History of Indian Railway
• It is a branch of civil engineering concerned with the design,
construction, maintenance, and operation of railways.
• Railway engineering includes elements of civil, mechanical,
industrial, and electrical engineering.
• Railway engineers handle the design, construction, and operation
of railroads and mass transit systems that use a fixed guideway
(such as light rail or even monorails).
• Typical tasks would include determining horizontal and vertical
alignment design, station location and design, construction cost
estimating, and establishment of signaling & controlling system.
• Railroad engineers can also move into the specialized field of
train dispatching which focuses on train movement control.
The gauge of a railway track is defined as the
clear minimum perpendicular distance between
the inner faces of the two rails.
Dimension of gauges
1. Broad Gauge(BG) 1676mm(5’6”)
2. Standard Gauge(SG) 1435mm
3. Metre Gauge(MG) 1000mm
4. Narrow Gauge(NG) 762mm(2’6”)
5. Light Gauge 610mm
Coning of Wheels
• Coning of wheels – The distance between the inside edges of
wheel flanges is generally kept less than the gauge. Gap is
about 38 mm on Either side. Normally the tyre is absolutely
ahead centre on the head of the rail, as the wheel is coned to
keep it in this central position automatically. These wheel are
coned at a slope
• Theory of coning:- On a level track, as soon as the axle moves
towards one rail, the diameter of the wheel tread over the rail
increases, while It decreases over the other rail. This prevents
to further movement And axle retreats back to its original
position (with equal dia or both rails and equal pressure on
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.
Functions of the rails:
To provide continuous and level surface for the
movement of trains with minimum friction with
steel wheels of the rolling stock;
Provide strength, durability and lateral guidance
to the track;
Transmit the axle loads to sleepers which transfer
the same load to the underlying ballast and
Bear the stresses developed due to heavy vertical
loads, breaking forces and temperature variance.
Length of Rails
On Indian Railways the standard lengths are the following:
Length = 12.80 m. (42 ft.) for BG (say 13 m) and
Length = 11.89 m. (39 ft.) for MG (say 12 m)
Corrugated or Roaring Rails
In certain places, head of rails are found to be
corrugated rather than smooth and straight,
when the vehicles pass over such rails, a roaring
sound is created which is intense enough to be
Due to battering action of wheels over the end of the rails, the
rails get bent down and get deflected at the ends. These rails are
called hogged rails.
Measures taken to rectify the hogged rails are:
Reason of Hogging!
Kinks In Rails
When the ends of adjoining rails move slightly out of position,
“shoulders” or “kinks” are formed.
Measures taken to rectify kinks in rails:
1. By correcting alignment at joints and at curved locations.
2. Proper packing of joints.
3. Proper maintenance of the track periodically in repect of
cross levels, gauge, alignment, welding of worn out portions
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.
These are the rails which should be removed on
account of their becoming unsafe for a railway
• Crushed Heads
• Square or Angular Break
• Split Heads
• Split Web
• Horizontal Fissures
• Transverse Fissures
• Flowing Metal in Heads
• Horizontal Cracks
Sleeper density is the number of sleepers Per
rail length. It is specified as (M+x) or (N+x),
where M or N is the length of the rail in meters
and x is a number that varies according to
factors such as axle load, speed, type & section
of the rail etc.
It varies in India from M+4 to M+7 for main
Track Fittings & Fastenings
• Fish plates
– Dog spikes
– Screw spikes
– Round spikes
– Standard spikes
– Elastic spikes
– Dog or Hook bolt
– Fish bolt
– Rag bolt
– Fang nut and bolt
– Wooden key for C.I. Chair
– M.S. key and steel trough
– Stuart’s key
– Morgan key
– Cotter and tie bars
– Cast steel chairs
– Mild steel and Cast Iron
To provide structural support for
the track, holding it in good line
To distribute the load evenly to the
subballast and subgrade and thus
help to provide stability
Provide for drainage
Ballast in railroad terminology is durable granular material placed between
the crosstie and the sub ballast to hold the track in line and grade.
The primary purposes of ballast are:
Types of Ballast
• Broken Stone
• Gravel or River Pebbles or Shingle
• Ashes or Cinders
• Brick Ballast
• Blast Furnace Slag
• Selected Earth
• For wooden sleepers = 5.1 cm
• For steel sleepers = 3.8 cm
• For under switches & crossings = 2.54 cm
Points & Crossings
• Points and crossings provide flexibility of
movement by connecting one line to another
according to requirements.
• They also help for imposing restrictions over
turnouts which necessarily retard the
• From safety aspect, it is also important as points
and crossings are weak kinks or points in the
track and vehicles are susceptible to derailments
at these places.
• It’s the simplest combination of points and crossings which
enables one track either a branch line or a siding, to take
off from another track.
• Parts of a turnout:
– A pair of points or switches
– A pair of stockrails
– A Vee crossing
– Two check rails
– Four lead rails
– Switch tie plate
– Studs or stops
– Bearing plates, slide chairs, stretcher bars etc.
– For operating the points – rods, cranks, levers etc.
– For locking system – locking box, lock bar, plunger bar etc.
How Railway Track Changes
It consists of the systems, devices and means by
which trains are operated efficiently and tracks
are used to maximum extent, maintaining the
safety of the passengers, the staff and the rolling
On the basis of Operating
• Detonating Signals (Fog or audible signals)
• Hand signals (Visual Indication signals)
• Fixed signals (Visual Indication signals)