SANT TUKARAM POLYTECHNIC INDURI. Subject: RAILWAY ENGINEERING

prepared by :

ONKAR KADAM

CIVIL ENGINEERING DEPARTMENT

RAILWAY ENGINEERING:-

Railway engineering is the branch of civil engineering dealing with the location , construction and maintanace of railroads.

For long distance passenger and goods traffic railway is cheapest mode of transportation.

Zones of indian railways : 1). Eastern railway (ER) 2). South eastern railway (SER)

3). Northern railway (NR) 4). North eastern railway (NER)

5). Southern railway (SR) 6). Central railways (CR) 7). Western railway (WR)

8). North east frontier railway (NEFR) 9). South central railway (SCR)

CLASSIFICATION OF INDIAN RAILWAYS :-Railways are classified according to type of gauge. They are mainly :

1). Broad gauge (B.G) :

In the case of the broad gauge, the clear dimensions are 1676mm or it is 1524mm. On out the world the share of a broad guage is 15 percent. When we look at some of the countriesin which the standard gauges have been provided found that they have been provided in United Kingdom, United States of America, Canada, Turkey and China.

In broad gauge, the clear horizontal distance between the inner faces of two parallel rails forming track is 1.676 m. It is normally used in India. It is suitable in dense populated Areas.

2). Meter gauge (M.G):

Meter gauge is the system of narrow gauge railways and tramways with a track gauge of 1,000 mm (3 ft 3 3⁄8 in). It has installations of around 95,000 kilometers (59,000 mi) in the world. It is the main gauge in some countries. In Europe large meter gauge networks remain in continuous use in Switzerland, northern Spain and for many European urban trams, although most meter gauge local railways in France, Germany, and Belgium closed down in the mid 20th century. With the revival of urban rail transport, in some cities meter gauge light metros were established, while in other cities meter gauge was replaced by standard gauge. In meter gauge, the clear horizontal distance between the inner faces of two parallel rails forming track is 1.000 m. It is suitable where traffic intensity is moderate. Suitable where the position of revenue generation is medium.

3 ).Narrow gauge (N.G) :

A narrow-gauge railway (or narrow-gauge railroad) is a railway with a track gauge narrower than the 1,435 mm (4 ft 8 1⁄2 in) of standard gauge railways. Most existing narrow gauge railways are between 600 mm (1 ft 11 5⁄8 in) and 3 ft 6 in (1,067 mm).

Since narrow-gauge railways are usually built with smaller radius curves, smaller structure gauges, lighter rails, etc., they can be substantially less costly to build, equip, and operate than standard gauge or broad gauge railways, particularly in mountainous or difficult terrain. The lower costs of narrow-gauge railways mean they are often built to serve industries and communities where the traffic potential would not justify the cost of building a standard or broad gauge line.

Narrow-gauge railways also have specialized use in mines and other environments where a very small structure gauge makes a very small loading gauge necessary. Narrow-gauge railways also have more general applications. Nonindustrial narrow-gauge mountain railways are or were common in the Rocky Mountains of the United States and the Pacific Cordillera of Canada, in Mexico, Switzerland, the former Yugoslavia, Greece, India, and Costa Rica. In some countries, narrow gauge is the standard, like the 3 ft 6 in (1,067 mm) gauge in Japan, Indonesia, Taiwan, New Zealand, South Africa, and Tasmania, and the 1,000 mm (3 ft 3 3⁄8 in) meter gauge in Malaysia and Thailand. In meter gauge, the clear horizontal distance between the inner faces of two parallel rails forming track is 0.762 m. It is suitable in tunnel areas.

ALIGNMENT:

The term alignment is used in both horizontal and vertical layouts to describe the line uniformity (straightness) of the rails. The horizontal alignment (or alignment in the United States) is done by using a predefined length of string line (such as 62-foot in the US and 20 meters in Australia) to measure along the gauge side of the reference rail. It is the distance (in inches or millimeters) from the midpoint of the string line to the gauge of the reference rail. The design horizontal alignment for tangent track is zero (perfect straight line on the horizontal layout). The design

horizontal alignment on the curved track in the United States is 1 inch for each degree of curvature. Any other readings indicate deviations. It is the centerline of a proposed track in a plan.

FACTORS AFFECTUING ON ALIGNMENT : 1) Funds available

2) Gauge of track

3) Traffic density

4) Position of tunnels in hilly areas

5) Cost of maintance and construction Etc.

