For ii Year Diploma Civil Engineering Students M.Shanmugaraj M.E., Lecturer / Civil V.S.V.N Polytechnic College Virudhunagar Tamilnadu India

1. Prepared by
M.Shanmugaraj
Lecturer / Civil
V.S.V.N Polytechnic College
Virudhunagar
UNIT-III RAILWAY ENGINEERING

2. 3.1 INTRODUCTION
Amongst the different modes of transport, Railways have their greatest utilization in the transport of large volumes of heavy and bulk commodities and passengers over long distances with safety, comfort and convenience.

3. History of Railways

4. Railways were first introduced to India in 1853 fromBombaytoThane
A British engineer,Robert Maitland Brereton, was responsible for the expansion of the railways from 1857 onwards.
The Allahabad-Jabalpur branch line of theEast Indian Railwayhad been opened in June 1867
In 1951 the systems were nationalised as one unit, the Indian Railways, becoming one of the largest networks in the world.

5. Indian Railways is the world'sninth largest commercial or utility employer, by number of employees, with over 1.4million employees. As forrolling stock, IR holds over 239,281Freight Wagons, 59,713Passenger Coachesand 9,549Locomotives(43 steam, 5,197 diesel and 4,309 electric locomotives).
As of 31 March 2013, 23,541km (14,628mi) (36%) of the total 65,000km (40,000mi) km route length was electrified.Since 1960, almost all electrified sections on IR use 25,000 Volt AC traction through overhead catenarydelivery.

6. Definition
Adhesion of wheels:-
Resistance offered by the friction between the metal surface of the rail and the wheel
Adzing of sleepers:-
In order to obtain an inward slope of 1 in 20 for the rail, the sleepers are cut to form a table. The process of cutting the wooden sleeper or casting the concrete sleepers accordingly is known as Adzing of sleepers.

7. Ash Pits:-
Long masonry pits, constructed longitudinally inside and under the track to collect the ash from steam locomotives
Ballast:-
Granular material used in packing under and around the sleepers to transfer load from the sleepers.

8. Check rails:-
The rails, which are introduced along the inner rail of a track on sharp curves for reducing the wear of rails, are called ‘check rails’.
Check rails are also provided along the straight rails opposite the crossings in turnouts

9. Check rails:-

10. Bearing plates:
Mild steel, or cast iron plates used for fixing the rail with wooden sleepers.
The rectangular plates made of either mild steel, cast iron, wrought iron, or malleable steel which are interposed between the foot of a flat footed rail and wooden sleeper to distribute the load on a larger area, are called bearing plates.

11. Bearing plates:

12. Bearing plates:

13. Chairs:-
For keeping the bull headed rail in proper position, special devices are provided in between the sleepers and the rails which is known as the Chairs.

14. Chairs :

15. Coning of wheel:-
"Coning of wheels" is what allows a train to take a turn without slipping off its tracks.

16. Coning of wheel:-

17. Creep of rails:-
The longitudinal movement of rails, in a track is known as creep of rails

18. Drop Pits:-
Pits constructed in the loco shed for taking down wheels of the locomotive during repair.

19. Examination Pits:-
Pits constructed for examination of the engines underneath

20. Detectors:-
Adefect detectoris a device used onrailroadsto detect axle and signal problems in passingtrains. The detectors are normally integrated into thetracksand often include sensors to detect several different kinds of problems that could occur.

21. Hogged Rails:-
A Hogged Rail is the surface defect of the rail in which the rail ends are bent downward at the joints.

22. Kinks:-
Lateral shift in rails due to loose joints and defective gauge is called as Kinks

23. Flag Stations:-
Arailroadstationwheretrainsstoponlywhenaflagorothersignalisdisplayedorwhenpassengersareto bedischarged.

24. Fouling Mark:-
It is the point beyond the converging point of two or more tracks before which train on one of those tracks have to be stopped so that train movement is not obstructed in other tracks.

25. Gang Hut:-
Residential quarters provided near the centre of the gauge beat are called gang hut

26. Guard Rails:-
Extra rails provided over bridges to prevent damage and derailment on the bridge

27. Heel:-
Tapered rail fixed to the main rails are called Heel.

28. Level crossing:-
Place when the road and railway line cross each other at the same level.

29. Rolling stock
Rolling stockcomprises all thevehiclesthat move on arailway
It usually includes both powered and unpowered vehicles, for example locomotives,railroad cars,coaches, andwagons

30. Stock rail:-
This is the main rail at the switch where the tongue rail fits against it.

31. Stock rail:-

32. Tongue rail:-
Tapered rail used in switch

33. Tube railways:-
Underground railways at about 27m or more in depth below the ground

34. Railroad station:
Set of installations of a railway, where passengers embark and disembark and goods are loaded and unloaded.

