It covers various processes involved in manufacturing of the Shell @MCF/RBL.

1. Modern Coach Factory, Raebareli
Presentation on
“Study Of Shell Manufacturing Process at
MCF/RBL”
Under the guidance of: Submitted by:
Mr. Umesh Singh Shikhar Gupta (VT-294)
(SSE, Training) 1403040099
B.Tech/ME/4th year/B

2. Shell Manufacturing
• The manufacturing of the shell is accomplished
with the assembly of Under frame, Side Walls,
Roof and Roof Bearer, End-Wall Assembly.
• The raw metal comes in the form of rolls of the
metal sheets. Three types of metallic sheets are
used at MCF/RBL viz.
• SSA (Stainless Steel Austenitic)
• SSF (Stainless Steel Ferritic)
• CS (Corten Steel)

3. Shell Manufacturing
1. Side Wall Manufacturing
2. Roof Manufacturing
3. Roof Bearer Manufacturing
4. Underframe Manufacturing
5. Center Buffer Coupler
5. Assembly of Shell
6. Skin Tensioning of Shell

4. 1. Side Wall Manufacturing
• Sheets from CTLS are now fed to CTLS
machine i.e. cut to length cum slitter machine.
• CTLS uncoils the sheet and straightens the
sheets without altering actual thickness and
other parameters of the sheet. After
straightening the sheet Slitting operation is
performed on the sheet.
• The thickness of sidewall sheets is 2mm.

5. CTLS Line

6. CTLS Line

7. 1.Side Wall Manufacturing
• The SSA comes in the size of 1.25 mm, 1.75 mm;
SSF comes in the sizes of 2 mm, 4 mm, 6 mm and
Corten Steel comes in the size of 3.16 mm, 4 mm,
5 mm, 6 mm.
• When the sheets are processed in the CTL line,
the processed sheets are being sent to three
stations viz. Shearing machine, Laser Cutting
machine and Press brake machine (800 tonnes,
160 tonnes, 200 tonnes, 400tonnes).

8. Laser Cutting Machine
• LCM (Laser Cutting Machine) is used to cut
complicated types of profile with a help of the
Laser. At MCF/RBL LCM is used to cut z-
members, U-channels, Angle, Rib, Roof flange,
brackets, etc.

9. Laser cutting and Welding machine
• LCWM (Laser Cutting and Welding machine) is
used to cut the complicated profiles like
window panels of 3-Tier and 2-Tier. It cuts the
required complicated profile with great
accuracy and finish. The operation of LCWM is
automated and the machine is CNC type.

10. Laser cutting and Welding machine
• When the window panels are cut from side
wall sheet then the sheet is send to the CNC
800 Ton Hydraulic Press Machine to form the
window curve of GS, SLR type coaches.

11. Laser cutting and Welding machine

12. Pick and place robot of LCWM

13. Cutting and welding head of LCWM

14. Welding Head performing laser welding of butt joined sheets

15. When the window panels are cut from side wall
sheet then the sheet is send to the CNC 800 Ton
Hydraulic Press Machine to form the window
curve of GS, SLR type coaches.

16. • Now the members are held in their positions. The
side wall assembly is now carried to the Robotic
MIG-Welding station. Where the intersecting
members are weld with each other. This machine
is CNC type and its operation is based on
programme.
• This completes the welding of intersecting
members. Now the CNC spot welding machine
welds the Sheet and members. Note that CNC
MIG- Welding welds the member to member and
CNC Resistance Spot welding is used to weld the
member and sheets.
• Now this completes the side wall assembly.

17. CNC spot welding machine

18. CNC Robotic MIG Welding m/c

19. 2. Roof Manufacturing
• Roof sheets are manufactured from 1.25 &
1.7mm Austenitic Stainless Steel. Roof Arches
are manufactured from 2 mm Ferritic Steel.
End plate and angles are manufactured from 4
mm Ferritic Steel. The middle portion of the
roof sheet is plain and manufactured from 1.7
mm Austenitic Steel. The roof is light weight
as compared to ICF coaches.

