methodology+for+track+linking

7/31/2019 Methodology+for+Track+Linking

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49 SIGNATURE OF THE BIDDER

LINKING OF RAILWAY TRACK WITH SHORT WELDED RAIL PANELS INLCUDING

SUPPLY OF BALLAST

1.0 SETTING OUT OF WORK

1.1 The center line of the BG track and other structures will be initially setout by the

Engineer or his representative and fix the centers and their faces. The contractor

shall thereafter set out the work and every part thereto fully. The contractor shall be

responsible for the accuracy of the lines, levels and dimensions of work in

accordance with the drawings further drawings, directions or instructions supplied at

any time to him and every facility shall be given to the Engineer. The contractor shall

also alter or amend any error in the dimensions, lines or levels or work set out or

constructed by him to the satisfaction of the Engineer.

1.2 The work shall be set out to the satisfaction of the Engineer, but his approval shall

not, nor shall his joining with the contractor in setting out the work relieve the

contractor from his entire and sole responsibility thereof.

1.3 Provide, fix and be responsible for the maintenance of all stakes, templates, profiles,

level marks, points etc., and must take all necessary precautions to prevent their

being removed, altered or disturbed and will be held responsible for the

consequences of such removal, alternations or disturbances should the same take

place for their efficient reinstatement.

2.0 LINKING

2.1 Lead the Rails, PSC sleepers, Points & crossings, ballast and other fittings from the

place where the materials for track are handed over to the site of work either by

head loads or other means and place the sleeper, in required number as specified

spacing and string out, the rails to pairs to facilitate linking of track. The rate quoted

should be inclusive of this element of leading.

2.2 Necessary cutting of rails and drilling of holes wherever necessary in the webs of

Rails to suit fish plate drilling machine, tools, labour consumable stores, handling, all

lead and lift etc.

2.3 The holes drilled should be exact to suit the fish plate holes and in case of chamfered

drilling a wrong hole, cut the end of the Rail and re-drill holes at each end as

required.


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2.4 The Rails shall be connected by means of a pair of fish plates using in the first

instance only 2 fish bolts and nuts, one in each Rail. Where joints are not welded

and provided fish plates jointly before fishing the Rail ends, the fishing edges of the

fish plates, the Rail ends and fish bolts shall be lubricated with contractor's grease

graphite and oil as directed by the Engineer at site of work. Correct expansion gaps

as directed by the Engineer shall be ensured between ends of Rails.

2.5 The points and crossing shall be assembled with full complement of materials as per

the relevant RDSO assembly / sub-assembly drawings at the locations defined by

point/SRJ chainages in the approved layout drawings, over correct spacing of

sleepers and aligned, leveled properly. The spring point lever boxes shall be installed

and all the moving parts shall be well oiled and greased.

2.6 Paint marks shall be made on the Rails paint as directed by the Engineer's

representatives to indicate the spacing of sleepers to be adopted.

2.7 The proposed PSC sleepers are to be placed on the finally leveled formation to the

correct spacing, levels and stringed on to the correct alignment.

2.8 Elastic fasteners such as ERC, grooved rubber sole plate, metal liners etc. shall be

used as per drawings / as directed by the Engineers representative to fasten the

rails to PSC sleepers securely.

2.9 The linked track shall be aligned correctly to the centre line pegs and the remaining

2 fish bolts and nuts shall be tied at each joint and tightened.

2.10 After the completion of the linking and alignment, first packing shall be given by

lifting the track to the required level as per subsequent paras.

2.11 2nd and 3rd packing also shall be carried out to keep up the track to the required

standards as per subsequent paras.

2.12 Handle the materials carefully while trucking out. Any damage or breakage involved

while handling, will have to be borne.

3.0 BALLASTING AND INITIAL PACKING

3.1 Stone ballast should be provided on the rolled formation and spread to the required

cushion as specified in the drawing/as directed by the Engineer-in-charge. After the

skeleton linking is completed should start initial packing.


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5.2 Alignment should be straight as verified by sighting. On curves, the alignment should

conform to correct versines as directed by the Engineer's representative who shall

certify the work. However, not more than a variation of (+/-) 20% will be permitted

at any of the location over the prescribed versines. On straights the variation in

alignment should not exceed 3 mm over 12/13 m rail depending on the rail length.

