IJEE

The International Journal of Elevator Engineering

Volume 4 Number 2

November, 2002 Published by: The International Association of Elevator Engineers

(HK-China Branch)

Editor: Ir Dr A.T.P. So, Scientific Advisor and Member of IAEE Board of Executives, Academic Secretary, IAEE (HK-China Branch), Associate Professor, City U of HK CONTENTS Research Papers Advancement in elevator technology for construction in densely populated cities by D. C. M. Lam Elevators for emergency evacuation and egress by R. E. Howkins Technical Notes Current technology and future developments in elevator simulation by R. D. Peters Safety edge confusion ? by D. Cooper

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International Journal of Elevator Engineering Editor: Ir Dr A.T.P. So, Scientific Advisor and Member, IAEE Board of Executives, City University of

Hong Kong, Academic Secretary, IAEE (HK-China Branch) Assistant Editor: Ir Dr W.L. Chan, General Secretary, IAEE(HK-China Branch), HK Polytechnic University Publication Managers: Mr J. Stier, Chairman, IAEE Administrative Board Mr S.K. Liu, Hon. Treasurer, IAEE(HK-China Branch), Chevalier (HK) Ltd. Paper Reviewers and Editorial Advisors (in alphabetical order): Dr L.R. Al-Sharif, London Underground Ltd., U.K. Prof F.H.Y. Chan, University of Hong Kong, H.K., China Dr Y.C. Chow, Chevalier International Holdings Ltd., Chairman, IAEE (HK-China Branch), H.K., China Mr G.M.W. Chui, Electrical & Mechanical Services Department, HKSAR Government, H.K., China Prof H.J. Cowan, University of Sydney, Editor, Architectural Science Review, Australia Prof A.K. David, Hong Kong Polytechnic University, H.K. Mr J. Halpern, Millar Elevator Industries, Inc., U.S.A. Mr J. Inglis, IAEE Worldwide Membership Co-ordinator, Australia Dr G.T. Kavounas, Intellectual Property Attorney, U.S.A. Mr M. Kawahira, Fujitec Co Ltd., Japan Mr H.S. Kuok, Chevalier (HK) Ltd., Vice-Chairman, IAEE (HK-China Branch), H.K., China Prof L.L. Lai, City University, U.K. Dr F.K. Lam, University of Hong Kong, H.K., China Mr Y.W. Law, Electrical & Mechanical Services Department, H.K.S.A.R. Government, H.K., China Prof B.B.P. Lim, Queensland University of Technology, Australia Mr A. Lustig, Chairman, IAEE Regional Co-ordinators, Israel Dr R. D. Peters, Peters Research Ltd., U.K. Prof C.Y. To, Chinese University of Hong Kong, University of Michigan, U.S.A. Mr W.S. Tong, Housing Department, HKSAR Government, H.K., China Mr K. Utsunomitya, Mitsubishi Electric Corporation, Japan Editorial Office: IAEE (HK-China Branch), Chevalier (HK) Ltd., 22/F, Chevalier Commercial Centre, 8, Wang Hoi

Road, Kowloon Bay, Kowloon, Hong Kong (Tel: 852-23315927; Fax: 852-27564852; E-mail: sk_liu@chevalier.com) Attn: Miss Betty Lee

Department of Building & Construction, City University of Hong Kong, Tat Chee Avenue,

Kowloon, Hong Kong (Tel: 852-21942904; Fax: 852-27844698; E-mail: bcrssyso@cityu.edu.hk) Attn: Miss Rebecca So

Articles for Publication: The International Journal of Elevator Engineering (IJEE) is the official journal of The International Association of Elevator Engineers and it is published two time a year by IAEE. This journal expedites communication among research scientists, engineers and scholars interested in the field of elevator engineering. We consider elevator engineering in the broad sense and the publication policy is to publish: (1) new original articles on research and development that have been appropriately reviewed by competent scientific and

technical people; (2) comprehensive reviews of developments in the field; and (3) pedagogical papers covering specific areas of interest in elevator engineering. Papers should not have been published in any other journal before and topics may include, but not limited to, the design, development, analysis, management, construction etc. of elevators (lifts), escalators, moving walkways and ramps, circulation etc. Those papers which have gone through a stringent reviewing process will be published in the journal as “Research Papers” while others without going through the reviewing process will be published as “Technical Notes” for fast announcement of new developments or concepts in elevator engineering.

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The International Journal of Elevator Engineering Volume 4 Number 2 November, 2002 Editor: Albert T.P. So, BSc(Eng), MPhil, PhD, CEng, MIEE, MCIBSE, MASHRAE,

RPE(E&BS), MHKIE, SMIEEE, Associate Professor, City University of Hong Kong, Hong Kong, China

Assistant Editor: W.L. Chan, BSc(Eng), MPhil, PhD, CEng, MIEE, MHKIE, MIEEE, Assistant

Professor, Hong Kong Polytechnic University, Hong Kong, China Published by: The International Association of Elevator Engineers The International Association of Elevator Engineers (HK-China Branch) First published in 1996 by THE INTERNATIONAL ASSOCIATION OF ELEVATOR ENGINEERS 2002 THE INTERNATIONAL ASSOCIATION OF ELEVATOR ENGINEERS British Library Cataloguing-in-Publication Data A catalogue record is available from the British Library Printed in Israel by IAEE COPYRIGHT NOTICE All Rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written writing of the Publisher. Further copies of The International Journal of Elevator Engineering can be obtained from IAEE Publications. Please complete the subscription form attached with this journal.

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PREFACE It is one of the main objectives of IAEE to promote "state-of-the-art" information of elevator technologies to all our members worldwide as well as researchers, engineers and other building professionals who are interested in elevator engineering. Early in 1993, I discussed the idea of publishing an international journal on relevant topics by IAEE during the World Congress, Elevcon, in Vienna with Executives of IAEE and obtained full support from them. The first volume of The International Journal of Elevator Engineering was published in 1996 as an annual edition. In order to ensure a high quality for the IJEE, each research paper received was reviewed by at least two referees who are globally renowned experts and scholars in related fields. To promote fast circulation of new idea and developments, we introduced a new section in Volume II, the Technical Notes which had not gone through the long reviewing process. All papers having completed the reviewing process are categorised in the section, Research Papers. In this Volume IV Number 2, we have included two Research Papers and two Technical Notes. This is the third edition of IJEE which is integrated with the IAEE Newsletters so that all members of IAEE will receive a complimentary copy of the journal. Although this edition was born a little bit late, Volume V Number 1 and Number 2 will be published very soon. We still aim at publishing IJEE twice per year, during the Fall and Summer. In the first Research Paper, Lam discusses the concept and technologies of JumpLiftTM which has been developed to serve the construction site and can be converted to a normal passenger lift within a very short period of time after the building is completed. In the second Research Paper, Howkins asks the question why elevator systems should not be used for safe, emergency egress and evacuation. He conducts a comprehensive review and discussion on this issue. In the first Technical Notes, Peters introduces a simulation software for traffic analysis as he sees that elevator simulation will become increasingly more flexible and powerful. In the second Technical Notes, Copper, looks at issues related to safety edges of landing and car doors. On behalf of the Editorial Board, I wish you all enjoy in reading this edition of IJEE, subscribing to the future volumes and perhaps contributing to IJEE. Ir Dr Albert T.P. So, Editor, Scientific Advisor and Member of Board of Executives, IAEE Academic Secretary, IAEE (HK-China Branch) Ir Dr W.L. Chan, Assistant Editor, General Secretary, IAEE (HK-China Branch)

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Research Paper

Elevators for Emergency Evacuation and Egress

Roger E Howkins Ove Arup International Ltd., Research & Development

13 Fitzroy Street, London. W1T 4BQ UK Fax: +44(0)20 7755 3669 E-mail:Roger.howkins@arup.com

KEYWORDS: Risk Assessment, Emergency Evacuation, Fire, Safety, Elevators

ABSTRACT Codes on a world-wide basis require new buildings, architects, developers and owners to provide provision for means of access to the building for citizens who have a disability, yet make no provision for the safe, rapid egress in an emergency evacuation, especially during fire conditions. Codes today consider that the passenger elevator to be incapable to fulfil this function, yet enlightened codes such as British Standard BS 5588 part 5 allow the fire-fighters to use an elevator which is designed to assist the fire-fighters to fight the fire. This paper will ask the questions, why cannot elevator systems in the “next generation” of building if correctly designed and risk assessment procedures are implemented, installed, commissioned and maintained should not be used for safe, emergency egress and evacuation? Also why are traditional methods of emergency egress considered safer when the potential hazards encountered during emergency evacuation conditions are greater?

