It cotains brief information of Open web girder standard bridges.

1. PROJECT REPORTPROJECT REPORT
onon
Course No. 10109Course No. 10109
By-By-
T.VIJAYAKUMAR AXEN/FBW/AJJ, S. RLYT.VIJAYAKUMAR AXEN/FBW/AJJ, S. RLY
S.ARUMUGAM ARULAPPAN AXEN/CN/TBM,S.ARUMUGAM ARULAPPAN AXEN/CN/TBM,
S.RLYS.RLY
H.S.SAXENA, AXEN(CON)/CCG, W. RLYH.S.SAXENA, AXEN(CON)/CCG, W. RLY

2. AcknowledgementAcknowledgement
We are grateful to –We are grateful to –
Sri V.B.SOOD, Professor BridgesSri V.B.SOOD, Professor Bridges
Who has guided us right through the study of this projectWho has guided us right through the study of this project..
We are also thankful to-We are also thankful to-
Sri N.K.KHARE, Course Director.Sri N.K.KHARE, Course Director.
For having helped us in training programme.For having helped us in training programme.

3. 3
INTRODUCTIONINTRODUCTION
 Open web girders are used for track bridges over valleysOpen web girders are used for track bridges over valleys
and large rivers.and large rivers.
 Standard length of open web girders in railways areStandard length of open web girders in railways are 30.5,30.5,
45.7, 61.045.7, 61.0 andand 76.276.2 metres.metres.
 Engineering workshops, Arakkonam is fabricating weldedEngineering workshops, Arakkonam is fabricating welded
type girder since 1981. Present production capacity istype girder since 1981. Present production capacity is 8080
MTMT per month.per month.
 With the past experience in welded girder fabrication, thisWith the past experience in welded girder fabrication, this
workshop taken up the work of fabrication open web girderworkshop taken up the work of fabrication open web girder
30.5m span for SC Railways in30.5m span for SC Railways in Purna - AkolaPurna - Akola section.section.
 Subsequently EWS/AJJ has manufactured 4 spans of openSubsequently EWS/AJJ has manufactured 4 spans of open
web girder 45.7m span for Nethravathi Bridge.web girder 45.7m span for Nethravathi Bridge.
 Presently, fabrication of 61.0m riveted type girder of 10Presently, fabrication of 61.0m riveted type girder of 10
spans for North Eastern Railway is under progress.

4. 4
SALIENT FEATURES OFSALIENT FEATURES OF
OPEN WEB GIRDEROPEN WEB GIRDER
 RDSO Drg No. BA – 11461 to BA – 11479 (M.B.G.RDSO Drg No. BA – 11461 to BA – 11479 (M.B.G.
Standard)Standard)
 Weight of girder – 65 MTWeight of girder – 65 MT
 Overall length of girder – 32.460mOverall length of girder – 32.460m
 Effective length of girder – 31.926m (Center toEffective length of girder – 31.926m (Center to
center of Bearings)center of Bearings)
 Height of girder – 7.637mHeight of girder – 7.637m
 Width of girder – 5.760mWidth of girder – 5.760m
 Type of loading – MBG LoadingType of loading – MBG Loading

5. 5
Flow Process Chart for Fabricating Open Web GirderFlow Process Chart for Fabricating Open Web Girder

6. 6
INSPECTION OF WELDEDINSPECTION OF WELDED
TYPE GIRDERSTYPE GIRDERS
 INSPECTION BEFORE WELDINGINSPECTION BEFORE WELDING
 INSPECTION DURING WELDINGINSPECTION DURING WELDING
 INSPECTION AFTER WELDINGINSPECTION AFTER WELDING

