UNIT 1: INTRODUCTION

Role of railways in transportation:The advantages of rail transport can be explained under the following categories

Political Advantages Social Advantages Economical Advantages

Political Advantages

1. Railways help to unite the people of different religions, castes, customs and traditions.

2. Railways network has enabled the central administration to become more easy and effective.

3. Railways have helped in the migration of the population from one region to the other for employment opportunities.

4. Railways have contributed a lot for developing national integration.

5. Railways have helped during wars for transportation of war equipments and armies.

Social Advantages

1. Railways provide a convenient, safe and cheap mode of transport for the country.

2. Railways have broadened the social out-look of the people.

3. Railways have eradicated the untouchability as passengers of different castes travel in the same compartment.

Economical Advantages

. 1. The finish products and the goods can be speedily transported by the railways t the places of their

consumption.

2. Industries have been developed even far from the places of the raw materials.

3. During famines, the railways play a vital role of transporting the food grains and cloths to the affected area.

4. Rails have provided employment to millions of people and thus, rails have helped in solving the unemployment problem.

5. The land cost increases due to opening of railway lines.

6. Rails have helped in fair distribution of population.

7. Rails help in transporting the labor from places of unemployment to industrial centers

Advantages and disadvantages of railway transport over other modes of transport facilities.

Sr. No. Item Highway Transport Rail Transport 1.

2

3.

4.

5.

6. 7.

8.

Tractive resistance

Right of way

Cost analysis

Gradients curves

Flexibility of movement

Pollution

Organization

Suitability

Pneumatic tires on road experience tractive resistance five times as compared to that of the railways.

It is open to all types of vehicular vehicles including pedestrians.

Cost of construction and its maintenance is less.

Steeper gradients up to 1 in 30 and relatively sharper curves may be provided.

Being more flexible it may even serve door to door.

It pollutes the environment more. Highway transport of controlled mostly by private sectors.

It is suitable for lighter goods and for passengers traveling over short distances.

Tractive resistance is less and hence hauling capacity is more.

The track being defined by two rails is suitable to trains designed for the track.

Cost of construction and its maintenance is more.

Flatter gradients> 1 in 100 and curves up to 10’ on broad gauge tracks, are generally provided.

Being less flexible, the movement of trains is restricted between fixed stations.

It pollutes the environments less.

It pollutes the environment less. Railways are controlled and managed by the Govt. organization. It is suitable for the carriage of heavy goods and for

Indian RailwaysThe first railway in India ran in 1853 from Bombay to Thane a distance of 34 km. In less than 150 years we have the largest network of railways in Asia. Indian railways employ about 17 lac people. For administrative convenience Indian railways have been divided into the following nine zones:

a. The Northern Railways

b. The Eastern Railways

c. The Western Railways

d. The Central Railways

e. The Southern Railways

f. The South-Eastern Railways

g. The North-Eastern Railways

h. The North-East Frontier Railways

i. The South-Central Railways

The Indian Railways have three types of railway tracks:

1. Broad Gauge

2. Meter Gauge

3. Narrow Gauge

Most of the railway tracks are broad gauge. Broad gauge tracks are 1.69 metre wide. The trains running in the plains use broad gauge tracks. In desert areas and other difficult areas where broad gauge tracks are difficult to be laid, metre gauge tracks are laid. These tracks are one metre wide that is why these tracks are known as metre gauge.

The third type is the narrow gauge. This track is 77 cm. wide. Narrow gauge tracks are laid in the hilly and mountainous areas. Kalka to Shimla, Darjeeling to Siliguri and Mettupalayam to Ooty are narrow gauge tracks. These different kinds of tracks are of great inconvenience. The railways have to make three types of railway engines and railway coaches to run on these rails. The passengers also face inconvenience when they have to shift from broad gauge to another gauge. The railways are trying to convert all metre gauge tracks into broad gauge tracks and some of the tracks have been converted into broad gauge.

