The History Of Trains

 
Steam Locomotives 

Wagons that are pulled along tracks have been used to transport material since the 16th century, but these these trains were drawn by men or horses until the invention of the steam locomotive. Steam locomotives enabled the basic railway system to realise its true potential. In 1804, Richard Trevithick  built the world's first working steam locomotive in South Wales. It was not entirely successful, but it encouraged others to develop new designs. By 1829, the British engineer Robert Stephenson had built the "Rocket", considered to be the forerunner of the modern locomotive.The "Rocket" was a self- sufficient unit,carrying coal to heat the boiler and a water supply for generating steam. Steam passed from the boiler to force the pistons back and forth, and this movement turned the driving wheels, propelling the train forwards. Used steam was the expelled in characteristic  "chuffs". Later steam locomotives,like "Ellerman Lines" and the "Mallard", worked in a similar way, but on a much larger scale.The simple design and reliability of steam locomotives ensured that they changed very little in 120 years of use, before being replaced from the 1950's by more efficient diesel and electric power. 


Diesel Trains 

Rudolf Diesel first demonstrated the diesel engine in Germany in 1898, but it was not until the 1940's that diesel locomotives were successfully established on both passenger and freight services, in the US.Early diesel locomotives like the "Union Pacific" were more expensive to built than steam locomotives, but were more efficient and cheaper to operate, especially where oil was plentiful. One feature of diesel engines, is that the power output cannot be coupled directly to the wheels. To convert the mechanical energy produced by diesel engines, a transmissions, and are known as "Diesel-Electric" locomotives. The diesel engine works by drawing air into the cylinders and compressing it to increase its temperature; a small quantity of diesel fuel is then injected into it. The resulting combustion drives the generator ( more recently an alternator ) to produce electricity, which is fed to electric motors connected to the wheels. Diesel-electric locomotives are essentially electric locomotives that carry their own power plants, and are used world wild today . The "Deltic" diesel-electric locomotive, similar to the one shown here, replaced classic express steam locomotives, and ran at speed up to 160 kph (100mph).

Electric and high speed trains 

The first electric locomotive ran in 1879 in Berlin,Germany. In Europe, electric trains developed as a more efficient alternative to the steam locomotive and diesel-electric power. Like diesels, electric trains employ electric motors to drive the wheels but, unlike diesels, the electricity is generated externally at a power station. Electric current is picked up either from a catenary  (overhead cable) via a pantograph, or a third rail. Since it does not carry its own power-generating equipment, an electric locomotive has a better power-to-weight ratio and greater acceleration than its diesel- electric equivalent. This makes electric trains suitable for urban routes with many stops. They are also faster, quieter,and less polluting. The latest electric french TGV (Train Grande Vitesse) reaches 300 kph (186 mph). Other trains, like the London to Paris and Brussels " Eurostar", can run at several voltages and operate between different countries. Simpler electric trains perform special duties- the " People Mover" at Gatwick Airport in Britain runs between terminals.

Train equipment 

Modern railway track consist of two parallel steel rails clipped on to a support called a sleeper. Sleepers are usually made of reinforced concrete, although wood and steel are still used. This distance between the inside edges of the rails is the track gauge. It evolved in Britain, which uses a gauge of 1,435 mm (4 ft 8.1/2 in), known as the standard gauge. As engineering grew more sophisticated, narrower gauges were adopted because they cost less to build. The loading gauge, which is equally important, determines the size of the largest loaded vehicle that may pass through tunnels and under bridges with adequate clearance. Safe train operation relies on following a signalling system. At first, signalling was based on a simple time interval between trains, but it now depends on maintaining a safe distance between successive trains travelling in the same direction. Most modern signals are colour lights, but older mechanical semaphore signals are still used. On the latest high-speed lines,train drivers receive control instructions by effective braking. For fast modern trains, which have considerable momentum, it is essential that each vehicle in the train can be brake by the driver or by a train control system,such as Automatic Train Protection (ATP). Braking is achieved by the brake shoe acting on the wheel rim (rim brakes), by disc brakes, or, increasingly, by electrical braking.


Tags: Trains, History, Modern
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About Ashith kp

An Energetic Blogger,Software Developer, Photographer From Thalassery,Kerala,India. Founder of Popskope Entertainment and WeBTv.India

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