RELAYING OF TRACK

PQRS

BY

Integrated Course No. 813(14-07-2008 to 26-09-2008)

• Salim Khan DEN,CR• Devendra Kumar AXEN,DMW• M C Mehra AXEN,WCR

SYNOPSIS

�Track renewal was carried out manually in the past. The heaver track structure with highest precision can not be achieved manually. Now the machines have taken over the work of renewal from the last decade.

NECESSITY OF MECHANISATION

�Limited time for traffic blocks

�Heavy structure of Railway track

�Requirement of large work force.

�Progress independent of seasonal variation

�Economical

�Better output & quality

�Improved safety at work site

MEANING OF MECHANISED TRACK RENEWAL

Renewal/Replacement of complete track or itsComponents i.e.rail,sleeper,turnout etc.with the

help of machines

METHODS OF MECHANISED TRACK RENEWAL

• PQRS • TRT• T-28

What is PQRS

PQRS (Plasser’s Quick Relaying System)is a mechanical relaying equipment being used for track renewal i.e. TSR or CTR

PRE-PLANNING

�Longitudinal levels should be taken & preparation of L-Section (i.e. initial level)

�Initial & final profile marked on the drawings�Quantity of ballast required should be assessed

and procured well in advanced�Site selection for base depot�Formation treatment�Deep screening

REQUIRMENTS OF BASE DEPOT

�It should be centrally located.�It should be easily approachable by road�Proper lightening arrangement should be available

for night working�Proper communication system should be available�Standby diesel generator should be available, to

take care the power supply failure.

550 m

AUXILIARY TRACK�Dynamic gauge of 3400mm.�Laid onCST plate or on wooden block @

spacing 2.0 meter.�For the movement of portal cranes.�Service rails are used for AT. If new rails

are available at site,they also may be used.�AT should be 50mm higher then existing

rails.

AUXILIARY TRACK

ACTIVITIES IN BASE DEPOT

�Unloading and proper stacking of new PRC sleepers.

�Fabrication of new panels with released rails

�Loading of new fabricated into BFR’s�Formation of PQRS rake

Contd. --------�Unloading of dismantled/ released panels

by crane�Dismantling of released rail panels�Segregation and stacking of released

materials �Disposal /Dispatch of released materials�Maintenance of machines.

PQRS RAKE

PRE LAYING OPERATIONS

�Remove all the ballast from crib & shoulder up to bottom of sleepers.

�Fittings & sleepers should be complete.�All obstructions should be temporarily

removed.�Whistle caution order for adjacent line

should be issued when mass labour working.

RELAYING OPERATIONS

�Ready memo from track machine operator.�PWI will get the required traffic block from

concern SM.�PQRS rake will proceed to site.�Existing track to be cut in rail panels.�Both cranes will pick up one panel each &

put into empty BFR’s

Contd.-------• Machines will come again, put one panel and load

into same BFR’s.• Leveling the ballast.• Machines will lift prefabricated panels from

BFR’s and put on the leveled surface.• On returning,machines will put released panels

and load into BFR’s• Packing of sleepers.• Stabilization by DGS.• Block clearance.

WORKING IN DOUBLE LINE AREA

� Take care the Infringement to adjacent track as per SOD.

�Infringement of S&T,OHE post and other obstruction should not affect the safe running of trains.

�Both rails should have same level.

WORKING IN PLATFORM AREA

�Due to space constraints,track to be slewed approximately 300mm out side.

�Removal of inside rail of AT.�Slewing the new track inside at original

layout .�Ballasting of track.�Packing & correcting L&X-levels.�Ensure safety of adjoining track.

IN CURVE PORTION�The extra earth work, ballast and treatment of

formations should be planned before actual relaying work.

�While working in curved portion, easement of curve be ensured so that geometry of curve may not disturbed.

�Auxiliary track in circular portion should be laid to provide super elevation as per design of new curve.

IN ELECTRIFIED AREA

�Intimation to elec. Deptt.�Work permit should be taken in writing.�Proper earthing should be done in the block

section. �Restoration of power supply .�Block clearance.

IN CONSTRUCTION PROJECT

�Sleepers are transported and stacked near level crossing.� AT laid with new rails.�Leveling of ballast. �Placing of sleeper at ballasted formation. �Laying of track with AT rails

POST RELAYING OPERATIONS

• Clearance of obstructions.• Complete the fittings, squaring of sleepers.• Recoupment of ballast and boxing of ballast.• Proper lifting and packing of track.• Picking up of left over materials.• Rail renewal.• Welding, laying of SEJ and Glued joint.• Dismantling of AT and laying in forward

direction.

Contd.----

�Restoration of fixture which were removed.�Relaxed speed restriction.

ADVANTAGES

�Damages to the concrete sleeper is avoided.�Better quality of track relaying.�Less requirement of labours as compared to

departmental.�Mechanised relaying is economical and

faster.�Progress of relaying is approximately 400

meter per effective block.

LIMITATIONS

�This is a semi mechanized system.�Auxiliary track often gets disturbed�Failure of portal cranes will pose great threat.�Great threat to restoration to traffic.�Track linking and rail renewal done twice.�Need supervision at two different locations.

CONCLUSION

In order to achieve speed along with quality in the renewal works, the

PQRS is a good method. Proper care in the various preparations will

increase the productivity and reduce time wastage during block.