l i a ation and high equipdent costs.

4 0 Government policies t o promote employment i n public wdrks include both f i s c a l measures and d i rec t action. The f i r s t take the follm of d i f ferent ia l duties . on imported equipment: since trucks are now assembled locally, the government imposes duties of 40% on hMrted trucks and 30% on a l l other imported equipment. Locally manufactured cars and trucks by contrast only carry a tax of 12%. As thesedu t i e s must be paid not only by private industry but also by Public Works Departments who buy equipment, it might be assumed that,given the budgetart constraints of the l a t t e r , these taxes would tend t o slow down mechanizatipn i n road construction. I n practice, however, th i s does not happen becaipse the investment budgets are almost exclusively financed out of foreign loans. I n 1970, for example, Morocco was granted a loan by the IBRD fbr purchase of road construction equipment (bulldozers, graders and loaderb ) on which no taxes were levied.

By far the more important e f fo r t i n the f i e ld of employment creation has been the d i rec t action program of National Promotim. Its1 scope and organization are therefore s e t out next i n more de ta i l .

!Che National Promotion Program I I

15 - National Promotion i s under d i rec t responsibility of the Head of State. Its declared objectives are :

- t o provide opportunities of productive and profitaGle work for the rura l underemployed;

- t o foster people's involvement i n Government sponsored

1/ $1 = Dirham (DH) 5. -

development e f fo r t s by providing opportunities for part ic ipat ion i n the planning and execution of program a c t i v i t i e s ;

- t o slow down migration from the land by means of improving conditions of ru ra l l i f e and work in the disadvantaged regions and ra is ing the standard of l iv ing of their inhabitants.

National Promotion has been i n existence since 1961 and currentlylprovides some 20 million man-days of unskilled labour annually. I n accordhnce with i t s objectives, National Promotion focuses on t e c m c a l l y s b p l e projects w i t h high inputs of unskilled labor and substantial impr~vement potent ial for agricul tural production (small i r r iga t ion projects, arboriculture ) as well as i n infrastructure (roads, feeder roads, communal buildings ) and regional development (clearing land of brush or stpnes, so i l- protection, reforestation). I

16. Administratively, there a re four project categories, each of which i s financed differently. , Part Qle - A projects are financed from the budgets of the M i n i t r i e s -(e.g., Ministry of Agriculture, or Public Works), or Provincial G 1 vernments. Workers employed i n t h i s project category are remunerated as follbws:

- unskilled labor i s paid DH h/day, DH 2.4 of which are a id i n

(= 4 kg. of wheat) by the National Promotion; ip cash by the Technical Service and the remainder i n kiqd I I

- workers who provide the services of an animal i n addi4ion t o the i r own, are paid DH 6/day, DH 2.40 of which is i n dash from the Technical Service, the r e s t i n kind from ~ a t d o n a l Promotion (one supplementary rat ion to feed the animal);

- overseers (of 50 men of l e s s ) and time-keepers are p&d DH 6 / d a y , ~ ~ 4.h of which are paid i n cash by the ~ech$cal Service and the remainder i n kind by the National Pro~otion;

- craftsmen and supervisors receive DH 8/day i n cash f r ~ m the Technical Service. I

I

These wage ra tes a re considerably lower than those paid by private firms; they often r e su l t i n a shortage of supervisory skills i n the program. Part Two B pro j ects are financed exclusively by National pr omotion. Remuneration levels are the same as under Part One A. Finally, there are smaller projects of s t r i c t l y loca l in teres t : Part Two-C projects provide payment for unskilled labor i n kind only; for Part Two-D projects, equipment and ski l led labor are furnished, but there i s no remuneration for unskilled labor. InfFastructure projects hardly ever f a l l under the C and D categories.

811 National Promotion projects a r e ruled by the following constraints:

- non-wage expenditures (e. g., small equipment, t ransporta t ion) cannot exceed 20 percent of the t o t a l project cost;

- a l l equipment requirements have t o be channelled throubh the cen t ra l provincial au thor i t i es of National Promotibn, even i f projects a r e under t h e d i rec t ion of one of the technical services such a s t he Ministry of Public Works. This tends t o create delays and ineff ic iencies .

17. Organizationally the actual work projects a re planned !at the provincial l eve l . They a r e discussed and worked out each year beltween the technical services and- the l o c a l au thor i t i es concerned, and sen t t o the Central Office of National Promotion for checking and approval. ;A similar check i s carr ied out by the representatives of USAID which contributes p a r t of t he remuneration through i ts provisions of wheat.

National Promotion work-sites r a r e l y employ more than 3d0 people - hence problems of housing and administration, a s well a s the effdct on the l o c a l economy are not important. Generally, nothing more than tdnts , and if necessary water, a r e provided. A l l workers and foremen a re rqcruited by the l o c a l 'rcaidll ( ~ o r t h kfrican Magistrate ), who a l so handles ( a l l payments t o workers regardless of which authori ty finances the pro jec t (e g. Province, Public Works, Agricdture , etc. ) . Workers can only be hired on $heir own v i l lage t e r r i t o r y and generally a r e not allowed t o work on a s i t $ under the authori ty of another caid. This makes it very hard t o develop c$mpetence among foremen and workers and r e s u l t s i n very low outputs of work: for earthworks this i s seldom higher than lm3/day. Also, there i s nb organization of work on an incentive basis, although it is admitted t h a t this would r e s u l t i n much greater productivity. The Moroccan experience thus woul b seem t o confirm the importance of i n s t i t u t i o n a l factors and incentives ( l ee Chapter IV) for actual outputs achievable by labor intensive methods. I

18. Limitations and Problems: It has been found, t ha t therle are considerable differences i n mobilizat'ion po ten t ia l for National Promo$ion work, both by region and seasonally. The greates t I~mobilizable" populatiod is i n t h e Rif: Tetouan provides 32,000 out of a t o t a l of an average 200 by National Promotion. Overall i n the country, September and most favorable, May and June the l e a s t favorable months for a t But while the program has been f a r from negligible i n a l l e v i a t hardships of r u r a l underemplojment, there are two problems it hds done l i t t l e to solve: urban unemployment, and especial ly the unemplo3xent qf the young.

I

An attempt to tackle the l a t t e r problem was qn f a c t mad$ i n 1966. The p i l o t project was the construction of a 50,000 m dam on thd 'lBou Regreg'!; it offered 67,000 workdays i n a l l . But the response was so poor t h a t the follow-up projects foreseen i n t h e Plan were never carr ied o u t . The young have shown themselves frankly h o s t i l e t o projects of this kind - not only because they are l i t t l e incl ined t o do manual labor ( e spec i a l ly fo r no pay) but a lso because they consider these projects dead-end jobs and a p a l l i a t i v e ra ther than a cure t o t h e i r unemployment problem.

Even i n the r u r a l context where National Promotion has been most successful, some serious problems have developed which have l e d t o a stagnation i n National Promotion a c t i v i t i e s i n recent years:

( i ) One problem has been the delay of payments t o the workers, resu l t ing from hold-ups i n the passing of the requis i te f inanc ia l l eg is la t ion , and from complicated t ransfers of funds from the yarious au thor i t i es concerned t o National Promotion and f i n a l l y t o the l o c a l caids, delays which a r e fur ther exacerbated by the lack of qual i f ied accounting personnel a t the l o c a l l eve l . It i s i n f a c t qu i te qommon t h a t men w i l l q u i t the s i t e a f t e r having worked for one or two montHs without being paid. Often they do not claim the i r wages, or they s e l l t he i r Itwork-card" t o a l o c a l tradesman a t a very low pr ice . Thus, wqile the delegation of responsibi l i ty for National Promotion e f fo r t s do- t o the l o c a l l eve l may be desirable po l i t i ca l ly , it nevertheless, by qreating a mu l t ip l i c i t y of decision centers, r e s u l t s i n i r r a t i o n a l decisi@ns injur ious t o the people the program i s designed t o help.

( i i ) The l imi ta t ion of the wages of sk i l l ed Workers t o DH 8/day when pr iva te contractors pay two-to three times t h a t amount p ra&t i ca l ly deprives National Promotion of competent sk i l l ed labor. I

( i i i ) The constra int t h a t 80 percent of National Promotion funds have t o be spent on s a l a r i e s - laudable i n i t s intent ion of s feguarding t the "human inves tmentll character of the program, has some unan; ic ipated lsecondaryl consequences. Of the remaining 20 percent, a t l k a s t half i s spent on transportation; t h i s leaves only a very l imited amounb t o spend on "back-up!' equipment. Even where the introduction of mixed ethods of construction could s ign i f ican t ly improve productivity, t he i r a 1 option i s unlikely, or even impossible, both for f inanc ia l and for ideolbgical reasons . Some experiments i n t h i s direct ion have, however, been s t a r tedl recent ly i n the Tetouan d i s t r i c t . Public works departments there use a; bulldozer followed by 30 men - and while it i s as yet too ear ly t o drab m y f i n a l conclusion, r e s u l t s seem t o be of i n t e r e s t both i n terms of co~st and employment.

( i v ) A coherent policy for National Promotion is very d i f f i c u l t t o achieve, because the d i f fe ren t Ministries contributing t o i t s (funds out of t he i r budgets see i t as a vehicle for achieving d i f fe ren t and (sometimes confl ic t ing goals. For the technical minis t r ies , such as ~ u b q i c Morks and Water Resources and Forests, it i s a fac tor of production amorlg others and they want t o use it as e f f i c i en t ly a s possible: by using nixed methods of construction, or even by r a i s ing wages t o obtain higher pa%oduqtivi&y. For the In te r ior Department by contras t the most important asflect of National Promotion i s i t s contribution t o lowering soc i a l disdontent and preventing soc i a l disorder: they want t o a f f ec t a max~muan number of people and productivity consider a t ions a re secondary.

But given a l l t h e d i f f i c u l t i e s and l imi ta t ions of t h e program, National Promotion i s s t i l l providing almost 20 mil l ion laborbdays annually and thus has a s o l i d achievement t o i t s c red i t . I ts importance i n road construction i s examined i n t he next section.

19 Achievements of National Promotion i n Road constructiun; A t t he inception of the program, in f ras t ruc ture p ro jec t s - most of tHem construction - -

of t e r t i a r y roads,- provided the bulk sf National Promotion wor~k. ]But the au thor i t i es l a t e r decided t h a t t he major focus of National ~r +otion should be on land improvement, and road construction a c t i v i t i e s now piresent only some 30% of National Promotion work. Table V-7' below d e t a i l s the development of road construction works ca r r ied out by National Promotion 4rom 1961 t o 1969 and t he i r r e l a t i v e importance i n t he ove ra l l program.

The t ab l e shows t h a t maintenance a c t i v i t i e s have decli~ned, while the number of days spent on construction of new roads have indreased. Regional t ab les (not reproduced here ) show t h a t in f ras t ruc turd a c t i v i t i e s a re most important i n t he Rif provinces and i n t he enclaves i d t he South. By contras t , t h e road construction a c t i v i t i e s i n t h e cen t ra l rlegions ( ~ e s , Casablanca, Rabat) a r e negl igible , p a r t l y because a dense network of roads ex i s t s , bu t no doubt a l so due t o t he f a c t t h a t t he urban unemployed a r e very hard. t o a t t r a c t i n t o National Promotion. I

I

With regard t o t h e t o t a l number of days worked i n Natiional Promotion, t h e t ab l e shows a stagnation of a c t i v i t y i n t he l a s t four yearls. Having shown the extent of road construction present ly handled by Na iona'l Promotion, we must next r e l a t e it t o the t o t a l publ ic works a c t i v i t i e s i 1 the country.

I

This w i l l allow us t o evaluate t he subs t i tu t ion potent ' ia l between equipment and labor i n t he Moroccan road construction indus trd.

I

20. The Road Budget: Tables V-8 and V-9 below show, f o ~ r the l a s t three years, t h e t o t a l budget of t h e Ministry of Public Works and thleACommunications Hnd the p a r t of it ai located spec i f i c a i l y t o road expendituresl.Li Bxpenditures on roads amounted t o 1 3 t o 15% of the budget of the Ministry of Public Works, or 2.2 t o 2.7% of the t o t a l government budget, abd 0.5 t o 0.6% of GDP. Road construction is thus no t a major p a r t of t o t a l economic ac t i v i t y .

L/ BCEOM; "The Moroccan Transportation Plan", Preliminary i epor t, Paris , February 1971.

Table V-8: Total Budget of the Ministry of Public Works and Communication

(DH 000)

PART- ONE: Oper a t ing Budget

Maintenance, heavy repa i rs

Other oper a t ing budget

Subtotal

PART TlnK): Investments

Total

Table V-9: The Road Budget

PART ONE Fund Allocations t o Roads

Maintenance, rebuilding and new pavements (primary and secondaf y roads ) 30,000 30,000 36,800

Subsidies t o Provinces fo r maintenance of t e r t i a r y roads 6,500

~ d n t e n a n c e of Tourist I t i ne ra r i e s 300 300

Subtotal 36,800 36,800 37,100

PART TWO Fund Allocations t o Roads (F'ive Year Plan)

Completion of 3-ye@ plan New works - Government

IBRD pro j ects Heavy repa i rs - Gover nment

IBRD projects Transport study Acquisition of equipment Tourist i t i n e r a r i e s Tertiary roads - general network

Beetroot projects Specific project (Loukhos, Berro) Mine roads ( Three-year Plan completion)

Subtotal

TOTAL BUDGET AUOCATIONS to Roads

To these funds m e added pro- rata a l locat ions from a general b u d @ , fund for Personnel, Equipment and miscellaneous expenditures, which increqsed the figures for the overa l l road budget i n the years considered to: I I

I

1968 = DH 77 m5llion

1969 = DH 99 mil l ion

1970 = DH 101 mil l ion

No separate f igures on employment i n roed construction a re availbble, but estimates:/ put employment i n t h e t o t a l sector of Wonstruction and Public Works! a t 77,000 i n 1968 and 82,000 i n 1970, which amoun$s t o 1.60% and 1.65% of t o t a l employment i n these years. This i s robghly the same number of jobs as were provided by National Promotion: assuming 250 mandays of work per year, i t offered the equivalent of 80,00b f u l l time jobs, with j u s t under one t h i rd of these i n road constructipn (see Table IV-7). I

I

These f igures would seem t o suggest t h a t any contr ibut io t o employment creat ion through manualization of road construction c t i v i t i e s can a t be s t only be a very l imited one. This impr.ession i s fur ep

industry.

.:: confirmed when we look a t the present organization of the road qonstruction I

Tne Road Construction Industry - 21. Unlike t h a t i n many other countries, the Moroccan road qonstruction industry s t i l l uses labor in tensive methods r e l a t i ve ly exBensivgly. Besides National Promotion, whose a c t i v i t i e s a re r e s t r i c t e d to very simndle works on t e r t i a r y roads, Public Works Departments use Force ~ c c d m t labour for maintenance work. Wages for Force Account labor are about 1 one- third of those paid by pr iva te firms: about DH 500/month for a form$n with 15-20 years experience; DH 6/day fo r a truck or grader operator. mqn illere are a lso qu i t e a number of p r iva te contractors, who use labow a h o q t exclusively. Some of them have annual turnovers of more than DH 1 mill ion. gost of the unskil led labor i s recrui ted loca l ly , while supervisors, t e c b i d i a n s and s p e c i a l i s t s a r e permanent personnel. Wages vary from day f Or unskilled labor t o DH20/day depending on the work s i t e , with the cornpaw B r o v i ~ n g equipment f o r camps and water, i f necessary, Highly mechdzed p ~ i v a t e contractors, of which there ere some ten w i t h an estimated a~mugl. t.wncver of

1_/ IIBPLD: 1lCurrent Economic Posit ion and Prospects of Msro~i;c.f:, B4~-42: September 1971.

DH 20 mil l ion fo r new construction, a r e thus s t i l l only a mino2 component of t he road construction industry. They do however carry out a l l works on primafy roads. Even in the construction of .qecondary and t e r t i a r y r o a k t he choice of technique fo r the various cons$ruction a c t i v i t i e s seems t o be influenced most by f i nanc i a l considerations:

Earthworks, offer ing by f a r t he g rea tes t scope f o r labqr subs t i t u t i on according t o the engineering analyses (see Chapted 11) a r e no longer ca r r ied out by manual labor on secondary road projects , probably because f i gu re s (from Public Works i n Tetouan prosdncd) show the following var ia t ions i n cost by type of contractor:

Pr ivate f i rm using labor: DB 5 . 2 0 / ~ ~ ~ ~ National Promotion : DH 4. 76/m3 (with i t s lower s a l a ry l eve l s )

I

DH 3 .40/m3 Mechanized p r iva t e firm:

Structures and drainage di tches e tc . f o r secondary roads a r e h4wever q u i t e commonly b u i l t by labor and Public Works Department engirieers r epo r t t h a t t h e qua l i t y of work var ies from excel lent with some firms t o mediocre with others. I I

Additional Employment Po ten t ia l i n Road Gonst~uct ion I

22. I n a f i n a l exercise, it has been attempted t o assess hqw many jobs could be created assuming t h a t de l ibera te po l ic ies towards t h i4 end - which would of course need t o be t rans la ted i n t o budgetaay allocatias$s - were put i n t o e f f ec t . Clearly, t h e National PPomotion e f f o r t has nqt a s ye t rea l i zed i t s maximum poten t ia l : it i s estimated t h a t a t leas4 60-78 mi l l ion week days/yea~s would be required t o cure r u r a l under sdp lopen t . I n the f i e l d of road cons-Lruction a c t i v i t y spec i f ica l ly , thefe would seem to be enough developments p ro jec t s t o be ca r r ied out t o p ro~hd4 employment f o r the next t en years. With in tens ive technical t r a in ing e f f o r t s a t a l l l eve l s and a streamlining of decision-procedure , i t would seem r e a l i s t i c t o assume t h a t i n f r a s t ruc tu r e a c t i v t t i e s could each double t he present l e v e l i n about seven years time. This wodd mean he creat ion of 26,000 new jobs (corresponding t o about 9 mil l ion man-days 1 i n a l l , or b,000 new jobs annually. This development would be gnsestly 1 f a c i l i t a t e d if - as has been foreseen i n the Plan - pr iva te contrac%srs whq t a v e experience i n working with unskil led labor were employed f o r o3ganizing and supervising National Promotion Workers. Continuing and ex4esnding t h e p rac t ice of using l o c a l tradesmen for various complementas; ':zldctf ons i n connection with road construction (e .g., supply of material , s3xp le s*uctures, e tc . ) would be an addi t ional employment-creating f a c t o ~ .

23 I f , however, we f ina l ly , r e l a t e the employment creation potent ial of the road construction sector - 4,000 new jobs annually - t o the number of jobs needed t o maintain even the present l eve l of employment - 140,000 new jobs annually - it must be concluded t h a t manualiza$ion of road construction ac t iv i t ies , while a useful element i n a neces$ary and worthwhile e f fo r t t o a l lev ia te the acute problems of under- andunemployment, i s no panacea for their solution. I ts most serious l imitat ion qesults from the f a c t tha t i t s potential i s l e a s t where the problems are grehtest: i n the areas of urban unemployment and unemployment of the young.

6 . Comparative Evaluation of the ~ Scope ~ for Labor subs t i tu t ion i n Road Construction and other Industries.

