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 – 15000
 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
facilitate turning of vehicle
to
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
 Welding can be done in depot
made at suitable location
 Each depot requires a level ground of
about 80-100 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- Off track
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
only one fourth joints welded in
block
And three fourth
joints are welded in
depot.
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
Depot
Depot
Free rail
Welded 4 RP
Rail
cutting
Squareness
testing
Bringing free rail to
depot
Bringing it to depot
Webgrinding
grinding for proper
Web
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
The Panel
TRR
Progress
 3 hr block being taken every day
 Approx 15 joints done in block
 Correspondingly 15 4RP 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