DISCUSSION Building codes whether they are Local, Regional or National make provision for access for the disabled such as ADA (Americans Disability Act -USA), DDA (Disability Discrimination Act – Australia) or M2 (The Building Regulations – UK) all of which require in general terms that citizens with a disability are treated equally in terms building access and personal facilities within the building. Which generally require that the elevator systems are provided with various devices such as tactile buttons, computer generated voice announcements, colour co-ordinated finishes and control devices set at certain locations and heights for the ease of the disabled and also the able-bodied or what is generally as classified as “universal access”. However, universal access becomes a prison to the citizen with a disability when an emergency condition occurs within a building, and a populated floor has to evacuated, the able bodied should be capable of using the stairways, or are they? Codes make provision for generally access but generally do not consider emergency egress for those with a disability. Statistics have shown that 19% of citizens have a disability, this percentage has increased by 1-2% since 1993 due to the ageing population, this will have an effect on the overall new building design population. If the building is designed for a high proportion of elderly citizens in the age range 60-69 years the proportion of those with a disability will increase to 40%. These high percentages of citizens with a disability will also affect the elevator system handling capacities but more importantly for those citizens with a disability it will cause additional hazards during an emergency condition, as it will create additional “bottle-necks” and “pinch-points” at designated emergency exits due to their lack of mobility. The next generation of building which will range from the multi storied high-rise tower to the low–rise developments, the population massing on each floor plate will be as high as possible high to enable the building developer the fastest return

on their investment. Although this floor massing will vary in each City or Country and will range from 1 person 6m2 for a dealer floor to 1 person 14m2 for a generally office building, of which on average 19% of the population will have a disability. Technically it could be argued that the building developer has a “duty of care” not only to provide safe ingress but also safe egress to the building under all conditions including emergencies, but do they? THE ELEVATOR SYSTEM When considering emergency evacuation by elevators in the next generation of building, the designer must consider the effects of overall safe population movement and how the flow can be monitored. Today elevator system designers consider how to move a percentage of the building population vertically up the building during a theoretical “up peak” period with a defined average waiting interval. A building design brief may require that the elevator system is required to move 17% of the designed building population within a 5 minute period with an average waiting interval not exceeding 30 seconds, elevator systems that cannot meet these basic criteria could be described as poor which will possibly have a negative marketing effect of the building and could reduce the marketable value of the building. With rental values of new high quality buildings e.g. in London exceeding £50.00ft2, it is vital to have the correct general elevator system during the up-peak conditions and also for day to day vertical movement. In the next generation of building, the general elevator system will also be required to assist in the phased evacuation of the building during an emergency condition, therefore the elevator designers will be required to model various scenarios to prove that the building is safe. These scenarios will include using the elevators to evacuate the building population from possible hazardous areas such as fire floors, above and below the fire-fighters bridgehead floors to “safe havens” within the building. These safe havens do not have to be outside the building and also very importantly they do not require the general evacuation of the

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total building but only evacuation from those levels considered at risk. With powerful elevator simulation programs such as Elevate it is now possible to model passenger movement and queuing lengths within elevator lobbies and with Fire Engineering programs such as Simulex which simulates how able-bodied people will react and move around a floor plate if a fire starts in a defined location. These powerful design tools and will form a vital part of any risk assessment, which must be carried out to evaluate the evacuation procedures within the next generation of building. ELEVATORS OR STAIRS From published accident statistics (refer to Section 6) the use of a stairways is a relatively dangerous activity during normal building use, within any building using stairways during an emergency could be considered negligent due to the inherent high risk of accidents and personal injury caused to the individual and also subsequently inflicted on others. Designers should consider the following design scenarios: • Time required to evacuate the primary floor to a safe

haven. • Time required to evacuate the primary and secondary

floors to safe havens. • Time required to evacuate the primary floor to the main

lobby. • Time required to evacuate the primary and secondary

floors to the main lobby. From studies carried out on tall buildings (buildings between 40 – 45 floors), it was considered that “when people are evacuating by stairs they are exposed to dangers” which were defined as “tiredness, becoming dizzy, slipping on surfaces or be less capable physically” and that “a stair evacuation will also take an unreasonable long time to carryout”.

During these studies it was timed that persons of high fitness levels took approximately 12 minutes to walk down to the ground floor using a firefighting stairway in a 42 storey building. The studies also concluded that a person able bodied or those with a disability “once inside the elevator, in an elevator evacuation control mode will be on the ground floor in approximately one minute” the 11 minutes additional risk by using the stairway was considered to be unacceptable. RISK ASSESSMENT For the elevator system to be used for emergency evacuation in the next generation of building it will be required to carry out a detailed risk assessments of the evacuation procedures being considered. As a starting point the elevator system designer will be asked, why is the elevator is safer than conventional evacuation methods i.e. stairways? Or to ask the question differently, if by detailed risk assessment procedures the elevator systems can be proved to be safer than the stairway during an emergency condition why should they not be used? The recognised basic norm of carrying out a risk assessment is to classify two critical factors: • Probability & Severity. These two factors are weighted to provide an overall Risk Category, from which the hazard rating can be determined and control measures put into place. The hazard rating is based on multiplying the probability and severity assessments, which give the over-all risk category. The risk assessment matrix is detailed in Table 1.

Probability Severity

Impossible x 1 Possible x 2 Probable x 3 Certain or near Certain x 4

Negligible x 1 Serious Injury x 2 Critical x 3 Catastrophic x 4

Risk Category Low = 1–3

Medium = 4-8

High = 9-16

Table 1. Risk Assessment Matrix See Table 2 for example of risk assessment.

Hazard: A buildings elevator system which is in a potential high risk location from vandalism or other anti social activities, what is the risk to the occupiers from broken glass?

Probability: category 3 (probable)

Severity: category 2 (serious injury)

Hazard Rating: probability (3) x severity (2) = (6) Medium

Control measures: Use laminated, toughened glass or use protective film on glass.

Table 2. Risk Assessment - Example

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INJURY STATISTICS Prior to considering the risk assessment procedures that need to be undertaken so that the elevator systems are to be used for emergency evacuation, relevant accident statistics relating to employees e.g. in office based industries need to evaluated. In the UK in the period 1998/99 there were approximately 223,000 office based premises employing approximately 3.8 million people. During the 5 year period 1994/95 to 1998/99 in the UK, there were 8,343 reported injuries in the office based industries, of these 13 were fatal and 6,319 resulted in the employee being off work more that 3 days, 27% (1,681) of these injuries resulted from a slip or trip, of which 309 were attributed to slipping on stairs. Of the 704 injuries attributed to falls, 387 involved a fall down stairs. The 6,319 injuries sustained 40% were sprains or strains or which 696 could be linked directly to stairways, during the 5 year investigation period only 5 injuries could be attributable to fire. These published statistics are very significant they indicate that using the stairway during normal building occupation is potentially a very hazardous activity, should this common everyday activity be attempted during an emergency condition where there could be mass population evacuation, slippery stair tread causing a minor slip or fall could have a “domino effect” causing not only possible serious injury, but probably fatalities caused by crushing, broken limbs and cardiac conditions. EVALUATIONS With any new concept there are justifiable fears and concerns which must be addressed and fears and prejudice overcome by scientific argument, and risk assessment procedures, and the doubters must come to discussions with an open mind and not “with their eyes wide shut” and importantly not with the

Towering Inferno Syndrome (T.I.S.) conceptions. T.I.S. is a journalistic headline grabbing statement, where new or inventive designs are quickly misjudged and the headline writers zero in on the publics fears and generic concerns on tall buildings based upon the disaster movie of the same name. What the journalists fail to highlight were the poor working practices, corruption and a total disregard for building codes and practices which were the underlying theme of the movie. There have been instances of first generation tall buildings where fires have resulted in loss of life, a review of these fires, came up with the following Design Based Conclusions: • Partial or no automatic sprinkler system • No fire detection or alarm systems • Lack of enclosed, fire rated stairways • Flammable wall & ceiling linings • Inadequate compartmentation between floors It must be emphasised that these fires occurred within first generation buildings, the next or 4th generation of building will be provided with all the safety features which were not installed or operational within the buildings where serious fires occurred. With the next generation of building, the perceived risks to people during evacuation by elevator can be described as: • Reliability • Smoke • Fire • Water • Radiation • Power Supply Although perceived concerns are valid they must be taken in the right context and relate to the safe evacuation and should also include traditional methods of evacuation by stairways, therefore the Risk Assessment methods should be re-defined, refer to Table 3.