24. The Morocco case seemed t o point up two conclusions: ~ ( i ) The employment potent ial for unskilled labor i n road const4uction, while by no means negligible, i s of limited impact: a t best, i$ offers l e s s than 3% of the additional jobs needed t o maintain present levels of employment. I

I I

( i i ) The employment potential for unskilled labour i n road consbuction is, however, consider able compared t o t h a t i n other industries; ~

I

It was next attempted t o assess whether the Morocco case i s exc!pptional, or whether it can be considered as f a i r l y typical for other lesb developed countries as well. I

I

25 When available s t a t i s t i c a l sources were examined t o detbmine what proportion of GDP and government expenditures i n l e s s developed countries typical ly are spent on roads, it was found that, generally, f i g p e s are available only for l t ransport and communications or 'public wo)ks as a whole. Also, figures include current ( v i z . administration and maintenahce) as well

I as capi tal expenditures: The limited data available show t h a t , typically, expenditures on ' transport and communications1 account for 10-2P percent of the t o t a l government budget or some 2 percent of GDP. For I dia (1968) and Pakistan (19699, f i ~ u r e s of 1% and 0.55% of GDP respective1 are quoted for road expenditures.- - The same source gives breakdowns o 1 expenditures between new construction and maintenance for a few selected couhtries . These figures would indicate a pattern of road expenditures thak shows consider able variation over time, wi th spending on maintenance bnly s l igh t ly more s table than tha t on new construction. E q e n d i t u r ~ s on roads then do not constitute a very large pa r t of the t o t a l economic Bctivity i n l e s s developed countries. Continued scope for improving network can be expected where rura l output i s increasing. It i s unlikely, h o ~ v e r , given the

&/ International Road Federation: llWorld Road S ta t i s t i c s , 1965-1969, Geneva, 1970.

many pressures on the scarce available resources of governments i n these countries - t h a t a much greater proportion of the i r budgets w i l l (or should) be allocated for road works.

26. While figures for expenditures specif ical ly on roads are d i f f i c u l t t o find, there i s even l e s s information on the kilometrage (by type) of roads bu i l t with the funds allocated, and almost no data on the emplOyment generated by road construction, or even by public works generally. I n Morocco, it has been estimated tha t one kilometer of road plrovided 20,000 - 30,000 --days of labor (source 31). I n Tunisia, 8,700 kms. of road constructed by predominantly equipment intensive methods iequired 8,615,000 man-days of labor, i. e. just under 1,000 labor days per lan. constructed (source 1 ) . With variations as large as these, cilculations, on the basis of 'average cost ' per lan of road, of investment costs per permanent job created i n road construction as compared with thbt i n other industr ies (for which available data are almost equally weak), was therefore not considered meaningful a t this stage.

27 A second approach t o r e l a t e the employment potential i n road construction with tha t i n other industr ies was t o compare the number of persons employed per year per u n i t of output. Table IV-10 below shows some figures on t h i s for selected countries and industries. It cin be seen from Table IV-10 tha t figures for the same industry vary s ignif icant ly between countries. The figures for India are consistently high, r e f l e ~ t i n g more labor intensive methods of indus t r ia l production. Some of the differences can be a t t r ibuted to different defini t ion of indus t r ia l a c t i v i t i e s which make the data not s t r i c t l y comparable, but roughly it can be concluded, that the different indus t r ia l ac t iv i t i e s provide between 50 and 250 perwnent jobs per million dol lars of output. If, i n a grossly simplifying approximation we assumed tha t the cost for the hypotnetical kilometre of road i n say, Table IV-3 would be of the order of $50,000 i f a l l additional expenses such as overheads, mobilization costs, etc. were added, there would then be:

966 j l a ~ o r days ) 210 (labor days/yr ) = 4-5

annual jobs, or 100-125 annual jobs per million dollars of output for the optimal solution a t a wage of $l/day. The equivalent for themaximum labor solution on the other hand would be:

20.160 (labor days ) 210 (labor days/yr ) = 96

annual jobs, and assuming an increase i n cost of 60% for the labor intensive method, between 1,200 and 1,400 annual jobs would be associated with one million dol lars of output. Thus, the equipment intensive methous of cons t ruc t i~n are clear ly within the range shown for other indus t r ia l ac t iv i t i e s , whereas the labor intensive solution gives a substant ial ly higher figure.

28. Quite apar t from the very approximate character of the f igures used i n t h i s calculation, there i s another important proviso ta be made. To draw any va l id conclusions, the technical ly f ea s ib l e subs t i tu t ion of labor fo r equipment would have t o be examined for these other i ndus t r i e s as well; the ineff ic iency costs of manyalization of techniques would have t o be established and compared with those for road construction t o assess the comparative advantage or disadvantage of implernent&ng labor in tensive techniques of production. While this i s c l e a r l y beyond the scope of t h i s report , i t i s however worth pointing ou t t h a t such calculations should be attempted: i f the cos t of equipment-intensive techniques versus optimal techniques arle evaluated qu i t e routinely, we should a l so look a t the r e l a t i v e cos t of in tensive techniques compared with optimal techniques i n an t o assess t he cos t of creat ing employment i n l e s s developed cduntries with a high surplus of unskil led labor .

D. The Labor Surplus Problem i n Less Developed Countries' ~ I I

29 I n t he l e s s developed economies, a labour surplus mayhanifes t i t s e l f i n several ways. There i s un l o en t narrowly definbd: this is u-1~' taken t o include only those out 5f*ively seeking 4t a t going wage r a t e s , and able t o work a s efficjently a s those already ccupied. I f chances of obtaining work a r e small however, a s i s of ten t 4 ue i n l e s s developed countries, people may be discouraged from ac t ive ly Seeking it. Thus it i s useful t o extend the def in i t ion of unemployment t o those who would seek work i f the chances of obtaining it were higher. qven i n t h i s expanded sense, unemployment includes only those without work. Since for most people i n l e s s developed countries, being without work fd r any length of t i n e means being without income, it i s a d i sas te r which somehow has t o be avoided. Unemployment i n the conventional sense i s therefo4e often confined t o par t i cu la r g r o u p for whom the immediate need t o earn enough fo r subsistence i s i n some way l e s s pressing - fo r example, yqung people and married women who a re able t o r e l y on others fo r support. This means t h a t d i f ferences i n the dimension of the employment problem f om one country t o another a re t o a very l imited extent, i f a t a l l , Jcked up a s differences i n measured unemployment ra tes . For example, It would be absurd t o suggest that , because r a t e s of unemployment i n 1ndia a r e a s low as three or four percent, while they a r e around twelve percen-tt i n Puerto Rico, labour i s more f u l l y u t i l i z ed i n India than i t i s i n ~ u d r t o Rico. This does not mean t h a t conventional unemployment i s unimportant i n l e s s developed countries: r a t e s of between eight and f i f t e e n perc$nt unemployment a r e not a typ ica l for the c i t i e s . But i t does mean t h a t unemp oyment and the circumstances i n which i t a r i s e s needs specia l and t o some ex en t separate treatment from the general problem of underuti l ized labour.

t 30 For the grea t bulk of the people i n l e s s developsd countries, the employment problem shows up a s one of underemployment, i .e . employment po ten t ia l which i s not f u l l y u t i l i zed . underemployment occurs i n two d i f fe ren t ways. The f i rs t occurs where the work avai lable i s spread th in ly over those available, so t h a t t he withdrawal of marginal workers would not cause output t o f a l l . It i s found i n the agr icu l tu ra l sector , where the farm i s the t r ad i t i ona l work place of t he whole family. I n the urban are*s, pe t t y

r e t a i l i n g a t s t a l l s and casual labouring work both involve much waiting between tasks; even l a rge employers may, by custom, r e t a i n s t a f f who a r e t r u l y redundant. The second i s the case of employees whose qff ic iency while working i s qu i t e high, bu t who cannot f ind su f f i c i en t hour^ or days of t h a t work, although they do perform some. This type of underemployment i s of ten associated with i r regula r ava i l ab i l i t y of work (harvesting, crop processing and transport , t o u r i s t seasons, e t c , ) where workers a r e f u l l y employed by any def in i t ion during a peak season, bu t a t other times cannot f ind any work a t a l l . This seasonal i ty aspect of the problem is pa r t i cu l a r ly important fo r consideration of the p o s s i b i l i t y of subs t i tu t ing labour for equipment i n road construation, since road construction i s of ten qu i te seasonal i t s e l f , dependiqg primarily on the l eve l , in tens i ty , and duration of ra iny seasons. I f the Peak of the agr icu l tu ra l season coincides with a l imited construction season there may be small scope for subs t i tu t ion i n road construction.

31. Wortl~while information on the extent of the labour pro4lem i s very scarce. The problems of measuring a labour surplus a r e disQussed f u l l y i n Turnham L( but it can be noted here t h a t t he t r ad i t i ons i n some less developed countries of women and children working a t busy t{mes, t he extended family i n the t r ad i t i ona l sector sharing the work availgble among a l l those who join it, and the l a r g e proportion of the work force who consider themselves as self-employed on a jobbing basis , make the$ problem even more d i f f i c u l t i n these countries than i n the developed c o d t r i e s . To avoid misleading conclusions, s t a t i s t i c s need t o be c l a s s i f i e 4 by occupational category, fo r not a l l categories a r e i n surplus, and they must a lso give d e t a i l s of seasonality. Somewhat paradoxically, while underemployment is probably most s i gn i f i can t i n l e s s developed cbuntries taken together, and cer ta in ly so i n most of the poorest countries of r i c a and Asia, it i s for unemployment t h a t we have the most r e l i a b l e informatio 3 s ince this i s comparatively speaking l e s s d i f f i c u l t t o measure. Table V - 1 1 provides estimates of unemployment i n r u r a l and urban areas for various cguntries.

32 Finally, drawing on t h i s and other information, the foilowing points concerning unemployment can be made with reasonable confifence:

I

a ) Unemployment would appear t o be r i s ing ; even where t he data ind ica te a reasonably constant ra te , t h i s invflves a rapidly r i s i n g number, especial ly i n urban areask Vp t o 20% of urban work forces may be unemployed, andl i n most c i t i e s examined, the proporti an f a l l s i n the tange 11 t o 17%.

1/ D. Turnham: IfThe Employment Problem i n Less Developed Countrieslr, - OECD, Paris , 1971.

I/ Table V-11: Urban and Rural Rates of Uhemployment

(percent of Labour ~ o r c e )

,Wban Rural Rate Ra$e - Notes -

Africa: -

Ceylon- - - - - - - - - - - - - - 1959/60 1968

China (~aiwan) - - - - - - - - - - 1968 K o r e a - - - - - - - - - - - - - - ~ ~ & ~ a - - - - - - - - - - - - - 1965

1961/62 Syria - - - - - - - - - - - - - 1967 I r a n - - - - - - - - - - - - - - 1956

1966 Philippines - - - - - - - - - - - 1967 West Malaysia - - - - - - - - - - 1967

America :

Survey Census Survey

Survey Survey Survey Survey Survey Survey Census Census Survey Survey

Argentine (Buenos Aires ) - - - - - 1966 Chile - - - - - - - - - - - - - - 1968 Honduras - - - - - - - - - - - - - 1961 Jamaica - - - - - - - - - - - - - 1960 Panama - - - - - - - - - - - - - - 1960

196'7 Tfruguay - - - - - - - - - - - - - 1963 Venezuela - - - - - - - - - - - - 1961 Colombia ( ~ o g o t a ) - - - - - - - - 1968

1963 1960

Survey Census Census Census Survey Census Census Survey

a. The unemployed "available" but Ifnot seeking11 work are incluqed i n rur a1 areas but not i n urban areas. Deducting this group might reduce the ru ra l percentage r a t e by about one third. The urban figure re la tes t o the a@ group 15-60.

b. Kingston. c. All Jamaica l e s s Kingston. d. Bogota.

-

1/ D. Turnham: op. c i t , Tables 111.1 and 111.7. -

b ) Cpen unemployment i n ru ra l areas i s generally much less , however. To some extent t h i s may r e f l e c t tha t the ru ra l labour surplus migrates t o the ci ty , but more generally the r u r a l surplus may be underemployed rather than unemployed.

c ) Young, inexperienced persons and those with middle leve ls of education are represented among the unemployed i n greater proportion than i n the work force as a whole. Many ~f these are apparently unemployed for long periods: it would seem t h a t those with jobs cl ing to them, and tha t the educated young take care and time i n select ing jobs, preferring t o remain unemployed rather than accepting unskilled jobs which may be available but offer lo we^ wages and l e s s prestige.

33 Despite the d i f f i cu l t i e s , there have been some attempts t o measure the extent of underemployment. One of the most comprehensive surveys appears t o be tha t undertaken i n Thailand i n 1967-68. This suggest& t h a t 26 percent of the r u r a l labour forcp/and 5 percent of the urban labour force workedless than 30 hours per week.- Table V-12 presents other s t a t i s t i c s assembled by Oshima 21 for selected Asian countries. Where shortfal ls i n hours worked are expressed i n terms of equivalent full- time unemplGyment, we see tha t underemployment i s estimated t o have accounted for two+thirds of the Philippines employment problem and one-third or more i n ~ e f i o n , India, Malaya, and South Korea i n various years.

Table V-12 : Estimates of Open and F'ull-Time ~ q u i v a l e n t Unemployrpent as Percent of Labar Force, Selected Asian Countri+s

Underemployment Total @en i n Equivalent W l - Equivalent

Year - Unemploynent Time Unemployment F'ull- Time Unempl - . India 1965 Ceylon 1960

6% 10%

~ a k i s t a n 1964/65 n.a.

Singapore 1966 9% Malaya 1962 Philippines

6% 1957/65 4%

Thailand 1963 (urban) 4%

S. Korea 1967 6% Taiwan 1963/66 lr% Hongkong 2%

1/ Thailand, National S t a t i s t i c a l Office: llReport of Labour Force Survey, - 1967-1968", Bangkok, 1969.

2/ 3. T. Oshima: WLabour Force 'Explosion1 and the Labor Intensive Sector - i n A3ia.2 Growth,lI University of Hawaii, April 1969 (mimeo). I

34. But shortfal ls i n hours worked are only one indicator and it may be tha t the previously mentioned disguised unemployment i s thei major form of underutilization. For this dimension of the problem, productivity or income measurement seems required. But here again only very gqneral indicators - whole economy income distr ibut ions or sectoral averades of productivity - are usually t o be found. In any event, as there i s no standard or widely accepted method of dealing with the measurenient of disguised unem~loyment, knowledge of underemployment is, i n quant5tative terms, grossly incomplete. But even the most limited f i e l d experience i s suff icient t o convince most people of the s ize of the problem; for most policy purposes, including those under discussion here, whether twenty or for ty per cent of the labour force i s underutilized i s perhaps not an issue of overriding consequence.

35 Probably the basic problem has been and continues to be the very rapid growth of population and therefore of labour force. Some s t a t i s t i c s about t h i s are shown i n Table V-13. On this score the forward estimates t o 1980 provide no reassurance about the future: job creation w i l l remain a major problem for many developing countries for the foreseeable future. Indeed, the projections (which are reasonably re l iab le since people entering the labour force over t h i s period are already born) indicate a worsening Stuat ion as labour force growth continues t o accelerate.

36. Finally, the problem i s being exacerbated by heavy migr4tion t o the urban areas. Reasons for this are many and varied. The modern sector industries are located i n the towns: they pay relative13 high wages t o the scarce ski l led labour and even the unskilled tehd t o be paid well above ru ra l subsistence wages. Improvements i n corn cations 7 have caused a rapid spread of knowledge about the higher wages an bet ter amenities available i n the towns. Further, the rapid spread of ducat ion i n ru ra l areas has raised the aspirations of many people, leading t o t h e i r dissat isfact ion with rura l conditions, and addingto the i r desire t o migrate t o towns, where previous savings or support from the extended f d l y enables

T them to wait i n pools of unemployment u n t i l work f i t t i n g the i r asfiirations or expectations becomes available. The modern indus t r ia l sect04 , however, tends t o be equipment intensive and creates few jobs. Furthermore, mecha- nization of taadi t ional c ra f t s displaces workers i n those f i e l d s . Hence, i n most of the l e s s developed countries there w i l l be i n the next decades a growing surplus of labor, a modern sector incapable of using it, and a t rad i t ional sector with diminishing poss ib i l i t ies to use it.

Table V-13: Estimates of Growth of the Labour Force i n Less Developed Countries

(Lines (1) i n millions; Lines (2) Decennial Rate of Increase i n percentage)

Ha jor Meas 1950 1960 1970 1980

East Asiaa 1. 339.3 378.5 436.0 508.6 2. - 11.6 15.2 10.7

South Asia 1. 302.0 349.1 419.8 520.1 2. - 15.6 20.3 23.9

b India 1. - 162.2 203 O h 263.2

2. - - 25.L 29 -4 C

Europe 1. 270.8 302.1 327.2 356.9 2. - 11.6 8.3 9 -1

Africa 1. 2.

North 1. .America 2.

Latin 1. America 2.

a. Including Japan.

b. The figures for India are for 1961, 1971, and 1981, respectiveiy.

c. Including the USSR.

d. Bcludes Polynesia and Micronesia.

Sources : India.? IS. N. Eaj , uProspects for Ehployment Opportunities i n the 19701 s, University of Cambridge Studies Committee Conferenbe, 1970 (mimeo) .

A l l other countries: Ypsilantis as quoted by 'Runham, op(. ci t .

37 Conclusio~vr: Given the lack of r e l i ab le data both on specif ic road construction expenditures and on employment i n road constru~ction, conclusions on employment potential off Ged- by manualisation of techniques must necessarily be h i g u y tentative. The above analyses would seem to indicate that:

( i ) the adoption of technically practicable I

labour intensive methods of road construction wi l l s ignif icant ly increase employment i n this sector. I

( i i ) However, the increase i n employment possible by ( manualization of road construction techniques ~ w i l l not s ignif icant ly lower unemployment i n ~ countries with a high surplus of unskilled 1abor.1

( i i i ) Employment provided i n road construction is I ~

bet ter suited t o a l lev ia te ru ra l underemployment ( than urban unemployment. I

I

( iv) Ins t i tu t ional and organizational factors influen e productivity of unskilled labor i n road construc ion significantly.

4 ~ I I

(v) The data currently available do not permit the , comparative evaluation of the employment potenti41 i n road construction and i n other industries. I

Chapter VI

Recommendations for hLzlther Work

1. The aim of the Phase I1 f i e l d studies i s primarily t o col lect r e l i ab le productivity data which can be used t o prepare production functions for the basic construction ac t iv i t i e s . I t i s recommended tha t research be carried out i n the following f ields:

(1) the productivity of labour and equipment and thi effec t on productivity of emir onment;

( 2 ) the costs of employing labour; ,

( 3 ) the costs of owning and operating equipment;

(4) mobilisation, supervision and other fixed costs ' incurred i n road construction and their relat ioh t o labour-intensive and equipment-intensive techniques;

(5) the development of a model t o simulate the highhay construction process which w i l l be capable of analysing the relevant data. (%is work w i l l be done by IBRD s t a f f . )

2. In view of the widespread effects of eneronment on productivity and the differences i n costs and practices between countries, and t o obtain maximum benefit from the Stage I1 studies, it i s recomended tha t the research should be res t r ic ted t o one or two countries. I n formulating proposals for the collection of productivity data, it i s f e l t t h a t it would be wise t o concentrate on those countries where the nee4 for , and acceptabili ty of, the concept of labour substitution i s greatdst. Another major consider ation i s the opportunity t o observe ongoing labdur intensive operations, which are not present i n many countries. It i s tQerefore proposed t h a t a consider able proportion of the data collec t ioe e f fo r t should take place i n India. It is a large country with a wide rang9 of environmental conditions and there should be l i t t l e d i f f i cu l ty inadequately covering the labour -intensive range of construction a c t i v i t i q . To widen the scope of the study, f i e l d work i n Indonesia i s also sugge$ted, mainly i n the island of Java. The Bank's involvement i n t h i s country should f a c i l i t a t e the collection of data, though it seems tha t it may be some time before major construction projects are undertaken. It i$ recommended tha t the active support of the government of India and Indonebia be sought t o f a c i l i t a t e the operation of the s taf f engaged i n data collection.