The passenger trains are of four types depending upon the speed of the trains:

1. Super fast trains

2. Mail trains

3. Express trains

4. Ordinary passenger trains

The people like to travel fast. Therefore some fast moving trains have been introduced. These trains are called superfast trains. These trains run at a speed of 100 km. to 150 km. per hour. Shatobdi Express, Rajdhani Express are some of the superfast trains. The other fast running trains are the Taj Express, The Pink City Express, Tamil Nadu Express, Himgiri Express, Karnataka Express and Shan-e-Punjab.

Express trains are also fast moving trains. They stop at most of the important stations for the convenience of the passengers. The mail trains are fast running trains. These trains do not stop at smaller stations but stop at all the important stations to collect and deliver mail bags. Passenger trains stop at all the stations. These trains move at a slow speed. Big cities like Delhi, Chennai and Mumbai have local trains. In Calcutta local trains are underground railways known as Metro Railways.

At present the Indian Railways have three types of engines — Steam engines, Diesel engines and the Electric engines. Steam engines are the oldest type of locomotives. These are run by steam and coal. They give out a lot of smoke. These engines are now out-dated. They are being replaced by diesel engines. Diesel engines run on diesel. These engines are more powerful and run faster. They emit lesser smoke. These engines are preferred to the steam engines. Electric engines are still more powerful. They emit no smoke and cause no pollution. These engines run more fast. Most of the superfast trains have electric engines and more tracks are being electrified. All types of railway engines are now manufactured in India at Chittranjan and Varanasi. All types of railway coaches are manufactured at rail coach factories at Perambur and Kapurthala.

Railways have two classes of coaches — First Class and Second Class. First class rail fare is quite high. Second class rail fare is less.

Most of the people travel by second class. Second class coaches are over-crowded. To avoid over-crowding some people get their seats reserved in advance. The reserved class coaches are not over-crowded. For the comfort of the passengers -

fans, lights and toilets have been provided in all types of coaches. Some trains have air conditioned coaches attached to them. These coaches keep us warm in winter and cool in summer. There are also two tier and three tier sleeper coaches in the trains. All these facilities have been provided by the railways for the convenience and comfort of the passengers. Some trains have pantry cars.

At the railway stations facilities like waiting halls, waiting rooms, toilet and drinking water are available. Tea, snacks, food, newspapers and magazines are also available at the stalls at the stations.

1.3 Selection of routesFollowing are the main routes connecting the four major cities — Delhi, Mumbai, Chennai and Calcutta in the four directions of the country:

Delhi to Mumbai:

There are two routes connecting Delhi and Mumbai. One route is via Agra, Jhansi, Bhopal, Itarsi and Bhusaval. The other route is via Bharatpur, Ratlam, Kota, Vadodara and Surat.

Delhi to Kolkata:

There are two routes between Delhi and Calcutta. One route is via Lucknow, Gorakhpur, Patna and Asansol. The other.route is via Kanpur, Allahabad and Varanasi.

Delhi to Chennai:

Delhi and Chennai are connected via Agra, Jhansi, Bhopal, Itarsi, Nagpur, Kazipet and Vijayawada.

Calcutta to Chennai:

This route lies along the Eastern Coast via Cuttack, Bhubaneswar, Vishakhapatnam and Vijayawada.

Indian railways are the most important means of transport in our country. It is also the most comfortable and the cheapest means. They also transport large and heavy materials like cement, coal, iron-ore, petroleum, food grains, jute and cotton. Raw materials are carried to the factories and the finished goods are transported to the markets by railways.

Railways are also important for the defense of the country. In case of emergency the railways transport arms, ammunition and men from one part of the country to the other part. In case of famine, floods, epidemics and other disasters, the railways carry food and medicines quickly to the part of the country, where they are needed.

Railways are doing very useful service to the nation. They are our national property. We should protect our national property in every way. We should not harm this property and should help to keep the trains and the railway stations clean

UNIT2: SLEEPER AND BALLAST

Sleeper are members generally laid transverse to the rails on which the rails are supported and fixed to transfer the loads from rails to the ballast and subgrade below.

Functions:

1. The primary function of a sleeper is to grip the rail to gauge and to distribute the rail loads to ballast with acceptable induced pressure.