6) Nature of ground

GAUGE or GAUGE LENGTH :- It is the clear horizontal distance between the inner faces of two parallel

rails Railway track gauge in India is complicated by historical usage of multiple track gauges. Indian railways uses four gauges: - 1,676 mm (5 ft 6 in) Broad gauge (BG), which is also called Indian gauge. - 1,000 mm (3 ft 3 3⁄8 in) Meter gauge (MG) - 762 mm (2 ft 6 in) Narrow gauge (NG), and - 610 mm (2 ft) Narrow Gauge.

Project unigauge that started in 1991 seeks to standardize the rail gauges in India by converting most of the MG and NG tracks to BG track. Some NG tracks

on which heritage trains run in hilly regions to shimla, darjieeling, ooty, kangra will not be converted. Delhi metro rail corporation constructed 1,435 mm (4 ft 8 1⁄2 in) (SG) in in 2010 and runs metro trains on 42 km (26 mi) of standard gauge in 2014. However, Delhi Metro is a separate urban mass rapid transit system not owned by Indian Railways.

FACTORS AFFECTING SELECTION OF GAUGE:

Funds available Volume of traffic Intensity of population Topography of the country Cost of construction etc.

BREAK OF GAUGE : In a railway track when up to some distance journey is by one type of gauge and remaining journey is by other type of gauge , that means when the uniformity of the gauge changes is called as break of gauge .

Advantages: Narrow gauges tend to be associated with smaller loading gauges and sharper curves, which tend to reduce initial capital cost. This offsets the costs of any traffic affected by the break-of-gauge. Historically narrow gauge railways were primarily built on marginal lines, mostly through hilly and mountainous terrain to cut costs and enable any type of rail service at all. Associated disadvantages were not recognized as much as many rail lines were operated independent of potentially connecting lines regardless of gauge as competing companies built and operated them.

Disadvantages: Transshipping freight from cars of one gauge to cars of another is very labor- and time-intensive, and increases the risk of damage to goods. If the capacity of the freight cars on both systems does not match, additional inefficiencies can arise. If the frequency is low, trains might need to wait a long time for its counterpart to arrive before transshipping. This is avoided by storing the goods, but that is also an inconvenience. Technical solutions to avoid transshipping include variable gauge axles, replacing the bogies of cars, and using transporter cars that can carry a car of a different gauge.

PERMANENT WAY:The permanent way constitutes the combination of ballast; rails and

fixtures. It consists of a pair of rails fixed to sleepers which rest on ballast.

The permanent way is the elements of railway lines: generally the pairs of rails typically laid on the sleepers ("ties" in American parlance) embedded in ballast, intended to carry the ordinary trains of a railway. It is described as permanent way because in the earlier days of railway construction, contractors often laid a temporary track to transport spoil and materials about the site; when this work was substantially completed, the temporary track was taken up and the permanent way installed.

COMPONENT PARTS:

1) Rails, 2)Sleepers , 3)Ballast, 4)Fixtures and Fastening , 5)Formation

1] . RAILS:

Modern track typically uses hot rolled steel with a profile of an asymmetrical rounded I-beam. Unlike some other uses of iron and steel, railway rails are subject to very high stresses and have to be made of very high-quality steel alloy. It took many decades to improve the quality of the materials, including the change from iron to steel. The stronger the rails and the rest of the track work, the heavier and faster the trains the track can carry. Other profiles of rail include: Bullhead rail; Grooved rail; "Flat-bottomed rail" (Vignola’s rail or Flanged T rail; Bridge rail (inverted U shaped used in Baulk road; Barlow rail (inverted V); and Grooved rail. North American railroads until the mid- to late-20th century used rails 39 ft (11.89 m) long so they could be carried in gondola cars (open wagons), often 40 ft (12.2 m) long; as gondola sizes increased, so did rail lengths. According to the Railway Gazette the 150 kilometer rail line being built for the Baffin land Iron Mine, on Baffin Island, will use older carbon steel alloys for its rails, instead of more modern, higher performance alloys, because modern alloy rails can become brittle at very low temperatures.

TYPES OF RAILS :

BULL HEADED RAILS :

FLAT FOOTED RAILS:

BULL HEADED RAILS:

2 ]. SLEEPERS : These are the members laid transversely .It is used as a supporting member to the rail.

a)Timber or Wooden Sleepers : The timber sleepers nearly fulfilled all the requirements of ideal sleepers and hence they are universally used. The wood used may be like teak, sal etc or it may be coniferous like pine. The salient features of timber/wooden sleepers with advantages and disadvantages.