Elevators Stairways

Risk Probability Severity Probability Severity

Reliability

Effects of Smoke

Effects of Fire

Effects of Water

Effects of Radiation

Power Supply

Table 3. Risk Assessment Comparison

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Risk Assessment procedures cannot give a defined statement, without considering the cause/effect and what design changes will need to be undertaken to achieve a risk assessment for all areas of perceived risks. RELIABILTY British Standard BS 5588 Part 5 Fire precautions in the design, construction and use of buildings: Part 5: 1991: Code of Practice for firefighting stairs and lifts [2], describes a standard design of elevator which is classified as a Firefighting lift, which is designed to be used by fire-fighters to assist them in fighting a fire. This elevator therefore is must operate in hazardous conditions such as fire, smoke, water and the by-products of a fire such as soot’s and fumes etc. This elevator must operate first time every time, if this design of elevator can be used as a design platform for the evacuation elevator, emergency evacuation by elevator becomes more than a concept it becomes a design reality. A correctly designed, installed and maintained elevator on average will only require breakdown assistance no more than 4 times each year, (although this can reduce to less than 1.5 per annum or increase to more than 5 in countries where the maintenance procedures require adapting) these world-wide breakdown averages are based upon elevator companies overall maintenance portfolio, which will range from simple elevators with manual doors and relay logic technology to the highly sophisticated computer based systems.

The newer the elevator stock the greater the overall reliability providing the systems have also been designed, installed, commissioned and maintained correctly. Although the duty cycle of an elevator system will alter from building to building, it can be assumed that a single passenger elevator in a group system within a commercial building will be required to operate on average for: • 50 weeks every year, assuming a 5 day week. • 9 hours each day. • 75 movements each hour. From these operational assumptions an average elevator in a group system will be required to work each year for: • 250(days) x 9 (hours) x 75 (movements) = 168,750

elevator movements each year. Statistics indicate that an elevator will require call back assistance only once every 42,188 movements or approximately every 62.5 working days. This risk is considered acceptable for a firefighting lift as defined by BS 5588: Part5: 1991 and therefore should be recommended as the minimum design platform emergency evacuation. Risk assessments should be carried out on the suitability of using stairways or elevators in normal and emergency operating conditions, examples are shown in tables 4, 5, 6 & 7.

Risk Assessment: Elevator Reliability - Normal Use

Hazard: Statistical breakdown trapping persons in elevator.

Probability: 1 breakdown every 62.5 working days (risk category 2)

Severity: Negligible no injuries (risk category 1)

Rating: 2 x 1 = 2 (Overall Risk Category = Low)

Control Measures: None required.

Table 4. Risk Assessment: Elevator Reliability – Normal Use

Risk Assessment: Elevator Reliability - Evacuation Condition

Hazard: Statistical breakdown trapping persons in elevator

Probability: 1 breakdown every 62.5 working days (risk category 2)

Severity: Negligible no injuries (risk category 1)

Rating: 2 x 1 = 2 (Overall Risk Category = Low)

Control Measures: In the statistically unlikely event of a elevator breakdown during an emergency, provide addition elevators and a safe method of escape from stalled elevator.

Table 5. Risk Assessment: Elevator Reliability – Evacuation Condition

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Risk Assessment: Stairway Safety – Normal Use

Hazard: Injury to persons using stairs

Probability: Possible (risk category 2)

Severity: Serious Injury (risk category 2)

Rating: 2 x 2 = 4 (Overall Risk Category = Medium)

Control Measures: Recommend that vertical movement is only by elevator.

Table 6. Risk Assessment: Stairway Safety – Normal Use

Risk Assessment: Stairway Safety – Evacuation Condition

Hazard: Injury to persons in crowded stairway conditions.

Probability: Certain or Near Certain (risk category 4)

Severity: Critical (risk category 3)

Rating: 4 x 3 = 12 (Overall Risk Category + High)

Control Measures: Only allow emergency evacuation by the elevator system as the Risk category for elevators is classified as Low.

Table 7. Risk Assessment: Stairway Safety – Evacuation Condition

By carrying out a risk assessment on all possible areas of design concern by assessing the g1 elevator system against traditional means of evacuation, correctly designed elevator systems can be used for emergency evacuation which is safe, reliable and rapid. The elevator designer must consider at a minimum the following factors and carry out detailed risk assessments for the stairways and elevator systems on the following areas of design: • Smoke Control • Effects of Fire • Effects of Water • Effects of Radiation • Reliability of Electrical Power Supply With key areas of design, requiring detailed risk assessment analysis it will enable the elevator design platform to proceed through the design development process, prior to incorporation into a new project design. SMOKE A risk assessment analysis will be needed to be undertaken on smoke control measures, comparing the effects of smoke possibly entering the stairways, lobbies and elevator systems, these risk assessments should consider but not be limited to: • Pressurisation of elevator shafts, lobbies & stairways. • Stack & Piston effects within elevator shafts & stairways. • Design of Elevator lobbies and stairways • Ventilation of elevator lobbies and stairways. FIRE Statistics show that fire alone is not the cause of fatal injuries,

the effects of combustion are the hazard areas, which can include smoke and radiated heat. The elevator designer must carry out a risk assessment on the effects of a fire rather than the fire itself. How will the areas of hazard possibly effect safe reliable evacuation operation of the elevator system or stairwell? WATER As a design issue water is not considered to be a major concern for elevators to be used for emergency evacuation, there are many location where elevators work reliably and in complete safety in fully external environments and in certain buildings these elevators are also classified as firefighting elevators as defined by BS 5588: Part 5. 1991. The risk analysis must consider the potential effects of water on the elevator system stairways, but also should consider: • Location of elevator machine space • Drainage within shafts and stairways • Location of sprinkler systems • Design and specification of electrical systems. RADIATION With any fire high temperatures are generated from the combustible source, this radiated heat requires control if it is not to effect people, buildings and life safety systems equipment, if people are in an elevator or stairway, an unprotected or insulated surface, e.g. which has a temperature of 100ΕC will cause a significant injury if a person touches the unprotected surface for risk assessment the following design issues will need to be considered:

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• Effects on elevator methods of suspension • Effects on elevator control wiring and control sub-systems • Effects on surface temperature • Effects on materials and fixing methods POWER SUPPLY A stable and reliable power supply is not only required to operate the elevator during normal and emergency conditions but it is also required to stairways in the form of general lighting, announcing systems or power to the pressurisation fans. The risk analysis will need to consider: • Protection of power supply • Primary and Secondary supplies • Duration of secondary power supplies DISCUSSION The evacuation of buildings by elevators should not be considered as the only means of escape in an emergency condition, correctly designed and positioned stairways will contribute to the buildings evacuation procedures. Architects and Building Developers must not be allowed to “design out” stairways in the fourth generation building but there is possible scope to reduce the overall number of stairways and improve the core/floor ratios. The severity of injuries related to using elevators during normal operation can be considered low, due to the fact that published data does not classify this type of accident. The only relevant accident data relates to injury during construction or maintenance phases of a building life. It is acknowledged possible that psychological effects may occur to passengers trapped in stalled elevators, these are normally phobias or heat stress related and are therefore, not considered to be reported accidents. With the fourth generation of tall buildings it will possibly be a minimum design requirement that evacuation elevators have a design platform based on the fire-fighting elevator. Where building occupant’s safety is concerned the possible extra costs associated with evacuation elevators will become insignificant when compared to possible costs should an accident occur and best possible design and duty of care was not adopted. It is also considered that the possible extra revenue that will be demanded for the safer designed, fourth generation building will significantly contribute to the possible additional elevator costs. CONCLUSIONS Controlled emergency evacuation within the next generation of building by elevators, is a global issue not only for the able bodied but also for the 19% of the working population who have or will have a disability. By use of detailed risk assessment procedures the modern elevator system can be designed to provide safe egress from buildings during emergencies. Design work currently being undertaken includes fault and event trees, occupant behaviour and effects on architectural design. The occupants of the next generation of building will demand the safe evacuation procedure to be only by the intrinsically

safe and reliable elevator system which have been designed, installed, commissioned for emergency evacuation. ACKNOWLEDGEMENTS The author would like to thank all colleagues at Arup for all their practical advice and locating reference material and Joff Manders of the AFAC (Melbourne) for being able to bounce ideas and concepts and most importantly give a firefighters realistic view to a engineering design concept. REFERENCES [1] Anderson C., Wadensten K., Elevator evacuation of a

high-rise building, Ove Arup International Ltd., London, August, 2000. Uuplished.

[2] BS 5588 Fire precautions in the design, construction and

use of buildings: Part 5: 1991 Code of practice for firefighting stairs and lifts , British Standards Institution, London, 1991.

[3] Blythe S., “People with disabilities, issues of egress”,

AFAC/SFS Melbourne Seminar, November, 2000. [4] Carroll J., Johncock A., Proceedings of international fire

engineering & vertical transportation workshop, Ove Arup International Ltd., London, October, 2000. Unpublished.

