I'm Irfan Nasir. Currently studying Civil Engineering at Mehran University of Engineering and Technology. This is a slide made by me on Defects in rails from the subject Transportation Engineering.

1. DEFECTS IN RAILS
Railway Engineering
Transportation Engineering

2. DEFECTS IN RAILS
Subject:Transportation Engineering
Topic: Railway Engineering
SubTopic: Defects in Rails
Slides presented by Irfan Nasir
F16CE-79
2ndYear, 3rd Semester
Section-C
Department of Civil Engineering
SubjectTeacher: Mr.Abdul Raqeeb Memon
Mehran University of Engineering &Technology Jamshoro Sindh Pakistan

3. Corrugated Rails
In certain places, the heads of the rails
are found not straight but corrugated
i.e., with a wavy surface.This
phenomena is called Corrugation and
the rails are called Corrugated Rails.

4. Examples from a metro system and from
the UK main-line railway are shown in Figs 3 and 4

5. Occurrence
 Corrugation occurs primarily in straight track and gentle curves, where
curving is undertaken with minimal flange (rim) contact.
 It is more likely to occur on the high than on the low rail in curves and is
associated also with track carrying relatively light axle load traffic, i.e.
<20 ton.
 In long tunnels along a track.
 On electrified section of a railway track
 If ballast consists of broken bricks, chances of corrugation are high

6. Causes
The phenomena of corrugation is complex and it is not possible to mention the
specific causes.
The following are possible factors which cause corrugation
1. Coning of engine wheels
2. Excessive slack or excessive tight gauge.
3. High speed of trains.
4. Non-uniformity of the diameter of engine wheels.
5. Presence of high humidity and dust in the atmosphere
6. Slipping of wheels of engines,
7. Small spacing between driving axles of the locomotives,
8. Steep gradient,
9. Sudden application of brakes,
10. Use of light wagons and coaches,
11. Use of steel having high nitrogen content and high tensile strength
12. Soft ballast
13. Vibration during rolling of rail section, etc
Conning is done to maintain the
vehicle in the central position
with respect to the track.
More info on conning
https://civilcompanion.wordpress.com/2016/08/09/c
oning-of-wheels/

7. Examples of Corrugation
For more information regarding corrugation visit
http://railmeasurement.com/assets/docs/090709-JRRT-corrugation.pdf

8. Hogged Rails
■ The rails which are bent vertically at the
ends are known as hogged rails and they are
formed due to wear of rails on ends.

9. Causes
Due to battering action of wheels over the
end of the rails, the rails get bent down
and get deflected at the ends.
Battering action
To damage, as by heavy wear:

10. How to rectify Hogged Rails
1. Cropping
The hogged rails should be removed and
replaced by new rails. However this will be very
uneconomical. But some economy is achieved by
using hogged rails on some unimportant lines

11. How to rectify Hogged Rails
2. Replacement
The end portion of the rail is cut-off and fresh
holes are provided for fish-plates and new rails
are attached.This cutting can be done either at
depot or at site.
This is done when the cropping is not sufficient
and if due to cropping the length of track is
shortened.

12. How to rectify Hogged Rails
3.Welding
Can also be improved by welding the worn ends of the rails.

13. The hogged rails can be improved or straightened
by some simple device such as dehogged maching.
It consists of a
1. Bottle jack
2. Length of old rail
3. Two sets of clamps
Note: It is used only when damage of track is not
large
How to rectify Hogged Rails
4. Dehogging
More info
http://www.brainkart.com/article/Dehogging-of-Rail
Ends_4303/

14. Buckling of Rails
Buckling means the track has gone out of its
original position or alignment due to
prevention of expansion of rails in hot weather
on account of temperature variations.

15. Example
Thermal Buckling

16. Precautions
The expansion gap should be sufficient,
The fish bolts should not be tightened up to such an extent as to prevent expansion or
contraction of rails
The contact surfaces between the fish plates and rails should be periodically lubricated,.
Precautions should be taken to reduce the creep,
Causes of Buckling
Insufficient expansion gape
Excessive tightness of the joint

17. Creep in Rails
 Creep in rail is defined as
the longitudinal movement
of the rails in the track in
the direction of motion of
locomotives.
 Creep is common to all
railways and its value varies
from almost nothing to
about 6 inches or 16cm.
More info on creep
http://www.engineeringarticles.org/wh
at-is-creep-in-rail/

19. Results of Creep
 Sleepers move out of the position
 Gauge disturbance
 Gap variation at joints and other parts, results in uneven stresses
 Points and crossings will be disturbed
 Difficult to refix rail with creep
 Interlocking mechanism also gets disturbed

20. Split Heads
In this type of failure, the head of rail is split up into two parts. If the surface of
cracks appears smooth and dark, when opened, the defective rail is known as
piped rail and is due to cavity formed during manufacture.
The vertical split head (UIC 113, 213) type of defect can be ascribed mainly to
metallurgical problems in the production of the rails.
More info on split heads
http://www.eurailscout.c
om/services/rail/-
vertical-split-head-
detection/

21. Vertical Split Heads cond…
Steel production methods used in the past, such as theThomas process generate a higher
concentration of phosphorus, Sulphur, nitrogen, manganese and hydrogen in the vertical
plane of symmetry of the rail.
If there are additional inclusions present in this level when the steel is produced, then this
may lead to the formation of cracks in the rail over a length of up to 120 meters and thus
to the breakage of the rail head over a great length.Thus, the vertical split head must be
ranked as one of the most dangerous rail defects.

22. Transverse Fissures
This is developed in the form of a fissure or a hole in the head of a rail. It is in the form of a
cross-wire crack which starts from a point inside the head and exhibits a sooth oval or
round bright spot.
Causes
It is due to defect of manufacture or due to overstraining of metal in service.
This defect is dangerous in the sense that the rail breaks before the defect becomes
visible causing the failure of the track

23. In this type of failure, a fissure is developed in the section of the rail and it gradually goes
on increasing. It is due to worn fish plates or insufficient ballast packing under the joint
sleepers.
Horizontal Fissure

24. THE END
ThankYou for your attention