INTRODUCTION TO

RAILWAY ENGINEERING

SAGAR SHIWAKOTIKATHMANDU ENGINEERING COLLEGE

11, July, 2011

Contents

• Introduction to railway• Classification of railways (on the basis of

gauge)• Rolling stock (moving parts)• Components of railway track (rails, sleeper,

ballast)

• Geometric design of railway track (cross section, gradient, super elevation)

• Maximum permissible speed• Railway points and crossings• Stations and yards• Platforms

Contents

• Modes of transport

Air, rail, road, water, cable, pipeline, and space.

• Rail transport is where a train runs along a set of two parallel steel rails, known as a railway or railroad. The rails are anchored perpendicular to ties (or sleepers) of timber, concrete or steel, to maintain a consistent distance apart, or gauge. The rails and perpendicular beams are placed on a foundation made of concrete, or compressed earth and gravel in a bed of ballast.

Components of a railway track (Permanent Way)

Rails

Sleepers (Ties)

Ballast

What are the advantages of rail transport?

• It facilitate long distance travel and transport of bulky goods which are not easily transported through motor vehicles.

• It is a quick and more regular form of transport because it helps in the transportation of goods with speed and certainty.

• It helps in the industrialization process of a country by easy transportation of coal and raw-materials at a cheaper rate.

• It encourages mobility of labour ad thereby provides a great scope for employment.

• Railway is the safest form of transport. The chances of accidents and breakdown of railways are minimum as compared to other modes of transport.

• The carrying capacity of the railways is extremely large. • It is the largest public undertaking in the country. Their

charges are based on charge what the traffic can bear principles which helps the poor. In fact, it is a national necessity.

Disadvantages

• The railway requires a large investment of capital.• Another disadvantages of railway transport is its

inflexibility. It routes and timings cannot be adjusted to individual requirements.

• Rail transport cannot provide door to door service as it is tied to a particular track. Intermediate loading or unloading involves greater cost, more wear and tear and wastage of time. The time cost of terminal operations are a great disadvantage of rail transport.

• Railway transport is unsuitable and uneconomical for short distances and small traffic of goods.

List of countries by rail transport network sizeRank Country

Railway length(km)

Date ofinformation

1  United States 226,427 (2007)

2  Russia 128,000 (2006)

3  China 91,000 (2010)

4  India 64,215 (2011)

5  Canada 57,216 (2007)

137  Nepal 59 (2006)

138 United Arab Emirates

52 (2009)

147  Western Sahara 5 (2008)

148  Laos 4 (2005)

149  Lesotho 3 (1995)

150  Monaco 2 (2002)

151  Vatican City 0.852 (2001)

World 1,370,782 (2006)

Track gauge (Rail gauge)

• The distance between the inner sides of the

heads of the two load bearing rails that make up a single railway line.

Various gauges used worldwide

Various gauges used worldwideGauge Width (mm) Used in

Standard Gauge 1435 England, USA, Canada, China, Australia

Broad Gauge (BG) 16761670

India, Brazil, ArgentinaSpain, Portugal

Broad Gauge (Russian Gauge)

1524 Russia, Finland

Cape Gauge 1067 Japan, Newzealand

Meter Gauge (MG) 1000915

India, FranceIreland

Narrow Gauge 672610

India, PakistanS. Africa

Which gauge is the best?• Historically…..

the choice of gauge was partly arbitrary and partly a response to local conditions

• Narrow-gauges - cheaper to build and can negotiate sharper curves

• Broad-gauges - give greater stability and permit higher speeds.

Classification of Railways

Classification of Railways on the basis of speed

Group Sanctioned Speed (Kmph)

A 160 or moreB 130 C 100-130D 100E 130

1. BG Routes

Classification of Railways on the basis of speed

2. MG RoutesGroup Max permissible

speed (Kmph)

Q Route > 75

R Route 75

S Route < 75

HIGH SPEED RAILS

• Passenger rail transport that operates significantly faster than the normal speed of rail traffic.