35. Water tower:
water container.

36. Tunnel: underground passage.

37. Viaduct: railway bridge.

38. Bridge:
Construction that allows passage between two points separated by a depression or an obstacle.

39. Overpass:
Elevation of a railway over a highway so they do not intersect.

40. Engine shed: Place where locomotives are stored.

41. Rails
A steel bar or continuous line of bars laid on the ground as one of a pair forming a railway track.

42. Sleeper
It isone of the cross braces that support the rails on a railway track

43. Ballast
Track ballastforms the track bed upon which railway sleepers are laid

44. Gauge
Rail gauge is the distance between the inner sides of the two parallel rails that make up a single railway line

45. Turn out
A complete set of points and crossings along with a lead rail is known as turnout

46. Turn out

47. Right Hand Turn out
If a train from main track is diverted to the right of the main route in the facing direction, then this diversion is known as Right-hand turnouts

48. Left Hand Turn out
If a train from main track is diverted to the left of the main route in the facing direction, then this diversion is known as Left-hand turnouts.

49. Points and Crossing
Special arrangement on railway track for enabling trains to divert from one track to another

50. Yards
System of tracks for various purposes such as receiving, storing and despatchof goods, wagons and passenger coaches, etc.

51. Signals
Device by which movement of train is controlled

52. Rail Gauges
Rail gauge is the distance between the inner sides of the two parallel rails that make up a single railway line
Rail gauge is the distance between two rails of a railroad.
Sixty percent of the world's railways use a 4 feet 8½ inch (1435 mm) gauge, which is known as standard gauge or international gauge.
Rail gauges larger than standard gauge are called broad gauge, and rail gauges smaller than standard are called narrow gauge.
A dual gaugerailway has three or four rails positioned so that trains of two different gauges can use it.
A place where different gauges meet is called a break of gauge.

53. Rail Gauges

54. Types of Rail Gauges
The different gauges prevalent in Indiaare of the following these types :-
Broad gauge (1676),
Metregauge (1000),
Narrow gauge (762 mm & 610 mm).

55. Types of Rail Gauges

56. 1.Broad Gauge
When the clear horizontal distance between the inner faces of two parallel rails forming a track is 1676mm the gauge is called Broad Gauge (B.G)
This gauge is also known as standard gauge of India and is the broadest gauge of the world.
The Other countries using the Broad Gauge are Pakistan, Bangladesh, SriLanka, Brazil, Argentine,etc.50% India’s railway tracks have been laid to this gauge.

57. Suitability :-
Broad gauge is suitable under the following Conditions :- (i) When sufficient funds are available for the railway project. (ii) When the prospects of revenue are very bright. This gauge is, therefore, used for tracks in plain areas which are densely populated i.e. for routes of maximum traffic, intensities and at places which are centers of industry and commerce

58. 2.Metre Gauge
When the clear horizontal distance between the inner faces of twoparallel rails forming a track is 1000mm, the gauge is known as MetreGauge (M.G)
The other countries using Metregauge are France, Switzerland, Argentine, etc. 40% of India’s railway tracks have been laid to this gauge.

59. Suitability :-
MetreGauge is suitable under the following conditions:- (i) When the funds available for the railway project are inadequate. (ii) When the prospects of revenue are not very bright. This gauge is, therefore, used for tracks in under- developed areas and in interior areas

60. 3.Narrow Gauge
When the clear horizontal distance between the inner faces of two parallel rails forming a track is either 762mm or 610mm, the gauge is known as Narrow gauge (N.G)
The other countries using narrow gauge are Britain, South Africa, etc. 10% of India’s railway tracks have been laid to this gauge.

61. Suitability :-
Narrow gauge is suitable under the following conditions :-
( i) When the construction of a track with wider gauge is prohibited due to the provision of sharp curves, steep gradients, narrow bridges and tunnels etc.
(ii) When the prospects of revenue are not very bright. This gauge is, therefore, used in hilly and very thinly populated areas. The feeder gauge is commonly used for feeding raw materials to big government manufacturing concerns as well as to private factories such as steel plants, oil refineries, sugar factories, etc.

62. Uniformity in gauges
One country should have only one gauge throughout its various parts.
But the policy of India and its Topographical, Geological and Financial conditions have led to adopt various gauges in its different parts.

63. Advantages of Breaking the Gauge
i). The most effective advantage of breaking the gauge is to render the railway an economical and profitable concern.
ii). It facilitates the provision of a steeper gradient, sharp curves and narrow tunnels by adopting a less wide gauge in hilly and rocky areas.

64. Disadvantages of Breaking the Gauge :-
i). It causes much inconvenience to the passengers while changing the train at station, with change of gauge.
ii). It causes delay in movement of people and goods.
iii). It results in wastage of time.
iv). It involves extra labourfor unloading and reloading the goods. The goods are also likely to be damaged or dislocated at the junction station, having change of gauge.
v). It requires the provision of extra and costly transshipment yards, godowns, sheds, etc. at every junction station having change of gauge. vi). It causes extreme difficulty in quick movement of military and ammunition during war days.

65. Loading gauge
Aloading gaugedefines the maximum height and width for railway vehicles and their loads to ensure safe passage through bridges, tunnels and other structures.
The loading gauge determines the sizes of passenger trains and the size ofshipping containersthat can be conveyed on a section of railway line and varies across the world and often within a single railway system.

66. Loading gauge
A loading gauge is the envelope or contoured shape within which all railroad cars, locomotives, coaches, buses, trucks and other vehicles, must fit.
It varies between different countries and may also vary on different lines within a country. For example, metro trains might have smaller loading gauge than conventional trains to allow smaller tunnels.
In that case metro trains may run on conventional tracks, but not vice versa.