[5] HSC, Key fact sheets on injuries to employees within the

office based industries reported to local authorities 1994/95 to 1998/99, Health & Safety Commission, U.K..

[6] Howkins R., “In the event of fire – use the elevators”, Elevator Technology 10, IAEE Elevcon 2000, 2000.

[7] Johncock A., “Emergency egress using vertical

transportation systems”, AFAC/SFS Melbourne Seminar, November, 2000.

BIOGRAPHICAL DETAILS Roger E Howkins is an Associate with Ove Arup International Ltd – Research & Development in London and is the leader of their vertical transportation team providing advice and assistance to Arup and private clients on a world-wide basis. He an advocate of the use of the use of elevators in fire conditions and also an authority on Panoramic Elevator design solutions and the systematic method of elevator modernisation and has an active interest in providing “universal access and egress” to building for people with a disability. Roger E Howkins has written a book on Lift Modernisation with a set of visual aids, he has also present technical papers on various aspects of elevator technology World-wide and is a regular contributor to Elevator World. Roger E Howkins is a Companion member of the Chartered Institute of Building Services Engineers (CIBSE) and sits on various National and International Code Committees.

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Technical Notes

Current Technology and Future Developments in Elevator Simulation

Richard D Peters

Peters Research Ltd, Boundary House, Missenden Road, Great Kingshill, Bucks HP15 6EB, UK

Fax: +44 (0)1494 716647 E-mail: richard.peters@peters-research.com

ABSTRACT Elevate is traffic analysis and simulation software used by consultants, elevator companies and researchers world-wide. The program runs under Windows, reflecting the dominance of this platform, and customers expectations for easy to use graphical user interfaces. Other platforms may need to be considered in future years. A detailed description of the main simulation classes provides an outline specification for Elevate’s object orientated elevator simulation. Elevator simulation is becoming increasingly more flexible and powerful. Current and possible future developments to Elevate are discussed. INTRODUCTION Elevator simulation models of varying sophistication have been written and applied for many years. The continuing improvements in computer technology and software development tools make increasing complex and comprehensive simulation models feasible. The author writes primarily from his own experience in developing the traffic analysis and simulation software package, Elevate[1]. Other simulation programs have different approaches, but most of the key issues, variables and functions will be similar. The discussion will be of interest to those who want to understand the basic principles of how an elevator simulation works. For aspiring authors of elevator simulations, the class descriptions and flow diagram provide a good starting point for development. SOFTWARE TECHNOLOGY When writing a simulation, choosing the software technology to apply is an early and important decision. The author began writing elevator simulation programs in the 1980’s. At that time, most engineering programs were being written for the IBM PC with Microsoft DOS. In the early 1990’s Microsoft Windows emerged as the dominant operating system and users began to expect easy to use, graphical user interfaces. Elevate is written using Microsoft Visual C++. This is the author’s favoured development tool as Microsoft Windows is currently the most widely used operating system. C++ allows the developer to apply objected oriented programming as discussed in following sections. It also produces very fast and portable (re-usable) code. Future development tools and platforms for elevator simulation will be determined by the continued dominance or loss in popularity of Windows. If Windows looses favour, alternatives will need to be considered. Two possibilities are:

• Java applications – the Java language is closely related to C++, but runs on a “virtual machine” that is available for different operating systems. So, a single version of the software can run under all popular operating systems. Other single source to multiple platform development tools are emerging, and will be popular with developers.

• Internet applications can be run on the user’s machine

(client side) and on the computer hosting the web site (server side). For an Internet elevator simulation program, the author envisages a client side application in Java to enter data, view the simulation display and present the results. The client side application would link to a server side application, which would perform the simulation calculations in C++ or other language.

Both alternatives are already technically feasible but the development platforms are less mature, so some advanced functionality would not be available, and the programs would run slower than native Windows applications. Software development tools are continually improving, so the best tools for elevator simulation need to be kept under review. Introducing objects Traditional structural programming techniques break a program into several smaller tasks by defining a set of functions. Object oriented programming (OOP) builds on this by introducing objects. In an object, both the variables and functions are grouped together. The behaviour (i.e. the variables and functions) of an object is defined by the class to which it belongs. Each object is an “instance” of a class. Object oriented programming uses abstraction to allow the programmer to consider the important details of the problem in hand, and to ignore unnecessary complexities. Encapsulation is applied to hide the details of a solution so that the solution is easier to understand. For an example of how OOP is mimicking the real world, consider Ginger the cat in Figure 1.

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Returning to elevators, we can define the class elevator with variables such as capacity and speed, and functions such as StartJourney(). We can create as many elevator objects as we need; each elevator object is independent, but may use all the variables and functions defined by the class. OOP helps break down complex problems into manageable parts that are easy to work with as they represent familiar ideas or components. The approach works extremely well for elevator simulation. The author’s original simulation program in Fortran became more difficult to enhance as the program became larger and more complex. Elevate is object orientated and currently has over 20 000 lines of software code, yet adding additional functionality is relatively straightforward. CLASS DESCRIPTIONS Elevate has over 30 classes. Many are related to the user interface and other supporting features. The main simulation classes, their principle variables and functions are discussed in the following subsections. Building class The building class defines the building in terms of number of stories and story heights. The variables and functions are summarised in Table 1.

Motion class The main purpose of the motion class is to enable an elevator object to determine its current position and speed while travelling. It can also tell the elevator when it will arrive at its next stop, and whether or not it can stop in time if a new call is registered in front of its next scheduled stop. The variables and functions for the motion class are defined in Table 2. Implementation is based on ideal elevator kinematics formulae[3]. Examples of the velocity – time plots generated by the motion class are given in Figure 2. Elevator class The elevator class defines an elevator (rated speed, capacity, floors served, etc.) and its current status (position, speed, load, etc.). The motion class is applied to enable the elevator to move according to the selected journey profile. The elevator class includes algorithms to allow elevators to answer landing and car calls according to the principles of directional collective control. (Most elevator control systems adopt a directional collective control strategy regardless of the complexities of the dispatcher algorithms.) The main elevator class variables and functions are defined in Tables 3 and 4.

Class Information Description member variables int m_NoFloors; no of floors in building double m_FloorPositions[MAX_FLOORS]; array of floor heights Functions double BuildingHeight(); calculates building height

Table 1 Building class variables and functions

The world has a class cat. Everything in the cat class has a set of the same variables (no of paws, age, sex, etc.) and a range of functions (if you chase it runs; if you pat it, it purrs). Ginger is an object, and an instance of the cat class. He has all the functions and variables of a cat. The cat class utilises abstraction and encapsulation: If we feed Ginger, he will eat without us having to understand the complexities of his digestive system; we can concentrate on the tasks in hand such as preparing his food and stroking him. Figure 1 Ginger the cat graphic from [2]

22

Class Information Description member variables double m_d; journey distance,(+ for up travel, - for down) (m) double m_D; absolute value of m_d (m) double m_v; rated speed, (always +) (m/s) double m_a; rated acceleration, (always +) (m/s/s) double m_j; rated jerk (always +) (m/s/s/s) double m_Tstart; motor start up delay (s) double m_t; time elapsed since journey commenced (s) double m_StartTime; time journey commenced (s past ref.) double m_CurrentTime; current time (s past ref.) double m_StartPosition; start position (m above ref. height) Functions double JourneyTime(); journey time for trip (s) char Condition(); journey condition (A, B, or C) int Slice(); calculates which time slice journey is in double Distance(); calculates the current distance travelled (m) double Velocity(); calculates the current velocity (m/s) double Acceleration(); calculates the current acceleration (m/s/s) double Jerk(); calculates the current jerk (m/s/s/s) double Position(); calculates current position (m above ref.) double EndTime(); time when journey will be complete (s past ref.) double MinDistance(); calculates minimum journey distance if elevator begins

slowing down immediately (m) int ConfirmDestination(); confirmation that elevator can no longer change

destination, that MinDistance() is same as m_D (1- confirmed, 0 - may change)

void DataChecks(); data checks called by constructor

Table 2 Motion class, variables and functions

0

0.5

1

1.5

2

2.5

3

Vel

ocity

(m/s)

0 2 4 6 8 10 Time (s)

