SKV welds - limitations Fatigue life only 50 % of Rail Skill of welder very important Quality control difficult Heating Tapping fusion The Age of weld also becomes a factor

SKV welds - limitations Requires very close in service monitoring USFD Joggle fish plating Hindrance in track maintenance Its Failure Biggest concern for P way Engineers

Scope of work TWR with FBWP taken up as pilot project Total Sanctioned TWR on SCRly is 700 Km 183 kms to be done through MFBWP in S C Rly Total number of joints – At present being done in SC-DHNE section of HYB divn

The Plant Plant mounted on a Road Truck modified to run on track also Speed on track 5 kmph Unlike Rail cum Road vehicle Turn table not provided Earthwork to be done in continuity of LC road to align the vehicle along the track Fencing to be removed to facilitate turning of vehicle

Working- On track Welding of running rail on which plant is standing is possible Being done in construction projects, however Problem of high joint/ mismatching of rail head has been reported Progress in open line will be limited because of limitation of traffic blocks

Working- Off track Welding can be done in depot made at suitable location Each depot requires a level ground of about x 10 mts. The top surface preferably should be at sleeper top level. Length of depot = lenth of welded panel +length of feed rail + working space. Length of panel - decided by the handling and trucking effort required to take the panel and put it along the track for TRR. Presently 3 rail panel is being made in depot

Working- From 4RP to ∞ 4 rail SW Panels welded in depot are kept in between the rails on the track for further in situ welding Short Panels are not inserted in track and welded to avoid getting high joints In between the rails sufficient level working space is available Running rail will infringe the working of plant if rail kept outside

Working- From 4RP to ∞ By keeping 4 RP on the roller in between the rails as is done in depot Proper head matching and proper butting force for welding is ensured

Working- From 3RP to ∞ The mix of depot and in situ welding ensures Good progress as And three fourth joints are welded in depot. only one fourth joints welded in block

Where is the other end ? Welded panel of any length as required can be made subject to track features like LC gate, bridge, points and Xing, SEJ etc.

Steps

Depot

Welded 4 RP Free rail

Squareness testing Rail cutting

Bringing it to depot Bringing free rail to depot

Web grinding Web grinding for proper current passage

Depot welding Depot Welding

Grinding of Weld

Geometrical tolerance test

USFD testing

Spreading Welded 4 RP along track

Putting the plant on track

Welding along the track Welding on Track

TRRThe Panel

Progress 3 hr block being taken every day Approx 15 joints done in block Correspondingly 15 4 RP to be made in depot hence 45 joints to be done every day in depot To make one KM track panel it will take 3-4 working days

Tests Parameter validation of plant Squareness of rail cut Geometric tolerance of weld after grinding USFD testing Load test

Training Two day course for supervisors in flash butt welding plant Moulaali Operator given training and tested Need for a training centre

Welding contract Cost ( for track where free rail has been converted into LWR with only SKV welds ) Cost of each welding = 2700 Cost of weld per KM = 170 x 2700 = 4.5 lakhs It includes handling of Rail in depot, Handling of short welded panel for in situ welding, grinding of Rail web current passage, grinding of weld for profiling, USFD testing, and cost of pull out test

Cost of ancillary work Approx 2.5 lakh per km It includes Making two cut for each welded joints ie 320 cuts per km trucking out 3 RP from depot to track TRR Making Depot at every two KM

Other precautions/activities

Measuring the corrosion pit

Match marking of rail ends to ensure head matching

Painting of old corrosion pit of liner contact

Sealing of liner contact area

Long welded panel kept on rollers

Problems faced Synchronizing the work Feeding the rail Locations without manned LC gate

Challanges How to do three RP TWR Scheme and schedule will be entirely different

Problems faced Synchronizing the ancillary and welding work Feeding the rail to depot