67. Loading gauge

68. Loading gauge

69. Loading gauge

70. In more recent times, the term loading gauge has fallen out of use among railway professionals, since it is a purely static concept and ignores other factors affecting clearance.
Indian Railways1,676mm(5ft6in)gauge track have very large loading gauge. 3,660mm (12ft0in) wide and 5,300mm (17ft5in) high for passenger traffic.
In India 3,250mm (10ft8in) wide and 7,000mm (23ft0in) high on the freight only lines, and 3,250mm (10ft8in) wide and 6,150mm (20ft2in) high on the passenger lines.
The smallest loading gauge for a railway of the1,676mm(5ft6in)gauge track isDelhi Metro. Which is 3,250mm (10ft8in) wide and 4,140mm (13ft7in) high.

71. Construction gauge.
By adding suitable clearance at the top side of the loading gauge construction gauge is obtained.
It decides the dimensions such as height and width of structures in bridges and tunnels along the track so that all wagons may pass through them without damage to the structures

72. RAILS
General
Rail is similar to steel girders. These are placed end to end to provide continuous and level surface for the trains to move

73. Functions of Rail:
To provide continuous and level surface for movement of train.
To provide a smooth pathway so that friction between rail and wheel become less.
Serve as a lateral guide for the running of wheels.
Transferring the load into the sleeper.
To bear the stresses developed in the track due to temperature changes and loading patterns.
To resist breaking forces caused due to stoppage of trains.

74. Requirements of an ideal rail
The main requirements of an ideal rail section are as under:
(1) The section of the rail should be such that the load of eh wheels is transferred to the sleepers without exceeding the permissible stresses.
(2) The section of the rail should be able to withstand the lateral forces caused due to fast moving trains.
(3) The underside of the head and top of the foot of the rail section should be of such a slope that the fishplates fit snugly.
(4) The center of gravity of the rail section should preferably coincide the center of the height of the rail so that maximum tensile and compressive stresses are nearly equal.

75. (5) The web of the rail section should be such that it can safely bear the vertical load without buckling.
(6) The head of the rail should be sufficiently thick for adequate margin of vertical wear.
(7) The foot of rail should provide sufficient bearing area on the underlying sleepers so that the compressive stresses on the timber sleeper remain within permissible limits.
(8) The section of the rails should be such that the ends of two adjacent rails can be efficiently jointed with a pair of fish plates.
(9) The surfaces for rail table and gauge face should be sufficiently hard to resist the wear.
(10) The contact area between the rail and wheel flange should be as large as possible to reduce the contact stresses.

76. (12) The composition of the steel should conform to the specifications adopted for its manufacture by Open Hearth of Duplex Process.
(13) The overall height of the rail should be adequate to provide sufficient stiffness and strength as a simply supported beam.
(14) The stiffness of a rail section depends upon the moment of inertia. The economical design should provide maximum moment of inertia per unit weigh of rail with due regard to other factors.
(15) The section moduliiof the rail section and that of a pair of fish plates should be adequate so as to keep the rail and fish plates within permissible limits.
(16) The foot of the rail should be wide enough so that the rail is stable against overturning.

77. Types of rail sections
1. Double headed rails
2. Bull headed rails
3. Flat footed rails

78. Types of rail sections

79. Types of rail sections

80. Double headed rails:
These were the rails which were used in the beginning, which were double headed and consisting of a dumb-bell section.
The idea behind using these rails was that when the head was worn out in course of time, the rail can be inverted and reused.
But as time passed indentations were formed in the lower table due to which smooth running over the surface at the top was impossible.

81. Bull headed rails:
In this type of rail the head was made a little thicker and stronger than the lower part by adding more metal to it, so that it can withstand the stresses.

82. Flat footed rails:
These rails are also called as vignole'srails.
Initially the flat footed rails were fixed to the sleepers directly and no chairs and keys were required.
Later on due to heavy train loads problems arose which lead to steel bearing plates between the sleeper and the rail. at rail joints and other important places these are the rails which are most commonly used in india.

83. Length of rails
The most common length for BG rails is 13m (42'8'') although double-length rails (26m, 85'4'') are seen in some places.
MG rails are usually 12m (39'4'') in length.
NG rails vary, but the commonest length is 9m (29'6''). Much earlier (before the metric system was adopted!), rails were generally produced in sizes of 11, 12, or 14 yards (33', 36', 42'), less commonly 13 yards (39') or 10 yards (30' -NG).

84. Factors governing length of rails:-
Manufacturing cost
Transportation facility
Lifting and handling operation

85. Welding of rails
Purpose of welding:
To increase the length of the rails
To repair the worn out or damaged rails
To build up worn out points and rails on the sharp curves

86. Welded rail sections are of two types:
Short Welded Rail or SWR which consists of just two or three rails welded together, and Long Welded Rail or LWR which covers anything longer.
The welding of rails is carried out in a depot by the "Flash butt welding process and at site by the "ThermitWelding" process.