3 It i s recommended tha t the following methods of dath collection should be used:

(1) d i rec t observation on current projects (not necessarily restr icted to road construction work) supplemented by an analysis of project records;

(2) interviews with PWD and other supervisory s t a f f , including those engaged on maintenance;

( 3 ) interviews with contractors and other organisations concerned with road construction (e.g., materials suppliers, equipment suppliers, army schools of engineering, road research laboratories, loca l consulting engineers, etc. );

Further thought should be given t o the poss ib i l i ty of collecting additional data by a postal questionnaire system, supplemented by visits frbm the f i e l d s t a f f . I n order t o carry out f u l l y the observations needed we recommend tha t the engineer i n charge be aided by a loca l engineer and three assistants.

4. The loca l engineer w i l l be i n charge of relat ions w i t h the contractors and the administration, (i .e. he w i l l f ind the so r t of prof ects l ike ly to present an in te res t for the study and the people whom Y t would be interest ing t o interview and carry out project record studies, ehpecially i n the case where a knowledge of the local. language was needed), and he w i l l supervise and part ic ipate i n the s i t e observations. The assistaDts (as well a s the engineers) w i l l observe the progression of the construction work t o record the work ra t e s and t o l i s t the methods used, ( i .e . number of labourers, tools, mechanical plant, e tc . ) and t o describe the clbmatic and environmental conditions.

5 . To carry out correctly the studies described above, the study team w i l l have to s tay for a f a i r l y long time on each s i t e . We do nqt think t h a t it w i l l be possible t o analyze more than three s i t e s per month i n this deta i l . To broaden the data, t h i s in-depth analysis w i l l be followed by brief observations on a large number of s i t e s . This analysis w i l l be done af te r the in-depth studies and w i l l be concentrated on certain ac t iv i t i e s which have been judged t o be especial lyinportant . Certainlyamajod ef for t w i l l be made t o determine productivity r a t e s and labour/equipmedt costs i n earthmoving operations . I

6. To assess the qual i ty of the work carried out by the $arious teams, laboratory t e s t s must be carried out. I f the administdation res- pnnsiblb. for execution of the profect has allowed for qual i ty verif icat ion testing, the ro le of the s t~ idy team w i l l be l imited to assuring tha t the t e s t s are correctly carried out and t o analyzing the resul ts . However, i f the administration has not allowed for t h i s testing, the study team must do it. Problems could ar i se i n this case between the contl'actor and the study team. It woula therefore be better i f these observatjjons were done on a s i t e where the administration already has close quality control of the work. If it does not prove possible to f ind a controlled s i t e , a control must be organized and executed by the administration, with the aid of the study team.

m e main t e s t s t o be done are:

- I n s i t u water content - Proctor t e s t - I n s i t u dry density - Identif icat ion t e s t s (sieve analysis, Atterberg t e s t s ) - Aggregate gr ading . Considering that the study team will not s tay a verylong time

on any one construction s i t e , and tha t the administration may not have the necessary test ing equipment on the s i t e , we recommend tha t l the engineer bring w i t h him a densitometer (membrane type) and e q ~ p n e n t for water content measurement. This equipment could be l e f t th the loca l administration when the team leaves. 7

Suggested Procedures I 7- We would suggest that the implementation of the abo+ recommendations be carried out i n four phases, v i z . : i

Phase I : A short pre-planning period for consuldations with the Bank and the f ina l i sa t ion of data collection procedures.

Phase I1 : A planning period i n India and Indones'a t o consult with the appropriate Governmen off ic ia ls , to devise programmes and it' neraries, and t o s e t up the f i e l d teams. t

Phase I11 : Data collection i n India and Indonesia i and the processing of the data. I

Phase I V : Analysis of the data and the writing o$ the report. I I

8. f ie main work t o be undertaken i n Phase I would be the form and extent t o which data i s t o be collected and reco would be necessary t o ensure that:

(1) data are adequate and t i n e i s not wasted i n rebording and processing unwanted information; 1

(2) a l l members of the f i e l d s taf f follow identicail procedures , par titularly uher e qualitative asslessments are involved. I

Close consultat ion w i l l be necessary with those responsible f o r the development of the computerised model before the f i rs t aspect can be f ina l i sed . The second aspect w i l l e n t a i l thorough br ie f ing of (and subsequent c lose l i a i s o n with and between) the f i e l d teams.

9 Some advance thought has been given t o the use of standard data co l lec t ion forms for the recording of environmental and produc t iv i ty data. The former would need t o record not only t he physical f ac to r s which can be quantif ied (e. g., temperature, r a i n f a l l ) but axso data p ~ t a i n i n g to.moet ( i f not a l l ) of the f ac to r s l i s t e d i n Chapter 111. Many of these fac tors (such a s nu t r i t i ona l standards, soc i a l a t t i t udes , e tc . ) would have t o be assessed qua l i t a t i ve ly i n the f i e l d by reference t o a r a t i ng system which would need t o be care fu l ly defined.

10. For the recording of productivity data, a d i f f e r en t data -col lect ion form would probably be needed for each of the a c t i v i t y groups. The l i s t of basic construction a c t i v i t i e s would be elaborated and fur ther disaggregated i n the l i g h t of the experience gadned during the analyses of the hypothetical road projects . The l a t t e r suggested the following s ix- f i e ld categorisat ion of a c t i v i t i e s :

(1 ) a c t i v i t y group; ( 2 ) sub-activity;

The above correspond t o the l i s t of basic construction a c t i v i t i e s .

( 3 ) the loca t ion of the a c t i v i t y wi thin . the work where this might have some e f f e c t on productivity (e.g., rock excavation i n earthworks and i n quarr ies) ;

(4) the type and s i ze of equipment used i n the ac t iv i ty ; ( 5 ) the type and s i z e of equipment assoceated with the

ac tiri t y (e . g . , the haulage vehicle) ; (6) the l eve l of qual i ty .

11. The standard forms would be devised t o cover a l l possible circumstances and a c t i v i t i e s (and groups of i n t e r dependent ac t iV i t i e s ) and to permit the d i r e c t coding of the recorded data. A period of about one month would be required for t h i s pre-planning phase.

12. Time and the lack of recent deta i led knowledge of the two countries has not permitted the preparation of de ta i led programmes and i t i n e r a r i e s for the fieldwork. It i s therefore proposed t h a t a senior engiaeer .Fully conversant with the study should v i s i t India/Indonesia accompanied by Bank o f f i c i a l s and the leaders of the f i e l d teams. They would consult j o in t l y with the appropriate government o f f i c i a l s whose advice and ass is tance would be sought before arrangements for the f i e l d work could be f ina l i sed . A period of about three weeks would be needed t o complete these arrangements and t o es tab l i sh the teams i n the f i e l d .

13.. I n Phase.II1 there would be one f i e l d team i n India and anoth* i n Indonesia. '.Each team would consist of a f a i r l y senior experienced agi~lsrr accompanied by a loca l ly recruited junior assis tant engineer, 'togethe? with counterpart personnel. To minimise costs, it i s suggested %hat the teams should t r a k l between main centres by a i r (or other public trqwpo~t),

.rel@ng. on the govqilment for o f f i c i a l transport locally. F c h %rave& w o d d be involved since i t i s envisaged tha t the majority of. projects (part icular ly the labour-intensive ones) would be small and it should be . possible to cover such projects i n some 2-3 days. Longer stays, possibXy Up 2-3 weeks, would be required for large projects, part icular ly since these would offer greater poss ib i l i t ies for research in to a l l aspects of %he s kudy ,

' l-4. The f i e l d teams would submit detailed reports on their prog;rsss a t regular intervals , together with completed data sheets. The l e f W . - would be coded, transferred t o punched cards, edited and processed $10- a form sui table for subsequent use. The data would be analysed from tb time so tha t guidance could be given to the f i e l d s t a f f on the eees j.n which they should concentrate their e f for ts and to correct any inadequacies i n collecting procedures, etc.

15 Concurrently with the fieldwork, it i s suggested that there WO&! be scope for extending the searches of recorded data, part icular ly those pertaining to India and Indonesia. Any such data would be recorded i n a formal&identical to tha t collected by the f i e l d teams.

16, Phase 111 of the study would probably extend over a period sot exceeding s i x months. It i s emphasized that during th is time i& wuZd

, no t be possible to cover the f u l l range of constructian actiwkk&.es i k l r a l l environments but a reasonably representative sample of the m s t significant ac t iv i t i e s should be achieved provided that the active s of the appropriate government departments i s obtained.

1 7 The analysis of the data and the writing of the ~epor&, would take about two months. Allowing for consideration of &a$% and including a reasonable margin for contingencies, the the require4 for the whole of the Stage I1 studies should not exceed 12 mn%bs. W repor t would include ?roposals for any subsequent studies wM& m&i3;13t B t o be necessary.

Bibliography

BIBLIOGRAPHY - ENGINEERING

1 - 'I Methodes manuelles e t methodes mecanisees pour l a construction e t I1en t re t i en des routes. (a report of the Low Cost Road Committee to the Mad Congress of Tokyo, 1967).

A general statement about the problem of substitution of labour for equipment which contains many interesting ideas but does not give any quantification.

2 - " Men who Move Mountains. an ILO report - 1963

An in depth study of manual earthworks. This report gives large quantit ies of productivity data and a very interest ing comparison between s e v e r d ways of hauling, (wheelbarrow, tipping trucks pushed by hand, head basket).

3 - It Price analysis of earthworks and structures on the Boitiers crossing of Tours -Bordeaux railway.

A n analysis made i n 1850, which gives many productiVity data related1 t o labour intensive earthworks, masonry and wooden framework. These productivity data have not been d i rec t ly used In our report, because the training, the t radi t ion and incentives of French labourers of the middle of the 19th century l ed , i n our opinzion, to higher output than those which can be obtained from unemployed people used as labourers in the second half of the 20th century.

4 - " Madagascar 1930."

A n estimating handbook prepared by the French administration in Madsgascar in 1930. The rates of output used fo r these estimates are lower than those used i n the price analysis of 1850 (source 3) but they seem to be more acceptable f o r work undertaken by unemployed men.

5 - Bigolet R.A.L.L. Sur l e chantier 1970 .If

An estimatimg handbook for small operations. This document has been used inz order t o complete the data of source 4 and to verify t h e i r coherence.

. 6 - Handbook f o r Ar t i l le ry Officers.

7 - Handbook fo r Infantry Officers.

These documents give productivity data about earthworks completed by un-trained labourers. The ra tes of output given by these sources and by Madagascar 1930 (source 5) are s imilar , but Madagascar 1930 gives much more de ta i l . Sources 6 and 7 therefore have only been used f o r verification.

8 - Galabru IfEquipement general des chantiers de terrassements.

This document gives data both f o r manual earthworks and f o r mechanized earthqoving operation, For manual operations, the variations of output with the quality of the s o i l and the height of l o a a g are clear ly shown. For mechanized work, elementary data a re given f o r the calculation of outputs. !This source has been used direct ly, and also fo r verifying, interpolating and dissaggregating data from other sources.

9 - Breakdown of prices of the following projects:

- Bangui MIBaiki road in the Central African Republic (1969) - Construction of roads i n Fbanda (1965) - Feeder roads i n Cameroon (Cocoa plantation)

These breakdowns have been prepared by contractors in order to just i fy t h e i r price l is t . They lead to a disaggregation somewhat different from that of t h i s report.Therefore the data from these sources have been interpreted and corrected before use.

10 - '!Management of mechanized highway maintenance by the Bureau of Public Roadsf1 (washington D.c.) .

11 - If La route en t e r re - Structure e t entretienn by Gerard Mellier

These two documents mainly r e l a t e to maintenance problems. However, they give interest ing information about the estimation of depreciation costs , operating costs and maintenance costs of equipment.

1 2 - If Cours de terrassernents par un groupe d t ingenieurs ( ~ y r o l l e s )

This source gives much information about the methods used fo r calculating the output of earthwork equipment and some productivity data about manual earthworks.

13 - l8 Cours d'engins mecaniques de l lEcole dfApplication du Genie f i l i t a i r e e f l

14 - l1 Earth moving guide to p r o f i t by Caterpillar Tractor Co.

These documents have been used as sources of productivity data fo r the equipment-intensive alternative. Document 14 gives very sophisticated tables f o r the calculation of output. But a l l t h i s inf onnation must be corrected f o r developing countries. On many s i t e s , a contractor said, the actual output is only a th i rd o r a quarter of tha t calculated from the earthmoving guide, In our calculations we have followed the output given by contractors, and only used these documents for interpolation o r extrapol.ation.

15 - "Bareme pour l a determination des charges d t m p l o i pour l e s principaw. materiels de Genie Civil," (~edera t ion Nationale des Travaux publics)

This document gives the depreciation cost and the maintenance cost of c i v i l engineering machines. It has been used f o r the estimation of the hourly costs in the equipment intensive alternative.

16 - I ts t r ic t ly Handmaden by Fu Hua Chin Engineering New Record 29 Dec. 1938 - page 817.

This document gives interest ing information about a cement-processed earthmad made manually i n China. It describes carefully the work and the time schedule and shows the poss ib i l i ty of carrying out by labour such ac t iv i t i e s as mixing, watering, and compacting natural s o i l s and cement processed so i l s .

17 - "A general appraisal of the s u i t a b i l i t y of rnanual/mechanical methods fo r various highway construction operations f o r adoption i n developing countries," S.R.Mehra - A communication t o the Low Cost Road Committee of the Permanent International Association of the Road Congresses ( ~ a c o n 1966).

This document gives the opinion of a very experienced engineer about the technical and economical poss ib i l i t i e s of substitution s f labour for equipment i n road construction. It provides interest ing ideas about semi-mechanized operations ( i .e. ,operations done manually w i t h the help of l igh t machinery), and indicates what i s , i n the opinion of the author, the desirable method to be adopted in developing countries f o r the principal ac t iv i t i e s in mad construction.

18 - It Construction and Maintenance Equipment, " (~ igkxay Research Board 1968) . A compilation of data on time u t i l iza t ion , -performance and costs. This report gives much basic data, very useful f o r the calculation 0 f outputs.

19 - "Economic Choice of Human and Physical Factors in Pro&etion,fl by Gerard Karel Boon of Stanford University) ( ~ o r t h Holland Publishing Company - Amsterdam).

This document analyses the poss ib i l i t fes of subst i tut ing labour fo r equipment, in the case of trench digging. The methodology i s carefully described.

20 - '(Etude de chaussees economiques en Afrique." Communaute Economique Europeenne - Serie developpement de llOutre-Mer no.5 ( ~ r u x e l l e s 1967).

21 - "Rapport sur une mission en Afrique Noiregl by P e l t i e r and Bonnenf ant, (B,C .E.O .Mu, 1952) .

22 - I1Ibads in Developing Countries - Design, Construction, Maintenance, l4 Odier, Millard, Dos Santos, Pimental Mehra: compiled under the direction of UNESCO, 1968.

These documents give much technical information on road construction i n developing countries - (methods of construction, environmental factors,etc.) .

- 154 - BIBLIOGRAPHY - ENGIrnERING

Scott Wilson Kirkpatrick & Partners

Serial No. Reference sub ject(1) ~sefulness(2)

1. ECAFE Report: "Manual Labour & its P, also 1 More Effective Use in Competition unit rates with Machines for Earthwork in the ECAFE Regiontt - Report of the Working Party on Earthmoving Operations, E. C.A.F.E. (UNO). Early 1960's.

ILO Report: "Men Who Move Mountains" P published by I.L.O. Management & Productivity Mission to India, 1963.

U.S. Dept. of the Army:

(1 ) Technical Manual TM5-250 "Roads P & Airfields", published by U.S. Dept. of the Army, 1957.

(2) Technical Manual P

British Army (~oyal Ehgineers) , P

(1 ) Supplementary Pocket Books No's. 5A ttRoadsn, 1960, 5B "Airfieldsn 1960, 5C "Earthmoving Planttt, 1951 , 5E "Quarries & Gravel Pits", 1959, also Royal Ek-gineersl Reconnaissance Pocket Book, 1944. -

(2) "Military EwineeringttVol .V P Part I "Roads & Airfieldsv, 1957 Vol. XVI "Engineer Construction Equipmentti, 1962, published by British War Office.

(3) Pamphlets from Civil mineering P School, Chatham.

Ghana Feeder Roads Programme: "Memoran- P durn on Rate of Progress of Works when Hand-loading Graveltt&. Adedevoh , Kofuridua, Ghana.

"6 Motorway, Lancaster By-Pass to P Penrith By-Pass: Re~ort on Ground Investigation, Trial Embankmenttt, published by Dept. of the Ehvironment, London.

Notes: (1 ) P = Productivity Data. ( 2 ) Vsefulness: 1 : Used for Hypothetical Road Project.

2: Consulted elsewhere during stii6.y. j: Not consulted but may be usef~l. 4: Consulted but not useful. 5: Not consulted, probably not useful.

Serial No. Reference Subject Usefulness

Company pamphlets :

(1 ) Euclid Corp. P 1 (2) Caterpillar Co. P 1 ( 3) A-B Vibroverken, Solna 1 , . Sweden . P 2

account of methods

(4) Libu Co. P 2

ILO Management Development Series P No.8 - Report of Technical Meeting - on Productive Ehployment in Con- struction in Asia, Bangkok, 1968.

llEconomic Choice of Human & Physical P Factors in Production", G.K. Boon, Stanford University, published by North Holland Publishing Co. ,\ Amsterdam, 1964.

"Report on the Recent River Valley P 2 Project in China", K. Sain & K.L.Ra.0 methods of 1955. Library of Central Water & organi sing Power Commission, Delhi, (not manual lab- available for lending or copying). our for

earthwork project

Field study on substitution of P equipment for labour on concrete finishing - Dr. M.L. Puri & N.R. Srinivasan, Central Road Research Institute, New Delhi. Journal of the Institution of Ehgineers (India) Sept. 1963.

"Soil Compaction by Vibroflotation", P 2 Vibroflotation Co. , 930 Fort account of Duquesne Boulevard, Pittsburgh 22. method

Project & Proposal for ~orks/~ancs P 2 M.62 Motorway, Chief Ehgineer, West Riding County Council, 1966.

M6 Motorway, Killington-Tebay - Operator 1 Contractor's estimating sheet. hourly

costs

Schedules of Dayworks Carried Out Daywork 1 Incidental to Contract Work, rates for The Federation of Civil Engineer- equipment ing Contractors ( ~ r i tain) , June 1968.


Building & Public Works Administra- P 1 tion, Estimating & Costiq, Spence Geddes 1948 - Newnes, London. "Strictly Handmade", Fu-Hua Chen, P Engineering News-Record 29-Dec- 38,

I1Field Studies on the Pulverisation Construction 3 of Black Cotton Soil for the Con- methods, pos- struction of Stabilized Road Bases" sibly produc- H.L. Uppal, L.R. Chadda, tivity data. P.K. Dhawan, Journal of the High- way Research Board, Jan. 1970.

Comparisons of methods,

for Various Highway Construction possibly Operations for Adoption in Devel- productivity oping Countries", S.R. Mehra, data presented at the Low Cost Roads Committee of the Permanent Inter- national Association of the Road Congresses, Macon, 23rd/24th May, 1966.

Report of the Rates & Costs Corn- P mittee, Ministry of Irrigation & Power, Government of India, 1956.

Trends in the Desipp & Construction P of Dams & Power houses, Kanwar Sain, 1962, Atma Ram & Sons, Kashmere Gate, Delhi 6.

"Capital-Labor Substitution in Man- Production 2 ufacturing in Underdeveloped functions in Co~ntries'~, Clague, Econometrica m u f a c turing ( N e w n ) July 1969,

lThe Factor Proportion Problem in Production Underdeveloped Areas", R.S. Function Eckhaus, American Economic Review, Sept. 1955.

"Cost Functions & Optimum Tech- Costmodel for 2 nology for Inter-City Highway complete trans- Systems in Developing C o ~ t r i e s ~ ~ , port system, A. Lago, Traffic Quarterly, Costa Rica October 1968.


