Railway engineering is a multi-faceted engineering discipline dealing with the design, construction and operation of all types of rail transport systems.

1. Introduction to Railway
engineering
Prepared By : Prof. Mayuri J. Patel
Assistant Professor
Civil Engg. Dept, DGGEC, Surat.

2. A Permanent Way
• Railway Track is also known as Permanent Way.
• A permanent way is the combination of rails,
sleepers, ballasts, fixtures and fastenings, etc.
• The purpose of use of a permanent way is to
provide the permanent facility for safety and
quick movement of normal commercial traffic
between the starting and destination stations.
• Permanent way costs nearly 40% of the total
investment to the railways.

4. Requirements of Ideal Permanent
Way
• Gauge: Correct & Uniform
• Cross Levels: Straight/Curved Sections
• Alignment: Straight & Free of Kinks
• Gradients: Uniform & Gentle
• Track: Resilient & Elastic
• Drainage: Stability, No Water-logging
• Lateral Strength: Shocks, Vibrations
• Easy Replacement or Renewal of Components
• Cost: Minimum (Construction Operation &
Maintenance)

5. Components of Permanent Way
• The Main Components of Permanent
Way are as Follows:
–Rails
–Sleepers (or Ties)
–Fasteners
–Ballast (or Slab Track)
–Sub grade

6. Track Components

10. • Gauge:
– Defined as the minimum distance between two rails.
• Rails:
– They act as girders to transmit the wheel load to the sleepers.
• Sleepers:
– They hold the rails in proper position with respect to their
proper tilt, gauge and level and transmit the load from rails to the
ballast.
• Ballast:
– Ballast is a high quality crushed stone with desired specifications
placed directly below the sleeper.
– Ballast distributes the load over the formation and holds the
sleepers in position and also functions as drainage layer.
• Formation:
– Formation is the compacted and prepared subgrade which is the
part of embankment or cutting.

11. • Natural subgrade:
– It is the soil in the natural ground on which the track rests.
• Ballast cushion:
– The depth of ballast below the bottom of the sleeper, normally
measured under rail seat is termed as ballast cushion.
• Ballast shoulder:
– Ballast provided beyond the sleeper edge is termed as ballast
shoulder
• Ballast base:
– It is the bottom width of ballast bed (typically 4.4 m in a BG
track).
• Formation width:
– It is the top width of embankment or bottom width of cutting
(typically 6.1 m in a BG track)
• Cess width:
– Width of formation beyond the toe of ballast is termed as cess
width.

12. Load Transfer

13. Gauge
• The gauge of a railway track is defined as the
clear minimum perpendicular distance
between the inner faces of the two rails.

14. Various gauges on Indian Railways
• The different gauges in India are of the
following these types :
1) Broad gauge (1676 mm),
2) Meter gauge (1000 mm),
3) Narrow gauge (762 mm & 610 mm)

16. Selection of Gauge
1) Cost of construction:
– There is marginal increase in the cost of earthwork, rails,
sleepers, ballast, and other track items with gauge.
– The cost of station buildings, platforms, signals, bridges,
tunnels and culverts etc., is same more or less for all
gauges.
– There is little proportional in the acquisition of land.
– The cost of rolling stock is independent of the guage used
for same volume of traffic.
2) Volume and nature of traffic:
– For heavier loads and high speed, the wider gauge are
required because subsequently the operating cost per tonne-
km is less for higher carrying capacity.

17. 3) Speed of movement:
– Speed is a function of dia. of wheel, which in turn limited
by the gauge. (wheel diameter = 0.75 x Gauge).
4) Development of areas:
– Narrow gauges can be used for thinly populated area by
joining under developed area with developed or urbanised
area.
5) Physical features of the country:
– Use of narrow gauge is warranted in hilly regions where
broad and meter gauge are not possible due steep gradients
and sharp curves.

18. Loading Gauge
• The loading gauge represents the maximum width
and height to which a rolling stock, namely, a
locomotive, coach, or wagon, can be built or loaded.
• In order to ensure that the wagons are not overloaded,
a physical barrier is made by constructing a structure.
• This structure consists of a vertical post with an arm
from which a steel arc is suspended from the top.
• The function of this structure is to ensure that the
topmost and the widest portion of the load will clear
all structures such as bridges and tunnels, etc. along
the route.

21. Construction Gauge
• The construction gauge is decided by adding
the necessary clearance to the loading gauge
so that vehicles can move safely at the
prescribed speed without any infringement.
• The various fixed structures on railway lines
such as bridges, tunnels, and platform sheds
are built in accordance with the construction
gauge so that the sides and top remain clear of
the loading gauge.

22. Rails
• The high carbon rolled steel sections, which are
laid end-to-end, in two parallel lines over
sleepers to provide continuous and leveled
surface for the trains to move and for carrying
axle loads of the rolling stock are called rails.

24. Scabbing
Rail

25. Rail
Rail

26. Functions of Rails
• It provides a continuous & level surface for movement
of trains .
• It provides a smooth & less friction pathway.
• Friction between the steel wheel & steel rail is about
1/5th of friction between pneumatic tyre & metalled
road.
• It serves as a lateral guide for the wheels.
• It bear the stresses developed due to vertical loads
transmitted to them – through axles & wheels of rolling
stock as well as – due to braking & thermal forces.
• It transmits the load to a large area of the formation
through sleepers & the ballast.

27. Requirements of Rails
• Rail should have the most economical section
consistent with – Strength, Stiffness & Durability.
• Centre of Gravity of rail section should preferably
be very close to the mid-height of the rail so that
the maximum tensile & compressive stresses are
equal.
• Tensile strength of rail should not be < 72 kg/m2
• To bring down the contact stresses to minimum
level, the contact area between the rail and wheel
should be as large as possible.