2. 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.

3. To support the rails firmly and evenly throughout. 4. To distribute the load transmitted through rails over large area of ballast underneath or to the bridge

girders as the case may be. 5. To hold the rails to proper level in turnouts and crossovers, and at 1 in 20 in ward slope along straight

tracks. 6. To provide and elastic medium between the rails and ballast and also to absorb the vibrations caused due

to moving axle loads.7. 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 the rails. 8. To provide the general stability of the permanent way throughout. 9. To provide the insulation of track for the electrified for signaling.10. To provide easy replacement of the rail fastenings without any serious traffic disturbances.

Requirements:

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 for 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.

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 to moving trains.

11. The material used for the sleeper be such that it does not attract the sabotage and the theft qualities.

Types of sleepers:

1. Timber sleepers 2. Steel sleepers 3. Cast iron sleepers 4. R.C.C sleepers 5. Pre-stressed concrete sleepers.

Advantages of timber sleeper Disadvantages of timber sleeperThey have proved very useful for heavy loads and high-speed trains.

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.

They are cheap and easy to manufacture. They do not maintain the gauge accuratelyThey have proved very useful for heavy loads and high-speed trains.

They easily develop cracks with beater packing

They can be handled easily without any damage. They require the highest maintenance cost as compared to other types of sleepers

They maintain the correct alignment They get easily disturbed from their positions under heavy loads

They are most suitable for track circuiting. They need special treatment for fire protectionThey can be used with or without ballast Their scrap value is lowThey can be used for gauntlet tracks They are not suitable for modern LWR track because of

their lighter weightThey are suitable in the areas having yielding formations.

Advantages of steel sleeper Disadvantages of steel sleeperThey are manufactured by a simple operation. Less number of fastenings are required and that too simple in nature.

They get easily rusted and corroded.

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.

Their lugs get broken easily.

The maintenance and adjustment of gauge are easy as compared to the other of sleepers.

They develop cracks at rail seats or near lugs.

These sleepers are rolled sections in one piece. The steel sleepers do not provide effective track circuiting.

They provide better lateral rigidity to the track These develop the tendency to become center bound because of slope at both ends.

They are not attacked by varmints. The overall cost of steel sleepers is more than that of timber sleepers

They are not susceptible to fire hazards. Their scrap value is good

Advantages of concrete sleeper Disadvantages of concrete sleeperThe concrete sleepers are quite heavy and thus provide longitudinal, lateral and vertical stability. Because of their weight, these sleepers are more suitable to LWR tracks

They are not economical because of high cost of construction

The concrete sleepers result in reduced rail bending stresses.

In case of derailments, heavy damage is caused.

The concrete sleepers reduce the wear of rolling stocks.

High standard of maintenance of track is required.

The concrete sleepers produce less vertical motion and thus provide a comfortable journey due to less noise.

The design and construction are both complicated.

The concrete sleepers have flat bottoms. That’s why mean modern method of track maintenance i.e. MSP and machine maintenance can be suitably employed.

They are more rigid.

The concrete sleepers are neither in flammable nor subjected to damage by corrosion or termite

They do not have any scrap value.

These sleepers have a long useful life of 50 years. It means rail and sleeper renewals can be matched.

The concrete sleepers with their fastening system maintain gauge, cross levels, twist, alignment, longitudinal level and unevenness of the track.

The concrete sleepers are suitable for track circuitingThe concrete sleepers can be manufactured from local resources.

Ballast:

The material used as an elastic cushion between the sleeper and the top of the formation, is called ‘Ballast’

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.

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.

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.

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.

Broken stones Gravels Sand Moorum Cinder (or ash) Brick bats Kankar Ballast earth.

Ballast Size

The broken stones either of too big size or too small size are found unsuitable for railway ballast. The size of ballast depends upon the type of sleeper, method of maintenance and the location of the track. The ballast which contains stones varying in size from 20 mm to 50 mm with reasonable proportion of intermediate sizes, is considered a best ballast for obtaining better interlocking.