25 NTechnological Transfer, Labour Rates of factor 2 Absorbtion & Economic Develop- substitution & mentu Howard, Dack & M.Jodaro, discussion of - 9

Oxford Economic Papers ondo don) various tech- Nov. 1969, POP- 395-403 nologies

26. "The Dual Nature of Industrial Co-existence of 2 Development in Japanbf, United labour & capital Nations, Industrialisation & intensive methods Productivity (~ew ~ork) 1 964 in same economy

27 Earthmoving by Manual Labour & P (more or less 2 Machines, ECAFE (uN). 1961 duplicates Ref.

No. 1 above)

28. Construction & Maintenance P, possibly unit 3 Equipment: A Cornpilation of Data rates on Time Utilization, Performance & Costs, 1949-1965, Highway Research Board Special Report 68. Highway Employment ~rends- and Requirements, ,EBB Bulletin 296

29 A Cost Comparison Study of Force Proportion of Account &Contract Construction labour by con-

struction activity, North Carolira, F .B .Farm11 & USA M.J.Kilpatrick, H E 3 Proceedings 35th Annual Neeting 1956

30 Etude de Chaussees Economiques Economic road 3 en afrique, Comwnaute studies in africa Economique Europeenne Serie Developpement de lf0utre-Her, No. 5, Brussels, 1967

Technical Meeting on Productivi-& P, scope for & Employment in Public Works in employing labour African Countries, Lagos 19-21 Dec. 1963. ILO: Conclusions & Papers k g e m e n t Development Series No. 1, Geneva, 1944

32 Labour-Intensive Methods in Low- P, also study of 2 Cost Road Corstruction - A Case of methods Study, J-Mueller, International Labour Review, Vol .lOl, No. 41 , April 1970


33 Roads in Developing Countries - Manual of con- 2 Desiga, Construction, Mainten- atruction methods, ance , Odier, Millard, Dos Santos, discussing Pimental Mehra: Compiled under environmental the direction of UNESCO, 1968 factors

Transport Technology for Model for con- 2 Developing Iiegions, A Study in struction & main- Road Transportation in Venezuela, tenance costs. E.M. Sobeman, MIT Press, Ehvironmental Cambridge, Mass. , 1966 factors

Economic Analysis of Highway Production func- 2 Design in Developing Countries, tion, opthisation R.M.Soberman, Highway Research of technology Record, No. 115

Industrialization and Produc- Comparison of 2 tivity, UN, Bureau of Economic labour & capital Affairs, "Capital Intensity in intensive methods Heavy mineering Construction" Bulletin No. 1, April 1958

"Capital Intensity & Costs in P, unit rates Earthmoving Operat ions", Industrialization & Productivity, UN Department of Economic & Social Affairs, Bulletirm No. 3, March 1960

Construction Productivity & P Employment in Developing Countries, W.P.Strasswann, International Labour Review, Vol . 101 , May 1970, P.P. 503-518

"Measuring Labour Produc tivitxl' , ILO, 1969, Studies & Reports, New Series N75

Estimating for Buildings and Public P Works, B. Price Davies, The Building Estimator Publications, Western Mail Office, Capcliff, 1932.

Sponls Architects' and Builders' Unit rates 4 Price Book, E.& F.N. Spon Ltd., London, 1 963.

Laxton's Building Price Book, Unit rates 4 Kelly's Directosiea Limited, Kingston upon Thames, Surrey, 1 969/70


Molesworth's Handbook of Engineering Formulae and Data, (sor ~lastmng) E .& F .N. Spon Ltd., London, 1 950.

44 Schedule of Rates of Hire, Hire rates for 1 'The ContractorsQ Plant Associ- equipment ation, London, 1 971 .

45 Shiftwork and Employment Production functions 3 Expansion, M. Kabaj, in ILR Vol . 91 , No. I , London, 1 971 .

46 Technological Change and Production functions 3 Economic Development, W.P. Strassman, Cornell University Press, Ithaca, N.Y., 1968.

47 A Theoretical Note on Labour Production functions 3

Development Studies, July, 1969.

@. Cost Functions for Conrparison Production functions 3 of Low-Cost Transportation Technologies, L.L .Vance , Jr . , Institute of Transportation and Traffic Engineering - Dissertation Series, University of California, Berkeley, April 1967.

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Appendix A

CONTENTS

Appendix A. Details of the Engineering Analyses

Page - 1. Specification of Data Utilized i n the Analyses

a. Productivity Rates b. U n i t Costs for Equipment c. U n i t Costs for Labor

2. The Hypothetical Road Projects

a. Basic Specifications b. Variations t o Simulate Terrain c . Variations t o Simulate' Road (pavement ) Type d. Quantities of Work e. Selection of Equipment f , Analyses of Projects

3. Production Functions for Road Construction Activities as Estimated by SWKP

Bulk Excavation i n Roadworks Rock Excavation i n Roadworks Rock Excavation i n Quarry (for crushing) Gravel Sub-base Gravel Base Macadam Base (from crusher t o s i t e ) Crushed Rock Base Water Distribution Chippings for Surface Dressings (from crusher t o s i t e ) Bitumen Distribution

4. Analysis of Costs per Kilometre f o r Different Road Types and Different Terrains by SWKP

High Quality Equipment-Intensive Method High Quality Labour-Intensive Method Intermediate Quality Equipment-Intensive Method Intermediate Quality Labour-Intensive Method Comparison between High Quality Equipment-Intensive and Labour-Intensive Methods Comparison between Intermediate Quality Equipment-Intensive and Labour-Intensive Methods Comparison between Equipment-Intensive High Quality and Intermediate Quality Methods Comparison between Labour-Intensive High Quality and Intermediate Quality Methods Effect of Differing Rates f o r Labour and Equipment

Tables Giving Comparative Cost of Equipment, Optimal and Labour-Intensive Methods ~ . 6 4

1. Data Utilized i n the Analyses of the Scope for Substitution

a. Productivity Rates

BCECPI Sources . For each elementary act ivi ty, the quantification of equipment- time and labor time has been aerivea irom tne rollowing documents as referenced i n tne ~ioliography:

Equipment-Intensive Methods

( a ) Estimating nandbooks prepared oy public works departments and equipment manufacturers I manuals i n part icular "Caterpillartt (see however comments I n the blollography, item 14).

(b) Breakdown of prices for operations similar t o those of Lhe hypothetical road projects, whicn have been completed recently i n various African countries (see item y i n m e bioliograpny).

( c ) Information from Contractors G,T,E, ( IlGrands ~ravaux de l l ~ s t l l ) who have carried out numerous projects i n Madagascar.

(d) BCECM reports and data and personal experience.

Labor-Intensive Methods

(a) Breadown of prices for road worm completed I n the past by labor -intensive metnoas

(b) Intervlew with contractors who have carried out roadworks by labor -intensive methods

(c ) Personal experience

In many cases we have not found the accurate breakaown required by our study i n these documents, and so we have been obliged t o estimate the quant ikes by znterpolating tne available data. For example, having only a price brealc- down for a haullng alstance o i 200 metres,we have extrapolated tne oreakdowns for 100 metres and 400 metres w i h the help of estimating nandbooks for pubhc works and contractors data. I n many cases the source I n Appendix B i s shown as tfbCECTM1 s estirnatelf . For tnese ac t lv l t i e s general indications have been gathered from many d i f ferent sources. This information was then consiaerea d t h i n the general perspective of the environmen~a conditions pertaining for the main sources consulted by BCEM, 1.e. the study of tne Bangui M t Baike roaa for the equipment ~ n t e n s l v e metnoa and the estimating handbook prepared by the French aaministration i n Madagascar i n 1930 for the labour intensive me tnod .

SWKP Sources. The main sources of productivity data used i n the analyses were the following:

(a) Brit ish ana US Army Engineers1 handbooks. (b) The ILO Report, nMen Who Move Mountainsn . (c) Ihe ECAFE Report of the working Party on Earth-

moving merations.

These were supplemented by: - (d ) ItBuilding and Public Works A d m i n i s b ~ a k i ~ ,

p t ima t ing and Costingn, by Spence Qeddes. ( e ) Estimating for Building and Public Worksn by

B. Price-Davies (1932 Edition). ( f ) kzclid and Caterpillar estimating boottlets . (g) Molesworb engineering hanabook. (h) B e ILU Report oi' the T e c b c a l Meeting on

Proauctive Employment i n Construction i n Asia, Bangkok 1968.

Ihe various sources are f u l l y aocumented i n Appendix B and the bibliograply,

Wherever possible, several sources cfdata were used t o estimate productivity i o r a particular act ivi ty. For equipment-intensive oper atlons , Britisn Army ra tes were,,generally given the greatest weight. Figures from INen' Who Move Mounsams were accepted a s being most r e l i ab le for manual earthmoving operations. For other ac t iv i t i e s by hand, EPitish Army figures were given preference. Since the l a t t e r give lower output rates for earthmoving operations than the former, it may be tna t laoour productivity figures a re somewhat inconsistent as between the various ac t iv i t ies .

Where necessary, data was adjustea t o allow for a SO-minute ork king hour and an 8-hour working day, otherwise working conditions uePe assumed to oe good and no allowance was made for nola-ups. Haul roads and paths were assumed t o oe i n good conht ion and of a s ize adequate for e f f ic ient use or the vehicles. Where aa i ly outputs were given i n the sources, an 8-hour working day was

SUUed.

It has been assumed -that a l l equipment and labour woula be fu l ly occupied throughout the day and t ha t there woulu be no i d l e time or spare capacity. This is c lear ly an unreal is t ic assumption for wnich allowance must be made i n interpreting tne resul t s of the analyses. For instance, il; is very a l f f i c u l t to exactly match the number of haullng vehicles t o the output of a loading machine ana some i d i e time i s unavoidable i n practice.

Further assumptions made i n relation'%o equipment incluae the following:-

(1) Stsuck loads have been assumed where calculations of theoret ical output have been usea fo r scrapers , snovels , vehicles, etc., except i n the case of loading excavated rock where 73% of m e rated ioad nas Deen used for shovels and for wheelbarrows.

(2) r'or the analyses of cost per kilometre oP road, the ou-cput r a t e of the combined excavating/loading/hauling/ unloading/spreading operation performea by a motor scraper (push loaded by a ~8 dozer) was arbiWQily divided in to the individual ac t iv i t i e s based on the time cycle oi' the operation.

Assumptions made i n regard t o ac~iv i -c ies carried out by labour include:-

(1) Short hauls of the 0kder of 10m. such as from s trean to water bowser, or rock p i l e to vehicle, have been included as pa r t of the loading operation.

(2) Tfie height for loading vehicles by hand has been taken as l . 5 m . and gangs have been assumed to consist of 6 men for trucks, 3 men for 3m3 t r a i l e r s , 2 men for lm3 carts .

(3) The operation for stripping topsoil has been taken t,o include loading in to baskets, hauling 10m. and unloading.

(4) The spreading operation for chippings and bitumen has included loading and a sh.ort haul.

b. U n i t Costs for Equipment

!the SWXP and EEOM analyses used the same u n i t costs or prices for the same or similar pileces of equipment and labour a s described herebelow and i n section c.

The time available for the study d id not permit a detailed analysis of the cost of owning, operating and maintaining equipment. The sources immediately available were : -

(1) !the Schedule of Daywork Rates published by the Federation of (Elritish) C i v i l Engineering Contractors .

(2 ) !Che Schedule of Rates of a r e published by the (Rri t i s h ) Contractors Plant Association.

(3) French daywork ra t e s from Bseme pow l a determination des charges dlemploi pow l e s pr incipaw materiels de Genie C i v i l , publie par l a Federation Nationale des Travaux Publics.

(4) Baywork schedules incorporated i n current and recent contracts for road construction i n the United Kingdom and i n various overseas countries.

These basic ra tes a re not d i rec t ly comparable since some i.nclude such items as operators1 wages and fuel , whereas others do not. 'key have therefore been adjusted t o be inclusive of a l l running costs (operators' wages, fue1,maintenance etc. ) but to exclude supervision and mobilisation costs. It was not possible to exclude the p r o f i t element which the owner of the equipment would expect t o make. On the other hand, a contractor hir ing equipment (and i t s operator) a t these ra tes would also expect t o make his own p ro f i t i n operating it, and t h i s i s not ref lected i n the r a t e s (which also exclude any p ro f i t on operatorsr wages, f u e l and lubricants ) .

Two examples i n the variations i n ra tes which occur i n practice ase shown below. The r a t e s have been adjusted as described i n 1.21. --

Motor Scraper, llm3 Struck Capacity

1 French daywork US $33.08/hour 2 UK plant h i re 21.51 3 UK daywork 19.87 b Contract daywork r a t e i n Jordan

(1966 ) u. 20

D8 Crawler P a c t o r with Dozer Blade

1 French daywork US $33.33/hour 2 Airport contract i n Brunei

( current ) 26.88 3 UK plant h i r e 19.89 4 UK daywork 14.55

French dayuork ra t e s were adopted i n the analyses. These ra tes include depreciation, the cost of f u e l (except for trucks and bowsers), maintenance and consumable stores, and insurance and tax for vehicles using public roads. They do not include mobilization costs, superas ion of operation, or operating s t a f f . These rates , which are shown i n Table 81, are levied for the whole period of hire , i r respect ive of whether or not the equipment i s working. For earthmoving plant these appeared t o be high i n r e l a t ion to r a t e s i n other countries, but the differences for othm equipment were not so great.

To appreciate the l imitations i n their use, it is necessary t o understand the basis on which h i re r a t e s ase normally calculated. First the l i f e of the equipment i s estimated i n terms of working hours, which vary with the nature of the work and the conditions under which it is carried out. It could range from some 8,000-10,000 hours for a bulldozer t o many times this figure for s t a t i c stone crushing plant. The anticipated annual hir ing period i s estimated and the corresponding l i f e of the equipment is calculated i n years. !The cost of the equipment, i n terms of original or estimated replacement cost, is written off over t h i s period, usually on a s t raight- l ine basis w i t h no allowance for residual value a t the end of the period. To this depreciation charge i s added such annual costs as insurance, financing charges, overheads, p r o f i t etc.

Table A.1: Equipment Costs and Fuel Consumtion Der hour, French dawork r a t e s

Hourly r a t e Equipment Hourly Hourly consumption including fue l

US$ Gas-oil O i l and o i l (a > ( l i t r e s ) ( l i tr es ) US$

Bulldozer, 270 hp (D.8.4) 25.98 D8 I1 + Ripper 28.88 Bulldozer, 185 hp (D7+) 19.12 D7 E B u l l + Ripper 21.02 Spreader box fo r bulldozer

3 1.52(b) Motorscraper 621, 11 or 15.3m 25.43 Motorgrader MG 12, 120 hp 6.06 Motorgr ader , MG l-4 9.18 Shovel "Traxcavatorlf, 1 m3 or 1000

l i t r e s 10.18 Motor t ractor , 75 hp 1.26 Compressor, 120 hp 2.68 Compressor, 80 hp 2.02 compressor, 60 hp 1.48 Pneumatic pick or d r i l l 0.10 Wagon dril l . 0.91 ruck, 6 m3 capacity 3.86 Water bowser, 10,000 li res 3 3.40 Water pump, 10 hp, 60 m /hr 0 - 4 Bitumen spreader or boiler, 600 l i t r e s 0.48 Bitumen spreader, 10,000 l i t r e s 5.42 Bitumen heater, 5000 li tr es 4.lO(d) Mechanical broom, towed 0.18 Fa-sing maelfine 18.00 (e) Chipping spreader 0.42

19 0.25 12-45 19 0.25 3 .53 23 0.30 5 .43 15 0.25 3.89 11.5 0.20 2.93

- - 0.10 - 0.91

0:6&4~ tres/km 0.04 litres/km 3.86 + 0.12/km 0.60 tres/km 0.04 litres/km 3.40 + 0.12/km 2 - 0.34

included included 0.48 80 0.5 4 . 1 7

included included 4.10 - - 0.18 included f ncluded 18.00 - - 0.42

Table A . l continued -

Pneumatic t i r e d self-propelled ro l l e r or compactor, 20 t 4-45 21

Pneumatic t i r e d r o l l e r or compactor, towed 10 t 0.43 -

S teel-wheeled road r o l l e r , 14/18 t . 2.24 8 Tandem steel-wheeled road r o l l e r ,

8/10 t Vibrating t r a i l e r r o l l e r , 5 t Hand-vibr a to r , 5 hp Stone crushing p lan t 500 m3/day No. 1 Stone crushing plant 500 m3/day No. 2 Granulator, 30 m3/day 3 m3 capacity c a r t or t r a i l e r 1 m3 capacity c a r t Driver and animals

Notes t o Table A. l :

a ) Net of overhead expenses and i d l e t i m e but including depreciation, running and maintenance costs other than labor and fue l .

b ) Assuming cost of spreader box i s 5% of t o t a l hourly cost of 270 HP bulldozer including f u e l and o i l .

c ) 0.70 l i t r e s per km. i n h i l l y t e r r a in . d) UK daywork r a t e . e ) There is no f igure for a paver i n t he BCEQ4 report , so SWKP assumed r a t e

for paver twice t he UK daywark r a t e to m a k e cempatible with BCEQM f igures for other heavy equipment.

f ) Assuming gas o i l = $0.10 per l i t r e , and o i l = $1.50 per l i t r e .

Source: Bareme de l a Federation Nationale des Travaux Publics, except a s otherwise noted.

The annual costs a re converted i n t o hourly costs on the basis of expected u t i l i s a t i o n and t o these are added the hourly operating costs of maintenance, fuel , operators1 wages etc. t o arr ive a t the h i r e rate . I n pract ice the calculations are complicated by the need $0 take in to account taxation regulations, investment allowances, plant obsolescence, and the Uke.

B e unit r a t e s for equipment are very dependent on the u t i l i s a t i o n rate . With the u t i l i s a t ion normally achievable i n road construction, the fixed annual charges are much greater than the hourly operating and maintenance costs, and overall costs can be reduced substant ial ly by increasing u t i l i sa t ion . Thus, equipment charges can be expected to vary substantially' from country t o country and w i l l be dependent on the nature of work and the environment i n which it i s carried out. On the basis of a SO-week year and a 40-hour week, the maximum u t i l i s a t i o n of equipment i s 2,000 hours per year. I n the United Kingdom, motor scrapers on roadworks are seldom u t i l i s ed for hore than 800-1,000 hours per year. A t the other extreme, it i s not uncommon on large earthmoving projects such as open-cast mining t o achieve annual u t i l i s a t ion r a t e s with shift-working i n excess of 4,000 hours. I n the United Kingddm quite substantial discounts are offered for long-term h i re which, i n effect , increases the u t i l i s a t i o n r a t e from the equipment owners1 viewpoint.

Insofar as the analyses of the hypothetical road projects given below are concerned, the equipment h i r e r a t e s used contain an allowance for unavoidable under-util isation due t o such factors as climatic conditions (insofar as they are similar t o those prevailing i n France). On the other hand, shorter-term lack of u t i l i s a t i o n due, for example t o sequencing d i f f i cu l t i e s , break downs and poor organisation would not be covered. This problem i s treated further i n paras. 3.16-3.28 below, where a sens i t iv i ty analysis of the af fec t of varying u t i l i s a t ion ra t e s on the cost per hour of a road scraper and the corresponding breakeven wage r a t e for labor substitution i s given.

I n comparing labour- and equipment-intensive methodd of construction i n the developing countries, more precise data on the costs of owning and operating equipment wi l l be needed. While t h i s would probably be available i n respect of haulage vehicles, proper ra tes would also have t o be established for most other items of equipment.

c. U n i t Costs for Labour.

The following da i ly wage ra tes for an 8-hour working day were assumed i n the analyses of the hypothetical road projects:

US $/day US $/hour Unskilled (labour-orientated)

Gener a1 labour Animal ca r t w i t h driver

Skilled (equipment-orientated)

Equipment operator Duck driver Operators ass is tant

Certain a l te rna t ive analyses (c lear ly ident i f ied i n the t ex t ) were done a t wage r a t e s of US$0.20 per day for purposes of comparison.

m e sk i l led r a t e s were deemed t o apply t o a l l but the simplest of equipment. With cer tain machines doing cer ta in ac t iv i t i e s , both a sk i l led operato2 and a semi-skilled ass i s tan t were assumed (e,g, a dozer worldng on clearing operations).