28. • Rail head: adequate DEPTH to allow for
vertical wear & sufficiently WIDE so that it
has a wider running surface available & also
has desired lateral stiffness.
• Rail Web: sufficiently thick to withstand
stresses arising due to loads bone by it, after
allowing for normal corrosion.
• Rail Foot: sufficient THICKNESS to
withstand VR & Hz forces after allowing
for loss of corrosion.
• Fishing angle: it must ensure proper
transmission of loads from the rails to the
fish plates.
• Rail Height: adequate so that rail has
sufficient vertical stiffness & strength as a
beam.

29. Composition of rail steel
• For ordinary rails :
– Carbon (C) - 0.55 to 0.68 percent
– Manganese (Mn) - 0.65 to 0.9 percent
– Silicon (Si) - 0.05 to 0.3 percent
– Sulphur (S) – 0.05 percent or below
– Phosphorus (P) – 0.06 percent or below
• For rails at points and crossings :
– Carbon (C) - 0.5 to 0.6 percent
– Manganese (Mn) - 0.95 to 1.25 percent
– Silicon (Si) - 0.05 to 0.2 percent
– Sulphur (S) – 0.06 percent or below
– Phosphorus (P) – 0.06 percent or below

30. Types of Rails
• The rails used in the construction of railway track are
of following types:
1) Double headed rails (D. H. Rails)
2) Bull headed rails (B. H. Rails)
3) Flat footed rails (F. F. Rails)

32. Double Headed Rails
• The rail sections, whose foot and head are of same
dimensions, are called Double headed or Dumb-bell rails.
• In the beginning, these rails were widely used in the
railway track.
• The idea behind using these rails was that when the
head had worn out due to rubbing action of wheels,
the rails could be inverted and reused.
• But by experience it was found that their foot could not
be used as running surface because it also got corrugated
under the impact of wheel loads.
• This type of rail is not in use in Indian Railways now-a
days.

35. Bull Headed Rails
• The rail section whose head dimensions are
more than that of their foot are called bull
headed rails.
• In this type of rail the head is made little thicker
and stronger than the lower part by adding more
metal to it.
• These rails also require chairs for holding them in
position.
• Bull headed rails are especially used for making
points and crossings.

38. • Merits:
– B.H. Rails keep better alignment and provide more
smoother and stronger track.
– These rails provide longer life to wooden sleepers and
greater stability to the track.
– These rails are easily removed from sleepers and hence
renewal of track is easy.
• Demerits:
– B.H. rails require additional cost of iron chairs.
– These rails require heavy maintenance cost.
– B.H. rails are of less strength and stiffness.

39. Flat Footed Rails
• The rail sections having their foot rolled to flat are called flat
footed or vignole’s rails.
• This type of rail was invented by Charles Vignole in 1836.
• It was initially thought that the flat footed rails could by fixed
directly to wooden sleepers and would eliminate chairs and
keys required for the B.H. rails.
• But later on, it was observed that heavy train loads caused the
foot of the rail to sink into the sleepers and making the spikes
loose.
• To remove this defect, steel bearing plates were used in
between flat footed rails and the wooden sleeper.
• These rails are most commonly used in India.

42. • Merits:
– F.F. rails have more strength and stiffness.
– No chairs are required for holding them in position.
– These rails require less number of fastenings.
– The maintenance cost of track formed with F.F. rails
is less.
• Demerits:
– The fittings get loosened more frequently.
– These rails are not easily removed and hence renewal
of track becomes difficult.
– It is difficult to manufacture points and crossings by
using these rails.

43. Standard Rail Sections
• The rail is designated by its weight per unit
length.
• In FPS Units, it is the weight in lbs per yard
and in Metric Units it is in kg per metre.
• A 52 kg/m rail denotes that it has a weight of
52 kg per metre.
FPS : Foot-pound-second System
MKS : Meter Kilogram Second system

44. Standard Rail Sections in Indian
Railway
Indian
Railway
Metric Units
52 MR (i.e.52 kg/m) ,
60 MR (i.e. 60 kg/m)
FPS units
90 R, 75 R,
60 R, 50 R
MR (IRS) stands for Metric Rail (Kg/m) as per Indian Rail Standards
R (RBS ) stands for British Rail (lbs/yd) as per Revised British Standards
Recently
Introduced in
IR

45. Standard Rail Sections & Rail
Length in IR
Gauge Rail section
Type of
section
Rail length
Rail section
Kg/m
Broad
gauge
60 kg/m 60 MR (UJC)
13 m (42 ft as per old
standards)
60.34 60 MR
52 kg/m 52 MR (IRS) 51.89 52 MR
90 lb/yd 90 R (RBS) 44.61 45 MR
Metre
gauge
90 lb/yd 90 R (RBS) 12 m (39 ft as per old
standards), except 90-
lb rails, which are of
13 m length
44.61 45 MR
75 lb/yd 75 R (RBS) 37.13 37 MR
60 lb/yd 60 R (RBS) 29.76 30 MR
Narrow
gauge
50 lb/yd 50 R (RBS)
12 m (39 ft as per old
standards)
24.8 25 MR
MR stands for Metric Rail
R stands for Revised British Specifications

46. Details of Standard Rail Sections for BG on
IR
• 90 R rail section was considered adequate
only for
– Annual traffic density of about 10 GMT (gross
million tonnes per km/annum),
– Speeds of up to 100 kmph,
– Axle loads up to main line (ML) standard, and
– Service life of about 20-25 years.

47. • Realizing to these limitations, the Indian
Railways, in the year 1959, designed a
heavier rail section of 52 kg/m to meet the
requirements of heavier and faster traffic.
• 52 kg/m rail section was recommended for use
on all BG main line routes with
– Future speeds of up to 130 kmph and
– Traffic density of 20-25 GMT.

48. • The traffic density on the BG track routes of
Indian Railways is increasing very fast.
• Accordingly, to meet the future requirements
of traffic, a new design has been finalized for
the 60-kg UIC section rail.
• 60 Kg/m rail section has been designed for
– Speeds of up to 160 kmph and
– Traffic density of about 35 GMT.