Figure 2 Velocity-time plots generated by motion class

23

Class Information Description about the elevator int m_Capacity; nominal elevator capacity (kg) double m_Velocity; rated elevator velocity (m/s) double m_Acceleration; rated elevator acceleration (m/s/s) double m_Jerk; rated elevator jerk (m/s/s/s) double m_MotorStartDelay; motor start up delay (s) double m_DoorPreOpen; door pre-opening (s) double m_DoorOpen; door open time (s) double m_DoorClose; door closing time (s) double m_DoorDwell1; door dwell time 1 (s) (time doors will wait until closing

if beam not broken) double m_DoorDwell2; door dwell time 2 (s) (time doors will wait until closing

after beams have been broken/cleared) int m_DoorBeams; flag for status of door beams (corresponding to

passenger transfer - 1 beams broken, 0 clear) how the elevator serves the building int m_NoFloors; no of floors in building int m_Home; home floor/default parking position double m_FloorPositions[MAX_FLOORS]; positions of floors in building (m above ref.) int m_FloorsServed[MAX_FLOORS]; floors served by elevator (1 yes, 0 no) about the current status of the elevator int m_CarCall[MAX_FLOORS]; car calls registered (1 registered, 0 not) int m_ParkCall[MAX_FLOORS]; parking calls; doors do not open doors on arrival int m_ParkOpenCall[MAX_FLOORS]; parking calls, elevator parks with doors open int m_UpLandingCalls[MAX_FLOORS]; up landing calls allocated to elevator by dispatcher int m_DownLandingCalls[MAX_FLOORS]; down landing calls allocated by dispatcher int m_TravelStatus; travel status, (1 travelling, 0 at floor) int m_Direction; direction of travel (-1 down, 0 neither, 1 up) double m_DestinationPosition; current destination position (m above ref.) double m_StartPosition; position current journey started (m above ref.) double m_JourneyStart; time elevator journey started (s past ref.) int m_CurrentLoad; current car load (kg) int m_DoorStatus; door status (1 fully open, 2 closing, 3 fully closed, 4

opening) double m_DoorsStart; time doors started opening/closing (s past ref.) double m_TimerT1; time timer T1 began (s past ref.) double m_TimerT2; time timer T2 began (s past ref.) double m_PersonStart; time current person began loading/unloading (s past

ref.) double m_CurrentTime; current time (s past ref.) double m_DestinationTime; arrival time next planned stop (s after ref.) double m_CurrentPosition; current position (m above ref.) double m_CurrentDistance; distance travelled on current trip (m) double m_CurrentVelocity; current velocity (m/s) double m_CurrentAcceleration; current acceleration (m/s/s) double m_CurrentJerk; current jerk (m/s/s/s) double m_QuickestStopPosition; next stop elevator can make (m above ref.) int m_DestinationFloor; current destination floor no.

Table 3 Elevator class variables

24

Class Information Description void Reset(building b); sets elevator to home position, cancels all calls, etc. int StartJourney(int floor); start journey to destination "floor" int ChangeJourney(int floor); change journey, new destination, "floor" void UpdateDestination(); check for calls allocated to elevator and set destination void SetDestination(); set destination/direction travel void Update(double CurrentTime); update time (s); this function updates the status of the

elevator (position, speed, door operation, etc.) void RemoveLandingCall(int direction, int floor); removes landing call - called by class when elevator

arrives at landing int LowestFloorServed(); returns number of lowest floor served by elevator int HighestFloorServed(); returns number of highest floor served by elevator int FloorAt(); return floor no if not travelling int FloorNo(double position); returns floor no at position double QuickestStopPosition(); next stop elevator could make (m above reference) double QuickestStopTime(); time of next stop elevator could make (s after ref.) int QuickestFloorStopFloor(); floor of next stop elevator could make double QuickestFloorStopPosition(); position of next stop elevator could make (m above

reference) double QuickestFloorStopTime(); time of next stop elevator could make (s after ref.)

Table 4 Elevator class functions

Dispatch class The dispatch class defines rules for allocating which elevator serves which calls. When a passenger presses a landing call, the dispatch class decides which elevator should serve the call. The dispatch class variables and functions are defined in Table 5. Person class The person defines a person, what time he/she arrives at the

landing station, where he/she wants to go, their mass, etc. Once the journey is complete, the class provides details about passenger waiting and transit times. Variables and functions of the person class are defined in Table 6. FLOW DIAGRAM Elevate is a time slice simulation; it calculates the status (position, speed, etc.) of the elevators, increments the time, re-calculates status, increments time, and so on. A simplified flow diagram of simulation is given in Figure 3.

Class Information Description member variables int m_Algorithm; dispatcher algorithm no. selected int m_NoFloors; number of floors in building int m_NoElevators; number of elevators double m_FloorPositions[MAX_FLOORS]; floor positions (m above reference) int m_UpLandingCalls[MAX_FLOORS]; up landing calls registered with dispatcher int m_DownLandingCalls[MAX_FLOORS]; down landing calls registered with dispatcher member functions void CancelLandingCalls(elevator l[MAX_ELEVATORS]);

cancel landing call when elevator arrives at floor

void Reset(building b,int NoElevators,elevator l[MAX_ELEVATORS]);

resets dispatcher, sets up member variables

int Update(double CurrentTime,elevator l[MAX_ELEVATORS],motor m[MAX_ELEVATORS], double SimulationTimeStep);

update dispatcher; this function updates the status of the dispatcher, allocating calls, etc.

Table 5 Dispatch class functions and variables

25

Class Information Description member variables double m_TimeArrived; time passenger arrived at landing (s past reference)

(taken to be when call button pressed). int m_ArrivalFloor; arrival floor int m_Destination; destination floor int m_Mass; passenger mass (kg) int m_LoadingThreshold; threshold determining whether passenger will get into

this elevator or wait for the next (%) e.g. 80% means that passenger will not load elevator if the elevator will then be >80% full

double m_LoadingTime; passenger loading time (s) double m_UnloadingTime; passenger unloading time (s) double m_TimeBeganTransfer; variable used to store when passenger transfer (loading

and unloading) began (s past reference) int m_CurrentStatus; current status of passenger's journey; 1 yet to arrive, 2

waiting, 3 loading, 4 travelling, 5 unloading, 6 journey completed

int m_ElevatorUsed; elevator used by passenger double m_TimeElevatorArrived; time responding elevator arrived, taken from when the

doors began to open (s past reference) double m_TimeReachedDestination; time responding elevator reached destination, taken

from when the doors began to open (s past reference) member functions void NewLandingCalls(double CurrentTime,dispatch& d);

registers new landing calls when passenger arrives

void Update(double CurrentTime,int NoElevators,elevator l[MAX_ELEVATORS],dispatch& d);

update status of passengers, adjust elevator load, break/clear beams, etc.

int Direction(); returns direction of call (1 up, -1 down) double WaitingTime(); passenger waiting time (s) double TransitTime(); passenger transit time (s)

Table 6 Person class functions and variables

26

Figure 3 Simplified flow diagram for object orientated elevator simulation

initialise elevator and dispatch objects

generate person objects

set time to when first person object arrives at landing

at correct time person objects register new landing calls with dispatch object

dispatch object allocates landing calls to elevator objects

START

elevator objects update their status (position, door state, etc.) and cancel answered landing/car calls

person objects update their status (waiting, loading, travelling, unloading or journey complete) - when a person object has finished loading, it registers a car call with elevator object

increment time

all person objects completed their journies?

END

YES

NO

27

FUTURE DEVELOPMENTS There are many possible developments to an elevator simulation program such as Elevate. Below are some of the enhancements that are in progress or under consideration. Closer integration with installed control systems Elevate allows users to program their own dispatcher algorithms into a dynamic link library (DLL) which is called by the program. There is ever increasing interest in and demand for this feature; simulation is an excellent tool for developing, testing and demonstrating control systems. Currently customers are programming dispatch algorithms in a format suitable for Elevate. In the future we envisage closer and closer links between Elevate and installed control systems, so that algorithms can be exchanged with compatible systems at the click of a button. Total building models There are a number of pedestrian modelling software tools. These have been developed to model the evacuation of buildings in an emergency, and the flow of people in transport terminals such as airports and train stations. These programs currently have either very crude or no elevator model. We are considering the possibility of linking programs so that the elevator model in Elevate can contribute a total models of building circulation. The more advanced pedestrian modelling software programs are object orientated, so the interface between programs is conceptually simple. In its normal mode, Elevate generates its person objects which push the landing buttons, wait for the elevator, get in and press the car call buttons, etc. In a total building model the person objects will be created by the pedestrian modelling software. A person object will move around the building until he/she needs to use an elevator, when he/she will be introduced into the elevator simulation model. Once their elevator trip is complete, the person object will be returned to the total building model at the new floor level. Traffic analysers In the assessment of passenger service quality, the most important traffic analysis results are average passenger waiting and transit times. Using simulation we can measure these results as we know at what time every passenger arrives, and how and when they are transported. Traffic analysers can be interfaced with an installed elevator control system to record the time every landing and car call is made and cleared. Many modern control systems incorporate similar functionality. A range of traffic and performance measures can be determined, for example: • average response time to landing calls by time of day • distribution of response times • distribution of car calls by floor A traffic analysers does not measure average waiting and transit times as an elevator does not know when someone arrives in a lobby; it only knows when a landing or car call button are pressed. There is often more than one person behind a call, but the traffic analyser will not know this. (For this reason, it is generally unreliable to use a conventional traffic analyser results to assess the demand on an existing system, or to

evaluate the benefits of modernisation. The author recommends that designers carry out surveys counting people as opposed to calls.) Within a simulation program it is straightforward to implement a compete traffic analyser. This will have a number of applications: • if using a simulation to model existing installations with

an installed traffic analyser, the simulation traffic analyser should present similar results.