I n the analyses by Scot t Wilson Kirkpatrick headmen (or gangers) have been t reated a s unskilled labour since they are essent ia l ly working members of the group (see Chapter I V 3.11, since i n the Bri t ish experience the premium paid t o headmen, perhaps 20% above t h a t of other labourers, would not const i tute a s ignif icant pa r t of the cost of unskilled labour. On the other hand, BCEC7M has adopted a r a t e for headmen some 250% greater than t h a t for unskilled labour whlch presumably r e f l ec t s a different t rad i t ion of organisation of unskilled labour.

No allowances have been made for associated payroll costs such as paid holidays, workman's compensation insurance, overtime and the l ike . These would a l l have t o be taken in to account i n pract ice as well as the costs of mobilisation, administration, supervision, provision and maintenance of hand tools, camps and associated f a c i l i t i e s and other similar expenses.

Certain of the foregoing items could be covered bymarking-up the wage rate , while others would be independent, within limits, of the labour employed and could be t reated as a fixed cost.

d. U n i t Costs for Materials.

The following unit r a t e s were assumed for materials delivered, unloaded and stacked a t the base camp:-

Bitumen US $70.00 per metric ton Gas O i l 0.10 per l i t r e Engine Oil 1.50 per l i t r e Explosives (including fues and detonators ) 2.00 per kg.

Distribution on the s i t e has been allowed for i n the case of bitumen as pa r t of the general construction ac t iv i t i e s . The cost of explosives includes an allowance for fuses and detonators.

No allowance have been made for storage f a c i l i t i e s f o r materials, nor for any other camp buildings and f a c i l i t i e s .

2. The Hypothetical Road Projects

Analyses were made of the principal quantities of work involved in one kilometre of a typical road 'construction project, varying the fo1Lowing:-

(i) Quality at high and intermediate levels (ii) Type of terrain, defined at three levels as

flat, rolling and hilly (iii ) Pavement construction, three types :-

A - Gravel sub-base, gravel base with two- coat surface dressing; B - Gravel sub-base, penetration macadam base with single coat surface dressing; C - Gravel sub-base, crushed rock base with two-coat surface dressing.

a, Basic Specification

The basic specification for the hypothetical road was:-

Width of surfacing (pavement) - 7.OOm.

Width of upper surface of base - 7.50m.

Width of shoulder - 1.25m.

Width of formation - 1O.OOm.

Side slopes of earthworks - 1:2

Thickness of subbase - 15cm.

Thickness of base - 15cm.

The following quantities of work applied in all cases for each kilometre of road:-

Clearing and grubbing in medium vegetation, including an allowance for borrow areas - 25,000m2

Stripping topsoil 10cm. thick - i5,000m2

Volume of sub-base

Volume of base

Average haul distance of subbase material - 1 km.

Volume of water required for compacting sub-bas e - 100,000 litres

'Average haul distance for all water - 2 km.

Variations t o Simulate Terrain

The quanti t ies of drainage excavation per kilometre were varied a s below:

Aver agb Volume - $ Rock Haul -

Fla t 5, om3 N i l 100m. Rolling 10,000 2 400 Hil ly 15,000 5 200

A l l excavation was assumed t o be so f t except:

(1) gravel for sub-bases and bases, taken a s hard material ( 2 ) rock

Twice as much explosive was assumed for rock excavation i n ditches a s i n bulk earthworks. For road type A (gravel base) where the dnly rock product required i s for chippings, the amount of explosives was increased 50 per cent above those assumed for rock excavation i n quarries for the other types of road.

The placing of material i n embankments, whether originating from cuttings or borrow p i t s , was assumed t o be a t the follo$ng r a t e s per kilometre:

F la t 5,000m3 Rolling 7,500 Hil ly 10,000

A l l rock excavated i n bulk earthworks was assumed t o be dumped and not incorporated i n embankments, and it was further assumed tha t no water would be required for compaction of earthworks.

The quanti t ies for topsoiling and grassing (15 cm. thick) per kilometre were assumed t o be:

F la t 4 ,000m' Rolling s,oOO Hilly 6,000

c. Variations to Simulate Road (pavement) m e

Average haulage distances for base material were assumed to be:-

Gravel 2 km. Macadam 5 Crushed rock 10

The quantities of water required per kilometre for compaction of the base material were assessed at:-

Gravel Macadam Crushed rock

70,000 litres 35,000 70,000

The rate of application of bitumen for the surface *easing was assumed to be 2.4 kg/m2 and for the penetration macadam, 2.2 kg/m2. In the former case, the bitumen would be applied in two equal coats. The average haul distance for bitumen wae, taken at 10 Ism., it being delivered to site in 160 litre drums.

Stcne sizes were assumed to be:-

Aggregate for macadam 40/70 Inm-

Crushed rock for base 0/30 Chippings for macadam dressing 1 5/25 Chippings for surface dressing 10/15

The rates of spread of chippings were:-

Macadam dressing 20 litre/m2 Surface dressing 12

The average haulage distance for the above stone products was taken to be 10 km, except for macadam base and dressing for which the distance is 5 km.

d. Quantities of Work

The quantities of work, in terms of bill items, were calculated on the basis of the above assumptions. No other items of work other than those specifically referred to were taken into account; in particular, culverting and bridgeworks were excluded.

In calculating the appropriate quantities, it was necessary to make further assumptions and these are listed below:

(1') Bulking factors for excavated soils w e e not taken into account and the quantities for loading., hauling, spreading and compacting are in terms of volume of undisturbed material.

(2) For gravel the volume excavated was taken to be equal to the volume of compacted material.

(3) For stone products, it was assumed that the volume remained constant from the point immediately following the excavation t h r o w the crushing activity to the final spreading and compacting activities. The expansion of rock during excavation was allowed for by calculating output figures by weight and then converting to volume by assuming a density for the loose material.

(4) No allowances were made for loss of material during crushing activities.

(5) The average haul distance between the quarry face and the crushing (or hand-breaking) point was assumed to be 200m.

3 (6) It 2 s assumed that 1m of grass roots would cover 200m and that the average haul distance would be 5 lan. The activities required for watering grass after planting were not taken into account.

(7) The topsoiling operation was assumed to consist of :-

Activity 4.1 Loading 12.3 Laying, tr- and compacting

and no allowance was made for hauling.

( 8 ) The heating of bitumen was included under the loading operation. This gave a large equipment content to the loading operation (and in future work it would probably be best to define this operation as a separate activity ) .

( 9 ) It was assumed that crushing plant would be so arranged as to permit gravity feeding from unit to unit and to the stockpile.

. - On the above assumptions, the bill items were broken down into the basic construction activities. The degree of disaggregation was greater than that shown in the list of basic construction activities. Firstly, to facilitate the checking of calculations, further sub-division of the basic activities was desirable and, secondly, it became necessary to allow for differing productivity rates within the same activity. Ekamples of the more important instances of the latter are given below:-

(1) Rock excavation i n a quarry i s markedly different from the smaller quanti t ies encountered i n bulk excavation.

(2 ) Labour productivity r a t e s for loading excavated materials in to baskets or wheelbarrows are much higher than for loading i n t o vehicles.

( 3 ) Hauling was further disaggregated by length of haul since haulage time (and hence cost) i s not d i rea t ly proportional t o the length of haul, par t icular ly with the shorter hauls.

( ) Differing types of base material were considered separately since the type of compaction plant and the e f fo r t required for compaction varies accorangly.

e. Selection of Eaui~ment

To simplify the analyses, a standard l i s t of equipment was Brawn up and the most suitable item for carrying out each ac t iv i ty was selected. It must be emphasized tha t the equipment assum& i s not necessarily the most e f f i c i en t for carrying out the partiaular operation and the analyses are l imited i n this respect. Wherever possible, the same equipment was assumed irrespect ive of the construct ion technique. Several types of haulage vehicle were considered i n the analyses.

The l i s t of equipment employed by SWKP i n the analyses and the ac t iv i t i e s carried out by each item are given below. The equipment employed by BCEOM was qui te similar, though not ident ical ; those items which do not precisely correspond with BCEOM items are marked with an aster isk.

(1) ~8 dozer - clearing and grubbing, s t r ipping topso i l , excavating gravel .

.rc (21 ~8 dozer wit'n spreader box - spreading sub-base and base materials for intermediate qual i ty (BCEOM used.Ml2 grader).

* (3 ) Ml2 grader - excavating ditches, finishing ear6h- works, sub-bases and bases. (BCEOM also used Ml4 grader. )

(4) l h 3 scraper (push loaded by ~8 dozer) - excavating s o f t materials i n bulk, hauling and spreading.

3 (5) 80 hp (8m /min) compressor with tools and explosives - for excavating rock.

3 1.h tracked shovel "Traxcavatortt - all loading activities except water and bitumen. (BCEOM used ltlrn3 shovel", not stating whether tracked or not.)

6(hn3/hr water pump - loading water. 3 6m truck - hauling all bulk solid materials a&

bitumen.

3 75hp tractor and 3m trailer - hauling all materials. 3 Bullocks and lm carts - hauling all materials bp to

5 lan for labour-intensive methods (categorised as lab our ) . 10,000 litre water bowser - hauling and spreadihg water.

60/75 hp paving machine - spreading sub-base anti base material for high quality. (BCEOM used M12 grader. )

5,000 litre static bitumen heating unit - for equipment -intensive method. (BCEOM omitted heater. )

600 litre mobile bitumen boiler - for labour- intensive method, intermediate quality.

10,000 litre bitumen distributor - hauling and spreading bitumen, both qualities equipment- intensive and high quality labour-.intensive methods.

Chipping spreader (attached to truck) - spreadipg chippings .

(1 7 ) 20 tonne pneumatic tyred roller, self -propelled 1 for compacting earthworks - both qualities equipment- intensive, high quality labour-intensive.

(18) 8-10 tonne pneumatic tyred roller, towed by 75 hp tractor - compacting gravel and surface dressin& intermediate quality.

(19) 14-18 tonne steel wheeled roller, self-propelled - compacting macadam and crushed rock base and hi@ quality surface dressing.

(20) 8-1 0 tonne steel wheeled roller, self -propelled - surface dressing (in addition to pneumatic-tyred roller) and topsoil.

3 (21) 500 m /day crushing plant - crushing rock for bases.

(22) 30m3/day crushing plant - crushing chippings for surface dressings.

(23) 75 hp t ractor sweeper - brooming and cleaning surfaces.

Hand r o l l e r s and rammers were assumed for compaction a t intermediate qual i t ies for labour -intensive operations and no equipment charges have been made for these and such items of hand tools as picks, shovels, watering cans, etc.

f . Analyses of Projects

. a The above ra t e s were used to determine the unit costs fdr carrying

out each ac t iv i ty a t both high and intermediate levels of quality. By comparing ra t e s for labour- and equipment-intensive techniques, the break-even wage ra tes were determined (as given i n Volume I, Chapter 11 .D ).

Production functions were prepared for the interdependent ac t iv i t i e s - those groups of a c t i v i t i e s comprising mainly excavalting, loading, hauling, unloading and spreading, where the method adopted for one ac t iv i ty r e s t r i c t s the choice of methods for other activikies. Based on these functions, the most e f f i c i en t haulage vehicle i n r e l a t ion to length of haul was selected for the subsequent analyses. These functions are given i n t'ne following section of this Appendix.

m e production functions for interdependent ac t iv i t i e s were then u t i l i s ed t o prepare functions for groups of similar operations, combining them and the individual independent a c t i v i t i e s together i n the quanti t ies required for the construction of one kilome t r e of the hypothetical road projects. The grouped operations, (which are given i n Volume I, Chapter 1I.E) are:

Earthworks a t intermediate qual i ty i n differ ing types of terrain. Sub-bases and bases a t intermediate quality. Surf ace dressings a t intermediate quality.

I n the l a s t ser ies of analyses (presented i n Volume I Chapter II.E), the work involved i n one kilometre of each of the hypothetical road projects was broken down i n t o basic construction ac t iv i t i e s and estimates of the costs of equipment and unskilled labour ( a t US $2.00 per day) were prepared for carrying out each ac t iv i ty by ei ther equipment- or labour -intensive technipes a t high and intermediate leve ls of quality. Costs were s m a r i s e d by ac t iv i ty group and on a kilometre basis. The construction methods assumed were those found t o be most e f f i c i en t during the preceding analyses.

The ef fec t of varying wage ra t e s was assessed by keeping equipment costs (including sk i l led labour) the same and reducing the cost of unskilled labour t o US $0.20 per day.

Costs were summarised by activity group and on a kilometre basis. The construction methods assumed were those found to be most efficient during the preceding analyses.

The effect of varying wage rates was assessed by keeping equipment costs (including skilled labour) the same and reducing the cost of unskilled labour to US $0.20 per day.

3. Production Functions for Road Construction Activities a s =timated by SWgP

The complete grouping of interdependent sequential a c t i v i t i e s in to production functions is:

a. Bulk Excavation i n Roadworks: excavating i n bulk i n so f t material, loading, hauling (various distances ) , unloading and spreading .

b. Rock Excavation i n Roadworks: excavating i n bulk i n rock, loading, hauling (various distances) and unloading.

c. Rock Excavation i n Quarry (for crushing): excavating i n bulk i n rock, loading, hauling and unloading.

d. Gravel Sub-base: excavating i n bulk i n hard material, loading, hauling, unloading and spreading ( a t two leve ls of quality).

d. Gravel Base: as above.

. Macadam Base (from crusher t o s i t e ) : loading, hauling, unloading and spreading ( a t two levels of quality).

g. Crushed Rock Base (from crusher to s i t e ) : loading, hauling, unloading and spreading.

h . Water Distribution: loading, hauling, unloading and spreading.

i. Chippings for Surface Dressings (from crusher t o s i t e ) : loading, hauling, unloading and spreading.

j. Bitumen Distribution: loading, hauling, unloading and spreading (including heating ) .

Production functions for the complete s e t of interdependent ac t iv i t ies , which were prepared only by SWKP, are given i n the following section.

(a) Bulk Excavation i n Roadworks

Table A.2 shows the various combinations of methods considered for carrying out each act ivi ty . fie l i s t does not cover all technically possible combinations and for simplicity it has been assumed tha t the excavating and loading operations would be carried out e i ther both by equipment or both by labour.

Table A.3 (upper portion) gives the corresponding equipment and labour inputs for these various methods of carrying out 1000 m3 of bulk earthworks i n f l a t t e r r a in where the average length of haul i s assumed t o be 100rn. Figure A.1 depicts these graphically.

The scraper operation, ident i f ied as point A, i s the most e f f ic ien t way of carrying out the operation wholly by equipment. Of the labour-intensive methods, point G i s the most e f f ic ien t , with haulage by wheelbarrow. However, the s t r a igh t l i n e A-G does not represent the production function for this operation since some of the other points l i e beneath this l ine . Point L, which represents excavating and loading by labour, hauling by t?actor/tr a i l e r and spreading by grader, i s an intermediate subst i tut ion possibdlity and it must l i e on the production function which follows the l i n e ALL-H-G. Hence, while the slope of the l i n e A-G gives the break-even wage r a t e ($1.70) for the whole operation, subst i tut ion along the slope A-L would be more advantageous with a break-even dai ly wage r a t e of $3.35, but along L-H-G the overall slope would drop t o $0.73. With an actual wage r a t e between t h b e two figures, substi tution would be advantageous only up t o point L.

Table A.3 (middle portion) and figure A.2 give a similar production function for earChworks i n h i l l y t e r r a in where the average length of haul is assumed t o be 200 m. I n this case Method J, hauling by bullbck car t , i s the most eff ic ient of the labour -intensive methods. Points L and IS, both u t i l i s ing tr actor/tr a i l e r units for hauling, are intermediate subs ti tut ion poss ib i l i t ies , and the production function follows the l i n e A-LFK-J. fie break-even da i ly wage r a t e f o r the overall operation i s $1.12 while the slopes of A-L and L-K-J are 3.80 and 0.49 respectively.

I n ro l l ing te r ra in the average length of haul has been taken as 400 m. and this condition i s presented i n Table A.3 (lower portion) and Figure A.3. Methods F, G and H (hauling by basket and wheelbarrow) have been excluded i n view of the length of haul. Again, the production function follows the l i n e A-L-K-J. The average subst i tut ion slope for tkie overall operation i s $0.92 per day while the slopes for A-L and I.,-K-J are 3.27 and 0.47 respectively.

These three examples demonstrate tha t the most e f f ic ien t equipment- intensive method for bulk earthworks i s by scraper but substitutYon for more than half of the equipment input is f inancial ly advantageous with wage r a t e s l e s s than about $3.25 per day by using t rac tor / t ra i le r d t s for hauling and carrying out the other ac t iv i t i e s by hand.

Table A.2. Construction Methods for Bulk Excavation i n Roadworks

Operation Construction Method for Activity Method Excavating Loading Hauling Unloading Spreading

A Scraper Scraper Scraper Scraper S C ~ aper

B D8 dozer Shovel i n t o muck Tipped from Grader truck truck

C D8 dozer Shovel i n to Truck Tipped from Labour truck truck

D D8 dozer Shovel i n t o Tractor and Tipped Prom Grader t r a i l e r t r a i l e r t r a i l e r

E D8 dozer Shovel i n t o Tractor and Tipped from Labour t r a i l e r t r a i l e r t r a i l e r

F Labour Labour i n t o Basket Tipped tram Labour basket basket

G Labour Labour i n t o Wheelbarrow Tipped from Labour wheelbarr ow wheelbarrow

H Labour Labour in to Wheelbarrow , Tipped from Grader wheelbarrow wheelbarrow

J Labour Labour in to Bullock c a r t Labour ~ Labour bullock c a r t

K Labour Labour i n t o Tractor and Tipped from Labour t r a i l e r t r a i l e r t r a i lq r

L Labour Labour i n t o Tractor and Tipped from Grader t r a i l e r t r a i l e r t r a i l e r

M Labour Labour i n t o Truck Tipped from Labour truck truck

N Labour Labour i n t o Truck truck

Epped from Grader truck

TABLE AJ DU'A PaR PRODUCl!I~ ~1~ Fae 1 . o m 3 OP BUM B C O A V ~ I ~ El R W W ~

Notes: Operation methods are defined in Table 5.2. Roductian functions are given i n F i v s 5.2A, 5.2B and 5.2C. Unitsfor E and L are US $ with daily vage rate of US $2.00 far unskilled labour.

NA = Not applicable.

- loom. Haul

Sw-rce: S W Estimates

. ,

-1-3

Unloading

Spread-

Totals

Hllly Terrain - 2 m . Haul Excavatmg, loa- d u g , unloading a d apreadmg as above

HaUlW

Totals

Rollmg Terrain - 400m. Haul

Exoavatq, loading, unload- - 1 dp.=2d-Lw 2 s above

Baullng

Fotals

112 - 28 - 2 8 -

433 -

321 - 193 -

514 -

321 -

233 -

554 -

$ - 31 - l o -

641 -

605 - 59 -

664 -

605 -

87 -

692 -

36 - 3 1 -

-

631 40

595 40

59 -

654 40

595 40

87 -

682 40

80 - 2 J

4 0 1 0

576 3

496 3

107 -

603 3

496 3

99 -

695 3

80 - 2

- 4 0 -

566 43

486 43

107 - 593 43

486 43

199 -

685 43

- 500

3 -

- 648

- 148

- 1000

- 1148

NB

AA

W.

