Remember me in your pray

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Assala mu alykum My Name is saqib imran and I am the
student of b.tech (civil) in sarhad univeristy of
science and technology peshawer.
I have written this notes by different websites and
some by self and prepare it for the student and also
for engineer who work on field to get some knowledge
from it.
I hope you all students may like it.
Remember me in your pray, allah bless me and all of
you friends.
If u have any confusion in this notes contact me on my
gmail id: Saqibimran43@gmail.com
or text me on 0341-7549889.
Saqib imran.

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RAILWAY
WHY CRUSHED STONES ARE USED IN RAILWAY TRACK
WHY CRUSHED STONES ARE USED IN RAILWAY TRACK:
The technical term for these crushed stones is “Ballast or track ballast. Tamping
machine is used to pack the track ballast under railway tracks to make the tracks more
durable. Usually, a 25–30 cm thick ballast layer (crushed stone 30/60) below the bottom
face of sleeper is provided along the track. This thickness varies based on many
parameters and conditions.
Following are the reasons for using crushed stones in railway track:
1. To hold the sleepers in place, both laterally and longitudinally (as they in turn hold the
rails in place & help maintain gauge.
2. To distribute the load of entire moving cargo from rails into the sub-base/formation
(ground below the ballast.
3. To maintain support of and distance between the cross ties.
4. To restrain heat expansion & contraction (due to thermal stresses), and ground
movements.

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5. To dampen the vibrations — as ballast provide cushioning effect (thus rendering
elastic property to the railway track).
6. To absorb vibrations — The air voids present between the stones absorb vibrations
and make it comfortable, not only for the traveling passengers but also for the residents
next to tracks.
7. To facilitate drainage & stop building up of precipitation from rough weather (which
can help — relieve frost heaves & maintain necessary shear stress in sub-base).
8. To overcome weed & plant growth from underneath.
9. To absorb much of the sounds & noises produced by train movements.
10. Minor adjustments can be made in the track as and when required.
SYSTEMS OF RAILWAY – SURFACE RAILWAY, ELEVATED RAILWAY,
UNDER GROUND RAILWAY, TUBE RAILWAY
SYSTEMS OF RAILWAY:
The railways can be provided above and below the ground surface suiting to the
topography of the area. Further, the railways below the ground surface can be
constructed just below the ground level or at greater depths.
There are four systems of railways:
1. Surface railways
2. Elevated railways
3. Underground railways
4. Tube railways.
1. SURFACE RAILWAY:
In this system, railways are provided over the ground. This is the most extensively used
and best rails throughout the world. In surface railways, various means like level
crossings, over bridge, under bridge etc are to be provided for crossing of the railway
and road traffic safely and efficiently.
2. ELEVATED RAILWAY:
In this system, the railways are provided at higher or elevated portion above the
surface. A continuous viaduct supported on piers, columns etc are constructed and the
track is carried on its steel deck. This system is very costly because stations, waiting
rooms, offices are to be constructed at higher levels requiring staircases, escalators
etc. This type of railways is proved in the heavily congested urban area where
underground railways cannot be constructed.

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3. UNDERGROUND RAILWAY:
In this system, the railway is provided just below the ground level. Tunnels are
constructed for carrying tracks through them and an overbridge is necessary at every
road-crossing to carry the road traffic over the railway traffic. Due to ventilation problem
in tunnels, electricity is the only source of power for traction in underground railways.
This system is provided in the heavily congested area where the traffic intensity on
roads is heavy.
ADVANTAGES:
a) This system provides rapid and unobstructed transportation.
b) This system helps in reducing traffic congestion problems.
c) This system provides safety during aerial attack in war.
4 TUBE RAILWAY:
The railway provided underground at a greater depth of about 18 m or more(upto 52 m)
is called tube railway.
This system of railways is so called as the section of the underground tunnels, carrying
the track, is circular like a tube. The main purpose of providing tube railways is to avoid
the interference of the tracks with water and gas pipes, sewerage systems and oil or
drainage pipes etc.
Some important features of tube railways are given below:
1. The railway stations have to be of cylindrical form.
2. Escalators or moving staircases are to be constructed to reach the tube railways.
3. Only electric traction is to be used to avoid the smoke and ventilation problems.
4. Automatic signaling system is to be used.
5. Such a mechanism of the train is to be used that it cannot start until all the doors are
closed and it automatically stops, is the signal is at stop position.