87. Advantages of welding rails:
(1) Welding of rails increases the life of the rails due to decrease in wear of the ends.
(2) Welded rails provide more comfort to the passengers due to smooth running of wheels over welded joints.
(3) Welding of rails reduces the creep because frictional resistances increase with the increase in rail length.
(4) As discontinuity of rails is reduced, the defects such as hammering rail joints, displacement of joint, disturbance in alignment and running surface, are also eliminated.
(5) A welded rail panel provides better track circuiting on the electrified tracks.
(6) Welded rails provide better performance and reduce the effects of impact on large span bridges.

88. (7) Long welded rail length dampens the intensity of high frequency vibrations due to moving loads.
(8) Welding increases the life and decreases the wear of rails.
(9) By welding of rails, the cost of track construction decreases due to elimination of a large number of rail joints.
(10) Fast and heavy traffic may be permitted on track with welded rails.
(11) The use of long welded rails, affords better longitudinal, lateral and vertical stability to the track.
(12) In a welded rail panel, the number of joints is less. This saves the fuel consumption as it eliminates the loss of strain and impact energy at the rail joints.
(13) In welded rail panels, the risk of sabotage and accidents, are considerably reduced.
(14) Welding of rails reduces the maintenance cost by about 20% to 40%.

89. Wear of rails
Wear on head of rail
Wear on ends of rail
Wear of rail on curve

90. Wear on head of rail
Wear on head of rail is due to abrasion on moving rails.
Due to grinding action of sand or dust between the rails and wheels of the train.
When train starts or applies brakes, the wheel just slides on the rails causing wear on the head.
Load coming on to a track may exceed the carrying capacity of the section. Thus causing the wear in the head of rail.

91. Wear on ends of rail
It is much greater than the wear on the head of the rail.
This type of the wear is resulted due to the blows which the rail receive when the wheel jumps the space between the rail ends.
The ends are battered by such blows.
The contact surface between the sleepers and the rail is worn as the as the effect of these blows increased.
The ballast under the sleepers will loosen due to increase in the intensity of vibrations, also he sleeper will depressed due the displacement of ballast, also the fish plates will get loose under the constant impact of increasing vibrations

92. Wear on ends of rail

93. Wear of rail on curve
On the curve the wear of the rail takes place in both inner and outer rails.
On the curve, the outer wheel has to move through greater distance than the inner wheel. And the inner wheel has to slide over the inner rail.
As a result of this sliding wear of the inner rail occur because the metal in the rail head is burnt.

94. Wear of rail on curve

95. Coning of wheels
The flanges of wheel is never made flat, but they are in the shape of cone with a slope of 1 in 20. (Sloping of the wheel from the vertical axis)
The coning of wheels is mainly done to maintain the vehicle in the central position with respect to the track.
It is done to maintain the vehicle in the central position with respect to the track

96. Coning of wheels

97. Advantages of coning the wheels
(i) Coning the wheels reduces the depreciation of the wheel rims and rails. Depreciation is caused because of the friction action of rims with inner faces of the rail top.
(ii) Coning also gives an option of lateral drift of the hinge with is wheels.
(iii) Coning also prevents, to some extent, the slipping of the wheels.

98. Hogged rails
A hogged rail is one with its end or ends bent in vertical direction. Caused due to battering action of wheels

99. Causes of Hogging
Due to loose packing under the joints and loose fish plates.
Preventing steps
Hogged rails are removed and replaced by new rails.
Deflected ends can be brought in to their original shape and size by welding
The deflected ends of the rails are cut off and fresh holes drilled for fixing the fish plates.
The bent or deflected ends of rails can be straightened

100. Bending of rails
On curves the rail is bent true to the curvature of the curve. In flat curves less than 30the rails need no bending as they are retained in curve position by the sleepers.
With curves more than 30it is desirable to bend the rails before fixing them with sleepers.

101. Bending of rails

102. Creep of rails
It is defined as the longitudinal movement of rails with respect to sleepers in a track.

103. Causes of creep:
Wave motion of trains.
Expansion and contraction of rails due to variation in temperature.
Due to starting, accelerating, slowing down (decelerating) and stopping of trains.
Rail deflection under the moving loads from the wheels
Heavy traffic in one direction
Greater on curves
Old rails have more creep
More with steep gradient
Poor maintenance of track

104. Effects of Creep:
Expansion gap is reduced, buckling of track take place.
Sleepers are moved out of a square.
Crossing points get disturbed.
Rail joints are opened, stresses are set up in fish plates and bolts.
Movement of switches is made difficult
Smashing of fish plate, bolts, bending of bars, kinks at joints

105. Prevention of creep:
Pulling back the rails
Provision of Anchors
Use of steel sleepers
Efficient and proper maintenance

106. SLEEPERS AND BALLAST
Definition:
Sleepers are used as a base for laying railway tracks. Sleepers were traditionally made from wood but are now usually made from concrete.
Ties are laid on top of sand, gravel or heavy crushed stone - called ballast.

107. SLEEPERS AND BALLAST

108. SLEEPERS AND BALLAST

109. Functions of Sleepers
In a railway track, sleepers perform the following functions:
(1) To hold the rails t proper gauge in all situations. i.e. exact gauge along straights and flat curves, slightly loose on sharp curves and slightly tight in diamond crossings.
(2) To support the rails firmly and evenly throughout.
(3) To distribute the load transmitted through rails over large area of ballast underneath or to the bridge girders as the case may be.
(4) To hold the rails to proper level in turnouts and crossovers, and at 1 in 20 in ward slope along straight tracks.
(5) To provide and elastic medium between the rails and ballast and also to absorb the vibrations caused due to moving axle loads.
(6) To maintain proper alignment of the track. On curves proper cant is provided by raising the outer rail and tamping he required quantity of ballast bellow thrails.

