Electric Railway Systems and Multiple Units

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An electric multiple unit or EMU is a multiple unit train consisting of self-propelled carriages, using electricity as the motive power. An EMU requires no separate locomotive, as electric traction motors are incorporated within one or a number of the carriages. Most EMUs are used for passenger trains, but some have been built or converted for specialized non-passenger roles, such as carrying mail or luggage, or in departmental use, for example as de-icing trains. An EMU is usually formed of two or more semi-permanently coupled carriages, but electrically-powered single-unit railcars are also generally classed as EMUs.

EMUs are popular on commuter and suburban rail networks around the world due to their fast acceleration and pollution-free operation. Being quieter than DMUs and locomotive drawn trains, EMUs can operate later at night and more frequently without disturbing residents living near the railway lines. In addition, tunnel design for EMU trains is simpler as provisions do not need to be made for diesel exhaust fumes.

History

Example_70---Trains of the Singapore MRT. EMUs are often used for rapid transit lines.

Types

The cars that form a complete EMU set can usually be separated by function into four types: power car, motor car, driving car, and trailer car. Each car can have more than one function, such as a motor-driving car or power-driving car.

+ A power car carries the necessary equipment to draw power from the electrified infrastructure, such as pickup shoes for third rail systems and pantographs for over head systems, and transformers.

+ Motor cars carry the traction motors to move the train, and are often combined with the power car to avoid high-voltage inter-car connections.

+ Driving cars are similar to a cab car, containing a driver's cab for controlling the train. An EMU will usually have two driving cars at its outer ends.

+ Trailer cars are any cars that carry little or no traction or power related equipment, and are similar to passenger cars in a locomotive-hauled train. On third rail systems the outer vehicles usually carry the pick up shoes, with the motor vehicles receiving the current via intra-unit connections.

Examples

Some of the more famous electric multiple units in the world are high speed trains: the Shinkansen in Japan and ICE 3 in Germany. The retired New York-Washington Metroliner service, first operated by the Pennsylvania Railroad and later by Amtrak, also featured high-speed electric multiple unit cars.

Example_71---German ICE 3 EMU (Deutsche Bahn)

The first EMUs were used on the elevated Liverpool Overhead Railway in 1893. The southern terminal of the railway was underground, giving the LOR the distinction of also being the first to use EMUs underground. Each carriage had its own electric traction motor and was specifically designed and constructed to be light in weight running on elevated steel sections. The first EMUs were two carriage trains later graduating to three carriages, with the front and rear carriages powered. Liverpool Museum retains an example of the Liverpool Overhead Railway EMU carriage.

In 1964, Tulloch Limited built the first double-decker trailer cars for use in Sydney; they ran with single deck electric motor cars. The first prototype double deck motor car was built by Comeng in 1969 and production versions entered service in 1972; these were the first fully double deck EMU passenger trains in the world. All CityRail electric commuter trains in Sydney are now double deck.

Gallery:

Example_72--- Australian OSCAR (H-set) EMU (CityRail)

Example_73--- Mumbai Suburban Railway old EMU (Indian Railway)

Example_74---Mumbai Suburban Railway new EMU (Indian Railway)

Example_75---Dual gauge EMU on the Chennai MRTS in India

Example_76---KRL Jabotabek ex-Japanese Toei 6000 series ( Indonesia)

Example_77---(top) Indonesian EMU KL3, services for KRL Jabotabek; (bottom) Belgian EMU AM80 "Break" unit

Example_78---An SWT Class 450 suburban unit at London Waterloo Station (UK)

Example_79--- Transperth B Series EMUs operate in Perth, Australia ; New Delhi Metro EMU in India

Example_80--- TSR double-decker train operate in Italy. Ferrovie Nord Milano

Example_81--- Russian ED4MKM-aero EMU

Example_82--- Iarnród Éireann 8520 Class EMU, operated on the DART line ; Swedish Railways EMU

Example_83--- Japanese JR East Type E233-1000 EMU test run Omiya, Japan ; Japanese JR West Shinkansen Type 500 EMU

Example_84---Russian ER2K EMU (No. 604)

Example_85---Chinese CRH3

Example_86--- Polish PESA ED59

Example_87---Polish 14WE in Warszawa Sródmiescie station

Example_88---Polish 19WE developed in 2008 by Newag

Example_89---Z 20500, used on Paris's RER and Transilien {France)

Example_90---Swiss Stadler FLIRT RABe 523

Example_91---Swiss BLS Line

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