50. Choice of Rail Section
• Designated by weight per unit length
– FPS: lb/yard (e.g. 90 lb/yard)
– MKS: kg/m (e.g. 52 kg/m)
• Factors affecting choice of rail section
– Heaviest axle load
– Maximum permissible speed
– Depth of ballast cushion
– Type and spacing of sleeper
• Rule of thumb:
– Max axle load = 560 x Sectional weight of rail lb/yard
or kg/m
– Max axle load for 52 kg/m rail= 560* 52 =29.12 tonne

51. Brand Marks on the Rails

52. • Every rail rolled has a brand marks on its web.
• It should be rolled in letters at least 20 mm in size and 1.5 mm in
height at intervals of 1.5 to 3.0 m.
• As per IRS-T-12-88, the brand marks are as follows:
– IRS : Indian railway standards specification,
– 52 kg : Rail section as 52 kg/m
– 710 : Grade of the rail. (There is 2 grades of the rail one is the
710 another is 880 grade)
– TISCO : Name of the company (Tata Iron and Steel Co.)
– II 1991 : Month and year of manufacture (February 1991)
– → : An arrow showing the direction of the top of the ingot
Process of steel making
– OB : Process of Steel Making (Open Hearth Basic)
IRS - 52 kg - 710 - TISCO - II 1991 → OB

55. • Except Rail wear and the battering of rail ends some
other types of defects may also develop in a rail as
below.
– Buckling of Rails
– Hogging of rail
– Scabbing of rail
– Wheel burns
– Shelling and black spots
– Corrugation of rails
– Kinks
Defects in rails

56. • 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.
Buckling
Buckling

57. Buckling
Buckling

58. • Hogging of rail:
– 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.
– Rail ends get hogged due to poor maintenance of the rail joint,
yielding formation, loose and faulty fastenings, and other such
reasons.
– Hogging of rails causes the quality of the track to deteriorate.
This defect can be remedied by measured shovel packing.
Buckling
Hogging

59. Hogging
Hogging
Hogging

60. • Scabbing of rail
– The scabbing of rails occurs due to the falling of
patches or chunks of metal from the rail table.
Scabbing is generally seen in the shape of an elliptical
depression, whose surface reveals a progressive
fracture with numerous cracks around it.
Scabbing
Scabbing

61. Scabbing
Scabbing
Scabbing

62. • Wheel burns:
– Wheel burns are caused by the slipping of the driving wheel
of locomotives on the rail surface.
– As a consequence, extra heat is generated and the surface of
the rail gets affected, resulting in a depression on the rail
table.
– Wheel burns are generally noticed on steep gradients or
where there are heavy incidences of braking or near water
columns.

64. • Shelling and black spots:
– Shelling is the progressive horizontal separation of metal
that occurs on the gauge side, generally at the upper
gauge corner.
– It is primarily caused by heavy bearing pressure on a
small area of contact, which produces heavy internal shear
stresses.

65. • Corrugation of 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.
– Corrugation consists of minute depressions on the
surface of rails, varying in shape and size and occurring at
irregular intervals.

67. • Kinks
– When the ends of adjoining rails move slightly out
of position, “shoulders” or “kinks” are formed.

69. Rail Wear
• The separation or cutting of rail due to friction
and abnormal heavy load is called wear.
• There are three types of wears of rail On the
basis of the position of wear:
1) Vertical wear: Wear of Rails On top of rail
head
2) Lateral wear: Wear at the sides of the rail
head
3) Battering of rail end: Wear at the end of rail

70. 1) Vertical wear
• The metal from the top of rail flows and forms
projections which are known as burrs.
Burr

71. • The causes of such types of wear are:
– Rails are worn out on top due to abrasion of the rolling
wheels over them.
– The heavy wheel loads are concentrated on very small
areas.
– Impact of heavy loads
– Corrosion of metal of rails
– Due to slipping action of wheels during starting and
when brakes are applied to the moving trains, the metal
of top of rail burns.

73. Railhead Wear and Side Cut Gauge

74. Rail Head Wear Measuring Instrument

75. Lateral wear
• This is the most destructive type of wear and occurs
on the rails laid on curves.

76. • The various causes of side wear of rails are:
– Due to centrifugal force along the curvature, the
grinding action of wheel flanges on the inner side of
the head of the rails is caused.
– The vehicles do not bend to the shape of the curvature
while moving over a curve. This results into the biting
of the inner side of the head of outer rail by wheel
flanges.
– The wear on the inner side of the head of inner rail is
mainly due to the slipping action of wheel on curve.

77. • Outer wheels have to cover a longer distance than inner
wheel as “pq” is greater than “rs”.
• But due to rigid connection between two wheels, they cover
the same distance and hence then inner wheel slips over the
inner rail, resulting in the wear of inner side of head of inner
rail.

82. Battering of rail end
• This wear of rails takes place at the ends of rails and
is found to be very much greater than the wear at the
top of rails.
• At the expansion gap, the wheels of the vehicle have
to take a jump and during this jump, they impart a
blow is the ends of the rails. This blow is the main
cause of wear of rails at ends.
• Due to successive blows, the ends of the rails are
battered.

86. Types of Wear on the basis of location
• Wear is more prominent at some special
locations of the track.
• These locations are normally the following:
– On sharp curves – Due to centrifugal forces
– On steep gradients – Extra force applied by the
engine
– On approaches to stations – Acceleration and
deceleration
– Tunnels and coastal areas – Humidity and
moisture

87. Methods to Reduce Wear
1) Use of Special Alloy Steel
– At places where, wear of rail is considerable, special alloy steel
rails are used. The cost of such rail is more but considerable
reduction of wear of such rails justifies the extra cost.
2) Good Maintenance of Track
– The track should be carefully looked after and joints should be
tightened if they become loose. A well maintained track would
definitely result in less wear of rails.
3) Reduction of Expansion Gap
– If the expansion gap has increased beyond a certain limit, it
should be reduced by packing the sleepers at the joints and
tightening fish bolts. This will result in the reduction of wear of
end of rails.