110. (7) To provide the general stability of the permanent way throughout.
(8) To provide the insulation of track for the electrified for signaling.
(9) To provide easy replacement of the rail fastenings without any serious traffic disturbances
(10) Holding rails to correct gauge and alignment.
(11) Firm and even support to rails.
(12) Transferring the load evenly from rails to wider area of ballast.
(13) Elastic medium between rails and ballast.
(14) Providing longitudinal and lateral stability

111. Requirements of a good Sleeper
A good sleeper should meet the following requirements:
(1) The initial cost and the maintenance cost of the sleepers should be low.
(2) The fittings required for fixing the rails on to the sleepers, should be simple which can be easily adjusted during the maintenance.
(3) The crushing strength of the sleepers should be more with moderate weight.
(4) They should be able to maintain a perfect alignment, gauge and levels of the rails and should afford efficient adjustment and maintenance.
(5) They should provide sufficient bearing area to hold the rail seats and for the ballast to be supported on, to resist the crushing due to movement of heavy axle loads.

112. (6) The sleeper spacing should be such as t remove and replace the ballast during regular maintenance operation.
(7) They should be capable to resist the shocks and vibrations caused due to fast moving vehicles at high speeds.
(8) They should provide insulation facilities for track circuiting in the electrified sections.
(9) The sleepers should be strong enough to withstand the pressure during packing process.
(10) The sleepers should be of such a design that they remain in their positions and do not get disturbed due t moving trains.
(11) The material used for the sleeper be such that it does not attract the sabotage and the theft qualities.

113. Types of Sleepers
Sleepers based on the materials
Timber sleepers
Steel sleepers
Cast iron sleepers
R.C.C sleepers
Pre-stressed concrete sleepers.
Sleepers depending on the location
Longitudinal sleepers
Transverse sleepers

114. Longitudinal sleepers
These are earlier form of sleepers which are not in use nowadays.
It consists of slabs or pieces of timber placed parallel to the rails.
To maintain the correct gauge cross pieces were provided.
These sleepers were costly
Noise created by the track is considerable

115. Longitudinal sleepers

116. Transverse sleepers
Also knows as cross sleepers.
Placed at right angles under the rails.
Eliminated the inconvenience of longitudinal sleepers

117. Transverse sleepers

118. Timber sleepers (Wooden sleepers)
Ideal type and universally used they are two categories of hard wood sleepers such as Sal, Teak, Konguetc., and soft vwoodsleepers such as deodar, chir, treated timbers are use in this categories.

119. Timber sleepers (Wooden sleepers)

120. Advantages of Wooden Sleepers:
(1) They have proved very useful for heavy loads and high- speed trains.
(2) They are cheap and easy to manufacture.
(3) They can be handled easily without any damage.
(4) They maintain the correct alignment.
(5) They are most suitable for track circuiting.
(6) They can be used with or without ballast.
(7) They can be used for gauntlet tracks.
(8) They are suitable in the areas having yielding formations.

121. Disadvantages of Wooden Sleepers:
They are easily subjected to wear and decay due to various factors, i.e. vermin, white ants, rail-cutting, warping, etc. Hence, these have a short life.
(1) They do not maintain the gauge accurately.
(2) They easily develop cracks with beater packing.
(3) They require the highest maintenance cost as compared to other types of sleepers.
(4) They get easily disturbed from their positions under heavy loads.
(5) They need special treatment for fire protection.
(6) Their scrap value is low.
(7) They are not suitable for modern LWR track because of their lighter weight.

122. Description of Wooden Sleepers
Size of wooden sleepers in mm : B.G. : For ordinary track 2750x250x130 (9ᾼx10῀x5῀)
Life of Sleeper: Durable 19 years (B.G.)/ 31 years (M.G.)

123. Steel sleepers
They are in the form of steel trough on which rails are fixed by keys or nuts or bolts

124. Advantages of steel Sleepers
The steel sleepers possess the following advantages:
(1) They are manufactured by a simple operation.
(2) They can be easily handled as theses are light in weight as compared to other types of sleepers. Hence, damages during handling and transporting are less.
(3) Less number of fastenings are required and that too simple in nature.
(4) The maintenance and adjustment of gauge are easy as compared to the other of sleepers.

125. (5) These sleepers are rolled sections in one piece.
(6) Their life is longer than that of other types of sleepers.
(7) They provide better lateral rigidity to the track.
(8) They are not attacked by vermin’s.
(9) They are not susceptible to fire hazards.
(10) Their scrap value is good.

126. Disadvantages of Steel of Sleepers
The steel sleepers possess the following disadvantages:
(1) They get easily rusted and corroded.
(2) They develop cracks at rail seats or near lugs.
(3) Their lugs get broken easily.
(4) The steel sleepers do not provide effective track circuiting
(5) The steel sleepers can only be for the type of rails for which theses are manufactured.
(6) These develop the tendency to become center bound because of slope at both ends.
(7) The overall cost of steel sleepers is more than that of timber sleepers.