- 31)

7 - 1 0 -

1 - 22

- 512

- 199

- 850

- 1049

UA

UA

NA

- 31)

1 0 -

5 -

5 490

5 177

- 850

5 1027

Hn

Hn

Hn

- 280

67

-

- 56)

- 283

- 490

- 773

- 283

- 910

- I193

80 - 2 3

1 - 40

80 - 2

10 -

36 - 3 3 1 -

- 40

lo5 236

36 - 3 1 -

10 -

412 233

376 233

59 -

435 233

376 233

07 -

463 233

115 196 422 193

% I93

59 -

445 193

586 193

87 -

473 193

I

25 236

107 L

132 2%

25 236

199 -

224 236

35 196

107 -

142 196

35 196

199 -

234 196

LABOUR

(b> Rock Excavation i n Roadworks

Table ~ . 4 shows the various combinations of construction methods considered for carrying out each act ivi ty. Again, the l ist i s not comprehensive and it has been assumed t h a t equipment loading would not be combined with hand excavation.

Table A.S and Figure ~ . 4 give the production functions for this operation i n h i l l y terrain, assumed haulage distance 200 m, and i n ro l l ing te r ra in where the distance is increased t o 400 m (no rock excavation was assumed i n f l a t terrain). Hauling by basket and wheelbarrow, methods F, G, L and M, were considered only for the shorter haul distances i n h i l l y terrain.

I n both cases hauling by bullock c a r t i s the most e f f i c i en t of the labour - intensive operations while tractor/* a i l e r units are more ef f ic ient than trucks a t the equipment-intensive end of the function. Both functions follow the l ines B-D-J-K. The overal l break-even wage r a t e i n h i l l y te r ra in w i t h the shorter haul is $1.07 per day which reduces t o $0.99 per day i n ro l l ing t e r ra in with the 400 m hauling distance. The slopes of the individual subst i tut ion l i n e s are the same i n both cases and are B-D 5.57, D- J 0.91 and J -K 0.45. I j n e B-D represents the change from shovel to hand loading of t r a i l e r s .

TADLE A.4: CONSTRUCTION METHODS FOR ROCK

EXCAVATION I N ROADWORKS

Note: This table a lso applies t o the "Rock Ekcavation i n Quaxry Opera,tionlf

Operation Method

A

B

C

D

E

F

G

H

J

K

L

M

Excavating

Compressor, drills and explosives

11

11

11

tt

11

11

Labour

11

11

11

11

Method f o r Activity

Hauling

Truck

Tractor and t r a i l e r

Truck


Bullock c a t

Wheelbarow

Basket

Truck


Bullock ca r t

Wheelbarrow

Basket

1

Construction

Loading

Shovel in to truck

Shovel in to t r a i l e r

Labour in to truck

Labour in to t r a i l e r

Labour in to bullock c a t

Labour in to wheelbarow

Labour in to basket

Labour in to truck

Labour in to t r a i l e r

Labour in to bullock c a t

Labour i n to wheelbarow

Labour i n to basket

Unloading

Tipped from truck

Tipped from t r a i l e r

Tipped from truck


Labour

Tipped from wheelbarow

Tipped from basket

Tipped from truck


Labour

Tipped from wheelbarow

Tipped from basket

LABOUR

FIGUREA.~ : PRODUCTION FUNCTIONS FOR 1000 M3 ROCK EXCAVATION IN ROADWORKS

KEY : 0 Hilly terrain, 200m haul x Rolling terraln, 400m haul

MAW -DAYS

c. 0 (for crushing)

Quarrying operations a re required i n the hypothetical road pro j ec ts t o provide material for crushed rock and macadam bases and for chippings for surface dressing (including macadam). This group of sequential a c t i v i t i e s covers the excavation a t the quarry face, loading, hauling an qssumed distance of 200 m from the quarry face and unloading a t the crushing point. The construction methods considered are ident ica l with those l i s t e d i n Table A.4 (for rock excavation i n earthworks ) .

The two functions given i n Table A.6 and Figure A.S.a.+e a simplified treatment of the subst i tut ion poss ib i l i t ies . !The' e f f o r t required t o excavate rock i s related, i n t e r a l i a , t o the s i z e in to which it i g broken and this depends on the s i ze of the crushing plant and the methodof hauling. A t the equipment-intensive end of the functions, two cases have bhen considered:-

(1) rock for the production of bases courses , . and ( 2 ) rock for the production of chippings.

I n the second case, a closer pat tern of blast ing has been assumed to provide smaller sized rock fragments. I n the labour-intensive method, excavating includes breaking to s i zes which can be carried by hand.

Hauling by bullock c a r t i s the most e f f i c i en t of the labour-intensive methods. The production functions follow the l i n e s A-B-D-E-K i n both cases. The overal l break-even wage r a t e s a r e $0.72 and 0.59 per day, the higher f igure applying t o the rock for chippings. The subst i tut ion slopes a re steep, averaging $5.50 per day, between A and D, the subst i tut ion of shovel-loaded trucks by hand-loaded t rac tor / t ra i le r units. For the remaining &lyses the production function has been taken t o start a t B and the slopes of the segments of the function for basecourse rock are:

B-D D-E E-K

u.s.a.36 per day 0 -47 0.33

and f o r chippings

B-D D -K

KEY :

e Rock for bas. coursos x Rock for chippings @ Common to both operations

LABOUR

MAN - DAYS

FIGURE A.S : PRODUCTION FUNCTIONS FOR 1000 M~ ROCK EXCAVATION iN QUARRY

(d) Gravel Sub-base

This operation covers the excavating, loading, hauling 1 km, unloading and spreading ac t iv i t i e s . The construction methods considered a re l i s t e d i n Table 8.7. Substitution i n the spreading operation a t the high l&vel of qual i ty i s not feasible since this i s an 'El category act ivi ty.

The production functions a t both levels of qual i ty are given i n Table ~ . 8 and Figure ~ . 6 . For high qual i ty the production function follows the l i n e A-G-J w i t h an average da i ly break-even wage r a t e of $0.80. A t intermediate quality, the function i s A-B-H-K w i t h an average slope of U.S. $0.94 per dqy. Substi- tut ing hand-loaded t r a i l e r s (points G and H ) gives average subst i tut ion slopes of $4.94 and $5.24 per day, respectively, a t high and intermediate levels of quality. A t the l a t t e r quality, the slopes of the segments are: -

A-B B-H H-K

U.S. $6.96 per day 4994 0.28

6 ) Gravel Base

'he construction methods considered for the excavating, loading, hauling, unloading and spreading gravel sub-base are ident ical with those defined i n Table A.7. For gravel base the length of haul has been assumed to be 2 km.

The production functions a t high and intermediate l e v e l s o f qual i ty a re given i n Table 8.8 and Figure A.7. The functions follow a s w l a r pat tern t o those for the sub-base and subst i tut ion slopes are:-

High Quality

A-J (overall) U.S. $0.38 per day A-G 3.98 G-J 0.2L

Intermediate Quality

A-K (over a l l ) 0.56 A-B 6.96 B-H 3.98 H-K 0.25

Again, the subst i tut ion of hand-loaded t r a i l e r s for shovel-loaded trucks i s par titularly advantageous.

e r a t i o n e thod

A.32

TA13LF: A. 7: CONSTRUCTION METHODS FOR GRAVEL

SUB-BASE GRAVEL BASE j MACADAM BASE,

AND CRUSHED ROCK BASE*

Construction Method f o r Act iv i ty

Excavating Loading

Shovel i n t o t ruck

Shovel i n t o t r a i l e r

Labour Labour i n t o t ruck

II

Labour i n t o t r a i l e r

Labour i n t o bullock c a r t

Hauling

Truck


Truck


Bullock c a r t

Tipped from Paver t ruck I D8 with

spreader box

spreading( 2 ,J

1 Unloading

11 1 N.A. I Labour

. spreading( 1 )

D8 with spreader box


11 I N.A. I Labour

Paver

D8 with spreader box

Tipped from truck

II I N - A = I Labour

Paver

Tipped from Pavkr I I D8 with t r a i l e r spreader box

!I 1 N.A. I labour

Labour Paver D 8 with spreader box

11 N . A,. 1 Labour

Spreading ( 1 ) - High q u a l i t y

Spreading ( 2 ) - Intermediate qua l i ty

N.A. - not appl icable at t h i s q u a l i t y l eve l .

TABU A.8: DATA FOR PRODUCTION FUNCTIONS FOR 1 ,000m3 GRAVEL SmBASE BND BASE

(11.9 dollars)

Notes: Operation methods are defined in Table 5.4. Production functions are given in Figures 5.5 and 5.6 Units for E and L are US $ with daily wage rate of US $2.00 for unskilled labour

NA = Not applicable

Activity

Gravel Sub-base

E~cavating

Loadin@;

Hauling - Ikm. Unloading

Spreading - High Quality

Spreading - Int. Gpality

Totals - High Gpality Totals - Int. Quality

Gravel Base

Excavating, loading, unloading & spreading as above

High Quality

kt. Quality

Hauling - 2km.

Totals - High Quality i d L A i s - kt. Quality

Source : SWIG Estimates

.-- -- ,

K

- 160

- 135

- 2100

67

NA

- 1

NA

- 2463

NA

- $3

- 4200

NA

- 4563

H

- 160

22 113

279 - 2

NA

- 50

NA

303 326

NA

24 326

501 -

NA

525 326

G

- 160

22 113

279 - 2 3

196 - 174 -

499 276

477 276

I 220 276

I98 276

501 -

.~ 721 2'16

699 276

J

- 160

- 135

- 2100

3 - 6 7 -

196 - 174 -

196 2462

174 2462

196 362

174 362

- 4200

196 4562

174 4562

D

467 - 251 - 279 - 2

NA

- 50

NA

999 53

NA

720 53

501 -

NA

1221 53

C

467 - 251 - 279 -

2 3

196 - 174 -

1195 3

1173 3

916 3

894 3

501 -

141'1 2

1395 3

A

467 - 331 - 155 - 31 -

196 - 174 -

I180 - 1158 -

1025 - 1003 - 245 -

1270 - 1248 -

B

467 - 331 - 155 -

31 - NA

- 50

NA

984 50

NA

829 50

245 -

NA

1074 50

@eration Method

E

E L E L E L E L E L E L E L E L E L E L

- 160

345 113

155 - 3 3 1 -

196 - 174 -

727 r5 705 273

572 273

550 273

245 - .

817 25'3

795 273

F

- 160

345 113

155 - 3 1 -

NA

- 50

NA

531 323

NA

376 2

245 -

NA

621 323

3 z 2 I Pa' E =

.. : I" > - W Y e x

( f ) Macadam Base (from crusher t o s i t e )

The construction methods considered are again ident ica l with those defined i n Table A.7. For macadam base, the length of haul has been assumed t o be 5 lcm. The two production functions are given i n Table A. 9 and Figure A.8.

For high quality, the subst i tut ion slope i s the l i n e A-J of value $0.17 per day. Since t h i s slope i s l e s s than $0.20 per day, subst i tut ion i s not p r a c t i c a e by our defini t ion and hence the production function consists of a single point A on the equipment axis.

A t the intermediate leve l of quality, the subst i tut ion slopes are:-

A-K A-B B-K

U.S. $0.204 per day 6.96 0.17

Hence the production function cons i s t s~of the l i n e A-B which consists of substitution of labour i n only the spreading operation.

It i s notable tha t trucks are more economic than t rac tor / t ra i le r units with a 5 km. length of haul.

E ! ! Crushed Rock Base

For this operation, the construction methods are the same a s those considered for the other basecourse materials and are defined i n Table 8.7. I n this case the length of haul i s assumed t o be 10 km. .

mamination of Table 11.9 shows tha t the production functions follow a similar pat tern for those for macadam base. Wucks are again the best method of haulage. For high levels of quality, no subst i tut ion i s possible and the production function consists of a single point on the equipment axis. A t intermediate qual i ty levels, substitution is res t r ic ted t o the spreading operation.

(US dollars]

Note: Operation methods are defined in Table 5.4. The production function for macadam base is given in Figure 5.7

Units for E and L are US $ with daily wage rate of US $2.00 for unskilled labour.

NA = Not Applicable

Activity

Macadam Base

Loading

Haul* - 5h.

Source: SWKP Estimates

Spreading - High Quality

Totals - High Quality

Crushed Rock Base

Loading, d o - and spreading as above

Operation Method

K

- 135

- 10500

H .

22 113

1165 -

J

- 135

- 10500

D

251 - 1165 -

A

1 - 538 -

G

22 113

1165 -

E

345 113

538 -

I?

E L E L E L E L E L E L E L E L E L E L

345 113

538 -

B

1 - 8 -

C

251 - 1165 -

(h) Water Distribution

Table 8.10 shows the various combinations of methods considered for carrying out the ac t iv i t i e s of loading, hauling (2 lan), mloading and spreading water .

&&nation of Table A . l l shows tha t substitution of ei ther method B or method C for method A would give a negative substitution slope; and substitution of ei ther method D or method E for method A would give a positive slope of l e s s that:. $0.20 per day. Hence no substitution is practicable and the produc-1;ion function i s a single point on the equipment axis.

Chippings f ~ r Surface Dressings (from crusher to s i t e )

The various combinations of methods considered for loading, hauling, unloading and spreading chippings for surface dressing are shown i n Table A.12. The haul distance is assumed t o be 5 lun for swface dressing macadam base.

' k i s production function i s given i n Table A.13 and figure 8.9. The substitution slopes are:-

A-G A- C C-G

~ . ~ . $ 0 . 2 4 per day 1.13 0.17

Hence the production function consists of the l i n e A-C, the substitution of spreading by hand for spreading by truck equipped with a chipping spreader.

There are similar substitution poss ib i l i t fes where the length of haul i s increased t o 10 lan, as i n the case of surface dressing for gravel and crushed rock bases. I n a l l cases, haul by truck is more economic than haul by tractor/ t r a i l e r uni ts and the slope of the production function i s $1.18 per day.

TABLE A.10 CONSTRUCTIOfl METHODS FOR

WATER DISTKII\T,rT I O N

Tractor and

Labow irmto

bullock c a r t

La,bola i ~ t o bullock cart

TBBLF .&.Jl: DATA FOB WODUCTION FmSCTION FOR 1 , o m 3 W A m DISlgIBUTIOH

Activity

Loading . .

Haul*

Unloading

Spreading

-

Totals

Operation Method

Notes:

Source :

Operation methods are defined in Table 5.5

Units for E and L are US $ with daily wage rates of US $2.00 for unskilled labour

SWKP Estimates

TABU Am12 CONSTRUCTION METIiODY FOR HAUEINQ AND SPREADING

CIlIPPINGS FOR SURFACE DKESSINGS

Note: In Methods A and B , the truck i s equipped with a chipping spreader.

( j ) Bitumen Distribution

lbis operation consis ts of the a c t i v i t i e s needed t o load, haul from the base camp, unload heat, and spread bitumen fo r surface dressing. Direct comparison between individual a c t i v i t i e s for labour- and equipment-intensive methods i s not possible since the a c t i v i t i e s d i f fe r i n themselves.

The following groups of a c t i v i t i e s have been compared:

Method A (equipment-intensive)

(1) Load bitumen by hand from drums i n t o a s t a t i c heater and heat bitumen.

(2) Pump heated bitumen from s t a t i c heater t o mobile dis t r ibutor .

(3) Haul heated bitumen from base camp t o s i t e (1o'lan.)

(4) Spread heated bitumen by dis t r ibutor .

!!%s method would be the same f o r high and intermediate levels of quality.

Method B (labour - intensive )

(1) Load bitumen i n drums in to truck by hand. (2) Haul drums i n . truck from base camp t o s i t e (10 Km.) (3) Unload bitumen i n drums from buck by labour a t s i t e . (4 ) Load bitumen from drums i n t o mobile heater by labour

and heat. (5) Unload and spread heated bitumen by labour.

This method would apply only for intermediate quality.

Method C (labour - intensive )

As method B but using t rac tor / t ra i le r units instead of trucks.

From Table A.&, it can be seen t h a t Method B i s superior i n tha t it en ta i l s a lower equipment cost than Method C while the labour content i s the same.

There a re no intermediate subst i tut ion poss ib i l i t i e s between the two methods and the production function i s a s t ra ight l i n e connecting A t o By of s lope $1.76 per day. Substitution i s therefore advantageous a t any lower wage.

TABU A.14: DATA FOR PRODUCTION FUNCTION FOR 1,000 TONNE BI!K?ME8 - ". DISTRIBUTION - INTERMEDIATE QUALITY

Notes : Operation methods are defined in Paza 5.55

The heating operation i s included under loading.

NA = Not applicable

Source : SWKP Estimates

4. Analysis of Costs per =ornetre for Different Road

Types and Different Terrains by SWKP

In t h i s series of analyses, the work involved in one kilometre of each of the hypothetical road projects has been broken down into basic construction ac t iv i t i e s and estimates of the costs of equipment and unskilled labour ( a t 82.00 per day) have-been prepared fo r carrying out each act iv i ty by equipment- and labour-intensive methods a t high and intermediate levels of quality. Substitution has been assumed to W e place provided that the break-even wage ra te i s shown t o be greater than $0.20 per day.

The methods assumed fo r carrying out each act iv i ty by equipment and by labour have been taken to be those found to l i e on the production function in the previous analyses. Those fo r the independent ac t iv i t i e s a re . l i s t ed in Table 11.3,whil.e those f o r the interdependent ac t iv i t i e s a re given in Table 11.13.

To permit comparison between a scraper operation t o r excavating, loading, hauling, unloading and spreading earthworks with labour-intensive methods in which each of the :interdependent ac t iv i t i e s can be costed individually, scraper !costs. have been allocated t o each act iv i ty t o accordwith i t s cycle time.

a. High Quality Equipment-Intensive Method (Table ~ ~ 1 6 )

Taking costs in f l a t te r ra in a s a base, the proportion- a t e increases in total. costs per kilometre in other terrain8 are given below:-

Terrain

Flat Rolling r n l y

Road Type A B C

1.00 1 0 0 0 1 000 1 040 1 033 1.32 1 073 1.61 1 059

The increases i n cost due t o more d i f f i cu l t te r ra in are seen t o be greater f o r the l e s s costly road type A (gravel base) and there is l i t t l e difference between types B and C.

With costs f o r road type A as a base, the proportionate increases in total costs per kilometre fo r the other road types are t -

Terrain

Fla t Rolling mly

Road Type A B

1 000 1 .20 1.00 1 .I5 1 0 0 0 1 .I2

The proportionate increases become smaller as the terrain becomes more di f f icul t .

I Rack exasvation in qumsry (for I ..A. I m r e e e o r I shovel ( -tor/ ( -tor/ I E.A. I h b o u -) 6 explosives t r a i l e r t r a i l e r I

I lhoPdam and crushed rock base I shovel 1 1 - 1 p a r 1 A 1 0 1 c k I M 1 ~ a b m r I box

Operation

~ ~ l l l (u~omt ion i n ~ t i ~ r k o - haul LOO m.

Bull esaavation in madrorlrsm~ - ha 200 and 400 m

Bw* -tion in roedmukm

I I I I I I I I I I

X.A. E.A. Pump Bomer X.A. i w r 1

L~bour - Utenaive 1

I I I I I I I hipp pings for surfaoe dressing R.A. 1.1. shovel 'huok* K.A. 'buck* 1.1. (b mshec t o e i te)

$lalLtY

E.A.

I.A.

8.1.

E x c a v a t ~

Labour

Labour

&uipnent - Intenaipe

bW

~abour

Labour

Labour

Bitumen distribution

Erosvat*

scraper

Soraper

Compressor & explosives

Bitumen distribution

ryyul* Wheal- %mow

Bullock oart

Bullock cast

Hi(lh

Replacing topsoil

Grass mote fo r sprigsing

bauwJ

soraper

Scraper

Shovel

Utes- mediate

Onlordiry(

~abour

Labour

Labour

E.A.

R.A.

..A.

BPul* S-per

Soraper

%actor/ trailer

Spcsldingl

1 s b o r 7

Labour

E.A.

R.A.

(planting)

Labour . into s t a t i c

E.A.