The alignment shall not deviate by more than

a) On straight 10 M chord 2 mm

b) On curves of more than 600 m radius, on 20 m chord the variation over

theoretical versines shall not exceed by more 4 mm.

c) On curves of radius less than 600 m on 20 m chord the variation over

theoretical versines shall not exceed by more than 5%.

d) Expansion gaps over average gap worked by recording 20 successive joints +

2mm.

e) Joints - Low joints not permitted -High joints not more than 2 mm.

f) Unevenness: - Measured on 3.60 m chord + 5 mm

g) Sleeper spacing with respect to theoretical spacing + 2 mm.

5.3 Gauge - Will be checked with track gauge and should be 1676 mm (5'-6") on straight

and on sharper curves upto 4o and above, 6 mm slack with a permissible variation of

(+) 3 or (-) 3 mm but not exceeding 1 mm between and two consecutive sleepers in

sharper curves.

5.4 Level - will be checked by gauge cum level board. Track should be free from sags

and low joints. Permissible variation of cross levels being (+) 3 mm but not

exceeding 1 mm between any two consecutive sleepers.

5.5 Track should be brought to final stage after rolling the track with light Railway

Engine.

6.0 TOLERANCES IN GEOMETRIC CHARACTERISTICS ON TRACK

S.No. Geometric characteristicsConstruction

toleranceOperatingtolerance

1. GAUGE

a) On straight -3mm to +3mm -3mm to +10 mm

b) On curves:

i) For radius 400 m and above -3mm to +3mm -3mm to 13mm


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S.No. Geometric characteristicsConstruction

toleranceOperatingtolerance

ii) For radius less than 400 m 0 to 6mm 0 to 19 mm

(Gauge should not exceed 1 mm between any two consecutive sleepers)

2. ALIGNMENTa) On straight over a base of 10 m. -2 mm to + 2mm -10mm to + 10mm

b) On curves over chord of 20 m.: -6 mm to + 6mm -7 mm to + 7 mm

3. CROSS LEVELS

a) On straight -3 mm to + 3mm -6 mm to + 6mm

b) On curves -3 mm to + 3mm -5 mm to + 5mm

(Cross level should not vary by more than 1 mm between any two consecutivesleepers)

4. UNEVENNESS

Over a base of 3.6 m -3 mm to + 3mm -10mm to +10 mm

5. TWIST

Over a base of 3.6 m

a) On straight and curved portion 2 mm per metre 3mm per metre

b) Over transition portion of thecurve

1 mm per metre 2mm per metre

7.0 LEVEL CROSSING

7.1 There are certain special requirements of track passing through level crossings,which are indicated below:

PSC sleeper with necessary fittings per rail seat should be used.

Free joint should not fall inside the level crossing and also within 3 m of

approaches from consideration of isolated attention to such joints not being

possible without disturbing the road surface.

Coal tar to be applied on rails of running lines, check rails and the entire

surface of the sleepers

Check rail clearance to be maintained between 51 mm and 57 mm during

service allowing for wear.

Ends of check rail to be flared beyond the edge of road to make the

clearance to 64 mm (on BG) so as to avoid hitting of a wheel set with wheel

flange worn down to 16 mm.

7.2 Wherever the track or the sidings cross roads/cart tracks carried more or less at the

same level as the track, level crossings have to be provided. The standards and


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specifications to which these level crossings should conform are set down here

under.

7.3 All roads/cart tracks should preferably be realigned within the limits of land to cross

the railway track at right angles. Where it is not economically possible to obtain anormal crossing, the skew angle of unmanned/manned level crossings should not be

more than 450.

7.4 At the level crossings, check rails should be fixed between the rails 2 metres more

than the width of gate and should be fixed between the rails with horizontal

clearances from the rail max.57 mm & min. 51 mm vertical clearances 38 mm min.

with check blocks to maintain the gaps. These rails can be of section 52 Kg/60 Kg. In

case of a skew crossing length of the guard rail must be increased in accordance

with the formula

X = L/Sin A

Where, X is the required length, L is the minimum length, measured at right angles

to the centre line of the road and A is the angle between the centre line of the road

and the railway track.

