Multiple-unit in the context of "Deutsche Bahn"

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⭐ Core Definition: Multiple-unit

A multiple-unit train (or multiple unit (MU)) is a self-propelled train composed of one or more carriages joined, and where one or more of the carriages have the means of propulsion built in. By contrast, a locomotive-hauled train has all of the carriages unpowered.

An implication of this is that all the powered carriages needs to be controllable by a single engineer or driver, which is a case of the broader concept of multiple-unit train control. In other words, all "multiple units" employ some variation of multiple-unit train control. In the broader context "unit" means any powered rail vehicle, including locomotives (that does not carry cargo) and powered cargo-carrying carriages. In the context of this article, "unit" refers specifically to the latter only (whether the cargo is passengers or some other cargo).

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Multiple-unit in the context of Tram

A tram (also known as a streetcar or trolley in Canada and the United States, or a Tramcar) is an urban rail transit type in which vehicles, whether individual railcars or multiple-unit trains, run on tramway tracks on urban public streets; some include segments on segregated right-of-way. Trams are a variant of light rail and are included within this broader category. However, they differ from it in their frequent integration into urban streets, lower traffic signal priority, coexistence with other vehicles, and lower capacity. Their units are capable of forming motor coaches or motorcars, which allows for the operation of longer trains.

Trams are usually lighter and shorter than main line and rapid transit trains. Most trams use electrical power, usually fed by a pantograph sliding on an overhead line; older systems may use a trolley pole or a bow collector. In some cases, a contact shoe on a third rail is used. If necessary, they may have dual power systems—electricity in city streets and diesel in more rural environments. Occasionally, trams also carry freight. Tramlines or tram networks operated as public transport are called tramways, or simply trams or streetcars, including systems separated from other traffic. Some trams, known as tram-trains, may have segments that run on mainline railway tracks, similar to interurban systems. The differences between these modes of rail transport are often indistinct, and systems may combine multiple features.

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Multiple-unit in the context of Electric multiple unit

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. An EMU is usually formed of two or more semi-permanently coupled carriages. However, electrically powered single-unit railcars are also generally classed as EMUs. The vast majority of EMUs are passenger trains but versions also exist for carrying mail.

EMUs are popular on intercity, commuter, and suburban rail networks around the world due to their fast acceleration and pollution-free operation, and are used on most rapid-transit systems. Being quieter than diesel multiple units (DMUs) and locomotive-hauled trains, EMUs can operate later at night and more frequently without disturbing nearby residents. In addition, tunnel design for EMU trains is simpler as no provision is needed for exhausting fumes, although retrofitting existing limited-clearance tunnels to accommodate the extra equipment needed to transmit electric power to the train can be difficult.

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Multiple-unit in the context of Streetcar line

A tram (also known as a streetcar or trolley in Canada and the United States, or a Tramcar) is an urban rail transit type in which vehicles, whether individual railcars or multiple-unit trains, run on tramway tracks on urban public streets; some include segments on segregated right-of-way. Trams are a variant of light rail and are included within this broader category. However, they differ from it in their frequent integration into urban streets, lower traffic signal priority, coexistence with other vehicles, and lower capacity. Their units are capable of forming motor coaches or motorcars, which allows for the operation of longer trains.

Trams are usually lighter and shorter than main line and rapid transit trains. Most trams use electrical power, usually fed by a pantograph sliding on an overhead line; older systems may use a trolley pole or a bow collector. In some cases, a contact shoe on a third rail is used. If necessary, they may have dual power systems—electricity in city streets and diesel in more rural environments. Occasionally, trams also carry freight. Tramlines or tram networks operated as public transport are called tramways, streetcars or simply trams, including systems separated from other traffic. Some trams, known as tram-trains, may have segments that run on mainline railway tracks, similar to interurban systems. The differences between these modes of rail transport are often indistinct, and systems may combine multiple features.

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Multiple-unit in the context of Diesel multiple unit

A diesel multiple unit or DMU is a multiple-unit train powered by on-board diesel engines. A DMU requires no separate locomotive, as the engines are incorporated into one or more of the carriages. When additional carriages are coupled on, their controls are connected through and a single driver can control every engine in the train. This also allows the driver to drive from a cab at either end, simplifying reversing. Diesel-powered single-unit railcars are generally regarded as DMUs for most operations, at least with smaller trains.

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