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TYPES OF LEVEL CROSSINGS USED IN RAILWAY – CLASSIFICATION OF
LEVEL CROSSING
WHAT IS LEVEL CROSSING?
The place where a railway line and a road cross each other is called level crossing.
TYPES OF LEVEL CROSSINGS:
The various types of level crossings may be classified depending upon the nature of the
ground, nature of the traffic on road and number of trains passing over the level
crossing.
1. Special class level crossing.
2. Class “A” level crossing.
3. Class “B” level crossing.
4. Class “C” level crossing.
5. Class “D” level crossing.

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1. SPECIAL CLASS LEVEL CROSSING:
This type of level crossing is provided on very important through roads where the traffic
is exceptionally heavy, to suit the individual site conditions. The design of such a level
crossing is not according to the rules as given for other types of level crossings.
2. CLASS “A” LEVEL CROSSING.:
These crossings provided on G.T roads.
Requirements:
1. The roads meeting at these level crossings should be straight at least for 30 m on
either side of the railway line.
2. The angle of crossing should be 90° but in no case less than 45°.
3. The minimum radius of curvature for approaches on either side should be 45 m and
their maximum gradient be in 1 in 30.
4. A level length of at least 7.5 m to act as a platform for waiting of vehicles beyond
each gate should be provided.
5. The minimum gate width should be 7.3 m which are all paved.
6. The gates should be at angles to the center line of the road on either side.
7. No part of the gate should be within 2.1 m of distance from the centerline of the
adjacent track.
8. The view of level crossing should be clear from approach roads.
9. Minimum two watchmen should be deputed to take care of such level crossings.
10. The huts of watchmen should neither be on road formation nor should they obstruct
the clear view of level crossings. the nearest edge of the watchmen cabin should be
minimum 6m.
3. CLASS “B” LEVEL CROSSING:
The level crossings provided on metalled roads of district level are known as Class “B”
level crossings.
Requirements:
1. Minimum gate width should be 3.7 m.
2. Minimum radius for approach road on either side of the crossing should be 30 m.
3. Minimum one watchmen should be deputed to take care of this level crossing.

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4. CLASS “C” LEVEL CROSSING:
The level crossings provided on unmetalled roads are called class “C” level crossing.
Requirements:
1 The minimum gate width should be 3.7 m.
2 A least a level road length of 7.5 m on either side of the crossing should be provided.
3 The road portion should be metalled up to 2.7 m beyond the position of gates on
either side of the crossing.
5. CLASS “D” LEVEL CROSSING:
The level crossings in the form of ramps provided at inlet into the railway fencing for
pedestrians and cattle to pass are called as class “D” level crossings.
Recommended Dimensions For Different Types Of level Crossings:
Serial No. Class Of Level
Crossing
Width Of
Gates In m
Minimum
Radius Of
Approach
Road in m
(Within 45m)
Maximum
Gradient Of
Approaches
1. Special Class 7.1 to 9.1 60 1 in 40
2. Class “A” 7.3 45 1 in 30
3. Class “B” 3.7 30 1 in 30
4. Class “C” 3.7 21 1 in 20
5. Class “D” 1.8 76 1 in 10
TYPES OF SLEEPERS USED IN RAILWAY – RAILWAY SLEEPER
TYPES OF SLEEPERS USED IN RAILWAY:
There are various types of sleepers used in railways, according to their suitability,
availability, economy, and design.