7. 7
INSPECTION BEFOREINSPECTION BEFORE
WELDINGWELDING
 Inspection of raw steel and its conformation to IS : 2062 Gr. ‘B’Inspection of raw steel and its conformation to IS : 2062 Gr. ‘B’
killed and normalised variety for plates over 12 mm thick.killed and normalised variety for plates over 12 mm thick.
 For plates of 10 mm and 12 mm thick, the condition ofFor plates of 10 mm and 12 mm thick, the condition of
normalisation is not necessarynormalisation is not necessary..
 In the absence of SAIL or Mill certificate, samples of plates withIn the absence of SAIL or Mill certificate, samples of plates with
code no. are being tested at ACMT/LAB/EWS/AJJ.code no. are being tested at ACMT/LAB/EWS/AJJ.
 Preparation of welding procedures specification sheets for variousPreparation of welding procedures specification sheets for various
welds involved in the fabrication of a particular span.welds involved in the fabrication of a particular span.
 Welding procedure qualification records and approval of weldersWelding procedure qualification records and approval of welders
are to be taken up after the approval of WPSS is received. (Ref.are to be taken up after the approval of WPSS is received. (Ref.
IS - 7307 part I and IS – 7310 part I).IS - 7307 part I and IS – 7310 part I).
 Whether welding consumables are of the brands as per the latestWhether welding consumables are of the brands as per the latest
instructions received from RDSO, as supplemented to IRS-M.28instructions received from RDSO, as supplemented to IRS-M.28
and IRS-M.39.and IRS-M.39.
 Transferring of cast number to cut pieces from parent metal.Transferring of cast number to cut pieces from parent metal.

8. 8
INSPECTION DURING WELDINGINSPECTION DURING WELDING
 Checking whether approved welding consumables are usedChecking whether approved welding consumables are used
by the welders.by the welders.
 Checking whether the approved welders do the weld.Checking whether the approved welders do the weld.
 Checking the approved parameters for welding is beingChecking the approved parameters for welding is being
employed and are being recorded in the register.employed and are being recorded in the register.
 Checking for any distortions and suggesting methods toChecking for any distortions and suggesting methods to
minimize them.minimize them.
 Marking defects etc observed during the inspection forMarking defects etc observed during the inspection for
rectification.rectification.
 Attempts to make I-section or any other member is permittedAttempts to make I-section or any other member is permitted
only after passing Radiographic Test on the Butt welded joint.only after passing Radiographic Test on the Butt welded joint.

9. 9
INSPECTION AFTERINSPECTION AFTER
WELDINGWELDING
 The fillet welds are checked by visual andThe fillet welds are checked by visual and
Dye-penetrant test.Dye-penetrant test.
 Defects noticed are to be rectified and detailsDefects noticed are to be rectified and details
are recorded.are recorded.
 Etching tests.Etching tests.
 Radiographic film test.Radiographic film test.

10. 10
VISUAL INSPECTIONVISUAL INSPECTION
 The finished welds shall be visually inspected and shall conformThe finished welds shall be visually inspected and shall conform
to the size and contour specified in the drawing.to the size and contour specified in the drawing.
 The following types of defects can be detected during visualThe following types of defects can be detected during visual
inspection.inspection.
– Weld defects at the surface such as blow holes, pipes,Weld defects at the surface such as blow holes, pipes,
exposed porosity, exposed inclusions, etc.exposed porosity, exposed inclusions, etc.
– Surface cracks in the weld metal or in the parent metalSurface cracks in the weld metal or in the parent metal
adjacent to it.adjacent to it.
– Damage to the parent metal such as undercut, burning,Damage to the parent metal such as undercut, burning,
overheating, etc.overheating, etc.
– Profile defects such as excessive convexity, concavity orProfile defects such as excessive convexity, concavity or
unequal leg lengths etc.unequal leg lengths etc.
– Incorrect finish, uneven welds, spatter, etc.Incorrect finish, uneven welds, spatter, etc.

11. 11
DYE PENETRANT TESTDYE PENETRANT TEST
 In the dye or liquid penetrant testing, a suitable liquid penetrant isIn the dye or liquid penetrant testing, a suitable liquid penetrant is
applied to the surface of the portion under examination andapplied to the surface of the portion under examination and
remains there for a sufficient time to allow the liquid in to anyremains there for a sufficient time to allow the liquid in to any
defect open at the surface.defect open at the surface.
 After the penetration time, the excess penetrant which remains onAfter the penetration time, the excess penetrant which remains on
the surface is removed.the surface is removed.
 Then, a light color absorbent called developer is applied on theThen, a light color absorbent called developer is applied on the
surface.surface.
 This developer acting as a blotter draws out a portion of penetrantThis developer acting as a blotter draws out a portion of penetrant
which had earlier seeped in to the surface opening.which had earlier seeped in to the surface opening.
 As the penetrant is drawn out, it diffuses in to the coating of theAs the penetrant is drawn out, it diffuses in to the coating of the
developer forming the indication of the surface discontinuities as adeveloper forming the indication of the surface discontinuities as a
flaws.flaws.

