08 Maintenance of Railway Tracks (Railway Engineering Lectures هندسة السكك الحديدية & Dr. Walied A. Elsaigh)

1. Dr. Walied A. Elsaigh
welsaigh@ksu.edu.sa
Asst. Prof. of Civil Engineering
Jumada’-I 1437H
CE 435
Railway Engineering
Maintenance
of Railway Track

2. Textbook
Page 24-1 to 24-25

3. What is the right time for maintenance ?
Daily (minor defects, manually)
Periodically (every 2-3 years)
Approach to Railway
Track Maintenance
Conventional RT maintenance
Done manually “Labour –based”,
simple tools are used Fully mechanized
Mixed process
(Labour + machines)
Machine-based RT maintenance
(mechanical appliances are used)
Two approaches are basically used for Railway maintenance

4. When RT Maintenance
Become Necessary?
1. Reduction in strength of track
structure due to
Consequences are:
 Changes to alignment.
 Changes to gauge.
 Changes to surface level of rails. Movement of
high speed trains
Heavy axle loads
High loading
Frequency
(repetition)
2. Deterioration of track structure due to environmental effects,
such as: rain water, wind and sun actions.
Consequences:
 Wear and tear of rails & wear to rolling stock.
3. Rail track exhibits other forms of defects such
as on curves, crossing, and bridge approaches.
No maintenance!
Faster wear
Rough riding quality
Derailment leading
to life loss

5. What Are The Advantages
of Proper RT Maintenance?
1. Increases the life of both track and rolling stock.
3. Safer and more comfortable transport mode encourages
more people and goods to use the rail transports leading to
better earning, less damage to environment, additional
economical value to goods…etc.
2. Provides smooth riding quality which brings comfort and
safety to passengers and goods.
4. Allow savings in operation costs (e.g. reduction in fuel
consumption due to reduced friction between rails & wheels).
Probably this is true for each and every engineered structure.

6. Items Checked for Maintenance
1. Surface of Rails
2.Track Alignment
3. Gauge 7. Rolling Stock
5. Track Components
8.Bridges & Tunnels
4. Drainage 6. Points & Crossings
Periodic
Maintenance

7. 1. Surface of Rails Maintenance
At straight sections of RT, the top surface of two rails should
be kept in level (same plane). On curved sections of the RT,
the outer rail should be kept at correct elevation above the
inner rail. This is to maintain the required super-elevation.
Packing
Is the method of forcing the ballast bellow the sleepers.
Deterioration mechanism: Due to heavy loads and vibration caused by
running train, ballast under sleepers get loose and depressions are formed
in plane of rails. Non-uniformity of subgrade would worsen the situation
(remember the importance of consolidation while constructing formation)
Entails the following operations:
Surfacing the Track / Leveling the Track
 Surfacing the track : The whole of the track is brought to a condition of
vertical evenness. Rails and track are kept in uniform level. Equal elevation
in the transverse direction is called leveling.

8. Cont. Surface of
Rails Maintenance
Boxing and Dressing the Track
 This is the process of filling the ballast between sleepers and beyond
ends of sleepers to required shape.
Lifting of the track
 Lifting the depressed track to required height
If lifting is done under traffic, then it should be done in the direction
opposite to traffic .
If both rails needs lifting, then they should be lifted simultaneously.
Spot Packing and Track lifting
 Consists of correcting the defects at a particular point and involves
lifting of 5 to 7 sleepers.
This task is one of the essentials of daily maintenance.
Required when defect extends over considerable length.

9. Cont. Surface of
Rails Maintenance
Surface Defects and Remedies
 Defects manifest due to lack of maintenance. RT defects may include:
High joint or riding joint: Top level of the joint is higher than rail level
why occurs? Due to over-packing of sleepers at joints OR sinking of
sleepers between joints.
Blowing Joints: A blow joint is caused when joint is rested on loose and
dusty ballast.
Mechanism? When wheel load passes over the sleepers resting on dusty
ballast, the sleeper sinks and when the wheel loads are relieved, the
sleeper rises with sucking up dust.
Causes? Thin layer of ballast, week sleepers, dusty ballast, worn out rail
ends, and wide expansion gap.
Remedial action? (1) Clean dirty ballast and repack joints with ballast.
(2) Improvement rail ends (dehogging of rails).
(3) Reduction of expansion gap.

10. Cont. Surface of
Rails Maintenance
Surface Defects and Remedies
Pumping joints: In rainy weather, blowing joint is affected by water and
gets converted into what is termed as “pumping joint”. The joint splashes
water as loads move on.
Causes? Same causes for blowing joints + bad drainage (dirt ballast does
not allow good and quick drainage.
Remedial action? (1) Cleansing of ballast.
(2) Provision of proper drainage.
(3) Remedies listed for blowing joints.
Hogged rails: Due to worn out of rail ends due to load repetition, the rail
gets bent down at its ends, creating what is termed as “hogged rails”.
Consequence ? Rough riding, more vibration leading to more defects.
Causes? loose packing under joints and loose fish plate.
Remedial action? (1) Replace joint, (2) Welding joint, (3) Dehogging,
(4) Cropping {Refer to handout}