Grader

OnloauwJ

~ o r a p s r

Scraper

-tor/ t r a i l e r

heater Pump into dietri- butor

Labour into e ta t ic

E.A. == Rot a plicable S-e: - Lt-tee

twck vith chipping Bpreader

ISbour

Sp* Scraper

S m p e r

E.A.

Distri- tutor

heater

E'E distributor

Shovel

Shovel

Mstri- tutor

ShoVel

I . A .

Shovel

c k

E.A.

k c k

Dietri- butor

Shovel

'huok

Dietri- tutor

Truck

E.A.

Lsbaur

b b o w (pl&?ng\

E.A.

2 ata t ic

B.A.

heater

% dietri- tutor

EY truoke

Distri- tutor

and mobile heatpr

Labour

'huck

I . A .

Labour

Dintri- tutor

Labour Labour

Labour Laboq

Labour

Motes r Road Type A - Gravel mt-base, gravel base and 2 - coat surface h s s i n g B - Gravel mbbnae, macadam base and single surface dressing C - Gravel subbase, crushed rock base and 2 - coat eurface dress*

Percentaga f i e 8 are given in braokets

Souroe: SWKP B t h t e s

BotiviQ b u p

Ib

1.

2.

3

4.

5.

6.

7.

9.

11.

12.

C

E - L

1100 - (9.4)

17 - (.I)

2182 - (18.8)

2031 3 (17.5) 2329 - (20.0) 231 4 (2.0) 966 - (8.3) 393 - (3.4)

1075 - (9.2) 41 83 (.3)

10365 90 (89.1)(-8) 1176 (10.11

11631

Billy

A

E - L

1100 - (6.7) %3 - (2.2)

4741 - (29.1) 2862 3 (17.5) 3551 - (21.8) 488 1 3 . 0

1106 - (6.8) 485 - (3.0) 265 - (1.6) 46 124 3

15007 128 (92.0)(.$ 1176

(7.2)

16311

Flat

A

E - L

1100 - (11.7)

17 - (.2)

2239 - (23.7) 1629 3 (17.3) 1272 - (13.5) 229 - (2.4) 966 -

(10.2)

394 - (4.2) 265 - (2.8) 41 83 (-4)

8152 86 186.5)(.9) 1176 (12.5)

9414

C

E - L

1100 - 7 138 -

(.9) 3 2 3 - (21.0) 2602 3 (16.9) 4088 - (26.5) 365 4 (2.4)

1036 - (6.7) 439 - (2.8)

1075 - (7.0) 4 103

(.33(.7)

14124 110 (91.6)(-3 1176

(7.6)

15410

Rolling

A

E - L

/1100 - ( 8 3 138 - (1.0)

3295 - (25.0) 2200 3 (16.7)

3031 - (23.0) 363 - (2.7)

10% - (7.8) 440 - (3.3) 265 - (2.0) 43 103 (-3)

11911 106 (90.3)(.@ 1176

(8.9)

13193

Description

Bite Reparetion

E r e a ~ t i n g Small @antities

Eroa~oting in k l k

u Wing

Unl~eaine - C ~ C ~ cod mnisbing

R'0d~ction of Local h t e r i a l e

KIecellanaoua

T e d

B

E - L

1100 - (9.7)

17 - (.I)

2217 - (19.6) 2060 3 (18.2)

1742 - (15.4) 231 4 (2.0) 974 - (8.6) 393 - (3.5)

1416 - (12.5)

26 83 (-2)

10176 90 (89-9)(.4 1078

(9.5)

11324

T e d

B

E - L

1100 - (7.2) 138 -

(.9) 3273 - (21.6)

2631 3 (17.4) 3501 - (23.2)

365 4 (2.4)

1044 - (6.9) 439 - (2.9)

1416 - (9.4) 28 103 (.2)

13935 110 (92.1)(-r) 1078

(7.1)

15123

Totals

hu fac tu r ad l h t e r i a l s

Total Cost per Km of Road

Tensin

B

E - L

1100 - (6.0) 363 - (2.0)

4719 - (25.9) 3293 3 (18.0) 4021 - (22.0)

490 5 (2.7)

1114 - (6.1) qe4 - (2.6)

1416 - (7.8) 31 124 ( 2 )

17031 132 (93.4)(.1 1078

(5.9)

18241

C

E - L

1100 - (5.9) 363 - (2.0)

4684 - (25.3) 3264 3 (17.6) 4608 - (24.9)

490 5 (2.6)

1106 - (6.0) 494 - (2.6)

1075 - (5.8) 46 124

(.2)(.7)

17220 132 (92.9)(.3 1176

(6.3)

1852e

Equipment costs as percentages of total costs per kilometre vary with terrain and road type as shown below:-

Terrain

Flat Rolling Hilly

~ o a d Type

A B c 86.5 89.9 89.1 % 90 3 92.1 91.6 92 .o 93.4 92.9

The equipment proportion of total cost increases as the terrain becomes more difficult but there is not a great deal of difference between road types.

Unskilled labour forms a very small part (around 1%) of total costs, irrespective of terrain and road type. The cost of manufactured materials is much the same for all road types and is not affected by the terrain. As a proportion of total co~ts it decreases from 1 2.5% for road type A in flat terrain to around 696 for roads type B and C in hilly terrain.

The most significant activity groups are excavating in bulk, loading and hauling. Taken together, they account for 54-5696 of total costs in flat terrain, 62-6596 in rolling terrain and 66-6896 in hilly terrain. Of the remaining groups of activities, site preparation and spreading are next in importance, together with the production of local materials for roads type B and C (due to the macadam and crushed rock bases).

b. High Quality Labour-Intensive Method able 8.1 2)

With costs per kilometre in flat terrain as a base, proportionate increases in total costs in other types of terrain are : -

Terrain

Flat Rolling Hilly

Road Type

A B C

lt.'here is a large increase in cost in rolling terrain but the aaaitional costs due to hilly terrain are of much less significance. There is not a great deal of difference between the differing road types.

B - Gravel nut-bee, macadam base and e w e -face &en* C - Gram1 nut-bee, cmshed rock base snd 2 - coat wface dreeeing

Percentage f ieurea asa @MP In W e t s

Source: SVBS F e t h t e s

~illg T-IU

A

E - L

- 1162 (4.1)

- 410 (1.4)

- 3933 7

11) 2520 (.4)(e.e) 140 16m00 (.5)(55.8) 8 1217 (4~2)

780 94 (2.7)( .3)

485 - (1.7)

- qzO (1.5)

- 204 (.7)

1526 25960 (5.3)(90.6)

14.1 176)

28662

A

E - L

- 1162 (4.3)

- 166 (-6)

- 2023 (7.4)

111 1816 (.4)(6.7)

137 17751 L5X65.4)

8 878 (3.2)

780 91 (2.9)( .3)

440 - (1.6)

- 420 (1.5)

- 175 (-6)

1476 24484 (5.4)(90.2)

tl76 4.3)

27136

Ictivity Cmup

Notes : Rosd Tme A - G m l nut-bee, p v e l b e e end 2 - coat surf- dress*

Flat

A

E - L

- - 1162 (6.e)

- 31 (4

- 1074 (6.3)

ll0 W 9 (.6)(5.2) 135 10213 (.e)(60.1)

8 253 (1.5)

7 W 196 (4.6)(1.1)

394 - (2.3)

- 420 (2.5)

- 148 (.9)

1427 14386 (8.4)(sq.7)

ta?h 16989

if0

1.

2.

3.

I 4. 5.

6.

4- 9.

11.

12.

L .

Bolllns T e d

B

E - L

- 1162 (3.8)

- 166 (.5)

- 4971 (16.2)

518 1868 (1.7)(6.1)

766 13327 (2.5)(43.5)

9 962 (3.1)

757 147 (2.5)( .5) 439 - (1.4)

- 4310 (14.1)

- 157 (.5)

2489 2740 (8.1)(88.4)

Kg) 30637

Donoription

Site PLaparstion

b b m t i w In 8msU 9lpntitibrr

F=WVatiw fnm2.k

I..=-

5 u l i ~

Unloeasag

%=.a-

'2aIpactisBandFiniahlng

Pmduotion of Looel llateriale

Mieoellsnsoua

Totala

~ a c t a u e d Hstariels

Total Cost per lh. of Baed

B C

E - L 6 - L

0

E - L

- 1162 (4.1) - 166 (-6)

- 4831 (17.2)

509 1858 (1.8)(6.6)

1359 13299 (4.8)(47.4)

8 959 (3.4)

780 91 (n.e)( .3)

439 - (1.6)

810 )20 (2.9)(1.5)

- 175 (.6)

3905 22961 (13.9)(81.9

8.2) 76

28042

Tensin

B

E - L

- - 1162 (5.7)

- 31 (.I)

- 4022 (19.7)

517 939 (2.5)(4.6)

764 5789 (3.7)(28.2)

9 337 (1.6)

757 252 (3.7)(1.2)

393 - (1.9)

- 4/10 (a.0)

- 1% (a6 )

2440 16972 (11.9)(82.$

t31;) 20490

- 1162 0.6)

- 410 (1.3) - 6&l (21.4)

C

E - L

- 1162 (6.5)

- 31 (4

- 3882 (21.7)

508 929 (2.8)(5.2)

1357 5761 (7.6)(32.2)

8 334 (1.9)

780 196 (4.4H1.1)

393 - (2.2)

810 420 (4.5)(2.3)

- 148 (.a)

38% 12863 (21.5)(71.9)

It?& 17895

- 1162 (3.9)

- 410 (1.4)

- 6743 (22.8)

520 2570 (1.6)(8.o)

769 11576 (2.4)(36.0)

9 1301 (4.0)

757 150 (2.4)( .5)

4s4 - (1.5)

- 4x0 .(13.4)

- 186

511 2560 (1.7)(~.7)

362 11548 (4.6109.0)

0 1298 (4.41

780 94 (2.6)( .3)

484 - (1.6) 810 420 (2-7)(1.4) - 204

(-6)

2539 28546 (7.9)(88.7)

t3.3) 078

32163

(.7)

3955 24437 (13.4)(82.6)

14-01 176

29568

The proportionate increases i n t o t a l costs per kilometre i n re la t ion t o those f o r road type A are:-

Terrain

Elat Rolling Hilly

Road Type

A B C

1 -00 1.21 1.05 1.00 1.13 1.03 1 .oo 1.12 i -03

Road type B gives r i s e t o much greater increases than type C, par t icular ly i n f l a t terrain.

Labour (unskilled) costs as percentages of t o t a l costs per kilometre vary with t e r ra in and road types as shown below:-

Terrain Road Type

A B C

F l a t 84 7 82.8 71 -9 % Rolling 90.2 88 .4 81 .9 Hilly 90.6 88.7 82.6

The labour content increases with d i f f i cu l ty of t e r ra in and is greatest f o r the roads with gravel and macadam bases.

The equipment contents, as percentages of t o t a l costs, are:-

Terrain Road Type

F l a t Rolling Hil ly

There is a signif icant reduction i n equipment content with ro l l ing t e r ra in which increases only marginally i n h i l l y terrain. Road type C needs much more equipment than e i the r A o r B.

The cost of manufactured materials forms a re la t ive ly small proportion of t o t a l costs , reducing as the d i f f i cu l ty of the t e r ra in increases.

The most significant activity group is that of hauling which accounts for the following proportions of the total cost per kilometre:-

Terrain Road Type

Flat 60.9 0.8) 31.7(3*7) 39=8(7=6) % I Rolling 65-9 0 -5) 46-0(2.5) 52.2(4.8) Hilly 56-3(0.5) %4(2 04)) 4 3 4 4 . 6 )

The figures above are for equipment and labour costs while those for equipment only are shown in the brackets. This activity is of great importance in labour-intensive work, particularly since it has a low break-even wage rate.

Excavating in bulk, particularly for road types 3 and C, is also of importance and the production of local materials for the macadam base type B road. All other groups of activities are of little significance compared with the above groups.

c. Intermediate Quality Equipment-Intensive Method able g.181

The proportionate increases in total costs per kilometre, using flat terrain as a base, are:-

Terrain

Flat Rolling Hilly

Road Type

A B C

1 .oo 1 .OO 1 .oo 1.41 1 *34 1 a33 1.74 1.62 1 .60

The increases due to terrain are seen to be greater for road type A and there is little difference between roads type B and C.

With costs per kilometre for road type A as a base, proportionate increases are:-

Terrain

Flat Rolling Hilly

Road Type

The increases reduce as the terrain becomes more difficult.

TlBtE A.18 8 ICAL ROAD WOJETS

Notes : Road Type A - Gravel aub-base, gravel b s e snd 2 - coat surface dressing B - Gravel sub-bee, m m ? d m base and single wface dressing C - Gravel aubbse , o&e&.mck base and 2 - coat =face b e s i n g

lercentsge f i w e s are given in braokete Soume: SWEP &timates

7

Ei1U Tenain

A

E - L

1100 - (8.5) 138 - (1.1)

3295 - (25.4)

2XX) 3 (17.0)

931 - (23.4)

363 - (2.8)

971 - (7.5) 264 - (2.0) 265 - (2.0)

43 103 (-3)

11670 106 (~o.l)(.e)

1176 (9.1)

12952

A

Activity Group Flat

A

E - L

1100 - (12.0)

17 - (4

2239 - (24.3)

1629 5 (17.7) 1272 - (13.0) 229 - (2.5) 901 - (9.7) 242 - (2.6) 265 - (2.9)

E4) 83

7935 86 (86.3) (.Y)

1176 (12.8)

9197

Uo.

1.

2.

3.

4.

5.

6.

7.

9.

11.

12.

Eolllng Terrain

B

Deaoription

Si te Preparation

Rcavating in -1 Brantitiem

b a v n t i q in B u u

LoadLag

Haul-

Untoding

Spreading

Co~rpctlng and PiPiahing

Productionofbcalkterisla

Wscellaneoue

Terrain

B

B - L

1100 - (9.9)

17 - (.I)

2217 - (19.9)

2060 3 (18.5)

1742 - (15.6)

231 4 (2.1)

909 - (8.2) 242 - (2.2) 1416 - (12.7) 26 83 (.2)

9960 90 (8~.5)(.8)

1078 (9.7)

11128

B

E - L

11W - (7-4)

138 - (.9) - tzf0)

2631 3 (17.7)

3501 - (23.5)

365 4 (2-4)

979 - (6.6)

264 - (1.8) 1416 - (9.5) 28 103 (2)

13695 110 (~2.0)(.7)

1078 (7.2)

14883

C

Totals

PIarmfaetured k tar ia l s

Total Coat per Km of Road

C

E - L

llW - (9.6)

17 - (.I)

2182 - (19.1)

2031 3 (q.8)

2 3 - (20.4)

231 4 (2.0) 901 - (7.9) 242 - (2.1)

1075 - (9.4)

41 83 (.4)

10149 90 (ee.g)(.e)

1176 (10.3)

11415

C

E - L 1100 - (7.2) 138 - (.9)

3238 - (21.3)

2602 3 (17.1)

4088 - (26.9)

365 4 (2.4)

971 - (6.4) 264 - (1.7)

145 - (7.1)

43 103 (.3)

13884 110 (91.5)(.7)

1176 (7.7)

15170

E - L

1100 - (6.0)

363 - (2.0) 4684 - (25.6)

3264 3 (17.9)

4608 - (25.2)

490 5 (2.7) 1041 - (5.7) 287 - (1.6)

1075 - (6.0)

46 124 (.3)

16958 132 (92.8)(.7)

1176 (6.4)

18266

E L L E - L

llW - (6.81

363 - 1100 - (6.1)

363 - (2.3)

4741 - (29.5) 2862 3 (17.8)

3551 - (22.t)

488 1 (3.0) 1041 - (6.5') 287 - (1.4) 265 - (1.4) 46 124 (.31

(2.0)

4719 - (26.2)

3293 3 (10.3)

4021 - (22.4)

490 5 (2.7) 1049 - (5.8) 287 - (1.6) 1416 - (7.9)

31 124 (.2)

14744 128 (91,~)(.8)

1176 (7.3)

16048

16769 132 (93.3)(.7)

1078 (6.0)

17979

Variations in equipment cost, as percentages of total cost, vary with terrain and road type as follows:-

. Terrain Road Type

Flat ' 86.3 89.5 88.9 % Rolling 90.1 92 .O 91 - 5 Hilly 91 -9 93 3 92.8

The equipment content increases as the terrain becomes more difficult, particularly from flat'to rolling, and is greatest with roads type B and C.

The labour content, as a proportion of the total cost, is much the same in all cases and, being less than 196, is of little significance. Total costs of manufactured materials are much the same for all types of road and are unaffected by the terrain; as a proportion of the cost per kilometre, they reduce as the terrain becomes more difficult.

. As in the equipment-intensive high quality meth*, the most sigmificant groups of activities are excavating in bulk, loading and hauling, which together account for the following proportions of the total costs per kilometre:-

Terrain Road Type

A B C

Flat 55.8 54.0 57-3 !% Rolling 65.8 63.2 65.3 Hilly 69.4 66.9 68.7

There is little difference between the various types of road, but the proportions increase as the terrain becomes more difficult, particularly from flat to rolling.

Of the other activity groups, the production of local materials for roads type B and C, site preparation and the spreading of materials are of most significance.

d. Intermediate Quality Labour-Intensive Method a able A.191

With flat terrain as a base, the proportionate increases in total costs per kilometre are:-

Terrain

Flat Rolling Hilly

Road Type

A B C

1 .OO 1 .OO 1 .DO 1 .61 1.51 1.58 1 .71 1.59 1.67

Costs increase significantly between flat and rolling terrain and the additional increases due to hilly terrain are much less. The increases are greatest for road type A.

Proportionate increases Using road type A as a base axe:-

Terrain

Flat Rolling Hilly

Road Type

A B

Road type B gives much larger increases than type C and they are greatest in flat terrain with little difference between rolling and hilly terrain.

Unskilled labour costs as percentages of total costs per kilometre vary with terrain and road type as'shown below:-

Terrain Road Type

Flat 91.2 88.2 78.0 % Rolling 94.5 92 .1 86.1 Hilly 94 *a 92 - 5 86.8

The labour content is proportionally greater in the more difficult terrain, the greater part of the increase occuring between flat and rolling terrain, but the labour proportion decreases as pavement standards are raised.

The percentage equipment contents are:-

Terrain Road Type

A B C

Flat 1.8 6 - 5 15.4 % Rolling 1.1 4.3 9 7 Hilly 1.1 4 1 9.2

The equipment content increases substantially with the higher types of road (pavement) but in all cases reduces as the terrain becomes more difficult, particularly between flat and rolling terrain.