20. • The sheets are now formed into shape
consisting of crests and troughs with the help
of CNC 200 ton Hydraulic Press Brake
machine. The material used for roof sheets is
SS.
• These z-sections are now bend into a curve
shape with the help of CNC Stretch-Bending
machine keeping in mind the radius to be
provided to the roof.

21. CNC Stretch Bending machine

22. Roof Assembly station

23. • The end edge of the roof is made into the uniform surface by
removing the crest and troughs. This is achieved by cutting
the edge surface deformities and hammering in so that it
takes the smooth and uniform shape as shown in the figure
below.

24. Assembled roof with ventilator

25. 3. Roof Bearer manufacturing
• The roof bearer is intermediate component used to join the side wall with
the roof. It is not possible to join the roof directly with the side wall
assembly so roof bearer is used as an intermediate component between
the side wall assembly and roof assembly. The reason is such large radius
of bend can only be achieved by use of an intermediate component.

26. 4. Under Frame Manufacturing
• Under frame is the base of any coach on which
the coach body is being build. It must be
sufficiently strong and resistant
• Cross members are held at their respective
positions also brackets are inserted between
them. After this under frame is advanced to the
Robotic MIG Welding station where robotic arms
perform the continuous run welding between
mating parts, these robotic arms are controlled
by a CNC controller based on a program

27. 4. Under Frame Manufacturing

28. Cross members being welded to under frame

29. CNC Robotic MIG Welding station

30. • Then the floor made of corrugated sheets of 1.25
mm thick is plug weld from the top to the cross
members. Then the under frame is inverted and
various components like yaw damper, water tank
mounting brackets are welded at their respective
positions.
• Up to this, whatever we have studied were the
major components of shell. But apart from these
in the completion of the shell body some ready to
assemble components like End wall Assembly is
weld to close the ends of the coach. End wall is
made of ferritic steel. To reduce its weight holes
provided in all stiffeners.

31. End Wall assembly

32. 5. Centre Buffer coupler
• The coupler provides a means of mechanically
connecting individual adjacent vehicles to
make a train. The coupler is located at both
ends of each vehicle. When connected to a
coupler of an adjacent vehicle, it allows the
vehicles to move independently to
accommodate track curvature and elevation
change while remaining connected (coupled)
together.

33. 5. Centre Buffer coupler
• LHB coaches have been provided with tight lock
centre buffer couplers instead of screw coupling.
• Couplers have anti climbing features because of
vertical interlocking. Couplers have adequate
strength for:
• Satisfactory hauling of a train of 26 coaches at
110 kmph
• Satisfactory hauling of a train of 18 coaches at
160 kmph

34. Schematic of CBC
Actual CBC installed

35. 6. Assembly of Shell
• Various steps are involved in the assembly of a
shell are. It starts with the mounting of under
frame, side walls are being carried from their
stations to the assembly station with the help
of EOT crane. This side wall is positioned and
placed over the edge of under frame.

36. 6. Assembly of Shell
• Initially side walls are supported by welding
them with steel rods which are welded to the
floor for making sure that the side wall is
perfectly vertical.
• Manual tacking at specific distances is
required to ensure the perfect mating edge for
feeding it to the robotic MIG welding machine
which performs continuous run welding.

37. Manual MIG welding equipment

38. • Now the roof is being carried with the help of
EOT crane to the shell assembly station and is
put over the side walls.
• The shell is now moved to the CNC MIG
welding machine which welds the edges and
makes the whole shell into a single solid shell.
This machine uses two robotic arms whose
operation is based on a program fed to
controller of CNC machine.

39. CNC MIG Welding station

40. Manual tacking of side wall and under frame

41. 7. Skin Tensioning of Shell
• After the assembly of shell, the final operation
which is done is Skin Tensioning.
A worker doing Skin Tensioning 4 Nozzle torch

42. Skin Tensioning have the following
advantages:
1. Stress relieving
2. Grain refining
3. Hardening of outer sheets
4. Checking of stress corrosions and good look
5. Uniform Shape relieve dents

43. 7. Skin Tensioning of Shell

44. Skin Tensioning equipment