1. An anchor link in a trailing end bogie of coach SR ACCN 99119 broke while the train was traveling, detaching the coach. Investigation found the anchor link pipe wall thickness was less than specified and there was a lack of fusion in the welding. 2. Both the anchor link and silent block were new parts that did not meet specifications - the silent block was undersized, allowing movement inside the housing. This imbalance led to failure of the improperly welded anchor link. 3. Corrective actions included introducing new testing of welds, ensuring proper sizes of parts, and measuring pressing forces during maintenance to prevent future failures.

1. दिकण रेलवे
SOUTHERN RAILWAY
कॆ दीय कमरशालायॆ, गोलडऩराक
Central Workshops, Goldenrock
ितरिचरापपिलल ६००००४/ Tiruchirappalli 620004
SR ACCN 99119
Anchor Link
Failure Analysis Report

2. COACH FAILURE ANALYSIS REPORT
1. Failure Reported:
Coach No. SR ACCN 99119 was detached en-route from train no. 12642 (NZM – CAPE,
Thirukkural Express) at Vijayawada on 27.01.2015 at about 13.30 hours, due to breakage of
Anchor Link in Trailing End Bogie No. RCF 032123/03 at housing end of Bogie Frame Transom and the
broken portion was hanging. This was found in Rolling-in-Examination when it arrived at PF-5 of
Vijayawada station and the coach was detached. The train resumed its service with a delay of about
100 minutes.
2. Detached Coach Details:
Coach No : SR ACCN 99119
Coach Make RCF
Date of put into service : 10.01.1999
POH : GOC – 10/11/2014
Return Date : 30.06.2016
No. of days worked : 77 days (Failure within 100 days)
Primary Maintenance : NCJ on 23.01.2015
Bogie Details in coach (As per
POH work diary)
: RCF 032123/03 & RCF 062760/06
(Date of POH of Bogies: 27.10.2014)
Owning Railway & Base Depot : S.Rly & TVC
3. Deputation of staff:
The following staff had been deputed & proceeded immediately for investigation of the failure.
1. Mr. P.Sureshkumar, SSE 2. Mr. Gnanasekaran, SSE
4. Joint investigation at Site:
Investigation was conducted at Vijayawada sick line on 28.01.2015 jointly by GOC team &
SSE/C&W/BZA/S.C.Rly. The observations are given below.
4.1 The failed Anchor Link stripped from Bogie No. RCF 032123/03 and put new anchor link.
4.2 The NPEV end of the coach ACCN 99119 left hand side Anchor Link pipe broken on the
welding joint to anchor link housing which is connected to bogie frame.
4.3 The other side of anchor link connected to bolster end. Welding joint is in good condition
and silent block is in slacked condition. The broken anchor link is new with black colour
paint and having sticker as “SGEW 06/13” on anchor link housing outside.
4.4 10% of breakage emanated from weld crack and pipe torn & broken.
4.5 Anchor link pin square end insertion in holding bracket on bogie end was found having
shim tack welding.
4.6 Locking plate was having corner hit marks as well as Anchor Link housing was having hit
marks on bottom.
4.7 Findings by the above team:
4.71 Micro play between Anchor Link housing and silent block coupled with weld defect
caused shearing force and breakage.
4.72 Broken anchor link taken by GOC shop for CMT testing & warranty claim on
supplier.
Page 1 of 7

3. 5. Photographs taken at site (BZA):
6. CMT Lab Analysis at GOC of Breakage of Anchor Link:
The failed anchor link was subjected to CMT lab analysis and the nutshell of the report is given below.
6.1 Observations given in the Lab report:
a) Chemical composition of the Anchor Link is conforming to the specification IS:10748/2004.
b) At the transom end of anchor link, the pipe was broken from the housing along the welded area.
c) Remnants of weld metal are partially available on the anchor link housing with fractured piece of
the pipe.
d) At the bolster end side, the silent block is freely moving inside the housing.
e) The wall thickness of the anchor link pipe is not uniform and varies from 3.62 mm to 3.76 mm as
against the specified value of 4.05 to 4.50 mm as per IS:1161:98 mentioned in drawing no. T-0-7-
604, alt – j/13.
f) About 21% of the circumferential welded area along the housing suffers from lack of fusion/
penetration.
g) The macro examination of fractured surface of the pipe reveals 25% of the area having voids
characteristic of sudden brittle fracture and the remaining 75% is having formation of shearing lips
characteristic of ductile fracture involving high torsion stresses.
6.2 CMT Lab Report - Conclusion:
a) The wall thickness of the anchor link pipe is not uniform and varies from 3.62mm to 3.76mm as
against 4.05mm (4.5mm minus 10% tolerance) specified for Heavy grade mentioned in the
specification IS: 1161/98 referred in the drawing no. T-0-7-604, alt – j/13.
b) Lack of fusion/Penetration of the weld metal with the anchor link pipe along the periphery of the
housing (around 21 %.). It is leading to loss of strength of the weld.
c) The molten metal sputtering near the weldment affecting the region near the weld cast has acted as
an initiation site for the process of failure to occur.
d) The play between the anchor link housing and the coupled silent block on the bolster side has
created an imbalance on the other side of the anchor housing at the transom end.
Page 2 of 7
Broken tube
hanging