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Based on the material used in the construction, the sleepers can be classified into the
following three categories:
1. Wooden sleepers.
2. Metal sleepers.
 Steel sleepers.
 Cast iron sleepers.
3. Concrete sleepers.
 Reinforced concrete sleepers.
 Prestressed concrete sleepers.
1. WOODEN SLEEPERS:
The sleepers made of timber are known as wooden sleepers. These sleepers were
widely used as the best type of sleepers as they fulfilled all the requirements of an ideal
sleeper. But these are now backdated and not used widely.
ADVANTAGES OF WOODEN SLEEPERS:
1. Timber is easily available.
2. The initial cost of wooden sleeper is low.
3. They require few fastenings which are also simple to design.
4. These sleepers are easy to handle.
5. Suitable for all types of ballast.
6. They can be used with every section of rails and for any gauge of track.
7. The extent of damage during accidents is less.
8. Best for track circuiting.
9. Easy renewal of the track.
DISADVANTAGES OF WOODEN SLEEPERS:
1. The life span of wooden sleepers is minimum (12 to 15 years) compared to other
types of sleepers.

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2. They are liable to decay, attack of white ants, wear, spike killing, cracking, splitting,
rail cutting etc.
3. The lateral and longitudinal rigidity of the track is less as the connections between the
rails and the sleepers are not so strong.
4. Difficulty in maintaining gauge of the track.
5. High maintenance cost.
6. Low scrap value.
Wooden Sleepers
2. METAL SLEEPERS:
The sleepers usually made of cast iron or steel are known as metal sleepers. Due to
growing shortage of timber to be used for wooden sleepers, their high maintenance,
cast and short life, metal sleepers are now being widely used.
Metal sleepers are two types:
a) Steel Sleepers: The sleepers made of steel are known as steel sleepers. Steel
sleepers are extensively used with excellent results.
Types of steel sleepers:
 Key type steel sleepers
 Clip and bolt type steel sleepers.
b) Cast Iron Sleepers: The sleepers made of cast iron are known as cast iron sleepers.
These sleepers are extensively used in India than any other country in the world.

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Types of cast iron sleepers:
 Pot or bowl sleeper.
 Plate sleeper.
 Box sleeper.
 CST-9 sleeper.
 Duplex sleeper.
ADVANTAGES OF METAL SLEEPERS:
1. Longer life span (35 to 50 years).
2. Uniform in strength and durability.
3. Gauge can be easily adjusted and maintained.
4. The lateral and longitudinal stability of the track is more.
5. Renewal is not frequent.
6 High scrap value.
DISADVANTAGES OF METAL SLEEPERS:
1. They require more fittings.
2. Metal is liable to rust.
3. Require more quantity of ballast.
4. These sleepers are not suitable for bridges, level crossing etc.
5. More damage during accident.

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Metal Sleepers
3. CONCRETE SLEEPERS:
The sleepers made of reinforced or prestressed cement concrete are known as
concrete sleepers.
Types of concrete sleepers:
a) RCC sleepers: The concrete sleepers constructed of reinforced cement concrete are
called RCC sleepers.
RCC sleepers are the following two types:
 Mono-black sleeper,
 Two back sleeper.
b) Prestressed Concrete Sleepers: The concrete sleepers constructed of prestressed
cement concrete are known as prestressed concrete sleepers.
ADVANTAGES OF CONCRETE SLEEPERS:
1. Long life span ( 40 to 60 years).
2. Require fewer fittings.
3. Adjustment of gauge is simple and easy.
4. They provide strong connections between rail and sleeper.
5. The lateral and longitudinal stability of the track is more.
6. Track circuiting is possible.
7. More durable and not liable to decay.
8. Less creep in the track.
9. They can withstand the stresses induced by fast moving and heavy traffic.
10. Low maintenance cost.
DISADVANTAGES OF CONCRETE SLEEPERS:
1. Initial cost is high.
2. Liable to break under rough handling or due to improper design.
3. Renewal is little bit difficult.
4. The scrap value is nil.

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Concrete Sleepers