• there is a theoretical relationship between the passenger

arrival rate and, the time from landing calls being cleared to being re-registered[4]. With simulation it will be possible to investigate this relationship further and possibly develop software that can estimate actual traffic flow from traffic analyser data.

Modelling of new technology Established technology dictates that an elevator moves in one dimension, up and down a shaft. And that there should only be one elevator per shaft. This is a major limitation, especially in high rise buildings where the relative core space required by the elevators is high. The ultimate solution it to have multiple elevators in a single shaft, and for them to be able to overtake though moving in at least two dimensions (side to side as well as up and down). Elevate is currently being extended to model this so that one of our customers can develop an appropriate control system for a research project. The drive technology to apply this control system is yet to be developed, but recent developments in self-propelled elevators [5] suggest that the concept is feasible. Multiple deck elevators Elevate currently models single deck elevators. Double deck elevators will be added to Elevate in due course. If required, it would be feasible to model triple, quadruple or even n deck elevators (where n is any number). CONCLUSIONS Elevator simulation is now readily available and increasingly popular for traffic analysis and control system design. In recent years software technology has developed so that complex programs are easier to develop. Object orientated programming technology is extremely helpful to the developer, and graphical user interfaces help make programs easy to use. An elevator simulation program requires many classes. We have discussed Elevate’s principle simulation classes, which are building, motion, elevator, dispatch and person. Elevate and other simulation programs will continue to be developed to provide increased functionality. Some current and future possible developments have been discussed. The author welcomes other comments and suggestions.

REFERENCES [1] Elevate traffic analysis and simulation software, Elevator

World, Inc.. [2] Perry G., Ross J., Visual C++ 1.5 By Example,

Indianapolis: Que Corp., 1994.

28

[3] Peters R. D., “Ideal lift kinematics: derivation of

formulae for the equations of motion of a lift”, International Journal of Elevator Engineers, Vol. 1, No. 1, 1996.

[4] Peters R. D., “Green Lifts?”, Proceedings of CIBSE

National Conference 1994, The Chartered Institution of Building Services Engineers, 1994.

[5] SchindlerMobile elevator, www.schindler.co.uk TRADEMARKS Elevate is a trademark of Peters Research Ltd. Microsoft, Windows and Visual C++ are either registered trademarks or trademarks of the Microsoft Corporation. BIOGRAPHICAL DETAILS Dr Richard D Peters has a degree in Electrical Engineering, and a Doctorate for research in Vertical Transportation. He is a Chartered Engineer, Member of the Institution of Electrical Engineers, and Member of the Chartered Institution of Building Services Engineers. He is Chairman of the Lifts Group of the Chartered Institution of Building Services Engineers and a visiting lecturer at UMIST.

Dr Peters worked for ten years with international engineering consultants Ove Arup & Partners. In 1997, he set up his own company, Peters Research Ltd to provide software development and engineering consultancy. Dr Peters provides advice on a range of vertical transportation issues to clients and has notable expertise in the mathematical modelling of vertical transportation systems. Dr Peters’ traffic analysis software used world-wide.

29

Technical Notes

Safety Edge Confusion?

David Cooper LECS (UK) Ltd,8 Hyde Gardens, Eastbourne,

East Sussex, BN21 4PN, UK Fax: 0044 1323 431326 Email: davidcooper@lecs.co.uk

The Lift Regulations 1997 states: “4.1 The landing doors and car doors or the two doors together, where motorised, must be fitted with a device to prevent the risk of crushing when they are moving” Badly worded I agree as the clause is not definitive about the item being the victim of the crushing action but my interpretation is that it is intended to mean “to protect a person or persons in the process of crossing the car/landing threshold against the possibility of crushing”. Forgetting the wording and looking at the meaning of the statement we have recently seen a new lift which has: No full height pre-contact detector edges No retractable device No door motor sensing facility But has a single beam light ray unit My immediate interpretation of this is that it fails to comply with the directive. My reasoning is that a light ray only provides limited protection against crushing and only at a certain height. Clause 4.1 states “to prevent the risk of crushing when they are moving”. Again, badly worded but one would have to assume that the clause is meant to prevent crushing per-se and not just at a singular height where the light beam is emitted / received? If one looks at EN81-1 clause 8.7.2.1.1.3 it states: “a protective device shall automatically initiate re-opening of the door in the event of a person being struck, or about to be struck by the door in crossing the entrance during the closing movement”. To my mind the key word are “about to be struck” and “or” as this suggests to me that a light ray alone is insufficient to comply. The confusion comes as to whether the standard means either A or B or simply A or B! It seems to me that the way to comply is to fit a detector edge that satisfies the detection prior to collision to be sure! In my opinion the statutory instrument and the standard are both badly worded and can be interpreted in different ways. On the other side of the coin, and if I were standing in the witness box and giving evidence, I would refer to precedence such as: Previous case histories of people making civil claims against lift owners for having been hit by a set of closing doors and, to what is my mind, a well worded clause in CIBSE Guide D (Chartered Institute of Building Services Engineers) entitled “Transportation Systems in Buildings” which, in section 7.8.6 states:

“photocell detectors provide remote sensing across the complete door entrance. They can be a useful addition inside the car, either on the door returns or built into the detector edge, but they should be provided in addition to a safety edge or detector, not as an alternative” I rest my case!

8

Research Paper

Advancement in Elevator Technology for Construction in Densely Populated Cities

Dante C. M. Lam

KONE Elevator (HK) Ltd, 30/F, Tower 1, Millennium City, 388 Kwun Tong Road, Kowloon, Hong Kong, China Fax: +852 2786 6677 Email: dante.lam@kone.com

Andrew Platten

University of Central Lancashire, U.K.

Rowson K. H. Lee The Hong Kong Polytechnic University

C. M. Yung

Shui On Construction Co., Ltd. ABSTRACT High-rise is the fundamental design criterion for construction in densely populated cities like Hong Kong. It dictates construction method, resources allocation and tender price. While conventional passenger hoist is unable to provide an effective and efficient vertical transportation in high-rise construction, JumpLift™ [a] is developed to serve this purpose with due consideration on safety, productivity and quality, as well as its convertibility to a permanent lift. There are theoretical justifications for the benefits and recognition of JumpLift™ . It is the attempt of this research to quantify the same in the Hong Kong construction industry from the perspective of users, developers and industry.

THE JUMPLIFT™ CONFIGURATION Figure 1 below shows the general arrangement of a JumpLift™ . For illustrative purpose, this JumpLift™ is installed inside a building site at the early construction stage providing an initial lift service from G/F to 6/F.

INTRODUCTION Safety in vertical transportation for construction workers has always been a main concern of the industry. While passenger hoists are still adopting the conventional technology, JumpLift™ , with recent innovative development in the concept and elevator technology, has put much effort to enhance passenger safety. With the successful application of this new vertical transportation means for construction workers, JumpLift™ has set a new standard for the industry and contributed towards a safer and healthier construction environment. BASIC PRINCIPLE OF JUMPLIFT™ JumpLift™ may be defined as the “builder’s lift” for construction use plus “permanent lift” for end users. It is designed to replace conventional passenger hoist used in construction sites. As its name infers, JumpLift™ “jumps” as the building “grows up” and it is converted to a permanent lift finally.

Contrary to a builder's lift which is driven by rack and pinion system on an outer wall of a building, JumpLift™ is driven by traction motor using suspension steel wire ropes inside a permanent enclosed lift shaft. While providing vertical transportation at lower floors, lift installation works are continued to extend the service floors upward in stages in pace with the construction programme. When the lift machine room is completed, the JumpLift™ will then be converted to a permanent lift. During the conversion process, major components such as traction motor, control panel, car and counterweight slings, buffers as well as lift shaft equipment can be retained.