88. 4) Exchange of Inner and Outer Rails on Curves
– Mostly on curves, where there is heavy wear at the top of head
of inner rail and heavy wear of the side of head of outer rail then
the top wear inner rail is exchanged with the side wear outer rail
and thereby life of rail is increased.
5) Use of Lubricating Oil
– The wear of rails can also be reduced by applying lubricating oil
on curves on the side of head of rails. The lubrication of rails can
be carried out manually or by mechanical equipment attached to
locomotive for rail.

89. 6) Providing check rails in sharp curves
7) Coning of wheels and tilting of rails
8) By welding or de hogging of battered ends of rails in time.
9) By application of heavy mineral oil under adverse
atmosphere.
10) By using bearing plates.
11) By regular tightening of fish bolts and packing of ballast .

90. Creep of 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 16 cm.
• Indications of creep:
– Closing of successive expansion spaces at rail joints in
the direction of creep and opening out of joints at the
point from where creep starts.
– Marks on flanges and webs of rails made by spike
heads by scratching as the rail slide.

91. Due to creep of rails, gap between railway track at one end gradually deforms until it
disappears and even expands the rail. The gap between railway track at the other end are
stretched, causing fishplate bolts to be pulled or broken.

93. Theories for the Development of
Creep
The important theories for creep development
are:
1) Brakes
2) Wave action or wave theory
3) Percussion theory

94. 1) Brakes / Drag Theory
• Drag Theory
– According to drag theory, the backward thrust of
the driving wheels of a locomotive has the
tendency to push the rail backwards, while the
thrust of the other wheels of the locomotive pushes
the rail in the direction in which the locomotive is
moving.
– This results in the longitudinal movement of the
rail in the direction of traffic, thereby causing
creep.
• Force acting at the time of starting, accelerating,
slowing down or stopping the train causes creep.

95. • As shown in the figure during the starting operation,
the wheel pushes the rail backward, while during the
stopping operation the rails are pushed forward.

96. 2) Wave Action or Wave Theory
• Creep is developed due to wave motion of wheels on
rails.
• Due to the load of the wheel, the portion of the rail
under load is depressed slightly.
• As the wheels move, the depression also moves with
them and previous depressed portion regains their
original level.
• Thus under the wheel of a train, wave motion is
developed. This wave motion tends the rail to move
forward.

98. 3) Percussion Theory
• According to percussion theory, creep is developed
due to the impact of wheels at the rail end ahead of a
joint.

99. • The horizontal component p of reaction R tends to
creep and the vertical component tends to bend the
rail end vertically i.e. to better the rail end.
• Thus as and when wheels leave the trailing rail and
strike the facing rail end at each joint, it pushes
the rail forward resulting in creep.
• Though the impact of a single wheel may be nominal,
the continuous movement of several of wheels
passing over the joint pushes the facing or landing
rail forward, thereby causing creep.

100. • The main factors responsible for the development of creep are as follows.
• Ironing effect of the wheel
– The ironing effect of moving wheels on the waves formed in the rail
tends to cause the rail to move in the direction of traffic, resulting in
creep.
• Changes in temperature
– Creep can also develop due to variations in temperature resulting in the
expansion and contraction of the rail. Creep occurs frequently during
hot weather conditions.
• Unbalanced traffic
– In a double-line section, trains move only in one direction, i.e., each
track is unidirectional. Creep, therefore, develops in the direction of
traffic. In a single-line section, even though traffic moves in both
directions, the volume of the traffic in each direction is normally
variable. Creep, therefore, develops in the direction of predominant
traffic.
Causes of creep

101. • Starting and stopping operations
– When a train starts or accelerates, the backward thrust of its
wheels tends to push the rail backwards.
– Similarly, when the train slows down or comes to a halt, the
effect of the applied brakes tends to push the rail forward.
This in turn causes creep in one direction or the other.

102. • Poor maintenance of track:
a) Improper securing of rails to sleepers
b) Limited quantities of ballast resulting in inadequate
ballast resistance to the movement of sleeper
c) Improper expansion gaps
d) Badly maintained rail joints
e) Rail seat wear in metal sleeper track
f) Rails too light for the traffic carried on them
g) Yielding formations that result in uneven cross levels
h) Other miscellaneous factors such as lack of drainage, and
loose packing, uneven spacing of sleepers.

103. Factors Effecting the Magnitude &
Direction of Creep
• Alignment of track: Creep is more on curves
than on tangent tracks.
• Grade of track: More in case of steep curves,
particularly while train moving downward with
heavy loads.
• Type of rails: older rail have more tendency
than new one.
• Direction of heaviest traffic: In heavier load
moving direction occurs more creep.

104. Effects of Creep
The following are the common effects of creep
• Sleepers out of square:
– The sleepers move out of their position as a result of creep and
become out of square.
– This in turn affects the gauge and alignment of the track, which
finally results in unpleasant rides

105. • Distance in gaps get disturbed:
– Due to creep, the expansion gaps widen at some places and close
at others.
– This results in the joints getting jammed.
– Undue stresses are created in the fish plates and bolts, which
affects the smooth working of the switch expansion joints in the
case of long welded rails.

106. • Distortion of points and crossings:
– Due to excessive creep, it becomes difficult to maintain the
correct gauge and alignment of the rails at points and
crossings
• Difficulty in changing rails
– If, due to operational reasons, it is required that the rail be
changed, the same becomes difficult as the new rail is
found to be either too short or too long because of creep.
• Effect on interlocking
– The interlocking mechanism of the points and
crossings gets disturbed by creep.

107. • Possible buckling of track
– If the creep is excessive and there is negligence in
the maintenance of the track, the possibility of buckling of the
track cannot be ruled out.
• Other effects
– There are other miscellaneous effects of creep such as breaking
of bolts and kinks in the alignment, which occur in various
situations.