7.5 On road approaches to all level crossings `Stop Boards' should be provided on the

road on either side of level crossing at suitable points within the boundary. These

boards shall be of size 675 mm, 525 mm attached to suitable posts embedded in

concrete and projecting 1.5 m above the road level bearing the indication of an

engine and a legend in bilingual prescribed by the Engineer-in-charge. The paint

used for writing out the legend shall be of luminous variety.

8.0 BRIDGES AND BRIDGE APPROACHES

8.1 Specifications and requirements of track on Bridges and Bridge approaches are

contained in Chapter II, Part G of Indian Railways Permanent Way manual.

8.2 Provision of Guard rails on Bridges.

8.3 Guard rail should be provided on all girder bridges (including Pre-stressed concrete

girder bridges without deck slab) whether major or minor. Guard rails should also be

provided on all major and important ballasted deck bridges and also on such other

minor bridges where derailment may cause serious damages.


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8.4 On all flat top, arch and PRC girder bridges with deck slab, where guard rails are not

provided, the whole width of the bridge between the parapet walls shall be filled with

ballast upto the top of sleeper level.

8.5 Sleepers: On steel girder bridges steel channel sleepers as per RDSO Drawing No.B-1636 and B-1636/1, and on ballasted deck bridges and bridge approaches PSC

sleepers as per RDSO Drg No. RDSO/ T-4089 to 4097, shall be provided to

accommodate the guard rails.

i) The typical arrangement showing important dimensions for fixing guard rails is

shown in the sketch and table below para 275(2) OF IRPWM. The same

should be followed.

ii) The guard rails should be splayed; ends of guard rails should be bent

vertically and buried; and a block of timber fixed at the end. Fixing of guard

rails to the sleepers shall be as shown in RDSO plans for steel channel

sleepers (for steel girder bridges) and PSC sleepers (for ballasted deck

bridges and all bridge approaches).

iii) The top table of the guard rail should not be lower than that of the running rail

by more than 25 mm. In the case of bridges on curves with super-elevated

track, the difference should be measured with reference to a straight line

connecting the running tables of inner and outer rails.

8.1 General

i) Track geometry on the bridge and bridge approaches should be maintained to

the best possible standards.

ii) Rail joints be avoided within three meters of a bridge abutments.

iii) Full section of ballast shall be maintained as per profile given in IRPWM.

iv) Correct cess level should be ensured.

v) Uniform and correct distance between the running rail and guard rail should

be maintained as per the prescribed dimensions.

vi) Where switch expansion joints are provided on the girder bridge, free

movement of the switch should be ensured.

vii) On small span girder bridges, where foot paths are not provided, walkways

should be provided in the centre of track over sleepers to help staff cross the

bridge during their inspection.

9.0 SPECIFICATION FOR TRACK BALLAST

9.1 Scope


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These specifications will be applicable for stone ballast to be used for all types of

sleepers on normal track, turnouts, tunnels and deck slabs etc. on all routes.

9.2 Detailed Specifications

9.2.1 General

Basic Quality: Ballast should be hard durable and as far as possible angular along

edges/corners, free from weathered portions of parent rock, organic impurities and

inorganic residues.

Particle Shape: Ballast should be cubical in shape as far as possible. individual

pieces should not be flaky and should have generally flat faces with not more than

two rounded/sub-rounded faces.

Mode of Manufacture: To ensure uniformity of supply, machine crushed

ballast should be preferred for broad gauge and metre gauge routes, procurement of

hand broken ballast shall be resorted to only with the prior personal approval of the

Engineer.

9.3 Physical Properties

Ballast sample should satisfy the following physical properties in accordance with

IS:2386 Pt. IV-1963 when tested.

- Aggregate abrasion value : 30% Max.

- Aggregate impact value : 20% Max.

The Water Absorption tested as per IS:2386 Pt-III 1963 should not be more than 1%.

