Introduction: Defects in a wagon Various defects in a wagon Defects in the wheel of a wagon and its causes Types of defects in a wheel Identification of defects in a wheel Wheel Defect gauge Checking the wheel for different defects using the Wheel defect gauge Defects in an axle Common defects in axles Hot Axle Internal cracks and flaws ( Introduction to Ultrasonic Testing ) Principle of UST

1. WAGON REPAIR WORKSHOP KOTA
(RAJ.) WEST CENTRAL RAILWAY
Submitted by Submitted to
Chanderveer Singh Dr K.B. Rana
16/140
RTU,KOTA

2. LIST OF CONTENTS
• Introduction: Defects in a wagon
• Various defects in a wagon
• Defects in the wheel of a wagon and its causes
• Types of defects in a wheel
• Identification of defects in a wheel
• Wheel Defect gauge
• Checking the wheel for different defects using the
Wheel defect gauge
• Defects in an axle
• Common defects in axles
• Hot Axle
• Internal cracks and flaws ( Introduction to Ultrasonic Testing )
• Principle of UST

3. Defects in a wagon
• Carriages and Wagons are always subjected to
heavy Linear and Transverse forces, wear and
tear, many types of defects can develop in the
components.

4. Various Defects in a Wagon
1)Corrosion of panels, floor plates and roof sheets.
2) Puncturing of panels due to improper loading.
3)Various defects in wheel and axles.
4) Weakening of welded joints due to loss of weld metal by
corrosion, wear and tear.
5)Wearing out of door hinges.
6)Distortion of doors mainly because of mishandling.
7) Defects in bearings system.
8) Wear and tear or breakage of miscellaneous fittings, such as
ladders etc
9) Defects in braking system
10) Defects in suspension system
11) Failure of welded joints.
12) Slackening of rivets due to the combined effect of ageing,
corrosion, wear and tear.

5. DEFECTS IN WHEELS
The main causes of defects in wheel are
1)Separation of metal from the wheel from wear
and tear.
2)Elevated temperatures which are generated
from severe braking.
3)Fatigue cracks propagation.

6. Shelled Tread
• Shelling can be identified by pieces of metal
breaking out of the tread surface in several
places

7. Shattered Rim

8. Thermal Crack
• Thermal cracks appear on a wheel tread due
to intense heating of the wheel arising out of
severe braking.
• Such cracks occur on the tread and generally
progress across the tread in a transverse &
radial direction.

9. Loose Axle
While assembling wheel with axle proper
interference should be maintained between
wheel and axle. Due to improper selection of
interference the wheel may shift outwards or
it may come out completely. Loose axle is a
rejectable defect.

10. Identification of defects in a wheel
• Thin Flange
• Sharp Flange
• Radius too small at the root of flange
• Deep Flange
• Flat faces on Tyre
• Hollow Tyre
To identify the type of defect wheel defect
gauge is used.

11. Wheel Defect Gauge

15. DEFECTS IN AXLES
• The most heavily loaded parts of railway
vehicles are the axles in the wheel.
• Their damage or breakdown would, in fact,
entail considerable material losses and
endanger human lives.

16. Common defects in axles:
• Bent Axle
• Hot Axle
• Failure of lubrication
• Failure of Roller Bearing components

17. Hot Axle
Hot axle in a railway vehicle occurs when inadequate wheel-
bearing lubrication or mechanical flaws (bearing failure) cause
an increase in temperature. If undetected, the bearing
temperature can continue to rise until there is a bearing “burn-
off” which may cause a derailment

18. Internal cracks and flaws
•Repairing and replacing can be done for the components on
which defects can be observed but what about the components
in which the cracks and flaws lie inside the bulk.
•The most effective and most economic solution for this problem
is the ultrasonic testing.

19. Ultrasonic Testing of wheels & Axles:

20. Principle of Ultrasonic Testing

21. Thank You