Figure 1 Configuration of JumpLift™

Controller

Protection

Traveling cable

deck

Cathead

Machinery

Suspension ropes

Lift car

Car sling

Counterweight

Buffers

Landing doorG/F

6/F

8/F

9/F

10/F

7/F

11/F

9

Cost saving for financing land cost In the following, a cost model will be established to calculate the cost saving for financing land cost for a project using JumpLift™ . First, the monthly loan payment can be derived as below: z = c (1 + r)-1 + c (1 + r)-2 +… … + c (1 + r)-n

Cost saving for financing land cost using JumpLift™ at today’s price

= Net present value of total loan payment for project using

passenger hoist - Net present value of total loan payment for project using JumpLift™

The JumpLift™ is installed inside a permanent lift shaft with landing doors provided on each floor according to the building design. The top of the shaft is sealed off with a protection deck at 10/F to prevent the ingress of foreign materials and water into the shaft. The hoisting machinery and control panel are located inside the temporary machine room (called cathead) at 8/F to allow the lift car to travel from G/F to 6/F providing lift service to construction workers. Service floors are extended upwards in accordance with the progress of the building by “jumping” the cathead to higher finished levels until the lift machine room is completed. INNOVATIVE CONCEPT AND ADVANCED TECHNOLOGY JumpLift™ is the combination of an innovative concept and advanced technology. In the past, space utilization of a constructing lift shaft did not receive much attention. The JumpLift™ concept makes use of this space for the provision of vertical transport for the construction workers while the building is still under construction. JumpLift™ is powered by a highly innovative permanent magnet synchronous motor named EcoDisc® [b]. The invention of this remarkable hoisting machine brings a major technical revolution in elevator engineering. This machine is a low friction gearless traction drive used in conjunction with advanced V3F control for speed variation. With the elimination of conventional rotor winding, the permanent magnet disc rotor could make the motor more compact in size and lighter in weight without sacrificing the power output. With this design, it becomes possible for a complete hoisting machine assembly to be installed inside a standard lift shaft. THE JUMPLIFT™ COST MODEL This part tries to quantify some outcomes by applying the JumpLift™ technology to high-rise buildings in Hong Kong construction industry. In fact, most data used in this part come from the research of previous studies and some of them are extract of professional journal[1]. Due to the fact that few quantitative studies of this nature are available, it is an attempt to establish relatively simple cost model to demonstrate the cost effective portion of JumpLift™ technique. Literature review and surveys are carried out mainly in the construction industries of Hong Kong and U.K. to gather some norms and means for this part of studies. To summarize the findings, it is noted that one of the most outstanding quantitative achievements of the JumpLift™ application in a speculative property market situation is time saving. This in turn lowers the cost to most developers. It is confessed that there are a number of limitations on these studies because it is difficult to quantify most named intangible advantages and disadvantages in this new technique in a special market environment. As this is a new attempt in Hong Kong construction industry, further studies have to be carried out to quantify other aspects of this new technology in construction industry.

where

z = loan amount (land cost + stamp duty + solicitor fee)

c = monthly loan payment for project using passenger hoist

c’ = monthly loan payment for project using JumpLift™

r = monthly interest rate (r = i/12, whereas i is the annual interest rate)

n = number of terms for project using passenger hoist n’ = number of terms for project using JumpLift™ k = monthly required rate of return (k = g/12, whereas

g is annual required rate of return) Work example: Take a construction site as an example that the loan amount z to be $312,000,000.00. Assume the annual interest rate i is 13% and the annual required rate of return g is 7%. Thus the monthly interest rate r is 1.0833% and the monthly required rate of return k is 0.5833%. When using conventional passenger hoist, take the number of terms n to be 36 months. This can be shortened to 34 months (n’ = 34) if JumpLift™ is applied. Cost saving for financing land cost using JumpLift™ at today’s price

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JumpLift™ = $340,463,129.38 - $338,941,186.89

= $1,521,942.49 The result shows a cost saving of around $1.5M for financing land cost using the JumpLift™ technology. Total cost comparison between Jumplift™ and passenger hoist [2] Taking the running cost into consideration, the total cost in relation to duration for conventional passenger hoist and JumpLift™ are shown in Figure 2 on next page.

For JumpLift™ , the cost calculation is based on the following assumptions:

- Material cost for convertible components is not included but the cost to make good convertible components is included;

- Re-usable components are subject to a linear depreciation of 20% per use;JumpLift™ is rated at 900 kg and running at 1.6 m/s;

- For comparison purpose, JumpLift™ jumps every 6 floors. In reality the number of jumps may be more subject to actual construction planning. Hence the cost may increase.

For passenger hoist, the cost calculation is based on the following assumption:

- The passenger hoist is rated at 1,300 kg and running at 0.65 m/s.

The costs of JumpLift™ are shown separately for private sector housing and public sector housing subject to a different split of convertible / re-usable components. It should be noted that the comparison between JumpLift™ and conventional passenger hoist is not exactly on identical terms. The passenger hoist is on a rental basis. Nevertheless, the total costs for JumpLift™ (private sector housing) and passenger hoist are more or less the same after 18 months of operation. JumpLift™ (public sector housing) remains the most expensive as only nominal components are retained when converted to a permanent lift.

Figure 2 Cost Comparison

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x

11

Further studies The above cost model is to quantify cost saving in using JumpLift™ technology by considering possible time saving in overall development process. The model is independent of other data that are not significantly affected by time saving concerned, i.e. professional fee, advertisement, marketing and the like. Again, the model is derived from previous research data where prevailing standard land lease, stamp duty, development criteria, procedures and the like are considered. This study cannot and is not intended to quantify the intangible benefits and limitations carried by the application of JumpLift™ in Hong Kong construction industry. Further in-depth studies are to be made to cover a wider spectrum including safety, quality, environmental issues, site culture, mentality of workers, synergy effect between builder and sub-contractors on the one side and all other possible limitations on the other. A CASE REPORT The JumpLift™ technology was first applied in Hong Kong at the construction project “Private Sector Participation Scheme Development, Tseung Kwan O Town Lot No. 62, Tseung Kwan O Area 65A, Tseung Kwan O” (TKO62 PSPS Project). The project comprises of eight residential tower blocks, plus carpark and shopping centre. Each residential tower block is 40-storey high, serviced by two low zone lifts (serving G/F to 20/F) and two high zone lifts (serving G/F, 21/F to 40/F). The final configuration of the permanent lifts being:

- Low zone (Lifts No. 1 & 2) – 900 kg / 12 persons / 2.5 m/s

- High zone (Lifts No. 3 & 4) – 900 kg / 12 persons / 3.5 m/s

The scheme adopted the use of one unit of JumpLift™ per block for two of the residential tower blocks. The project team’s decision was to apply the JumpLift™ system in Blocks 1 and 2, using the high zone lift shaft no. 4 in both residential tower blocks. Design features adopted for Jumplift™ System Rated load – The rated load of the JumpLift™ is dictated by the size of the lift shaft. Therefore its maximum rated load cannot exceed that of the permanent lift, i.e. 900 kg for TKO62 PSPS Project. Rated speed – The maximum rated speed of the JumpLift™ is limited to not exceeding 2.0 m/s by local code[3]. The rated speed of the JumpLift™ is designed to be 1.6 m/s. Drive arrangement – The choice of drive arrangement is made to provide the most convenient solution. A “bottom-mounted” arrangement will take up the lowest floor as the temporary lift machine room. Since there is neither basement nor podium floors, the top -driven arrangement is chosen to maintain a free access from the G/F level. Floors served – The JumpLift™ stops at every floor covered by the lift travel. Additional temporary openings have to be reserved at low zone floors for this purpose and later made good upon final conversion to the permanent lift. Jump interval – A 3-floor jump is considered appropriate for TKO62 PSPS Project.

Mechanism of jump – Steel core-forms are used for construction of the lift cores in TKO62 PSPS Project. This construction method causes difficulties in using the tower crane for lifting the JumpLift™ equipment in the jump process. A “self-jump” mechanism using an electric chain hoist is used which saves the trouble of arranging special craneage time of the tower crane. Conversion to permanent lift – To ease the client’s deep concern on the “second-hand” perception of lift equipment, all JumpLift™ equipment will be replaced except the guide rails and their mounting brackets when converting to a permanent passenger lift. Review on actual results achieved The JumpLift™ system was first put into service on 22 September 1999 in Block 1 and 5 October 1999 in Block 2 of TKO62 PSPS Project respectively. Both of them were decommissioned on 15 August 2000. The following are a list of benefits made from the viewpoint of the builder: Not affecting façade finish – The JumpLift™ system adopted for use in TKO62 PSPS Project was installed inside the lift shafts. There was absolutely no effect on the external façade works. This benefit is considered fully achieved by the builder. Continuous monitoring for lift shaft dimensions – Installation of JumpLift™ equipment and guide rails was generally five floors below the floor under construction. Checking of lift shaft dimensions and plumb was done promptly and followed closely with the progress of the structural construction work.