4. 7. Dimensional Check of the failed components:
Anchor Link Housing Bore Silent Block
Inner Diameter of Anchor Link
Housing supplied by
M/s. Sugovri Engineering Works,
Howrah
Silent Block (Outer Diameter)
supplied by
M/s. MGM Rubber Co. Kolkata
Interference
Sample
Drawing
Size
(mm)
Side
Actual
(mm)
Sample
Drawing
Size
(mm)
Side
Actual
(mm)
As per
Drawing
Actual
І
90.470
to
90.515
1
1 90.520
І
90.525
to
90.550
1
1 90.260
0.01
to
0.08
0.210
to
0.760
(Clearance
fit)
2 90.490 2 90.280
3 90.510 3 90.280
1 90.520 1 89.760
2 90.460 2 90.140
3 90.450 3 90.130
Note: From the above table, the fit is only clearance fit and as against the force fit. Hence the silent block
is freely moving inside the housing.
90.520
90.490
90.51090.450
90.460
90.520
90.280
90.280
90.260
90.130
90.140
89.760

5. Anchor Link pipe: Thickness of Anchor Link pipe supplied by M/s. Sugovri Engineering
Works, Howrah
Sample
Drawing
Size
Thicknes
s (mm)
Side Location
Actual
Thickness
(mm)
1
4.05 mm
to
4.50 mm
1
1 3.660
2 3.620
3 3.640
4 3.680
5 3.700
6 3.760
7 3.720
8 3.740
Page 3 of 7
8. Traceability of failed components:
8.1 Anchor Link:
The failed anchor link was a new one as per the sticker “SGEW 06/13” available on the anchor link
housing. The procurement details of the item is given below.
Sl.
No.
Supplier Name P.O.No.
Supplied
Qty.
(Nos.)
Received
Date
Inspected
by
1.
M/s. Sugouri
Engineering
Works, Howrah
04.12.0161.1.01521
dated 27.05.2013
886
24.09.201
3
RITES
8.2 Silent Block:
The stamping of manufacturer details on the silent block indicates “MGM 06/14”. The procurement
details is given below.
Sl.
No.
Supplier Name P.O.No.
Supplied
Qty. (Nos.)
Received
Date
Inspected
by
1.
M/s. MGM Rubber
Company, Kolkata
04.13.0160.1.04425
dated 10.02.2014
2500 19.07.2014 RDSO
9. Preventive check on the items available at GOC belonging to the same consignment:
3.660
3.740
3.680
3.720
3.760
3.640
3.620
3.700

6. Anchor Link Silent Block
Inner Diameter of Anchor Link
Housing supplied by
M/s. Sugovri Engineering Works,
Howrah
Silent Block (Outer Diameter)
supplied by
M/s. MGM Rubber Co. Kolkata
Interference
Sample
Drawing
Size
(mm)
Side
Actual
(mm)
Sample
Drawing
Size
(mm)
Side
Actual
(mm)
As per
Drawing
Actual
I
90.470
to
90.515
1
1 90.400
I
90.525
to
90.550
1 90.526
0.01
to
0.08
0.020
to
0.200
2 90.440
2
1 90.510
2 90.602
2 90.510
II
1
1 90.430
II
1 90.602
2 90.510
2
1 90.480
2 90.551
2 90.510
Note: As per the tabulation given above, both the items are confirming to the drawing dimensions.
Page 4 of 7
10. Failure analysis based on the available evidences –Lab Report, dimensional check,
photographs and joint observation by SSEs/GOC & SSE/BZA:
10.1 Based on the identity on the failed components both Anchor Link and Silent Block were newly
fitted during POH.
10.2 Anchor Link housing bore diameter is 90.450 mm to 90.520 mm as against the drawing size of
90.470 mm to 90.515 mm (dimension checked at six locations as per table above).
10.3 Silent block outer diameter is 89.760 mm to 90.280 mm as against the drawing size of 90.525
mm to 90.550 mm. i.e. the silent block is undersize.
1
1
2
1
22
Side 1 Side 2