Advantages of Timber Sleepers

1. They are much useful for heavy loads and high speeds2. They have long life of 10-12 years depending upon the climate, condition,

rain, intensity, nature of traffic, quality of wood etc3. Good insulators and hence good for track circuited railway tracks4. They are able to accommodate any gauge5. Suitable for salty regions and coastal areas6. Can be used with any section of rail

Disadvantages of Timber Sleepers

1. Liable to be attacked by vermin so, they must be properly treated before use

2. Liable to catch fire3. They do not resist creep4. They are affected by dry and wet rot5. Become expensive day by day6. Life is shorter compare to others

b) Steel sleepers: They are in the form of steel trough inverted on which rails are fixed directly by keys or nuts and bolts and used along sufficient length of tracks.

Advantages of Steel Sleepers

1. Have a useful life of 20-25 years.2. Free from decay and are not attacked by vermins3. Connection between rail and sleeper is stronger4. Connection between rail and sleeper is simple5. More attention is not required after laying6. Having better lateral rigidity7. Good scrap value8. Suitable for high speeds and load9. Easy to handle10.Good resistance against creep

Disadvantages of Steel sleepers

1. Liable to corrosion by moisture and should not because in salty regions2. Good insulators and hence cannot be used in track circuited regions3. Cannot be used for all sections of rails and gauges4. Should not be laid with any other types of ballast except store5. Very costly6. Can badly damaged under derailments7. Way gauge is obtained if the keys are over driven8. The rail seat is weaker9. Having good shock absorber as there is not cushion between rail foot and

ballast

c) 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.

Advantages Concrete Sleepers

1. Durable with life range from 40-50 years2. They can be produced on large quantities locally by installing a plant3. Heavier than all other types thus giving better lateral stability to the track4. Good insulators and thus suitable for use in track circuited lines5. Efficient in controlling creep6. They are not attacked by corrosion7. Free from attacks of vermin and decay, suitable for all types of soils8. Most suitable for welded tracks9. Prevent buckling more efficiently10.Initial cost is high but proves to be economical in long run11.Effectively and strongly hold the track to gauge12.Inflammable and fire resistant

Disadvantages Concrete Sleepers

1. Difficult to be handled2. Difficult to be manufactured in different sizes thus cannot be used in bridges

and crossing3. Can be damaged easily while loading and unloading

3) BALLAST:Railway Ballast is the foundation of railway track and provide just below the sleepers. The loads from the wheels of trains ultimately come on the ballast through rails and sleepers.

Functions of BallastSome of the important functions of railway ballast are:

1. To provide firm and level bed for the sleepers to rest on 2. To allow for maintaining correct track level without disturbing the rail road

bed 3. To drain off the water quickly and to keep the sleepers in dry conditions 4. To discourage the growth of vegetation 5. To protect the surface of formation and to form an elastic bed 6. To hold the sleepers in position during the passage of trains 7. To transmit and distribute the loads from the sleepers to the formation 8. To provide lateral stability to the track as a whole

Requirements for Ideal BallastThe ideal material for ballast should fulfill the following requirements

1. It should be possible to maintain the required depth of the material in order to distribute the load of passing train on the formation ground

2. The material to be used for ballast should not be too rigid but it should be elastic in nature

3. The material for ballast should be of such nature that it grips the sleepers in position and prevent their horizontal movement during passage of train

4. It should not allow the rain water to accumulate but should be able to drain off the water immediately without percolating

5. It should be strong enough a resistance to abrasion

Materials for BallastThe following materials are used for ballast on the railway track.

1. Broken Stone 2. Gravel 3. Cinders / Ashes 4. Sand 5. Kankar 6. Moorum 7. Brick Ballast 8. Selected Earth

BALLAST

4) FIXTURES AND FASTENING :The arrangement required for connecting the rail end together and for fixing rails to sleepers in a track is called as fixtures and fastening.

A). FIXTURES:

1. FISH PLATES 2.BEARING PLATES 3.CHAIRS

B). FASTENING:

1. SPIKES 2. BOLTS 3. KEYS

CONING OF WHEEL: If the flanges of the wheel are flat then due to shocks there will be movement between wheel and the rails and due to which, vehicle will not be maintained in central portion and there will be unequal distribution of load. Therefore the flanges are made in the shape of cone with a slope of 1 in 20. This termed as coning of wheel. The Surface of wheels are made in cone shape at an inclination of 1 in 20, and the same slope is provided in the rails (see fig), this is known as coning of wheels. The diameter of wheel is different at different cross section of the wheel, when the train running on the straight track try to move in any direction, the diameter of the wheel increases over one rail and the wheel assembly is automatically forced to move back in its original central position due to difference of distances moved over two rails. Whereas on a curved track, due to centrifugal force the train is forced in outward direction, the diameter on outer track increases and the distance on two tracks are adjusted.

Purpose:

1. To keep the train in its central position of the rails, coning does not allow any sidewise movement on a straight track.

2. to allow the wheels to move different distances on a curved track and thereby reduce wear and tear.

THA NK YOU