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, but electrically powered single-unit railcars are also generally classed as EMUs. The great majority of EMUs are passenger trains, but versions also exist for carrying mail.
17-620: The HR5000 is an electric multiple unit rapid transit car ordered from Hyundai Rotem for the Los Angeles Metro Rail 's B and D lines. Following a decision by the Los Angeles County Metropolitan Transportation Authority (Metro) not to purchase additional CRRC HR4000 trains, bids were sought for new subway trains. In January 2024, 182 cars were ordered from Hyundai Rotem , with options for 50 more cars. These will enter service prior to
34-537: A contract to CRRC for 64 trains, with contract options for 218 cars. These HR4000 trains were planned to enter service in 2020, with introduction into service currently planned for 2024. Construction delays for trains were caused by supply chain issues as a result of the COVID-19 pandemic , as well as compliance with the Uyghur Forced Labor Prevention Act . Following these construction delays, and
51-483: A motor-driving car or power-driving car. On third rail systems, the outer vehicles usually carry the pick up shoes with the motor vehicles receiving the current via intra-unit connections . Many modern two-car EMU sets are set up as twin or "married pair" units. While both units in a married pair are typically driving motors, the ancillary equipment (air compressor and tanks, batteries and charging equipment, traction power and control equipment, etc.) are shared between
68-676: A time. Trains will enter service prior to the 2028 Olympic Games and Paralympic Games , with all trains in service by 2030. This United States train or rolling stock-related article is a stub . You can help Misplaced Pages by expanding it . Electric multiple unit EMUs are popular on 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
85-417: 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. Multiple unit train control was first used in the 1890s. The Liverpool Overhead Railway opened in 1893 with two-car electric multiple units, controllers in cabs at both ends directly controlling
102-738: The China Railway High-speed in China, ICE 3 in Germany, and the British Rail class 395 Javelin. 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, known as the Budd Metroliner . EMUs powered by fuel cells are under development. If successful, this would avoid
119-474: The cab car or the driving van trailer on push-pull trains for multiple-unit train control and the transmission of lower voltage electricity ( head end power ). Jumper cables are electrical cables between the road tractor and a semi-trailer or a full trailer or the electrical cables between an automobile and any trailer . A car with a "dead" (discharged) battery can be made to start by supplying it with power from an external source, such as
136-542: The 2028 Olympic Games and Paralympic Games , with all trains in service by 2030. As of 2024, the Metro Rail subway fleet is at least 26 years old, with the Breda A650 trains built in two batches between 1988 and 1997. New trains will allow for future replacement of all Breda A650 trains, expanded train service including a four-minute train frequency, and extensions of the D Line over three phases. In 2017, Metro awarded
153-469: The United States. In February 2024, a $ 663.7 million contract for 182 cars was awarded to Hyundai Rotem, with options for 50 more cars. Although Hyundai Rotem's bid was more expensive than Stadler, Metro indicated that the contract was not solely awarded on price. Cars will be delivered in two-car trains, with a capacity of 245 passengers. Trains will be capable of running in multiple, up to three trains at
170-402: The batteries are charged via the electric pickup when operating on electric mode. EMUs, when compared with electric locomotives , offer: Electric locomotives, when compared to EMUs, offer: Jumper cable Jumper cables , booster cables or jumper leads are electric cables to connect two rail or road vehicles. Jumper cables are between the locomotive , the railroad cars and
187-431: The battery of another car. The jump leads used to make the necessary temporary connection are also commonly called "jumper cables". These usually are equipped at the ends with alligator clips . This locomotive-related article is a stub . You can help Misplaced Pages by expanding it . This article about an automotive part or component is a stub . You can help Misplaced Pages by expanding it . This truck-related article
SECTION 10
#1732854945543204-485: The construction of electric traction railways and trolley systems worldwide. Each car of the train has its own traction motors: by means of motor control relays in each car energized by train-line wires from the front car all of the traction motors in the train are controlled in unison. 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
221-416: The need for an overhead line or third rail . An example is Alstom ’s hydrogen -powered Coradia iLint . The term hydrail has been coined for hydrogen-powered rail vehicles. Many battery electric multiple units are in operation around the world, with the take up being strong. Many are bi-modal taking energy from onboard battery banks and line pickups such as overhead wires or third rail. In most cases
238-541: The outer end of the pair, saving space and expense over a cab at both ends of each car. Disadvantages include a loss of operational flexibility, as trains must be multiples of two cars, and a failure on a single car could force removing both it and its partner from service. Some of the more famous electric multiple units in the world are high-speed trains: the Italian Pendolino and Frecciarossa 1000 , Shinkansen in Japan,
255-584: The passing of the Transit Infrastructure Vehicle Security Act by Congress in 2019 which prevents the use of further federal funding for CRRC, Metro decided not to exercise the options in the CRRC HR4000 contract in 2022. In December 2022, Metro began procuring new subway trains with a request for proposals . Three bidders took part, Hitachi Rail , Hyundai Rotem and Stadler Rail . All three manufacturers have production facilities in
272-551: The traction current to motors on both cars. The multiple unit traction control system was developed by Frank Sprague and first applied and tested on the South Side Elevated Railroad (now part of the Chicago 'L' ) in 1897. In 1895, derived from his company's invention and production of direct current elevator control systems, Frank Sprague invented a multiple unit controller for electric train operation. This accelerated
289-426: The two cars in the set. Since neither car can operate without its "partner", such sets are permanently coupled and can only be split at maintenance facilities. Advantages of married pair units include weight and cost savings over single-unit cars (due to halving the ancillary equipment required per set) while allowing all cars to be powered, unlike a motor-trailer combination. Each car has only one control cab, located at
#542457