9.4 Size and Gradation

Ballast should satisfy the following size and gradation:

a) Retained on 65mm sq. mesh sieve - 5% Maximum

b) Retained on 40mm sq.mesh sieve

for machine crushed ballast - 40% - 60%

c) Retained on 20mm sq.mesh sieve - Not less than 98% for machine

crushed. Not less than 95% for

hand broken.

9.5 Oversize Ballast

i) Retention on 65mm square mesh sieve


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A maximum of 5% ballast retained on 65mm sieve shall be allowed and no

deduction in payment shall be made for this.

ii) In case ballast retained on 40mm square mesh sieve exceeds 60% limit

prescribed in 2.31 (b) above, payment at the following reduces rates shall bemade for the full stack.

iii) 95% of payable rates if retention on 40mm sq.mesh sieve is between 60%

(excluding) and 65% (including).

iv) 90% of payable rates if retention on 40mm sq. mesh sieve is between 65%

(excluding) and 70% (including)

v) In case retention on 40mm square mesh sieve exceeds 70% the stack shall

be rejected.

vi) In case of hand broken ballast supply 40mm sieve analysis may not be

carried out. However ensure that the ballast is well graded between 65mm

and 20mm size.

9.6 Under size Ballast

The Ballast shall be treated as undersize and shall be rejected if:

i) Retention on 40mm sq.mesh sieve is less than 40%

ii) Retention on 20mm square mesh sieve is less than 98% (for machine

crushed) or 95% (for hand broken)

9.7 Method of Sieve Analysis

i) The screen for sieving the ballast shall be of square mesh and shall not be less

than 100cm in length 70cm in breadth and 10cm in height on sides. The

following tolerances in the size of holes for 65mm and 20mm sieve shall be

permitted.

65mm square mesh sieve Plus Minus 1.5mm



The squareness of the individual hole in the sieves viz. 65mm, 40mm and

20mm should be ensured. The sieves to be used for the ballast measurement

shall be obtained from approved suppliers of the Railways.

ii) While carrying out sieve analysis, the screen shall not be kept inclined, but held

horizontally and shaken vigorously. The pieces of ballast retained on the


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screen can be turned with hand to see if they pass through but should not be

pushed through the sieve.

iii) The percentage passing through or retained on the sieves shall be determined by

weight (volume by water displacement method).

9.8 Sampling and Testing

9.8.1 A minimum of 3 samples of ballast for sieve analysis shall be taken for measurement

done on any particular date even if the numbers of stacks to be measured are less

than three.

9.8.2 The tests viz. determination of abrasion value, impact value and water absorption

should be got done through approved laboratories in the presence of the Engineer.

9.8.3 In order to ensure supply of uniform quality of ballast, the following norms shall befollowed in respect of sampling, testing and acceptance.

9.8.4 On supply of the first cum, the tests for size, gradations, abrasion value, impact value

and water absorption (if prescribed) shall be carried out by the presence of the

Engineer. Further supply shall be accepted only after this ballast satisfies the

specifications for these tests.

9.8.5 Subsequent tests shall be carried out as follows:

Supply in stacks Supply inwagonsFor stack of

volume lessthan 100cum

For stack ofvolume morethan 100cum

a) Size and gradation tests.- No. of tests

- Size of one sample *

One for eachstack

0.027 cum

One for eachstack.

0.027 cum forevery 100 cumor part thereof

One for eachwagon.

0.027 cum

b) Abrasion value, impactvalue and water absorptiontest @ testing frequency

One test every 2000 cum.

This sample should be collected using a wooden box of internal dimensions 0.3m x

0.3m x 0.3m from different parts of the stack/wagon.

@ these tests shall be done for the purpose of monitoring quality during supply. In

case of the test results not being as per the prescribed specifications at any stage,

further supplies shall be suspended till suitable corrective action is taken and

supplies ensured as per specifications.


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The above tests may be carried out more frequently if warranted at the discretion of

the Engineer. All tests are based on IS: 2386 Part-IV 1963.

10.0 GENERAL

During the course of construction as well as during maintenance, it has to be

ensured that, there is no infringement to Indian Railway Schedule of Standard

Dimensions (B.G.)

methodology+for+track+linking

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