workshop Practices in Fabrication of girder.

1. Presentation on First Phase of
Training
By:
MOHD FURQAN
J.E (BRIDGE)
Presented To:
MOHAMMAD FAIZ
XEN(B & F),Manmad

2. Bridge Engineering Dept.
• Bridge Dept. is responsible for upkeep and maintenance of all
type of Girder Bridges of 12.2 m and above spans.
• Includes Technical inspection of steel structure, oiling &
greasing of bearing, painting of structure etc.

3. TRAINING
@ CENTRAL ENGINEERING
WORKSHOP

4. DRAWING SECTION
As per work order, Drawing are received from RDSO (Research
Design & Standard Organization), Lucknow.
Drawing Comprises of these many Sheets.
1.General Arrangement.
2.Stress sheet.
3.Camber diagram.
4.Details of Bearing.
5.Details of Top & Bottom Chord.
6.Details of End Raker & Portal Bracing.
7.Details of vertical & Diagonal.
8.Details of bottom & top chord joint.
9.Details of cross Girder & Stringer/Rail Bearer.
10.Details of Sway Bracing , bottom and Top lateral Bracing.
11.Erection Drawing.
12.Shipping list.

5. General Arrangement

6. Stress sheet

7. Camber diagram

8. Details of Bearing

9. Work done by Drawing Section.
• To study updated Drawings Received from
RDSO.
• To Calculate Its Weight and Cost.
• To calculate its Painting Area.
• To prepare Estimates & Technical Check of
Bills.

10. TEMPLATE SHOP
• Templating means Setting out Drawing to the
Scale on Floor.
• Layout is Plotted for Nominal
Dim. As well as Camber Dim.
• Material List: Means material
required for fabrication of bridge.
• Working Drawing: Drawing
that fabrication unit understands.
Note: Templating can be done on
Autocad Software instead of Floor also. Template Floor

11. Duties of Template Shop.
• Layout plotting on Template Floor.
• Preparing Material/Cutting List.
• To calculate Weight each Member.
• To find Painting Area.
• Provide working drawing to fabricators.

12. CUTTING SECTION
• MARKING.
• CUTTING TOLERANCE: While Marking, Cutting
Allowance as per IS 1852.
• GAS REQUIRED: Oxy- Acetylene.
• PRESSURE: 1.5 Kg/ sq. cm for Acetylene.
for Oxygen it may vary with Thickness.
• NOTE: Undercutting & Overcutting shall both be avoided.
Thickness (mm) Tolerance (mm)
Below 16 3
16-32 4
32-50 5
50 above 6

13. Top Flange Cutting by PUG machine
Angle Section Cut
Stiffeners Cutting by GAS Cutter.

14. JIG SECTION
• What is JIG?
It’s a custom made tool, used to control the Location of Drill
holes.
Drilling with the Help of JIG. 30.5 m Top Flange JIG.

15. -Master Piece: Component of Bridge to its Actual
Dimension as per Drawing.
- Jig: An Assembly used for Precise Drilling as to
obtained Symmetric Pieces.
• Note: Each & every time Bushes are checked with Plug
Gauge.
• Master & JIGs are verified by PCO & RDSO Seperately.
Fabricating JIG for Diagonal
Member.

16. PLUG GAUGE
• Simply GO-NOGO Gauge.
• Go End should go inside ferrule,
that shows diameter of jig hole is ok.
• If No-Go End plug gauge goes inside
bush hole, bush has to be replaced
with new one. Ferrule or Bush
Plug Gauge

17. Work done by Jig Section
• To fabricate Master Piece.
• To fabricate New Jigs.
• Repair & Maintenance of Old Jig.
• Bent Plate of 30.5,45.7,61.0 & 76.2 m Span.
Bottom Gusset at Lo

18. WELDING SHOP
• To Join various Structural members
• Types of Joint such as Butt, Tee, Lap and
Corner joint are as follows.
Fillet Welds

19. Members Depicting welded portions.

20. Flaws Introduced during Welding.
• Incomplete Fusion.
• Porosities.
• Blow holes.
• Undercuts.
• Hot & Cold cracks.

21. RIVETTING SHOP
• Riveted connection are used for connecting various
Structural Members.
• Rivets are superior to bolts as they are hammered up,
while Hot and they contract on cooling thereby
causing frictional resistance b/w connected metal
surface.
• Rivets are heated uniformly to a light Cherry Red
Color.(temp. b/w 550-1000 Celsius).
• For snap head,Lenth of Grip is calculated
L=G+G/8+1.5D

22. Types of Rivet Heads

23. Riveting

24. Defects in Rivets.
• Cracked Head.
• Over burnt Rivet.
• Loose Rivet.
• Variable Shank Length.
Note:110 gm Hammer is used to detect loose
Rivets on site.

25. SAW SECTION
• Submerged Arc Welding as arc is Submerged
Under Flux.
• Flux: Granulated flux shields and
protects molten weld from atmospheric
contamination.
• Electrode Wire: SAW filler material usually
a standard wire, Electrodes are generally
copper coated to prevent rusting and to increase
their electrical conductivity.

26. Advantages of SAW
• Deep weld penetration.
• Minimal welding fume or arc light is emitted.
• Welds produced are sound, uniform, ductile, corrosion resistant.
• Arc is always covered under a blanket of flux, thus there is no chance of
spatter of weld.
Pieces of slag from
Submerged arc welding
SAW Undergoing

27. PAINTING SHOP
Procedure for Painting.
1) First Coat: Zinc Chrome.
2) Second Coat: Zinc Chrome / Red Oxide (Primer).
3) Third Coat: Red Oxide.
Procedure for Metalizing.
1) On metalized Surface apply etch Primer.
2) Second Coat: Zinc Chrome Primer.
3) Third Coat: Aluminum Paint as per IS 2339.
Note: Surface should be cleaned by sand blasting, wire
brush or sand paper before Painting or Metalizing.

28. FABRICATION OF PLATE GIRDER
• Templating.
• Master Jig.
• Material List.
• Material Cutting.
• Edge Grinding.
• Tack Assembly.
• Full SAW.
• Drilling.
• Final Finishing.
• PCO Inspection
• Rectification.
• RDSO Inspection
• Painting.
• Dispatch.
WPG Ready For Dispatch
WPG Ready For Dispatch

29. Site visit @ Bhima Bridge.
• Bridge No & Name: 301/1 Bhima Bridge.
• Span: 18.3 m @ 23 spans.
Purpose:
• During Inspection of bridge it was found that
cracks were developed at top flange.
Solution:
• It was suggested to provide cover plate where
excessive cracks are visible for time being,
after that going to change the whole Top
Flange.

30. Site Visit @ Godavari Bridge
• Bridge No & Name: 193/1 Godavari Bridge.
• Span: 22.66 @ 5 Spans.
Purpose:
• During Inspection of bridge it was found that
Bearing Plate 3 in No's got some crack on its
surface.
Solution:
• Old Bearing Plates were Removed and
replaced by a New one.
• Total 2 hours of block was taken.

31. REFERENCE
• Bridge Manual.
• B1 Specification.
• Steel Structure Fabrication for Railways by
N.L.Nadgouda.
• Inspection & Maintenance of steel girders by
IRICEN,Pune.
• Bridge inspector's handbook by Northern Publication
1987.