12. 12
Defects noticed in D.P.Defects noticed in D.P.
TestTest
Blow hole
( Enlarged view )
After rectification of
defects

13. ETCHING TESTSETCHING TESTS
 Etching tests on run-off coupons and at theEtching tests on run-off coupons and at the
edges of girders for checking the root fusionedges of girders for checking the root fusion
and throat length.and throat length.
 Etching tests are conducted on smooth,Etching tests are conducted on smooth,
clean surface by –clean surface by –
– applying 2 % nitric acid.applying 2 % nitric acid.
– cleaning it with water.cleaning it with water.
– cleaning it with alcoholcleaning it with alcohol
 Then check the leg length, throat andThen check the leg length, throat and
penetration and recording the details inpenetration and recording the details in
Etching Test Register.Etching Test Register.

14. 14
RADIOGRAPHIC FILM TESTRADIOGRAPHIC FILM TEST
 Butt joints, if any, have to be done by submerged arc weldingButt joints, if any, have to be done by submerged arc welding
and radiography (Gamma Ray) testing has to be done toand radiography (Gamma Ray) testing has to be done to
ensure the quality of weld.ensure the quality of weld.
 In radiography, the ability of short wave length radiations suchIn radiography, the ability of short wave length radiations such
as X-ray and Gamma rays to penetrate the object opaque toas X-ray and Gamma rays to penetrate the object opaque to
ordinary light is utilized to produce a shadow of any internalordinary light is utilized to produce a shadow of any internal
defect or image.defect or image.
 To check the Internal defects of weld in Butt Weld Joints onTo check the Internal defects of weld in Butt Weld Joints on
Flange and Web plate Joints.Flange and Web plate Joints.
 For radiographic examination, Iridium 192 isotope is used.For radiographic examination, Iridium 192 isotope is used.
Radiographic tests are conducted as per IS : 1182 / 1983.Radiographic tests are conducted as per IS : 1182 / 1983.

15. 15
NUMBERING OF PANELNUMBERING OF PANEL
POINTSPOINTS
30.5 m Span OWG30.5 m Span OWG

16. 16
CAMBER IN STEEL GIRDERCAMBER IN STEEL GIRDER

17. 17
CAMBER IN STEEL GIRDER –CAMBER IN STEEL GIRDER –
Contd..Contd..
 Steel triangulated (open web) girders are providedSteel triangulated (open web) girders are provided
with camber to compensate the deflection underwith camber to compensate the deflection under
load.load.
 Out of the total design camber, the partOut of the total design camber, the part
corresponding to dead load is called dead loadcorresponding to dead load is called dead load
camber.camber.
 The balance is called live load camber which shouldThe balance is called live load camber which should
be available as visible and measurable camber inbe available as visible and measurable camber in
the girder when not carrying the live loadthe girder when not carrying the live load

18. 18
MAIN COMPONENTS OFMAIN COMPONENTS OF
OPEN WEB GIRDEROPEN WEB GIRDER
 PRIMARY MEMBERSPRIMARY MEMBERS
 SECONDARYSECONDARY
MEMBERSMEMBERS

19. 19

20. 20
PRIMARY MEMBERSPRIMARY MEMBERS
 Bottom chordBottom chord
 Top chordTop chord
 End RakersEnd Rakers
 DiagonalsDiagonals
 Vertical membersVertical members
 Floor systemFloor system
– Cross girdersCross girders
– Rail bearers or stringersRail bearers or stringers

21. 21
SECONDARY MEMBERSSECONDARY MEMBERS
 Bottom lateral bracingsBottom lateral bracings
 Top lateral bracingsTop lateral bracings
 Sway bracings and knee swaySway bracings and knee sway
 Portal bracings and knee portalPortal bracings and knee portal
 Corner bracketsCorner brackets
 End stools and end bracketEnd stools and end bracket
 Main gussetsMain gussets
 BearingsBearings

22. 22
BOTTOM CHORDBOTTOM CHORD

23. 23
TOP CHORDTOP CHORD

24. 24
END RAKERSEND RAKERS

25. 25
DIAGONALSDIAGONALS

26. 26
VERTICAL MEMBERSVERTICAL MEMBERS

27. 27
FLOOR SYSTEM –FLOOR SYSTEM – CROSS GIRDERSCROSS GIRDERS

28. 28
FLOOR SYSTEM –FLOOR SYSTEM –
RAIL BEARERS OR STRINGERSRAIL BEARERS OR STRINGERS

29. 29
TRIAL ASSEMBLY AT THETRIAL ASSEMBLY AT THE
WORKSHOPSWORKSHOPS
 Selection of assembly siteSelection of assembly site
 Erection facilitiesErection facilities
 AssemblyAssembly
 Camber measurementCamber measurement

30. 30
SELECTION OF ASSEMBLY SITESELECTION OF ASSEMBLY SITE
 The assembly of Girder has to be done onThe assembly of Girder has to be done on
a firm and leveled platform.a firm and leveled platform.
 Hence, the concrete platform availableHence, the concrete platform available
nearby the Structural Shop was selected.nearby the Structural Shop was selected.