127. Cast iron sleepers
Sleepers made of cast iron are called cast iron sleepers
Type of Cast Iron Sleepers :
A) C. I. Pot Sleepers
B) C S T-9 Sleepers

128. Cast Iron Pot type sleepers
Consists of two hollow pots of circular or elliptical shape placed inverted on the ballast section.
Two pots are connected by the tie bars of section 5cm X 1.25cm,
Each pot has two hoes for ballast packing and inspection, the rail is placed on the top of the pot in a rail seat

129. Cast Iron Pot type sleepers

130. Cast Iron Plate type sleepers
Consist of rectangular plates of size about 86cm X 30.5cm, with projecting ribs under the plates for their lateral stability.
The tie bars can be fixed to the plate keys, gibs, cotter keys and distance piece etc.
It also provide an effective bearing area on BG

131. Cast Iron Plate type sleepers

132. Advantages of Cast Iron Sleepers
• Long life upto50-60 years
• High scrape value as they can be remolded
• Can be manufactured locally
• Provided sufficient bearing area
• Much stronger at the rail seat
• Prevent and check creep of rail
• They are not attacked by vermin

133. Disadvantages Cast Iron Sleepers
• They are prone to corrosion and cannot be used in salty formations and coastal areas
• Not suitable for track circuited portions of railways
• Can badly damage under derailment
• Difficult to maintain the gauge as the two pots are independent
• Require a large number of fastening materials
• Difficult to handle and may be easily damaged
• Lack of good shock absorber
• They are expensive

134. Concrete sleepers
R.C.C and pre-stressed concrete sleepers are now replacing all other types of sleepers except to some special circumstances such as crossing bridges etc here timber sleepers are used.
They were first of all used in France round about in 1914 but are common since 1950.
They may be a twin block sleepers joined by an angle iron.
It may be a single block pre-stressed type.
Concrete sleepers are much heavier than wooden ones, so they resist movement better.

135. Concrete sleepers

136. Advantages Concrete Sleepers
• Durable with life range from 40-50 years
• They can be produced on large quantities locally by installing a plant
• Heavier than all other types thus giving better lateral stability to the track
• Good insulators and thus suitable for use in track circuited lines
• Efficient in controlling creep
• They are not attacked by corrosion
• Free from attacks of vermin and decay, suitable for all types of soils
• Most suitable for welded tracks
• Prevent buckling more efficiently
• Initial cost is high but proves to be economical in long run
• Effectively and strongly hold the track to gauge
• Inflammable and fire resistant

137. Disadvantages Concrete Sleepers
• Difficult to be handled
• Difficult to be manufactured in different sizes thus cannot be used in bridges and crossing
• Can be damaged easily while loading and unloading

138. Pre-stressed concrete sleepers.
The concrete is put under a very high initial compression.
All the disadvantages of RC sleepers have been eliminated by pre stressing sleepers
Two types of pre stressed sleepers (i) Pre-tensioned sleeper (ii) Post tensioned sleeper

139. Pre-stressed concrete sleepers.

140. Sleeper Density
Sleeper density= Number of sleepers per unit rail length (per unit track length for welded rail)
Number of sleepers per rail varies from N+3 to N+6 for main tracks, N-Length of the rail
Minimum DensityMKS: Minimum sleeper density= M+7 (BG) FPS: Minimum sleeper density= N+3 (MG)
Factors affecting spacing/density
Axle load and speed
Type and section of rails
Type and strength of sleepers
Type of ballast and ballast cushion
Nature of formation

141. Ballast
It is a layer of broken stones, gravel or any other such gritty material laid and packed below and around sleepers.
The material used as an elastic cushion between the sleeper and the top of the formation, is called ‘Ballast’

142. Requirements of Good Ballast
Ideal ballast should possess the following characteristics:
(1) It should resist crushing under dynamic loads.
(2) The designed depth of the ballast should be able to distribute the weight of passing trains on the formation underneath uniformly.
(3) It should not make the track dusty due to powder formation under dynamic wheel loads.
(4) It should be reasonably elastic.
(5) It should have resistance to abrasion and weathering
(6) It should be non-porous to provide durability to the ballast.
(7) It should hold the sleepers laterally and longitudinally under all conditions traffic, especially on the curves.
(8) It should be able to facilitate easy drainage to rain water

143. Functions of Ballast
The main functions of ballast of a railway track are as under:
(1) It provides a hard and level bed for the sleepers.
(2) It holds the sleepers in proper position during the passage of moving trains.
(3) It provides to some extent an elastic bed for the track.
(4) It transmits and distributes the moving load of the trains from the sleepers to the formation uniformly.
(5) It protects the formation surface from direct exposure to sun, rain and frost.
(6) It provides a proper drainage to the track, keeping the sleepers in dry condition.

144. Functions of Ballast
(7) It obstructs the growth of vegetations at the track formation.
(8) It provides proper super elevation to the outer rail on curves.
(9) It provides an easy means for correcting the unevenness of the track.
(10) It provides the lateral and longitudinal stability to the track
(11) It protects the sleepers from capillary moisture of formation.
(12) It provides a media for absorption of all impacts caused by rolling stock.