Accordingly, the following sizes have been recommended on India railways.

1. for wooden sleeper tracks ….. 50 mm

2. for steel sleeper tracks ….. 40 mm

3. for points and crossings ….. 25 mm

Sub-Ballast and Blanket

Sub-ballast: A layer of suitable material interposed between the stone ballast and the formation soil is called sub-ballast.

Function of sub-ballast: The function of eh sub-ballast is to distribute the loads of the rolling stock more evenly and over lager area of the formation soil.

Blank: The layer of a suitable material provided on the top of a poor formation is called a blanket.

Functions of blanket:

It improves the bearing capacity of the formation.

It avoids interpenetration of ballast and the soil.

It avoids the formation of ballast pockets.

It prevents the bottom soil to heave up and thus avoids mud pumping conditions.

It safely drains off water from the top ballast.

RAIL FIXTURES AND FASTENINGS

The various types of rail fixtures and fastenings commonly used in a permanent way are the following:

Fish plates Bolts Spikes Chairs Keys, cotters and tie bars Bearing plates Guard rails Check rails M.C.I. insert Rubber pads

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Fish plate:

A 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. 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.

The main functions of fish plates are as under.

They keep the rail section in vertical and horizontal plane so as to maintain continuity of rails.

They allow free longitudinal movement of rails.

They provide the necessary expansion gap at the joint.

They provide the stability and strength to the rail joint.

They support the underside of the head of rail and top of the foot of rail.

They resist the stresses due t lateral and vertical bending movements without getting distorted.

They absorb the shock caused by the jumping of the wheel over the expansion gap.

Spikes

Spikes are used for fixing the rails on sleepers with or without bearing plates below the rails. A good spike should hold the rail properly so as to obtain perfect gauge. It should also be strong enough t resists the motion of the rails. It should be cheap and of such a design the fixing and removing it, is easy.

The various types of spikes commonly used on Indian Railways are:

Dog spikes

Screw spikes

Round spikes

Elastic spikes.

Chairs

Chairs are used for holding double headed (D.H) and bull headed (B.H) rails on the sleepers with proper gauge. The chairs are invariably made of cast iron and they distribute the load from the rail on the sleeper through their flat bottoms.

Keys, Cotters and Tie Bars

Key: A small tapered piece of wood or metal, which is used to fix a rail to the chair, is known as a key. The following types of metal keys are in common use:

Stuart’s key Morgan key Coiled key

Cotters: The cotters are used for fixing the tie bars with cast iron sleepers. A cotter is a wedge shaped mild steel plate with a split in either horizontal or vertical plane.

M.S Tie Bars: Mild steel tie bars are used for connection and holding the pots or bowls together.

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

Guard Rails

The rails, which are provided on bridges of long spans with open floor, parallel to the running rails in order t prevent derailed wheels from falling off the bridge, are called guard rails. These are fastened to sleepers at a fixed distance apart from either running rail in inter rail space.

Guard rails are also provided on level crossing to provide a path way clearance to the running wheels.

M.C.I Insets

The Malleable Cast Iron (M.C.I) inserts are fixed into the concrete during their manufacturing process.

The inserts are of two types:

Stem type M.C.I.: These inserts are used in normal pretension concrete sleepers. The weight of the system insert is 1.6 kg per piece.

Gate type M.S.I. insert: These inserts are used in post-tensioned concrete sleepers. The approximate weight of gate type M.C.I. insert is 1.7 kg per piece.

Bearing Plates

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. The bearing plates are required not only to distribute the load but also to reduce the rubbing action of the rail seat on the sleeper. These also limit the compressive stresses on the sleeper. The friction between the bearing plate and the sleeper reduces the lateral forces on the spike and thus these help to improve the gauge holding capacity of the sleeper

Rubber Pads

A rubber pad is interposed between the food of rail and concrete sleeper. The main functions of a rubber pad are:

It dampens and absorbs the vibrations of the rail. It easily absorbs the shocks. It resists the lateral movement of the rail. It prevents abrasion of the rail bottom surface. It provides good electrical insulation for an electrified track.