11. Cont. Surface of
Rails Maintenance
Surface Defects and Remedies
Buckling of Track: The track, especially in hot weather, goes out of
alignment on both tangents and curves.
Causes? Insufficient gaps at joints, tightened fish plate, welded track with
insufficient strength.
Consequences? Derailment which can lead to fatalities or damage to goods
Remedial action? (1) Tighten & lubricate fish plate to proper joint function.
(2) Use of steel sleepers.
(3) Proper anchoring for welded rails.
Centre bound Track: Under rolling load, settlement of ballast under rail
seat is more than under the centre of sleepers (sleepers deflects more at
the ends), This deflection is named as “centre bound track”.
Remedial action? (1) Loosen ballast under the centre of sleepers and pack
under the ends.
(2) Open a drain under the centre of sleepers.

12. Cont. Surface of
Rails Maintenance
Surface Defects and Remedies
Corrugated or Roaring rails: The heads of rails corrugate (fine depressions
on the surface of rails). Causes roaring sounds when wheels pass over it.
Causes? Found at places where trains brakes or starts its journey, other
reasons such as: composition of steel used to manufacture rails.
Consequences? (1) Unpleasant roaring sound which cause discomfort to
passengers and residents along side the rail track
(2) Vibration causes further deterioration to other track
elements.
Remedial action? (1) Replace rail if corrugation is severe and the defect is
limited to small number of rails
(2) Grind top surface of rail, a grinding train moving at
3 km per hour can be used (as in Germany).

13. 2. Track Alignment
Maintenance
What makes the track to go out of alignment?
Increase hammering action of
wheels on one of the pair rails while
less or no hammering on the other.
Why hammering differs ?
Variation in cross levels.
Inadequate super-elevation.
Non-uniformity of gauge.
Improver packing of ballast.
Poor subgrade.Formation of kinks.
Kink in Rails: Adjoining rails slightly move out of position.
Causes? Loose packing at joints, Defects in gauge and alignment,
Defects in cross levels at joints, closing of rail joints, and Uneven wear
for rail heads.
Consequences? Unpleasant jerk for train, further kink at places other
than joints will form, risk in turning operation for kinks formed at curves.
Remedial action? (1) Periodic maintenance for cross level, gauge..etc.
(2) Correcting alignment at joints and curved sections.

14. 3. Gauge Maintenance
Uniformity of the gauge should be properly maintained all-over
the track. Failure to achieve gauge uniformity will negatively
influence the riding quality.
Loosening of track & sleeper fittings
What causes gauge variation?
Tight gauge and slack (relaxed) gauge: tight gauge is
always better since it prevents lateral play of wheels.

15. 4. Restoration of Proper
Drainage Proper drainage ensures smooth
riding quality and longer track life.
Tasks involved in
restoring drainage
cleaning of ballast
dust and weeds
allows water to
stay for long time
in ballast and may
percolate to
formation causing
defects to track.
surface drainage
clean and slope-
maintained side
drain (ditches) to
provide good
surface drainage
Subsurface drain
Under ground
drain.
Inverted filter
blanket
cleaning of cess
To prevent
collection of
water. Cess to
clean from
grass and be
sloped outward.

16. 5. Track Components
Maintenance
Worn out rails: When replacing worn out rail, one has to take
care of the final table. The new rail become higher than other
adjoining rails, resulting in damage to rail ends. If it is done as
part of daily maintenance, then used rail has to be fitted.
Broken or cracked rails: A sleeper is to be placed under the
fractured rail until rail is replaced.
Maintenance and Renewal of Rails
Corrosion of rails: If inner rail on curve is
corroded then it has to be replaced immediately.

17. Cont. Track Components
Maintenance
Spot Renewal
The defective sleeper and the
fitting of sleeper are renewed
Remove ballast below old sleeper.
Take broken sleeper out.
New sleeper is fitted and packed.
Through Renewal
Rails are removed and sleeper are
taken out and replaced and rails
are put back.
Maintenance and Renewal of Sleepers

18. Maintenance and Renewal of Fittings
Fish-plate and fish bolt are the most important fittings for jointed rails
Cont. Track Components
Maintenance
Graphiting of Fish Plate
Apply lubricant containing graphite.
To protect fish-plate against corrosion
To allow free expansion.
To increase the life of fish plate and bolts.
Track imprest A stock of all usual materials, such as rails, sleepers,
fish-plate, bolts and other fittings, is permanently maintained at selected
place for immediate replacement. These materials are known as track-
imprest. They are to be used only in emergency. Items must be replaced
as soon as possible.

19. 6. Points and Crossing
Maintenance
Switches are regarded to be the weakest points of the track
and receives most of derailments incidents. Thus it should be
watched constantly.
Inspection of switches should be done under moving train
loads. Because some of their defects can be picked up only
when train load moves on.
Causes for switch defects
Wear of fittings and pins.
Creep of track.
Poor maintenance.

20. Signalling During
Maintenance Work
It is necessary to warn the train drivers
when maintenance work is in progress.
Short duration maintenance
work ( less than three days).
Then temporary flags would
be satisfactory
Long duration maintenance
work ( more than three days).
Then temporary fixed signals are
required (discuss next sessions)