145. Types of Ballast
Keeping in vies the availability, workability, durability and strength of the ballast different materials have been used as ballast. The most important types of ballast materials used in.
(1) Broken stones (2) Gravels (3) Sand (4)Moorum(5) Cinder (or ash) (6) Brick bats
(7) Kankar(8) Ballast earth.

146. (1) Broken stone:
Best material for railway track.
Due to high interlocking action it holds the track to the correct alignment and gradient
Granite, Quartzite, hard stones, lime stones are some of the varieties of stones

147. (2) Gravel:
Obtained from river beds or pits
Cheaper than broken stone
Has excellent drainage property
Requires screening before use

148. (3) Ashes and Cinder:
Residue obtained from coal used in locomotives is cinder
Has good drainage property
Corrosive property
Should not be used where steel sleepers are used

149. (4) Sand:
Best materials for ballast
Good drainage property
Gives silent track
Good for packing of cast iron pot sleepers

150. (5) Moorum:
Decomposed lateriterocks
Red in colour
Under heavy loads crumbles to powder
Used in sidings and embankments

151. (6) Kankar:
Found in the form of nodules of varying size
Useful for metregauge and narrow gauge tracks with light traffic

152. (7) Brick ballast:
Over burnt bricks are broken in to small pieces, used as ballast
Fairly good enough drainage property
Becomes powder under heavy traffic and tracks become dusty.

153. (8) Selected earth:
Good quality earth can be used for newly laid tracks and sidings

154. RAIL FASTENINGS AND PLATE LAYING
Rail joints
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.

155. RAIL FASTENINGS

156. Types of Rail Joints
According to Position of joints
(i)Square joints (ii) Staggered joints
According to position of sleepers
(i) Suspended joints(ii) Supported joints (iii) Bridge joints (iv) Insulated joint (v) Compromise joint

157. According to Position of joints
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
Staggered Joints:
Joint in one rail is exactly opposite to the centre of the other parallel rail is called as Square Joint
In India this type of joint is used in curves
It gives smoother running to the track.

158. According to Position of joints

159. According to position of sleepers
(i) 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

160. (ii) 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

161. (iii) 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

162. Rail fastenings:
A rail fastening system is a means of fixing rails to railroad ties.
The terms rail anchors, tie plates, chairs and track fasteners are used to refer to parts or all of a rail fastening system.
Various types of fastening have been used over the years.

163. Rail fastenings:

164. Fish Plates:

165. Fish Plates:
Afishplate,splice barorjoint baris a metal bar that is bolted to the ends of two rails to join them together in atrack
The top and bottom edges are tapered inwards so the device wedges itself between the top and bottom of the rail when it is bolted into place.
In rail transport modelling, a fishplate is often a small copper or nickel silver plate that slips onto both rails to provide the functions of maintaining alignment and electrical continuity

166. Fish bolts:

167. 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

168. Spikes:
Arail spike(also known as acut spikeorcrampon) is a largenailwith an offset head that is used to secure rails and base plates torailroad tiesin the track.

169. Spikes:

170. Chairs and Keys:
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.

171. Chairs and Keys:

172. Keys:
They are wedge-shaped wooden or metal pieces. They keep the rail in proper position
Wooden keys are cheaper but liable to be attacked by vermin’s, the initial cost of metal key is more but their life is ten to 15 times more than wooden keys.

173. Bearing plates:
Rectangular plates made up of mild steel or cast iron
Used below flat footed rails to distribute the load on a larger area
Prevents damage of the sleepers due to rubbing action
Holds the spike firmly to the sleepers

174. Bearing plates:

175. Bearing plates:

176. Blocks:
To hold the check rail at the required distance, small blocks of steel are inserted in between two rails
These blocks may touch either the webs or the fishing faces or both

177. Blocks:

178. Elastic fastenings:
Arail fastening systemis a means of fixingrailstorailroad ties
The conventional rigid fastenings are not able to meet the higher stresses. Therefore elastic fastenings are used
This may protest against the shocks, vibrations

179. Elastic fastenings:

180. Elastic fastenings:

181. Elastic fastenings:

182. Requirements of Elastic fastenings:
It should have sufficient elasticity
It should provide longitudinal and lateral rigidity to the track
It should be able to use all types of sleepers
It should be durable
It should be easy to insert and remove

183. Anchors and anti-creepers:
Creep can be checked by using Anchor and Anti-creepers.
Anchors are fastenings which are fixed to the sleepers at foot of rails
Anchors are fixed at come required intervals in the rails
They depend up on the traffic, curves points, crossings

184. Anchors and anti-creepers:

185. Anchors and anti-creepers:

186. Anchors and anti-creepers:

187. Plate laying:
The operation of laying out and connecting sleepers and connecting rail and sleepers is known as Plate laying
The point of commencement of the new track to be laid is the existing rail head
In new track sleepers are laid directly over the formation, after compaction the track is then lifted and ballast is packed around the sleeper