Lifting capacity – The rated load of the JumpLift™ was dictated by that of the permanent lift, i.e. 900 kg in the case of TKO62 PSPS Project. Although the lifting capacity of the JumpLift™ was lower than that of the passenger hoist (1,300 kg), the convenience, efficiency and speed of operation of the JumpLift™ had more than made up the difference. Speed of travel – The rated speed of the JumpLift™ was 1.6 m/s. Comparing with the speed of the passenger hoist, i.e. 0.5 – 0.7 m/s, the efficiency of operation was much better as demonstrated by the frequency of usage of the JumpLift™ .

Operation not hindered by adverse weather – All along the usage period of the JumpLift™ , the equipment had been well shielded off from the weather by the protection devices designed and installed for the application. A set of purposely -built weatherproof deck was provided above the cathead and had been performing very well in keeping rainwater away from the lift shaft and equipment underneath. The installation worked extremely well and enabled continuous lift service even under very adverse weather conditions. Operational safety – The JumpLift™ installation adopted for use in TKO62 PSPS Project incorporated the following safety features, which well surpassed the conventional passenger hoist: - Totally enclosed car cage similar to permanent

passenger lift design; - Solid lift doors similar to permanent passenger lift

design; - Lift car sufficiently lit up with fluorescent light;

- Overload protection with alarm. The constant presence of lift installation team on site provided

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instant and prompt maintenance services that further assured operational safety and reliability of the JumpLift™ . Environmentally friendly – As JumpLift™ was installed inside the enclosed lift shaft, noise and dust emission to the surroundings was kept to a minimum. The “jump” operations were done in fact during night-time but due to the silence of operation and the acoustic insulating effect of the centrally located lift shaft, there had been no problem in the application for the construction noise permit for the work.

Scaffold-free lift installation method – The JumpLift™ installation employed the “scaffold-free” installation method.

The conventional bamboo scaffold was not required. Instead a set of aluminium scaffolding spanning only three floors fixed on top of the cathead was used for the installation of the lift shaft equipment such as guide rail brackets, guide rails and trunkings. This improved safety during the erection process reduced the need for making good work otherwise caused by the erection of the bamboo scaffold. Service available for all floors – The JumpLift™ system adopted at TKO62 PSPS Project made 3-floor jump according to Table 1 below:

Topmost Floor Served Block 1 Block 2

6/F 22/09/1999 - 9/F 29/09/1999 05/10/1999 12/F 05/10/1999 11/10/1999 15/F 21/10/1999 01/11/1999 18/F 15/11/1999 22/11/1999 21/F 30/11/1999 06/12/1999 24/F 17/12/1999 28/12/1999 27/F 08/01/2000 17/01/2000 30/F 26/01/2000 02/02/2000 33/F 21/02/2000 28/02/2000 37/F 01/04/2000 06/04/2000

Table 1

After each jump, lift service was available for all floors from G/F up to the topmost floor, giving the best transportation efficiency. Improved productivity – Work progress for the following trades involving bulky material indicated a general picture of the difference in residential tower blocks using the JumpLift™ system versus that using the conventional passenger and material hoists (Table 2). Progress of work for these trades in Blocks 1 and 2 using the JumpLift™ system was generally ahead of that for Blocks 4 and 7 using the conventional passenger and material hoists. The productivity of overall building activities had improved by 19% by using the JumpLift™ technology.

Availability of permanent lift service – To cater for the extensive works needed to convert to the permanent lift installation, JumpLift™ system for Blocks 1 and 2 was taken out of service for decommissioning on 15 August 2000. Conversion works were completed within 45 days, and permanent lift service was made available well before project completion date. Maintaining lift service – Continuous service of vertical transportation was maintained throughout the construction period. While the JumpLift™ service was suspended for 45 days at the conversion phase, other lifts in Blocks 1 and 2 were already available to provide uninterrupted lift services.

Progress up to (Floor No.)

JumpLift™ Passenger & Material Hoists

Progress Item to Work Date

Block 1 Block 2 Block 4 Block 7

02/01/2000 26/F 24/F 21/F 20/F 06/03/2000 35/F 33/F 30/F 29/F 30/03/2000 38/F 35/F 33/F 31/F Timber door frame

29/04/2000 40/F 40/F 38/F 38/F 02/01/2000 19/F 20/F 15/F 16/F 06/03/2000 33/F 33/F 30/F 31/F 30/03/2000 34/F 34/F 31/F 32/F

Window frame

29/04/2000 40/F 40/F 38/F 37/F 02/01/2000 4/F 5/F 4/F 3/F 06/03/2000 14/F 15/F 13/F 11/F 30/03/2000 20/F 20/F 16/F 13/F

Bath tub

20/04/2000 29/F 29/F 23/F 20/F

Table 2

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CONCLUSION JumpLift™ , with its innovative concept and advanced technology, has set a new standard of vertical transportation for the construction industry. Its advantages of more stringent safety provisions, fast speed, high traffic handling capability, accessibility to every floor, as well as all weather operation provide construction workers an efficient and effective means of lift service that better facilitates site installation, supervision, inspection as well as quality control works that in turn lead to a shortened construction cycle. From the case report, observation showed that the productivity of overall building activities had improved by 19% by using the JumpLift™ technology. There is, however, still room for enhancement. In the case report, the JumpLift™ and conventional passenger hoist were applied with identical project planning. If project planning were specially programmed for the JumpLift™ , the productivity of overall building activities would definitely be further improved. In densely populated cities like Hong Kong, the building construction industry is usually planned in fast track operation. However, project planning is usually constrained by inefficient and ineffective vertical transportation. JumpLift™ will therefore be the solution. For the sake of further developing our construction industry, it is absolutely worthwhile to explore more from the JumpLift™ technology, especially on legislation, monitoring and promotion … . REMARKS [a] JumpLift™ is a trademark of KONE Corporation. [b] EcoDisc® is a registered trademark of KONE Corporation. REFERENCES [1] The Hong Kong Surveyor, Hong Kong Institute of

Surveyors, Vol. 11, Issue 1, March, 2000. [2] Lee, R. K. H., Lam D. C. M., Yung C. M., “Innovative

concept = JumpLift application in building construction”, The Hong Kong Surveyor, Vol. 11, Issue 1, March, 2000, pp.14-21.

[3] Code of practice on the design and construction of

builders’ lifts, Electrical and Mechanical Services Department of H.K.S.A.R., Hong Kong, 1996.

BIOGRAPHICAL DETAILS Dante C. M. Lam MSc(Eng), MIEEE, FHKQMA KONE Elevator (HK) Ltd. Mr Dante C. M. Lam graduated from the University of Warwick with MSc in Engineering. He is now the Director of Field Operations in KONE Elevator (HK) Ltd., one of the leading multi-national elevator companies. During the past 19 years, Mr Lam has taken different managerial positions in both building contractor and E & M contractors. In recent years he has been the speaker and guest lecturer for his profession in some local academic institutes, including the Hong Kong Polytechnic University, Hong Kong Institute of Engineers, Hong Kong Institute of Surveyors, Association of Cost Engineers and some key construction companies in Hong Kong.

Andrew Kevin Platten BSc(Hons), PhD, MCIOB University of Central Lancashire, U.K. Dr Andrew Kevin Platten graduated from the University of Manchester Institute of Science and Technology with BSc (Hons) and PhD in Building Engineering. Currently the Head of Department, Department of Built Environment, University of Central Lancashire, Dr Platten is responsible for the professorial posts, academic members of staff, post graduate research students, as well as the Centre for Research in Fire and Explosion Studies. His main teaching activities include construction design and technology, performance of components and materials, construction and project management – quality management, team leadership and dynamics, project planning and programming. Dr Platten is now involved in a number of research projects and has issued over 20 publications and papers since 1984. Rowson K. H. Lee BSc, MSc, ARICS, AHKIS, FACostE The Hong Kong Polytechnic University Mr Rowson K. H. Lee is a Chartered Surveyor and is lecturing in the faculty of Construction and Land Use, the Hong Kong Polytechnic University. Rowson is the founding member of the Chinese Research Institute of Construction Management, and currently, he is the chairman of the Association of Cost Engineers (H K Region). Rowson has been involved in a number of research projects of main interest in construction contracting and project cost control. C. M. Yung BSc(Eng), CEng, MCIBSE, MHKIE, RPE Shui On Construction Co., Ltd. Ir C. M. Yung is a Chartered Building Services Engineer. Having been working in the construction industry for over 25 years, Ir Yung has extensive experience in the design, installation and maintenance of building services engineering plants and systems. He is now the Manager of the Electrical and Mechanical Engineering Department of Shui On Construction Co., Ltd., one of the leading building construction companies in Hong Kong. In recent years Ir Yung has been involved in the development and introduction of new techniques and methods for application in building construction.