31. 31
ERECTION FACILITIESERECTION FACILITIES
 Road mobile crane was utilized for erection.Road mobile crane was utilized for erection.
 Gantries and Hoist were arranged since theGantries and Hoist were arranged since the
height of the crane was only 9m and theheight of the crane was only 9m and the
requirement was about 10m for handling therequirement was about 10m for handling the
top chord and diagonal.top chord and diagonal.

32. 32
ASSEMBLYASSEMBLY
 The bed for assembly was made with ISMB 400
mm and packing plates about 200mm to facilitate
assembly.
 The bed was checked and leveled with water
level.

33. Contd..
• Bottom chords 2 nos. were
laid from one end with
bottom gussets and the cross
girders assembled in between
bottom chords, also stringers
in between cross girders.

34. Contd..Contd..
 Black bolts 50 %Black bolts 50 %
and drifts 50 % areand drifts 50 % are
used for connectingused for connecting
the joints. (In fieldsthe joints. (In fields
40 % holes filled40 % holes filled
with drifts andwith drifts and
remaining withremaining with
black bolts as perblack bolts as per
manuals.)manuals.)

35. Contd..Contd..
 Similarly the successiveSimilarly the successive
bottom chords were laid withbottom chords were laid with
cross girders and stringers.cross girders and stringers.
 Bottom laterals wereBottom laterals were
assembled in position.assembled in position.
 The cross measurement andThe cross measurement and
diagonal measurementsdiagonal measurements
checked and tightened all thechecked and tightened all the
black bolts.black bolts.
 Insert the camber jacks overInsert the camber jacks over
platform below every bottomplatform below every bottom
panel joints in such away thatpanel joints in such away that
all the joints are in run outall the joints are in run out
condition except central jack.condition except central jack.

36. 36
Contd..Contd.. Levels were taken at top ofLevels were taken at top of
bottom chord at every nodal jointbottom chord at every nodal joint
 Erect all the vertical members atErect all the vertical members at
nodal point and diagonals werenodal point and diagonals were
fixed subsequently withfixed subsequently with
temporary gussets. (Gussetstemporary gussets. (Gussets
holes are drilled for the camberholes are drilled for the camber
profile)profile)
 Check to ensure that bottomCheck to ensure that bottom
chords is in one level.chords is in one level.

37. 37
Contd..Contd..
 Provide camber to all panel joints of bottom chordsProvide camber to all panel joints of bottom chords
as per camber diagram by lowering the jacks atas per camber diagram by lowering the jacks at
the ends, keeping central jacks with out disturbing.the ends, keeping central jacks with out disturbing.
 Check the camber readings and adjust forCheck the camber readings and adjust for
correctness.correctness.

38. contdcontd
 Top chord members are to be elastically strained, so thatTop chord members are to be elastically strained, so that
erected from centre to outwards.erected from centre to outwards.
 Temporary gussets were replaced with permanent gussetsTemporary gussets were replaced with permanent gussets
before drifting.before drifting.
 Drifts are driven with hammer, check for trueness of holes in theDrifts are driven with hammer, check for trueness of holes in the
adjacent group holes.adjacent group holes.
 Care should be taken so that holes are not damaged.( elongatedCare should be taken so that holes are not damaged.( elongated
or teared).or teared).

39. 39
Contd..Contd..
 5 Ton Pulley block was used for5 Ton Pulley block was used for
assembling the members to keep theassembling the members to keep the
joint in position.joint in position.
 End Rakers were erected in the last,End Rakers were erected in the last,
the upper end was first connected andthe upper end was first connected and
drifted, then connection was made atdrifted, then connection was made at
lower end.lower end.
 Sway bracings, top laterals bracingsSway bracings, top laterals bracings
and portal bracing were erectedand portal bracing were erected
subsequently.subsequently.
 All joints were tightened and drifted.All joints were tightened and drifted.

