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Locomotive

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A locomotive is a specialized rail vehicle designed to provide motive power for a train.

Loco 14055 WDM3A Trichy Junction Aug22 A7C 02342
Loco 14055 WDM3A Trichy Junction Aug22 A7C 02342

While locomotives traditionally pull trains from the front, modern rail operations often use different methods. Push-pull operation is now quite common in many rail systems. For very long or heavy freight trains, companies use distributed power. This involves placing one or more locomotives at the front, the rear, or even at intermediate points throughout the train. All these units remain under the control of the leading locomotive.

HXD1D 0115@NXH (20180518091616)
HXD1D 0115@NXH (20180518091616)

Steam locomotives were the primary motive force for railways for many decades. The mechanism relies on a boiler to generate steam for movement. First, combustible fuel like coal, wood, or oil is burned to heat water. This process produces steam, which is then used to move reciprocating pistons. These pistons are connected to the locomotive's main driving wheels. To keep running, locomotives must carry fuel and water. This is done either by using onboard tanks, called a tank locomotive, or by pulling a separate car called a tender.

R761-mx1
R761-mx1

History shows a rapid evolution of steam technology in the early 1800s. Richard Trevithick built the first full-scale working steam locomotive in 1802 for an ironworks in Shropshire, England. In 1804, a Trevithick locomotive completed the first recorded steam-hauled journey in South Wales. Matthew Murray's Salamanca, a twin-cylinder rack locomotive, became the first commercially successful model in 1812. Later, George Stephenson built Locomotion No. 1 for the Stockton & Darlington Railway. His son, Robert Stephenson, built the famous Rocket in 1829. The Rocket won the Rainhill Trials, helping the Stephenson company become a major builder in the UK, US, and Europe.

Steam power eventually gave way to more efficient internal combustion engines. Steam locomotives were expensive to operate compared to modern alternatives. British Rail found that crewing and fueling steam engines cost about 2.5 times more than diesel engines. Because of this, most steam locomotives were retired between 1950 and 1970. North America transitioned away from steam during the 1950s, while continental Europe finished by the 1970s. Today, steam power is mostly found on heritage railways.

Teplovoz Eel2 (2)
Teplovoz Eel2 (2)

Internal combustion locomotives use engines that burn fuel to create motion. These engines connect to the driving wheels through a transmission. Most of these locomotives keep the engine running at a near-constant speed. The first kerosene-powered draisine was built by Gottlieb Daimler in 1887. While it was an early rail vehicle, it was not a true locomotive because it carried no payload. The first successful petrol locomotive in the UK was built in 1902 for the Deptford Cattle Market. Later, diesel-electric technology became the most popular form of internal combustion propulsion.

Diesel-electric locomotives use a diesel engine to power an electric generator. A major breakthrough occurred in 1914 when Hermann Lemp patented a direct current electrical control system. This design used a single lever to coordinate both the engine and the generator. It became the prototype for almost all modern diesel-electric controls. In 1924, the Eel2 diesel-electric locomotive began operations in Germany. It was designed by a team led by Yury Lomonosov and operated for nearly thirty years.

Die Daimler Motor-Draisine erstmals im Sommer 1887 zwischen Esslingen und Kirchheim-Teck erprobt
Die Daimler Motor-Draisine erstmals im Sommer 1887 zwischen Esslingen und Kirchheim-Teck erprobt

Electric locomotives draw power from an outside source rather than carrying fuel. This electricity is supplied through overhead lines, a third rail, or onboard batteries.

Eastleigh Works geograph-2383942-by-Ben-Brooksbank
Eastleigh Works geograph-2383942-by-Ben-Brooksbank

To collect power from overhead wires, locomotives use a pantograph or a trolley pole. A pantograph is a hinged frame that holds collecting shoes against the wire. This method is especially useful for high-speed travel. Most electric locomotives use axle-hung traction motors. These motors transfer power to the axles using spur gearing. The gear ratio depends on the job; freight units use high ratios, while passenger engines use low ratios.

First electric locomotive, built in 1879 by Werner von Siemens
First electric locomotive, built in 1879 by Werner von Siemens

Electric power offers significant economic advantages for railway systems. Electric locomotives generally cost 20% less to purchase than diesel locomotives. Their maintenance costs are also 25% to 35% lower. Furthermore, they can cost up to 50% less to run daily. Electricity is often generated at large stations and distributed through the railway network. Some systems use direct current (DC), while others use alternating current (AC). The first electric passenger train was presented by Werner von Siemens in 1879.

Bombardier ALP-45DP at Innotrans 2010
Bombardier ALP-45DP at Innotrans 2010
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🖼️ Images & Media (13)
File:R761-mx1.jpg
R761-mx1.jpg
File:Loco 14055 WDM3A Trichy Junction Aug22 A7C 02342.jpg
Loco 14055 WDM3A Trichy Junction Aug22...
File:HXD1D 0115@NXH (20180518091616).jpg
HXD1D 0115@NXH (20180518091616).jpg
File:Die Daimler Motor-Draisine erstmals im Sommer 1887 zwischen Esslingen und Kirchheim-Teck erprobt.jpg
Die Daimler Motor-Draisine erstmals im...
File:Teplovoz Eel2 (2).jpg
Teplovoz Eel2 (2).jpg
File:Lokomotif listrik ESS 3200 di Stasiun Tanjung Priuk..jpg
Lokomotif listrik ESS 3200 di Stasiun...
File:Eastleigh Works geograph-2383942-by-Ben-Brooksbank.jpg
Eastleigh Works...
File:First electric locomotive, built in 1879 by Werner von Siemens.jpg
First electric locomotive, built in 1879...
File:B-and-O electric.jpg
B-and-O electric.jpg
File:Ganz engine Valtellina.jpg
Ganz engine Valtellina.jpg
File:Battery loco 16 at West Ham.JPG
Battery loco 16 at West Ham.JPG
File:Wingrove & Rogers 6092.jpg
Wingrove & Rogers 6092.jpg

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