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Railway Engineering: Lec. No.1
1- Introduction
The history of railways is closely linked with civilization. As the
necessity arose, human beings developed various methods of transporting
goods from one place to another. In the primitive days goods were carried
as head loads or in carts drawn by men or animals. Then efforts were
made to replace animal power with mechanical power.
In 1769, Nicholes Carnot, a Frenchman, carried out the pioneering work
of developing steam energy. This work had very limited success and it
was only in the year 1804 that Richard Trevithick designed and
constructed a steam locomotive. This locomotive, however, could be used
for traction on roads only. The credit of perfecting the design goes to
George Stephenson, who in 1814 produced the first steam locomotive
used for traction in railways.
The first public railway in the world was opened to traffic on 27
September 1825 between Stockton and Darlington in the UK.
Simultaneously, other countries in Europe also developed such railway
systems; most introduced trains for carriage of passenger traffic during
that time. The first railway in Germany was opened from Nurenberg to
Furth in 1835. The USA opened its first railway line between Mohawk
and Hudson in 1833. The first railway line in Iraq was Baghdad line
(Istanbul – Baghdad) 2400 km between (1903-1940).
Railway Network in Iraq:
Baghdad – Mosul 412 km
Mosul – Rabi 112 km
Baghdad – Basra 542 km
يجيب – ةثيدح – كوكرك 272 km
ةبيعش – دادغب 572 km
تاشاكع – مئاقلا 150 km
Different Modes of Transport
Our environment consists of land, air, and water. These media have
provided scope for three modes of transport—land transport, air transport
and water transport. Rail transport and road transport are the two
components of land transport. Each mode of transport, depending upon its
1 Dr. Gofran J. Qasim
Railway Engineering: Lec. No.1
various characteristics, has intrinsic strengths and weaknesses and can be
best used for a particular type of traffic as given below.
Rail transport Owing to the heavy expenditure on the basic infrastructure
required, rail transport is best suited for carrying bulk commodities and a
large number of passengers over long distances.
Road transport Owing to flexibility of operation and the ability to
provide door to-door service, road transport is ideally suited for carrying
light commodities and a small number of passengers over short distances.
Air transport Owing to the heavy expenditure on the sophisticated
equipment required and the high fuel costs, air transport is better suited
for carrying passengers or goods that have to reach their destinations in a
very short period of time.
Water transport Owing to low cost of infrastructure and relatively slow
speeds, water transport is best suited for carrying heavy and bulky goods
over long distances provided there is no consideration of the time factor.
Railway as a Mode of Land Transport
There are two modes of land transport, railways and roads, and each has
its relative advantages and disadvantages. These have been summarized
in Table 1.
Table 1. Rail transport versus road transport
Feature Rail transport Road transport
The movement of steel
wheels on steel rails has the The tractive resistance of
Tractive basic advantage of low a pneumatic tyre on
resistance rolling resistance. This metalled roads is almost
reduces haulage costs five times compared to
because of low tractive that of wheels on rails.
resistance.
A railway track is defined on Roads, though having
two rails and is within well defined limits, can
protected limits. Trains work be used by any vehicular
Right of way as per a prescribed schedule traffic and even by
and no other vehicle has the pedestrians they are open
right of way except at to all.
2 specified level crossings. Dr. Gofran J. Qasim
Railway Engineering: Lec. No.1
Owing to the heavy The cost of construction
Cost analysis infrastructure, the initial as and maintenance of roads
well as maintenance cost of a is comparatively cheaper.
railway line is high.
The gradients of railways Roads are constructed
Gradients tracks are flatter (normally normally with steeper
and curves not more than 1 in 100) and gradients of up to 1 in 30
curves are limited up to only and relatively much
10° on broad gauge. sharper curves.
Due to the defined routes and Road transports have
Flexibility of facilities required for the much more flexibility in
movement reception and dispatch of movement and can
trains, railways can be used provide door-to-door
only between fixed points. services.
Railways have minimum Road transport creates
Environment adverse effects on the comparatively greater
pollution environment. pollution than the
railways.
Railways are government Barring member state
Organization undertakings, with their own government transport,
and control organization. road transport is managed
by the private sector.
Railways are best suited for Road transport is best
carrying heavy goods and suited for carrying lighter
Suitability large numbers of passengers goods and smaller
over long distances. numbers of passengers
over shorter distances.
2- Railway Track Gauge:
Gauge is defined as the minimum distance between the inside heads of
two rail 5/8 in. below the top of rail. Iraqi Railways follows this standard
practice and the gauge is measured as the clear minimum distance
between the running faces of the two rails as shown in Fig. 2.1. In
European countries, the gauge is measured between the inner faces of the
two rails at a point 14 mm below the top of the rail.
3 Dr. Gofran J. Qasim
Railway Engineering: Lec. No.1
2.1 Gauges on World Railways
Various gauges have been adopted by different railways in the world due
to historical and other considerations. In British Railways, a gauge of
1525 mm (5 feet) was initially adopted, but the wheel flanges at that time
were on the outside of the rails. Subsequently, in order to guide the
wheels better, the flanges were made inside the rails. The gauge then
became 1435 mm (4' 8.5"), as at that time the width of the rail at the top
was 45 mm (1.75"). The 1435-mm gauge became the standard gauge in
most European Railways. The approximate proportions of various gauges
on world railways are given in Table 2.
Table 2. Various gauges on world railways
Type of Gauge Gauge % of total Countries
gauge (mm) (feet) length
Standard England, USA,
gauge 1435 4' 8.5" 62 Canada, Turkey,
Persia, and China
India, Pakistan,
Broad gauge 1676 5' 6" 6 Ceylon, Brazil,
Argentina
Broad gauge 1524 5' 0" 9 Russia, Finland
Africa, Japan, Java,
Cape gauge 1067 3' 6" 8 Australia, and New
Zealand
India, France,
Metric gauge 1000 3' 3.5" 9 Switzerland, and
Argentina
23 various Different Different 6 Various countries
other gauges gauges gauges
4 Dr. Gofran J. Qasim
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