108. Remedies of Creep
1) Pulling back the rails:
– Pull back the rail to its original position by means of crow bars and
hooks provided through the fish bolts wholes of rails
– By considering the position of joints relative to sleepers and both rails
should be in respective position.
2) Provision of anchors:
– By use of anchors and sufficient crib ballast.
– For creep 7.5 cm-15 cm 4 anchors per rail
– For creep 22.5 to 25 cm 6 anchors.
3) Use of steel sleepers:
– Sleepers should be made up of good material with proper fitting.
– Sleepers should provide good grip with ballast to resist the movement
of sleepers.
– Increase in no. Of sleepers.
4) Increase in sleeper density

109. crow bars

110. Rail anchor is designed to eliminate creep of track. The rail anchors provide a large bearing
surface against both rail base and tie, avoiding undo cutting and wear, thus prolonging the life of
wooden ties.

111. Fair V Anchor

113. Hydraulic rail tensioner

114. Ballast Cribber

115. RAIL JOINTS

116. Rail Joint
• Rail joints are necessary to hold the adjoining ends
of the rails in the correct position, both in the
horizontal and vertical planes
• Weakest part of the track
• In order to Provide expansion and contraction due to
variation in temperature, certain gap is provided at
each joint.
• This gap causes a break in continuity of rails in
horizontal as well as in vertical plane, forming the
weakest point of the track.

117. Types of Rail Joints
• According to Position of joints
a) Square joints
b) Staggered joints
• According to position of sleepers
a) Suspended joints
b) Supported joints
c) Bridge joints
d) Insulated joint
e) Compromise joint

118. According to Position of joints
1. Square Joints:
• Joint in one rail is exactly opposite to the joint
in the other parallel rail is called as Square Joint
• Common in straight tracks
Square Rail Joints

119. 2. Staggered Joints:
• Joint in one rail is exactly opposite to the centre of
the other parallel rail is called as Staggered Joint.
• In India this type of joint is used in curves.
• It gives smoother running to the track.
Staggered Rail Joints

120. According to Position of Sleepers
1. Suspended joints:
• The rail joint when placed at the centre of two consecutive
sleepers is known as suspended joints
• The load is evenly distributed on two sleepers.
• When joint is depressed both rails are pressed down evenly
Suspended Rail Joint

121. 2. Supported joints:
• When the sleeper is placed exactly below the rail
joint, it is known as supported joint.
• Do not give sufficient support with heavy axle
loads.
Supported Rail Joints

122. 3. Bridge joints:
• Similar to suspended joint, but a metal serving
as a bridge to connect the ends of two rails
• The bridge is placed at the bottom of rails and
it rests on two sleepers

123. Bridge Joint with Metal Flat
Bridge Joint with Bridge Plate

124. WELDING OF RAIL JOINT

125. Welding a Rail Joint
• The purpose of welding is to join rail ends
together by the application of heat and
thus eliminate the evil effects of rail joints.
• There are four welding methods used on
railways.
1. Gas pressure welding
2. Electric arc or metal arc welding
3. Flash butt welding
4. Thermit welding

126. 1.Gas Pressure Welding
• In this type of welding, the necessary heat is produced
by the combination of oxygen and acetylene gases.
• The rail ends to be welded are brought together and
heat is applied through a burner connected to oxygen
and acetylene cylinders by means of regulators and
tubes.
• A temperature of about 1200°C is achieved.
• At this temperature, the metal of the rail ends melts,
resulting in the fusion and welding together of the
ends.

127. • The rails to be welded are clamped at the wall by applying a
pressure of 40 t pressure, heated to a temperature of about 1200°
C to 1400° C, and butted with an upset pressure of about 20 t.
• Then the joint is again heated to a temperature of 850° C and
allowed to cool naturally.
• It has been seen that this method of welding is cheaper as
compared to flash butt welding.
• The quality of this welding joint is also claimed to be quite good.
• There are both stationary and mobile units available for gas
pressure welding.

128. • The process has not yet been adopted on a large scale by Indian
Railways.
• The main reason behind this is its limited output and the
difficult and irregular availability of gas.
• India has only one plant that offers gas pressure welding, which
is located at Bandel on the Eastern Railways and the progress
in this plant has been nominal.

131. 2.Electric or Metal Arc Welding
• In this method, heat is generated by passing an
electric current across a gap between two
conductors.
• A metal electrode is energized by a voltage source
and then brought close to another metal object,
thereby producing an arc of electric current between
the two objects.
• A lot of heat is generated by this electric arc, causing
the two rail ends to fuse or weld.

132. • This type of welding can be done using any of the
following methods.
a) Insert Plate Technique
b) Scheron Process
c) Enclosed Space Technique
• Indian Railways has recently started welding rail
joints using the metal arc process on a trial basis and
the performance so far has been satisfactory.

135. 3.Flash Butt Welding
• In flash butt welding, heat is generated by the electric resistance method.
• The ends of the two rails to be welded are firmly clamped into the jaws of a
welding machine. One of the jaws is stationary, while the other one is
moveable and as such the gap between the two rail ends can be adjusted.
• The rail ends are brought so close together that they almost touch each
other. An electric current of 35 kA is passed between the interfaces of the
two rails, developing a voltage of 5 V.
• A lot of flashing (sparking) occurs and considerable heat is generated by
the passage of electrical current between the rail ends.
• The rail ends are automatically moved to and fro by the machine till the
temperature rises to a fusion limit in the range of 1000°C to 1500°C.
• At this time, the rail ends are pressed together with pressure and final
flashing takes place joining the two rail ends together.
• High-quality welded joints are produced by the flash butt welding method.

136. https://www.gleisbau-welt.de/encyclopedia/maintenance-of-way/mechanised-track-
laying/welding-technology/flash-butt-welding/

137. Flash Butt Welding

138. 4.Thermit Welding of Rails
• This is the only form of site welding which is
being adopted universally.
• The method was first developed by Gold
Schmidt of Germany towards the end of the
nineteenth century.
• A code of practice for welding rail joints using the
alumino-thermic process has been developed by
Indian Railways.
• The code defines the method of welding and the
precautions and steps to be taken before, during,
and after welding for the production of
satisfactory weld joints.

