Electric multiple unit
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| Multiple unit trains |
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| Subtypes |
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Electric multiple unit |
| Technology |
| By Country |
An electric multiple unit or EMU is a multiple unit train consisting of more than one passenger carriages where all carriages in the train carry passengers, using electricity as the motive power. No locomotive is used as electric traction motors are incorporated within one or a number of the carriages
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History
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. This gave the EMUs the further distinction of being the first EMU light-rail carriages. The first EMUs were two carriage trains later graduating to three carriages, with the front and rear carriages powered.
The advanced, innovative carriages for the day, were the precursor of the modern rapid transit EMUs, bearing a similar appearance. Liverpool Museum retains an example of the Liverpool Overhead Railway EMU carriage. http://www.liverpoolmuseums.org.uk/mol/collections/transport/overheadrailway.aspx
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
 German ICE 3 EMU (Deutsche Bahn). |
 Australian OSCAR (H-set) EMU (CityRail). |
 Mumbai Suburban Railway old EMU (Indian Railway). |
 Mumbai Suburban Railway new EMU (Indian Railway) |
.jpg) 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. |
 A British SWT Class 450 suburban unit at London Waterloo Station. |
 Transperth B Series EMUs operate in Perth, Australia. |
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 New Delhi Metro EMU in India |
 Russian ED4MKM-aero EMU. |
 Iarnród Éireann 8520 Class EMU, operated on the DART line. |
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 Japanese JR West Shinkansen Type 500 EMU. |
 Russian ER2K EMU (No. 604). |
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.jpg) Polish 14WE in Warszawa Śródmieście station. |
 French Z 20500, used in Paris's RER and Transilien commuter rail lines. |
 An electric multiple unit in Switzerland. |
 Swiss BLS Line. |
See also
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Wikimedia Commons has media related to: Electric multiple units |
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