Electric multiple unit

SEPTA EMUs near Paoli, PA, USA.

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

An electric multiple unit or EMU is a multiple unit train consisting of many carriages using electricity as the motive power.

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. Amtrak has since replaced the Metroliner EMU cars with regular locomotive-hauled trains, but converted some of the EMU cars to coach cab units for "push-pull" operations on some of its lines, especially the Harrisburg-New York Keystone service.

EMUs are also popular on commuter and suburban rail networks around the world due to their fast acceleration, pollution-free operation and quietness. 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.

Gallery

Dual gauge EMU on the Chennai MRTS in India.	Indonesian EMU ex Toei 6000 series from Japan services for KRL Jabotabek.	Indonesian EMU ex Tōkyū 8500 series, services for KRL Jabotabek.	Belgian EMU AM80 "Break" unit.	A British SWT Class 450 suburban unit at London Waterloo Station.
Transperth B Series EMUs operate in Perth, Australia.	New Delhi Metro EMU in India	Russian ED4MKM-aero EMU.	Swedish Railways EMU	Japanese JR East Type E233-1000 EMU test run Omiya, Japan.
Japanese JR West Shinkansen Type 500 EMU.	Russian ER2K EMU (No. 604).	Chinese CRH3	Polish ED59.	Polish ED74.
Polish 14WE in Warszawa Śródmieście station.	Polish 19WE developed in 2008 by Newag during the final tests in CNTK in Warsaw

See also

Wikimedia Commons has media related to: Electric multiple units

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• ja:電気車の速度制御 Speed control of electric railcars (Japanese)