139. • General Principle:
• The principle behind this process is that when a mixture of finely
divided Aluminium & Iron Oxide, called Thermit Mixture, is
ignited, a chemical reaction takes place which results in the
evolution of heat and the production of iron and aluminium oxide:
Fe2O3 + 2Al = 2Al2O3 + 2Fe + heat
• In this reaction, 159 g of iron oxide combines with 54 g of
aluminium to give 102 g of aluminium oxide, 112 g of iron, and
182 kcal of heat. The reaction is exothermic and it takes about 15-
25 sec to achieve a temperature of about 2450°C.
• The released iron is in the molten state and welds the rail ends,
which are kept enveloped in molten boxes. The aluminium oxide,
being lighter however, floats on top and forms the slag.

140. Thermit Welding of Rails

141. TRACK FITTINGS &
FASTENINGS

142. Track Fittings & Fastenings
• Track fittings and rail fastenings are used to keep the rails in
the proper position and to set the points and crossings
properly.
• They link the rails endwise and fix the rails either on chairs
fixed to sleepers or directly on to the sleepers.
• The important fittings commonly used are:
1. Fish plates
2. Spikes
3. Bolts
4. Chairs
5. Blocks
6. Keys
7. plates

144. Types of track fittings
1 Joining rail to rail
Fish plates, combination fish
plates, bolts, and nuts
2 Joining rail to wooden sleepers
Dog spikes, fang bolts, screw
spikes, and bearing plates
3
Joining rail to steel trough
sleepers
Loose jaws, keys, and liners
4 Joining rail to cast iron sleepers Tie bars and cotters
5
Elastic fastenings to be used with
concrete, steel, and wooden
sleepers
Elastic or Pandrol clip, IRN
202 clip, HM fastening,
rubber pads, and nylon liners

145. Fish Plates
• The name 'fish plate' derives from the fish-shaped
section of this fitting.
• Fishplate, splice bar or joint bar is a metal bar that is
bolted to the ends of two rails to join them together
in a track.
• They maintain the continuity of rails & allow
expansion and contraction of rail due to
temperature difference.
• They Maintain correct alignment of line both
horizontally & vertically.
• Fishplate is a small copper or nickel silver plate that
slips onto both rails.

148. Fish Bolts
• Made up of medium or high carbon steel.
• Fish bolts have to undergo shear due to
heavy transverse stresses.
• Length depends on the type of fishplate used.
• For 44.70Kg rail, a bolt of 2.5cm dia and
12.7cm length is used.
• These bolts get loose by the traffic variations
and require tightening from time to time.

152. Spikes
• A rail spike is a large nail with an offset head
that is used to secure rails and base plates to
rail road ties in the track.

154. Requirements of good spikes
• The spike should be…
a) Strong enough to hold rail in position &
enough resistance to motion to retain its
position.
b) Cheap in cost
c) Deep as possible for better holding power
d) Easy in fixing and removal from sleepers
e) Capable of maintaining the gauge

155. 1. Dog Spikes
• Commonly used
• Hold rail flanges with timber
sleepers
• Shape of head of spike resembles
ear of dog , hence called dog
spike
• Section of spike is square –
shape & bottom part is either
pointed or chisel shaped
• Cheapest
• Easy in fixing and removing
from sleepers
• Maintain better gauges

159. 2. Screw Spikes
• Tapered screws with V- threads used to fasten rails
with timber sleepers.
• Head is circular with square projection
• Holding power is double than that of dog- spike
• Resist lateral thrust in better way
• More costly
• Gauge maintenance is more difficult
• Driving operations are similar to dog -spikes

162. 3. Round Spikes
• Head either cylindrical or hemispherical
• Used for fixing chairs of bull headed rails to
wooden sleepers
• Limited use only

164. 4. Elastic Spikes
• This spikes absorbs the wave motion of rail without
getting it loose.
• Provide better grip and result in reduction of wear
and tear of rail.
• Commonly used in British railways

168. Chairs
• Chairs are required to hold bull headed rails and double
headed rails in position
• Made of cast iron and help in distributing the load
from the rails to thee sleepers
• It consists of two jaws and a rail seat.
• The web of the rail is held tightly against the inner jaws
of the chair and a key is driven between the rail and the
outer jaw of the chair
• The chair are fixed with the sleepers by means of spikes
• The shapes of chairs depend upon the type of rails used.

174. • Keys are small tapered pieces of timber or steel to fix rails
to chairs on metal sleepers.
• Keys may be either straight or tapered.
• Types of keys are:
a) Wooden key for C.I. chair
b) M.S. key for steel through sleepers
c) Stuart’s key
d) Morgan key
e) Cotter and tie bars
• Wooden keys are cheap
• Initial cost of steel keys is high. But life is about ten times
more than wooden keys. So steel keys are preferred.
Keys

176. KEY

177. KEY
KEY

178. Bearing Plates
• Bearing plates are rectangular plates of mild
steel or cast iron used below F.F rails to
distribute the load on larger area of timber sleeper.
• Advantages:
a) To distribute the load coming on rails to the
sleepers over a larger area and to prevent skidding of
the rail in the soft wooden sleepers.
b) Prevent the destruction of the sleeper due to
rubbing action of the rail.
c) Adzing of sleeper can be avoided by bearing plates.

179. • Disadvantages:
a) Plates rattle when loose
b) When any hole for a spike is failed and a new
hole is to be made , all spikes in the bearing
plate have to be pulled out which affects good
hold of spikes.
c) When bearing plates are loose , they admit
moisture and result in mechanical wear of
sleepers

183. Blocks
• Types of blocks:
a) Heel blocks
b) Distance blocks
c) Check block
d) Crossing block

185. Ballast
Ballast

186. Ballast
• Ballast is a layer of broken stones, gravel or any other
such gritty material laid and packed below and around
sleepers.
• Railway Ballast is the foundation of railway track and
provide just below the sleepers.
• The loads from the wheels of trains ultimately come on
the ballast through rails and sleepers.