188. Methods of plate laying:
Tram line method or side method
Telescopic method
American method

189. Tram line method or side method:
This method is used for plate laying in flat country
Used when new track is laid nest to the existing track
For plate laying of new track, either of the following two methods may be adopted
(i)A service road is constructed parallel to the proposed track and the materials are transported to the site of the work

190. Tram line method or side method:

191. (ii)A temporary rail line parallel to the proposed track and the materials are transported in wagons. This temporary line is known as tram line
In this method all the materials are taken from the central depot in material trains on the existing track and are spread on the formation of new track
After completing spreading, the work of assembling is started from one end manually

192. Telescopic method:
This method is used very widely in India
A large central depot is constructed near the junction of the existing railway or highway and the proposed railway line
The manual force is divided in to (i)Material gang (ii)Linking-in-gangs (iii)Packing-in-gangs

193. (i) Material gangs:
These gangs unload the materials from the trains
They carry the materials to the rail head and supply them to the linking-in-gangs.
These gangs distribute sleepers, rails, fishplates, bolts etc. to the required places

194. (ii) Linking-in-gangs:
These gangs mark the centre line of the proposed track and place the sleepers at required place
Rails are placed on the sleepers
Successive rails are joined together by fishplates, bolts with expansion joints
After joining the rails are fixed to the sleepers

195. (iii) Packing-in-gangs:
These gangs correct the rails to the required level and gradients by packing earth or ballast below and around the sleepers

196. American method
This method involves all mechanical work
This method consists of fixing rails to the sleepers and lifting the whole unit by heavy cranes.
First one is linked with the rail head, then the train moves ahead by one rail length and the same procedure is repeated.
This method is un-economical one and is not used in India

197. PlasserQuick Relaying System (PQRS method)
This is a mechanical method of laying railway track in Indian Railways
This method is used for relaying existing track under traffic condition without interrupting the flow of traffic
Following equipments are used for PQRS method of plate laying
(i)Sleeper layer (ii)5 tonne portal crane (iii)Track jacks (iv)Hand gantries (v)Engine (vi)B.F.R (open wagon for carrying long rails) (vii)B.F.R for carrying sleeper (viii)B.F.R for old materials

198. PlasserQuick Relaying System (PQRS method)

199. Auxiliary track

200. An auxiliary track is laid with a gauge length of 3.4m.
This is to carry the required equipments and materials for laying new work.
The auxiliary track is laid over wooden blocks on cast iron posts at two metresinterval.
The level of auxiliary track is laid with the same level of track.
The portal crane moves on the auxiliary track and it is used to lift and carry the rail panels.
Sleepers layers is a machine which is used for laying sleepers with required spacing and alignment
The jacks are used to support the track laying at uniform level. Hand gantries are used for moving the rails in longitudinal direction at lifted position.

201. Method of relaying:
Work of relaying the track is normally divided into the following stages:
(i)Preliminary work:
To prepare schedule of materials per 100m length or per km of the track.
The entire quantity is collected at the central store, from which day to day requirements is drawn

202. (ii)Laying of the track:
Removal of the fittings.
Removal of rails and sleepers
Placing of new sleepers
Laying of rails
Laying of second rail
Finishing
(iii)Construction of the track:
Tightening of the fittings
Distribution of ballast
Further packing of ballast
Return of released material to store

203. MAINTENANCE OF TRACK
Necessity of Maintenance of track:
Increases the life of track
Provides comfortable ride to the passenger
Provides safety to goods
Increase the life of rolling stock
Operating cost is reduced
Safety to passengers

204. Maintenance of track:
The railway track requires proper watch and ward for security reasons
Maintenance of railway track consists of
(i) Daily maintenance (ii) Periodic Maintenance
For daily maintenancethe track is divided in to sections of 5 to 8 kmslengths.
Each section is look after by a gang

205. The daily maintenanceconsists of
General inspection of the track
Checking up of all fastenings and fittings
Tightening of bolts wherever required
Reporting by unusual occurrence
The periodic maintenanceconsists of detailed inspection of the track to detect defects in the track which may not be detected during daily maintenance.
The various aspects of periodic maintenance are as below
Maintenance of track alignment
Maintenance of track drainage
Maintenance of track components
Maintenance of level crossing

206. Maintenance of track materials:
The top surface of the rails should be kept at the same level
Ballast under sleepers should be regularly packed
Defective sleepers should be replaced immediately
Worn-out rails should be replaced
Kink or fracture rails should be replaced
Fastening should be tightened and oiled
Gauge should be checked and corrected
Ensure that both the rails are at same level
Maintain track drainage properly
Oiling and greasing of fishplates regularly
Flanges and check rails should be kept free from dust

207. Maintenance of Bridges:
Proper embankment should be provided near the bridge
Avoid scouring near abutments and piers
Flood control measures should be taken near the bridges
Riveted joints should be inspected periodically
Bed blocks should be checked regularly
Steel bridges should be painted regularly
Bearings of the girders should be oiled regularly
Masonry works should be inspected regularly

208. Maintenance of rolling stock:
Lubrication of all reciprocating parts and bearings
Wornoutparts should be replaced the rolling stock
It is necessary to clean the different parts every day
All axles which have run 3,22,000Km should be replaced
A passenger vehicle used for 30years should be dismantled and re-assembled
The locomotive boilers have to be carefully maintained and removed every 15 years