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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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