187. Ballast

190. Functions of Ballast
• It provides levelled bed or support for the railway
sleepers.
• It transfers the load from sleepers to subgrade and
distributes the load uniformly on subgrade.
• It prevents the longitudinal and lateral movement of
sleepers.
• It offers good drainage to the track. It drain off the
water quickly and to keep the sleepers in dry conditions.
• It discourage the growth of vegetation.
• It hold the sleepers in position during the passage of
trains.

191. Requirements for Ideal Ballast
• The ideal material for ballast should fulfill the following
requirements:
– It should be possible to maintain the required depth of the
material in order to distribute the load of passing train on the
formation ground
– The material to be used for ballast should not be too rigid but it
should be elastic in nature
– The material for ballast should be of such nature that it grips the
sleepers in position and prevent their horizontal movement
during passage of train
– It should not allow the rain water to accumulate but should
be able to drain off the water immediately without percolating
– It should be strong enough a resistance to abrasion

192. Materials Used for Ballast
• The following materials are used for ballast on
the railway track.
– Broken Stone
– Gravel
– Cinders / Ashes
– Sand
– Kankar
– Moorum
– Brick Ballast

193. Types of Ballast According to
Material
• 1. Broken stone Ballast
– Broken stone is a widely used ballast in railways.
– It is obtained by crushing hard stones like
granite, hard trap, quartzite etc.
– limestone and sandstone can also be used.
– It is suitable for high-speed railway tracks.
– The broken stone selected as ballast should be
hard, tough and non-porous.
– It should stay strong against bad weather
conditions.

198. • Benefits of Broken Stone Ballast:
– Broken stones are hard, tough and durable.
– Hold the sleepers in a strong position and provide
stability to the track.
– Suitable for heavy traffic tracks and for high-speed tracks.
– Economical with respect to their durability.
– Require less maintenance.
• Drawbacks of Broken Stone Ballast:
– Since broken stones are not easily available, their initial
cost is a little high.
– Produce noise when the train is moving on the track.
– They are sharp and angular and hence wooden sleepers
may be liable to damage by these broken stones.

199. • 2. Sand Ballast
– Sand can also be used as a ballast material.
– It is well suitable under cast iron sleepers and
can be seen in desert railway tracks where plenty
of sand gets accrued on the track.
– Coarse sand is best suitable as ballast than fine
sand.

203. • Benefits of Sand Ballast
– It provides excellent drainage facilities to the track.
– Well suitable for Cast iron sleepers and does not
produce any noise while the train is moving on track.
– Cheap and abundantly available material.
• Drawbacks of Sand Ballast
– Sand may blow off easily due to vibrations produced
by train or due to high winds. So, a frequent renewal
is required.
– Excessive wear of sleepers and moving parts can
occur due to friction developed by sand.

204. • 3. Gravel Ballast
– Gravel is a naturally occurring material formed
by the erosion of rocks.
– They are suitable for all types of sleepers and are
usually round and smooth and can be obtained
from river beds, gravel pits etc.

207. • Benefits of Gravel Ballast:
– It occurs naturally and hence is cheap and easily available.
– Properly cleaned gravel offers excellent drainage facilities to the
track.
– Well packed gravel requires less maintenance and has high
durability.
• Drawbacks of Gravel Ballast:
– Because of their smoothness and roundness, they may get separated
from the bed under vibrations.
– Since it occurs naturally, it may contain some amount of earth or clay
which should be cleaned. If not cleaned, the drainage properties of
gravel may get affected.
– Sieving should be done to eliminate small size gravel particles
otherwise they may affect the drainage properties.
– Produce noise when the train is moving on the track.

208. • 4. Moorum Ballast:
– Moorum is formed by the decomposition of
laterite.
– It is available mostly in red color and, sometimes,
in yellow.
– If the track is to be laid on black cotton soil,
moorum can be used as a blanketing material
or sub-ballast since it prevents permeability of
water into the subgrade or formation.

210. • Benefits of Moorum Ballast
– Moorum is good as a sub-ballast especially in the
case of weak soil subgrades.
– Provides good aesthetics to the track.
• Drawbacks of Moorum Ballast
– It is very soft and when subjected to vibrations gets
converted into a powdered form and blows away.
– It requires frequent maintenance.
– Not recommended unless there is no other material
available.

211. • 5. Coal Ash or Cinder Ballast
– Coal ash also called cinder is the by-product of
coal-fired power plants and railway locomotives.
– It can be used as a ballast material since it is
cheaply available and also possesses good drainage
properties.
– It is used as a ballast especially for station yards
and as initial ballast for newly constructed tracks.

215. • Benefits of Coal Ash Ballast
– It is economical and abundantly available.
– It has excellent drainage properties.
– It can be handled with ease and is light in weight.
• Drawbacks of Coal Ash Ballast
– Turns into dust when subjected to loads.
– Makes the track dirty and complicates the
maintenance procedure.
– It is not recommended when steel sleepers are used
because of its corrosive action.
– The rails may also get affected by the corrosive
action of coal ash.

216. • 6. Brickbat Ballast
– Brickbats are nothing but crushed pieces of
bricks which are generally over-burnt.
– Under-burnt brickbats are not suitable since
they are not as porous as over-burnt brickbats.

218. • Benefits of Brickbat Ballast
– Porous brickbats have good drainage properties.
– Brickbats are useless products of brick industries
and hence can be bought at cheap prices.
• Drawbacks of Brickbat Ballast
– When subjected to loads they turn into a powder
which can be easily blown away by the wind.
– The brick dust makes the track dirty and
demands frequent maintenance.

220. Sleepers

221. Sleepers
• Wooden, cast iron, steel or RCC members which
are laid transverse to the track alignment to
Support the rails and to transfer the load from
the rails to the under line blast are called
sleepers.
• Railway sleepers also called railroad ties, railway
ties or crossties.