40. Contd..Contd..
 Lowered the jacks duly keeping theLowered the jacks duly keeping the
end supports in position.end supports in position.
 Dead load camber was checked byDead load camber was checked by
leveling instrument, also with waterleveling instrument, also with water
level. The measurements recordedlevel. The measurements recorded
as L1-11 mmas L1-11 mm (13.1 mm)(13.1 mm) , L2- 22 mm, L2- 22 mm
(21.0 mm)(21.0 mm) , L3- 26 mm, L3- 26 mm (26.3 mm)(26.3 mm)
,L4- 22 mm,L4- 22 mm (21.0 mm)(21.0 mm) and L5- 10and L5- 10
mmmm (13.1 mm).(13.1 mm).

41. 41
COST OF THE GIRDERCOST OF THE GIRDER (Per MT)(Per MT)
Revenue RateRevenue Rate
DescriptiDescripti
onon
CostCost
(in Rs.)(in Rs.)
StoresStores 41459.041459.0
44
LabourLabour 26791.926791.9
88
LabourLabour
OncostOncost
31346.631346.6
22
StoresStores
OncostOncost
1607.521607.52
TotalTotal 101205101205
Home Rly. RateHome Rly. Rate
DescriptionDescription
CostCost
(in Rs.)(in Rs.)
RevenueRevenue
RateRate
101205.00101205.00
ProformaProforma
Oncost @ 41%Oncost @ 41%
23836.8323836.83
FreightFreight 3014.663014.66
TotalTotal 128057128057
Foreign Rly. RateForeign Rly. Rate
DescriptionDescription
CostCost
(in Rs.)(in Rs.)
RevenueRevenue
RateRate
101205.0101205.0
00
ProformaProforma
Oncost @Oncost @
91%91%
52906.1352906.13
FreightFreight 3014.663014.66
SupervisionSupervision 4608.124608.12
ProfitProfit 10882.7910882.79
TotalTotal 172617172617

42. PROBLEM ENCOUNTERED &PROBLEM ENCOUNTERED &
REMEDIAL MEASURES.REMEDIAL MEASURES.
 The Bottom chords after fastening with bolts and drifting,The Bottom chords after fastening with bolts and drifting,
the jacks were lowered for the camber but due to thethe jacks were lowered for the camber but due to the
shorter length of bottom chord member, the camber notshorter length of bottom chord member, the camber not
formed.formed.
Solution:Solution:
 The bottom chord joints were loosened and replacedThe bottom chord joints were loosened and replaced
with under size bolts and also removed drifts , thenwith under size bolts and also removed drifts , then
achieved the required camber after erecting the topachieved the required camber after erecting the top
chord and end rakers.chord and end rakers.
 Care was taken to drive the drifts and close supervisionCare was taken to drive the drifts and close supervision
was made to avoid elongation and tearing of drilledwas made to avoid elongation and tearing of drilled
holes in gussets and members.holes in gussets and members.

43. PROBLEM ENCOUNTERED &PROBLEM ENCOUNTERED &
REMEDIAL MEASURES.REMEDIAL MEASURES.
 Leveling instruments were tried to measure theLeveling instruments were tried to measure the
camber. It was a failure due to the poor accuracy incamber. It was a failure due to the poor accuracy in
reading on a length of 30M.reading on a length of 30M.
 Measuring of camber with Piano wire 0.5mm DIA, 10Measuring of camber with Piano wire 0.5mm DIA, 10
kg weight at both end as per bridge code was akg weight at both end as per bridge code was a
failure due to sag in 30M length.failure due to sag in 30M length.
Solution:Solution:
 Water level with a diameter of 6 mm and length ofWater level with a diameter of 6 mm and length of
40M was used to check the level of the girder.40M was used to check the level of the girder.

44. PROBLEM ENCOUNTERED &PROBLEM ENCOUNTERED &
REMEDIAL MEASURES.REMEDIAL MEASURES.
 Slight deformation of the chord members fabricatedSlight deformation of the chord members fabricated
by welding has been observed and some gap wasby welding has been observed and some gap was
formed between top chord end and junction U1.formed between top chord end and junction U1.
Solution:Solution:
 Jacks were used to close the gap by lifting the floorJacks were used to close the gap by lifting the floor
system. Further, 5 Ton pulley block was used tosystem. Further, 5 Ton pulley block was used to
erect the member in position.erect the member in position.