7. 10.4 The silent block should be force fitted into the Anchor Link Housing. But as per Sl.No. 2 & 3
above, the fit is only clearance fit and hence the silent block is freely moving inside the housing.
10.5 The wall thickness of the anchor link pipe is not uniform and varies from 3.62 mm to 3.76 mm
as against the specified value of 4.05 to 4.50 mm as per IS:1161:98 mentioned in drawing no. T-
0-7-604, alt – j/13.
11. Conclusion:
11.1 The prime reason for the failure is the breakage of Anchor Link pipe at weld point due to lack of
fusion/ penetration. The firm M/s. Sugovri Engineering Works, Howrah had used pipe with
lesser wall thickness and failed to weld properly. The firm should have ensured correct usage of
items with proper quality control during manufacturing process.
11.2 The silent block is found undersize, which causes play between Anchor Link Housing and silent
block. This created imbalance on the other side of the Anchor Link Housing, where weld failure
happened. The firm M/s. MGM Rubber Company, Kolkata should have ensured strict quality
control of their manufacturing process.
11.3 Both the failed items are under warranty and the firms were asked to supply the items as
warranty replacement. The firms had been advised to depute their staff to GOC for joint
inspection of the failed components for further action.
Page 5 of 7
12. Corrective/ preventive actions taken:
The following corrective / preventive actions had been implemented.
Sl.
No.
Maintenance Instructions
as per CAMTECH manual
Clause
No.
Repair Practice followed
at GOC Workshops
Corrective / Preventive
Action taken
1. Replace the anchor link, if
worn or corroded. Repair
the anchor link, if found
cracked (normally at weld
joints) under magna flux
testing, by re welding after
316e (i)
Anchor
Link
Anchor Links dismantled
from POH Bogies are
100% stress relieved in
oven. Then, they are
subjected to chalk test
for welding crack.
a. Magna flux testing is
introduced now to
assess weld quality
of Anchor Link.
b. A Plug gauge has

8. gouging. Refit new silent
block in every POH.
The corroded/ bent/
cracked/ twisted Anchor
Links are disposed as
scrap. No repair is
undertaken in Anchor
Links. New Anchor Links
are replaced in place of
corroded/ bent/
cracked/ twisted ones.
been developed to
check the Anchor
Link Housing bore
before pressing with
silent block.
1 (a) Magna flux testing is introduced now to
assess weld quality of Anchor Link
1(b) Plug gauge has been developed to check the Anchor
Link Housing bore before pressing with silent block.
Page 6 of 7
Sl.
No.
Maintenance Instructions
as per CAMTECH manual
Clause
No.
Repair Practice followed
at GOC Workshops
Corrective / Preventive
Action taken
2. Replace the silent block, if
the rubber is perished
(indicated by fretting) or
loose in the anchor link
housing, or the silent block
pin is worn thin or loose in
silent block rubber.
It is a “Must change item”
in every POH (18 months)
as per CAMTECH/2008/
Coach-POH/1.0 issued
316e (ii)
Anchor
Link
Silent blocks are
renewed 100% during
POH. They are force
fitted in the Anchor Link
using Hydraulic press as
specified.
a. Pressure gauge has
been fitted in the
pressing machine to
observe the
pressing-on
pressure.
b. Ring gauge is made
available to check
the outer diameter
of the silent block
before pressing.

9. inJan-2008 by CAMTECH.
The silent block should be
force fit in the anchor link
and the silent block pin
should be slide fit in the
anchor link bracket.
Note: Corrective/ preventive action mentioned at sl. No. 1(b) & 2(b) ensures the correct
Interference for Force Fit.
Previously Pressing machine
without pressure gauge
Pressing machine with pressure gauge
after fitment
2(a) Pressure gauge has been fitted in the pressing machine to observe the pressing-on pressure
2(b) Ring gauge is made available to check the outer diameter of the silent block before pressing
********
Page 7 of 7
Ring
Gauge

10. inJan-2008 by CAMTECH.
The silent block should be
force fit in the anchor link
and the silent block pin
should be slide fit in the
anchor link bracket.
Note: Corrective/ preventive action mentioned at sl. No. 1(b) & 2(b) ensures the correct
Interference for Force Fit.
Previously Pressing machine
without pressure gauge
Pressing machine with pressure gauge
after fitment
2(a) Pressure gauge has been fitted in the pressing machine to observe the pressing-on pressure
2(b) Ring gauge is made available to check the outer diameter of the silent block before pressing
********
Page 7 of 7
Ring
Gauge