224. Functions of sleepers
• Hold rails to correct gauge & alignment
• Holding gauge in proper level
• Act as elastic medium
• Support the rails firmly & evenly
• Distribute the load transmitted from the rolling stock over
large of ballast
• Provides stability to permanent way
• To provide the insulation of track for the electric field
tracks of signaling
• To provide easy replacement of rails fastening

225. Requirements of Ideal Sleeper
• The sleepers to be used should be economical, i.e they
should have minimum possible initial & maintenance
cost.
• Moderate weight – easy to handle.
• Fixing & removing of fastenings should be easy.
• Sufficient bearing area.
• Easy maintenance & gauge adjustment.
• Track circuiting (electric insulation) must be possible.
• Able to resist shocks & vibrations.

226. Types of Sleeper
• Depending upon the position in a railway
track, railway sleepers may be classified as:
1) Longitudinal Sleepers
2) Transverse Sleepers

227. 1. Longitudinal Sleepers:
• These are the early form of sleepers which are not commonly used
nowadays.
• It consists of slabs of stones or pieces of woods placed parallel to
and underneath the rails.
• To maintain correct gauge of the track, cross pieces are provided at
regular intervals.

230. • At present this type of sleepers are discarded mainly
because of the following reasons.
– Running of the train is not smooth when this
type of sleepers is used.
– Noise created by the track is considerable.
– Cost is high.

231. 2. Transverse Sleepers:
• Transverse sleepers introduced in 1835 and since then they
are universally used.
• They remove the drawbacks of longitudinal sleepers:
– the transverse sleepers are economical,
– silent in operation and
– running of the train over these sleepers is smooth.

232. • Depending upon the material, the transverse sleepers may
be classified as:
1) Timber or Wooden Sleepers
2) Metal Sleepers
• Cast iron sleepers
3) Steel sleepers
4) Concrete sleepers
• Reinforced concrete sleepers
• Pre - stressed concrete sleepers

233. Wooden Sleepers
• The timber sleepers nearly fulfilled all the
requirements of ideal sleepers and hence they are
universally used.
• Sal, deodar and chir are mostly used as they are
cheaper.
• Teak is not much used due to high cost.

234. Sizes of wooden sleepers and bearing areas

238. • Advantages:
– Low initial cost
– Few & simple fastening
– Easy to handle
– Suitable for all types of ballast
– Can be used with every type of rail
– Less damage during accident
– Easy renewal of track
– Absorb shocks & vibrations
– More useful for yielding formations

239. • Disadvantages:
– Short life
– Liability of decaying
– Easily attacked by Termite (white ants) & weather
– Connections between rail and sleepers are not strong
– Maintenance of gauge is difficult
– Higher maintenance cost
– Susceptible to fire
– Low scrap value

240. • Sleeper Dimension:
• The wide dimension on a crosstie (sleeper) is
referred to as a tie face, and the narrow
dimension is called the side.

241. Steel Sleeper
• Steel sleepers having long useful period.
• steel sleepers are in the form of inverted channels
with folded ends & having thickness 12 mm.
• Ends of rolled sections are flattened in the shape of a
spade to retain the ballast.

242. • Requirements:
– Maintain perfect gauge.
– Should not get pushed easily out of position.
– Contain high strength.
– Provide sufficient bearing area of rail.

247. • Advantages:
– Very durable
– Easy to maintain gauge & lesser maintenance
probs.
– Better lateral rigidity
– Lesser damage during handling & transport
– Easy to manufacture
– Not susceptible to vermin attack
– Not susceptible to fire attack
– Good scrap value.

248. • Disadvantages:
– Liable to corrosion
– Unsuitable for track circuiting areas
– Liable to become centre bound due to slopes at
two ends
– More fittings are required in number
– More ballast is required as compared to other
types.

249. Cast Iron Sleepers

251. • Advantages:
– Easy to manufacture
– Lesser liable to crack at rail seats
– Useful life 50 to 60 years.
– Provide high lateral & longitudinal stability to
track
– Lesser liable to corrosion
– Scrap value is high
– Low maintenance cost

252. • Disadvantages:
– High initial cost
– Gauge maintenance is difficult as tie bars get
bent up
– Broken easily if not handled carefully
– Need large number of fittings
– No elastic bed, so great damage in accidents

253. Concrete / RCC Sleepers

256. • Advantages:
– Concrete sleepers being heavy give more elastic modulus,
strength & stability to track
– Great resistance to buckling of track
– Best suited for modern maintenance methods for track as they
are flat at bottom.
– They are neither susceptible to be attacked by vermin,
corrosion nor are they inflammable
– Due to longer life, rail and sleeper renewals can be matched.
– They could be easily manufactured locally with local available
materials
– More life

257. • Disadvantages:
–Manufacturing process, transportation,
handling & laying is difficult & costly
because they are heavy.
–Excessive damage can be caused in
derailment
–No scrap value

258. Sleeper less Track

261. Pre-stressed Sleepers
• Advantages:
–The P.S.S result in reduced rail pending
stresses
–The P.S.S reduce the wear of rolling stocks.
–The P.S.S produce less vertical motion.
–Life 50 years.

262. • Disadvantages:
–Not Economical – high cost.
–Derailments – heavy damages caused.
–Maintenance – high cost.
–Rigidity – more.
–Scraped no value.

263. Twin-Block Sleepers
• Lighter by 30% compared to a regular concrete
sleeper thus allowing it to be manually moved and
the four faces of the two blocks resist movement
better.
• Excellent for some lighter track forms like those
used for tramway systems.

264. Plastic sleepers
• Made of old tires and recycled plastic
• Cost about 50% less and save on trees
• Practically impervious to the seasons, but
otherwise exhibit the same properties as their
wooden counterparts with respect to damping
of impact loads, lateral stability, and sound
absorption.

267. Coning of Wheels
• The Surface of wheels are made in cone shape at an
inclination of 1 in 20, and the same slope is provided
in the rails this is known as coning of wheels.
• The coning of wheels is mainly done to maintain the
vehicle in the central position with respect to the
track.

268. Coning of wheels – Straight and Curved Tracks

270. THANK YOU