I

w A . 1 9 1 C U ROAD PROJETS

-UTE PITUJZY IdBOUE IWIESIVE HElWJES

Iictss : Road Type A - Gravel subbase. gravel baae snd 2 - coat surface dressing B - Gravel subbase, ma& baas and mingle surface dressing C - Gravel subbame, c d e d rock baae snd 2 - coat surface dressing

Percentage f-s are given in brackets

Some: SWW Estimates

A

E - L '

- 1162 (4.0)

- 410 (1.4)

- 3933 (13.7)

113 2520 (.4) (8.8) 140 16000 (.5) (55.7) 8 1217

(4.2) 43 9 7 ( . l ) (1.1) - logo

(3.8) - 420

(1.5) - 204

(.7)

304 27263 (1.1)(94.8)

1176 (4.1)

28743

Aotivity G m p

C

E - L

- 1162 (4.1)

- 166 (-6)

- 4831 (17.2)

509 1858 (1.8)(6.6)

135913299 (4.8)(47.4) 8 959

(3.4) 43 363 (-2) (1.3) - 902

(3.2) 810 420 (2-91(1.5) - 175

(-6)

2729 24135 (9.7)(86.1)

1176 (4.2)

28040

Hilly Terrain

B

E - 1 1

- 1162 (3.6)

- 410 (1.3)

- 6881 (21.3)

520 2570 (1.6)(7.9) 769 11576 (2.4)05.8) 9 1301

(4.0) 34 404 (e l ) (1.2) - 1090

(3.4) - 4310

(13.3) - 186

(-6)

1332 29890 (4.1)(92.5)

1078 (3.3)

32300

A

E - L

- 1162 (4.3)

- 166 (.6)

- 202) (7.5)

ll1 1818 (-4) (6.7) 137 17751 (.5) (65.6) 8 878

(3.2) 43 304 (-2) (1.1) - 902

(3.3) - 420

(1.6) - 175

(-6)

299 25599 (1.1)( 94.5)

1176 (4.3)

27074

Iio . 1

2

3

4

5

6

7

9

11

12

C

E - L

- 1162 (3.9)

- 410 (1.4)

- 6741 (22.7)

511 2560 (1.7)(8.6) 136211548 (4.6)(~8.9) 8 1298

(4.4) 43 366 (-1) (1.2) - l o p

(3.7) 810 420 (2.7)(1-4) - 204

(.7)

2734 25799 (9.2)(86.8)

1176 (4.0)

29709

Rolling Terrain

B

E - L

- 1162 (3.8)

- 166 (.5)

- 4971 (16.2)

518 1868 (1.7)(6.1) 766 13327 (2.5)(43.5) 9 962

(3.1) 34 401 (.I) (1.3) - 902

(2.9) - 4310

(U-1) - 157

(.5)

1327 28226 (4.3)(92.1)

1078 (3.5)

30631

C

E - L

- 1162 (6.5)

- 31 ( . a

- 3882 (21.9)

508 929 (2.9)(5.2) 1357 5761 (7.6)02.5) 8 334

(1.9) 3 468

t.2) (2.6) - 715

(4.0) 810 420 (4.6)(2.4) - L18

( 4

2726 13850 (15.4)(78.@

1176 (6.6)

17752

A

E - L

- 1162 (6.9)

- 31 (.2)

- 1074 (6.4)

110 889 (a61 (5.3) 135 10213 (.a) (60.8)

8 253 (1.5)

43 409 (-3) (2.4) - 715

(4.3) - 420

(2.5) - lqS

(.9)

296 15314 (1.8)(91.2)

U76 (7.0)

16786

Description

Si te Reparation

Q c p n r t i n g S m a l l ~ t i t i e s

EnX~e tSng in WllL

Loadine

Havling

Unloading

Spreadins

Comacting and F i n l u

Production of Looal Materials

Pliacellaneou

Eat Terrain

B

E - L

- 1162 (5.7)

- 31 ( 4

- 4022 (19.8)

517 939 .2.5)(4.6) 764 5789 (3.8)(28.5) 9 337

(1.7) 34 506 ( ~ 2 ) (2.5) - 715

(3.5) - 4310

(21.2)

- 130 (-6)

1324 17941 (6.5)(88.2)

1078 (5.3)

20343

Totals

lkmfactuced Materials

Total Cost per Rm of Road

Costs of manufactured materials account for between 7.0 and 5.5% of the total costs per kilometre, reducing as the terrain becomes more difficult.

By far the most important of the activity groups is hauling, which accounts for the following proportions of the costs per kilometre : -

Terrain Road Type

Flat 70.0 0.8) t 32.3 3 - 0 1 I 40.1 (7.6) Rolling 66.1 0.5) 46.02.5)) Hilly 56.2(0.5) 38.2(2.4)

The figures above are for equipment and labour costs combined while those in brackets are for equipment only. Again, this activity is of great importance in carrying out work by labour- intensive methods.

Other important groups of activities are excavating in bulk for roads type A and B (1 3.7 to 22.7%) and production of local materials for road type B with the macadam base (1 3.3-21.2%).

e. . Comparison between High Quality Equipment-Intensive and Labour-Intensive Methods

Comparing the total costs per kilometre given in Tables 8.16 and 8.17 the percentage increases in total cost arising from maximum practicable labour substitution are given below:-

Terrain Road Type

Flat Rolling Hilly

The increases are much the same for roads type A and B and are greater than those for road type C. The greatest increases occur in rolling terrain while those in flat and hilly terrain are much the same.

The above comparisons are based on a daily wage rate of U.S .$2.00 for unskill.ed labour. For total costs to remain the same, the break-even wage rates (U.S .$ per day) for unskilled labour would need to be:-

Terrain Road Type

Flat Rolling Hilly

Hence the financial advantage of labour substitution (to the maximum practicable extent) is greatest in hilly terrain and least in rolling terrain. Road type C offers the greatest advantage while type B offers the least. Partial substitution would undoubtedly affect these rankings.

f. Comparison between Intermediate Quality Equipment-Intensive and Labour-Intensive Methods

The percentage increase in total costs per kilometre arising from labour substitution at the intermediate level of quality are:-

Terrain Road Type

, Flat Rolling Hilly

The increases are much the same for roads type A and B but they are significantly less with road type C. The greatest increases occur in rolling terrain. In all cases, these increases are higher than the corresponding figures for high levels of quality (see para 5.1 02)

For total costs per kilometre to remain the same, the break-even wage rates (u.s.$ per day) for unskilled labow would need to be:-

Terrain Road Type

Flat Rolling Hilly

Hence hilly terrain offers the greatest and rolling terrain the least financial advantage in labour substitution to the maximum practicable extent. Road type C offers the greatest advantage and type B the least. However, partial substitution would undoubtedly affect these rankings. In all cases, the break-even wage rates are higher than the corresponding figures for the high level 'of quality

g. Comparison between Equipment-Intensive High Quality and Intermediate Quality Methods

Lowering quality standards for the equipment intensive methods reduces the total costs per kilometre by the percentages shown below: -

Terrain

Flat Rolling Hilly

Road Type

A B C

2 03 ? -7 1.9 0/0 1.8 1.6 1.6 1.6. 1.4 1: .4

The proportionate reductions in cost are very small but axe greatest in flat terrain and for the gravel-based road type A.

Lowering quality does not affect the total labour costs but reduces the costs of equipment by around U.5 .$220,240 and 260 per kilometre, respectively, in flat, rolling and hilly terrain.

h. Comparison between Labour-Intensive High Quality and Intermediate Quality Methods

Lowering quality standards with labour intensive methods affects total costs per kilometre by the following amounts:-

Terrain Road Type

Flat -1 .1 -0.7 -0.7 % Rolling -0.2 C 0 Hilly +0.3 +o. 4 +O.5

The effects on total costs are very small and are less than with equipment intensive methods

The decreases in equipment cost per kilometre are:-

Terrain Road Type

Flat $1 1 31 $1116 Rolling

$1 1 50 11 77 1162 1176

Hilly 1222 1 207 1221

which are offset by the following increases in labour cost:-

. . Terrain Road Type

Flat ;d 928 969 987 Rolling 1415 1156 1194 Hilly 1303 1134 1362

The slight increases in total costs arising,from lowering quality standards in rolling and hilly terrain are due to the higher cost of labour needed to.replace the savings in equipment.

i. Effect of Differing Rates for Labour and Equipment

The analyses of costs per kilometre of road have been based on a daily wage rate of U.S .;62.00 for unskilled labour. Also included in the labour category are bullock carts at a daily rate, inclusive of the driver, of U.S .$I 6.80 of which u.S.N.80 represents the cost of the cart. While these rates might correspond to actual wages paid in the developing labour- surplus countries, the resource cost of labour might be considerably lower.

French daywork rates have been assmed for equipment together with rates for skilled and semi-skilled operators which would be representative of actual wages in many developing countries. In practice actual equipment rates (including operators ) might be marginally higher, in financial terms, than those assumed but economic costs could be greater.

To assess the effects of varying the relative costs of equipment and labour, an extreme case of reducing unskilled labour costs to U.S. 20 cents per day has been taken while keeping equipment rates the same. The effect on individual activity groups in Tables A.16,A.17,A.1 8 and A.19 can be seen by dividing the labour costs by ten. The effect on total costs per kilometre is summarised in Table 8.20

At high levels of quality, the percentage reductions in total cost arising from maximum practicable substitution are given below:-

Terrain Road Type

Plat Rolling Hilly

TkaLE A.20

UBSKILlED LBBOUP. COST US $0.20 PE3 DAY

I Flat Terrain I Rollillg Terrain I Hilly Terrain

Road m e

Lsbour-Inteneive, High Wlibj %uipment

labour

Materials

Totalm

Fquipent-Intensive, Eli& Wlity Equipment

labour

Materials

Totals

Equipment-Intensive, Intermediate Wity

Equipment

labavr

Moterials

A B C

( Totals

8152 10176 10365

9 9 9 1176 . 1078 U76

9337 11263 11550

Labour-Intensive, Intermediate wity

Epuipment

Labour

Materials

A B C

1 Totals

A B

13935 14124 11911

11 11 11

1176 1078 1176

13098 15024 15311

Source : SWW &timates

15m7 17031 17220

13 13 13

1176 1078 1176 - 16196 18122 18409

The propo:-tionate reduct ions i n t o t a l become i:.reater as t h e t e r r a i n bccornes nor-e t i i f f i c u l t b u t become l e s s with t h e more c o s t l y road types.

These reduct ions should be compared wi th t h e ir lcreases scheduled i n pa ra 5.1 02 at a wage rate of U.S.$3.00 p e r day.

A t i.:ltermediate l e v e l s of q u a l i t y , the percentage reduc- t i o n s i n t o t a l c o s t pe.r ki lometre a r i s i n g from labour subs- t i tu- t i o r ~ a r e : -

Terra i n

F l a t Ro 1 1 ing Hii l y

Road Type

Again the p ropor t iona te reduct ions a r e g r e a t e r w i t h i n c r e a s i n g l y d i f f i c u l t t e r r a i n and wi th t h e l e s s c o s t l y road. types .

These r educ t ions should be compared with the inc reases scheduled i n pa ra 3.104.

With equipment- intensive methods, lowering t h e l e v e l s of q u a l i t y from high t o intermediate reduces t o t a l c o s t s p e r k i lometre by t h e percentages shown below:-

T e r r a i n

F l a t Ro l l ing H i l l y

Road Type

A B C

2.5 1 .9 1.8 0/0 1.8 1.5 1.5 1.6 1 . 4 1.4

The reduct ions are small and va ry only s l i g h t l y from thoSe l i s t e d i n pa ra 5.106.

Lowering q u a l i t y s t anda rds f o r labour- in tens ive methods reduces t h e c o s t s p e r k i lometre as fol lows:-

T e r r a i n Road Type

P l a t Ro l l ing H i l l y

These reduct ions a r e s u b s t a n t i a l l y g r e a t e r than those l i s t e d i n para I]. 108 (which a r e based on a U.S.$2 .OO p e r day wage r a t e ) . The p ropor t iona te reduct ions a r e g r e a t e s t i n f l a t t e r r a i n and a r e l e s s wi th the more c o s t l y road types .

5. Tables diving Comparative Cost of Equipaent,

Optimal and Labar-Iatensive Hetbds

Tabla A.21 Comparati~~? %st of E.;ui?nk=nt t0ptim.d and Libor-Inhsive YPZI~OQG for 1 b- of ibad i'y+w a { . b ? L i l S : :~%rr . i~~i ) far &.IN - $l./&y .

Intrr ir.cd~%Ce tul1rt.L

Estixatas Hased on SXKP Data.

(u.s. m u a r s ) hbr-JntensiPE

ActiwLty Equipawt Solution 0uti1m.l M x . Solution

clearing and grubbing 1 Stripping topsoil 100 Ercavating in bulk-eoft ma-irla, lmding,

haulbig, auiloading, spmadlng CcPpactlng and flnlshing Ereavatfng in bulk r o d

55f 380

acavating ditches %a soft a a b r W a 30 &canting ditches i n rock 107 -8 triaming~minpilcthg top-u 199

T m r . *- Total EartMrka

Bxcarotiug, loading, hauling, unloading, spreading gravel 1,969 - 515 277 - 2 ,093

Loading, hsullng, ualoadtng, water It7 - &7 - 0 - Conpactlug and finishing Po - - 8& - 8& - 562 jsl It?

Total Gravel Subbase 21106 2 J77 2a

[Iraval Base

kcavatlng, loading , hauling, unloading, apmadiw grate1 - 630 195 b 2 ,738

Lodhg , hauling, unloading, e e a d i n g wabr - 33 - E . - Compactipe and i in iBing 64 - - 60 60 1,595 - M 3 255 33 2,798

T o b l G r a d Base L J a 918

h a d u g , houUng,-heating, unltadlng, apaadbg bituasn

Loading, hauling, -lo** s p = w a p p i n g r Compactkrg Ud flnlshhg B-ng and cleanlag surface

Total Surface Dlasslng

~VTAL msl PER KIKDWXER u,88o - 9 13.028 -

Eo, E2 Eqldpmnt Coat in U.S.S. Ia, LZ Labor &st (a lso labor days a t w-).

Table 1.22 Ccinp~ratise of Lluipmnt, Optim~l an1 Labor-1-tensive Yethods for 1 hs, of t b ~ d Type A \ dl l ill:: L't,rr.iln) I'or n r i b b - .&L/Aiy

Hl.;h k u . ~ l l L ~

E s t h t e s Bayed on SbXP Dsta . (U,S" b l l a r s )

Actiri tq Equiprsent Solution Optimal nir b b o r Intensive So1uti.o n

QeoPiag aud grubbing 1 ~ m Stripping topsoil 100 Exoarntirag in bulk-soft ~ f s r i d l s

loadPng, h u l b g , unloading, apsra&g

CcmgactAng a d fiai6Nng EXoavatba 511 bulk rock

5%2 380

Exwva,%iag ditches in =it m$ceri& 30

Exaavating ditches i n rock 107 triw~ com~acuq

Total Eapthworksr

Gram1 Subbase

Eccarstirng, loading, bB1Uq) uploading, spreading gram1 2,006 - 8k8 235 333 2,093

baa- J hauling uoad ing , swad iae water &7 - h7 - W -

~ o ~ a c ~ n ~ ~ a n d finishing 128 - 128 - 128 - 2 ,181 - 1,023 235 598 2,093

Total Gravel Subbase 2,601

Gravel Base

Excavating, b d n g , haLd%Iig~ unloading, spreading gravel 1,525 - 865 166 333 2,737

Loading, b a n g , unloading, s p a d i n g water 33 - 33 - . 33 -

Comp.cting and fllrishbg 91 - 91 - 91 - 969 166 I67 2.737

Total Gravel Base

= = r n ~ , a a n g r b-8 unloading ~ c k i n quarry 90 - 65 6 -

Roductbn of ohipuings 26L - - 210 - 210 135

loading, h a d n g J

u n l o a ~ w , spreading chipplngs 165 - 116 l12 ll6

loading, hauling , heating , 112

unloading ,spreading bitumn 270 1 270 1 270 1 Coupacting and finishing 80 - 81, - 8k - Bmodng aud cleaning surface 31 - - 17 - 17

900 1 535 76 lr70 kO5 Total Surface h s s i n g 901 - 8ll !I£

TOTAL: Cost rpr Kilone'tm 12.115 - (Er61vdha structures, engirmerfng slme mision. mhriEiration, d d d s t r a t i m a d d s c a b a s o u s costs. 1

I b , E2 4uipmen't Cost i n U.S.9. lo, L2 Labor Cost (also labor days a t Wday).

Estirutes Based on B C D M Data

Salution SDlutiD n AotidW - Fa Lo E2 L2

Ear&hmr.ks

aem* =el gmbbiwj 1AO 21 l a 0 n - 1,751 St~mie(d upso i l 915 - 915 - - 1,266 Ihra&3va03ng, low* h l ~ , udLQactLn$ &a W - Q O ~ ~ materials 6,996 - 6 1896 - 2 1oa6&o %=odine LO3 - &03 - - &*acting and finlrixing &&9 - &9 - - 2,072

2,481

gxcovatdon in bulk rock 312 37 312 37 231, 702 PhcavaWq soft i n mall quantitiae 137 2 137 2 270 Exavating rock in s m a l l quantities 61 19 61 1.9 l&9 Wne8 *-I mmpacting topsou 1,512 k0 - b69 &69

a625 u9 1 0 1x3 2,380 19,800 T o t a l ~ w o r k a

Oravsl Subbaacs

Ebtavatbgb loading, ha-, unloading gsavel 2 n u - 2 ,668 - 1&56 1,3W SprwaQng lz3 9 123 9

5; 516

L o d n g , Plaulbg, unloading, spreading water 53 1 53 P 1 C%qacting and finishiq 87 h &3 25 kj 25

2,931 Ilr 2,887 35 1,552 1 a 8 e Total Gravel Subbase u!& u ? 5

Gravel Base

kcam*g md h d i Q g 829 - 829 - 273 921 Haulbg end udleadiiw @2 - &22 - a 2 1295 Spmadlng 82 9 82 9 - Loadbg, hading , spreading uater 37 1 37 1 $7 1

365

Qqacting and f i n i & i q l&O 7 LO 2h la0 2& 1, 1 0 7 7

~ota.7. &am1 ease 1Szl U& U2 Surfaca Dmasiug

Production sbms 166 l8& 52 270 52 270 badtLag a b ~ i e e 38 - - 6 - 6 EPUUng and udoadtLag ~wne a 1 7 1 17 1 - hduct ion 10/15 chippiags

3M 3 8 32 3 8 32 9 8 32

Bitumn spmadng 102 2 102 2 102 2 h a w shippings aaul (10 CLI~PPIUSS) 1x7 1 117 1 11.7 1 Spread CNppings 1 conpacting arsd f b a p s h i ~ 7 - a - 7 -

613 312 5% 629 T O W Surface Dressing &

TOTAL Coat Far lCLlowtm - (Eacluiiag s k c t w e s engineerlarg,

fabb A.2h 8 Omparative Cost of tqdpme.nt, O p t i d and Labor lntensire &tho& for om KilOl~etm of E~3.d r y w A (.~llirp Terrain) for dage = $UP=

H i s Q u d i t ~

htimatas Baaed on BCIDU Data

(U.S. Dollara) BquW-t opt- Labor Snteosfw Solutb n Solution Solution

A & i r P t J - Es Lo E2 12

Ea~thllork6

Gba&.ag sad grubbing 21 1480 n - 187% StrlppLng &paoil - 915 1,266 Bm~aMng sot t bulk, h d l n g r hPJiqJ u d l o P u 6,896 - 6,896 2 J i 6 PO&O Sg9aectLag LO3 1 LO3 - - b 8 p ~ a t h g md finishing 707 707 - 7 4

2 $81 - Sxcavatl.ng rock bulk, loading^ haullug, udlodng 3.2 37 3 2 37 2% 702 broa~ating soft J.dl quanu tiea 2 l37 2 . 270

137 19 &ca%'aUng rock small quantl.tias 61 & +$ g - lM haink?, = - I =*curre - Totd Earthworks

m+ m z&2 Td% @ram1 Subbase

6xoavating, loadlug, hauling, UalOaUlng p a n 1 2%

- 2~~ - I&% 12 16L 12 m 6M,

13%

Watering, loadngp hauling, Ilpl-dillg~ 53 53 53 1 m a c t b g and finishing

u'o i uo uo Totd Otaml Subbaae

rn m 2 s

i$

Gram1 Base

Bopvoti~ig gram1 ) h a d n g Hauling Md unloading apreadlng Loading, hauling, spreadlug; watar -g finishing.

Total Qraval Base

Surface Ibessing

Pmduction 8-8 IPrding stones Haling and u n l o a d k stones Pmduction 1 0 m ctdpp-s Flituaen spreading

1 z %%"&*bgo dgFQ1lgr

Cempacuw Md f l d E b L c r g

Total Surface Dressing

Subtotal EquiplaSnt/Labour l7A81 Is0 15,816 9% 6&3 21r JObB

TOTAL Costs per Kllone tm

(Qcl\ELj.n# structures enginaering, superridon, wtdl iaatbn, adaiaistrative, and Ibsesllamma costs.)

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