• The U.S. Department of Transportation's reasonably expected to reach sustained speeds of more than 125 mph (201 km/h)

WORLD RECORD

• The world record for conventional high-speed rail is held by the V150 of France, a specially configured and heavily modified train which clocked 574.8 km/h (357.2 mph) on a test run.

• Aerodynamic designs (to reduce drag, lift, and noise), air brakes, regenerative braking, stronger engines, dynamic weight shifting, etc

• High Speed train in France (> 574 Kmph)

Rolling Stock of Railway(Moving Parts)

• Locomotives

– Fire box and boiler

– Proper Engine

– Framework

– Tender

• Coaches• Wagons– Timber– Cattle– Oil– Petrol– Hopper (ballast, minerals, coals)– Well (bulky particles)– Power– Refrigerated wagons

RAILWAY POINTS AND CROSSINGS

POINTS AND CROSSINGS• To divert trains from one track to another, a

special arrangement is made….so that

…the inside flange of the wheel can move on the diverted track.

• Such arrangement is called “POINTS AND CROSSINGS”

A Right Hand Diversion

• Points + crossings =

TURNOUT

POINTS AND SWITCHES

• A railroad switch or points is a mechanical installation enabling railway trains to be guided from one track to another at a railway junction.

POINTS AND SWITCHES

Electric, Hydraulic or Manual

CROSSINGS

• It is a special form of construction to provide flange way clearance between two rails to be crossed.

• To achieve this, a gap is provided from throat to nose of crossing over which the wheel jumps.

Components of CROSSING of a Right Hand Turnout

Throat

• How a railway frog point works

• Railway point switch changing

• Railway point switch changing

• To ensure that the wheel negotiates the gap properly and doesn’t strike the nose, the outer rail is guided with the help of CHECK RAILS.

CROSSINGS

Characteristics of a good crossing:

• Should be rigid• Frog and wing rails should be protected

against damage so that the wheels do not bump into the gap.

• Frog should be of sufficient thickness.

Types of crossings

• Acute angle (V-Crossing)• Obtuse angle crossing• Square Crossing

REQUIREMENTS OF A GOOD TRACK

• Gauge should be correct and uniform• Alignment of track should be correct• Transition curves should provided wherever

required• Perfect cross levels between rails• Gradient should be as gentle as possible• Points and crossings (turnouts) should be

designed and maintained properly

CAPACITY OF RAILWAY TRACK

• Maximum number of trains that can run safely on any length of track per hour.

• Maximum number of trains that can be handled in a yard …TERMINAL CAPACITY.

Specification of Indian Railways1. Sleeper density = no. of sleepers per rail

length.Generally, 1 sleeper in every meter length.Depends on: axle load, speed, strength of

sleeper, depth of ballast.Sleeper density = n+ x (x = 7 usually)

n = length of each rail2. Rails: 13 m long (for BG track)

• Example: If sleeper density is n + 6 for a BG track, calculate the number of sleepers in 960 m length of railway.

Length of each rail = 13 mTotal no. of rails in 960 m = 960/13 = 74No. of sleeper in each rail = 13 + 6 = 19So, no. of sleeper in 74 rails = 74 x 19 = 1406

3. Materials required per KM length of track

1. No. of rails per km = (1000/13) x 2 = 1542. Weight of rail per km = (154 x 13) x 60 = 120,120

kg (@ 60 kg/m)3. No. of sleepers per km = (154/2) x (13 + 7) = 15404. No. of fish plates per km = 77 x 2 = 1545. No. of bolts per km = 154 x 4 = 6066. No. of bearing plates per km = 1540 x 2 = 30807. No. of fasteners = (1540 x 12)8. Quantity of ballast per km = (0.2 x 3.35 x 1000)

cubic meter

FISH PLATE AND FISH BOLTS

BEARING PLATE (BENEATH THE SLEEPER)