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. Diesel-powered single-unit railcars are also generally classed as DMUs. Diesel-powered units may be further classified by their transmission type: diesel–mechanical DMMU, diesel–hydraulic DHMU, or diesel–electric DEMU.
InterCity was introduced by British Rail in 1966 as a brand-name for its long-haul express passenger services.
The British Rail Class 108 diesel multiple units were built by BR Derby from 1958 to 1961, with a final production quantity of 333 vehicles.
The British Railways Class 24 diesel locomotives, also known as the Sulzer Type 2, were built from 1958 to 1961. One hundred and fifty-one were built at Derby, Crewe and Darlington, the first twenty of them as part of the British Railways 1955 Modernisation Plan. This class was used as the basis for the development of the Class 25 locomotives.
The British Rail Class 121 is a single-car double-ended diesel multiple unit. 16 driving motor vehicles were built from 1960, numbered 55020–55035. These were supplemented by ten single-ended trailer vehicles, numbered 56280–56289. They have a top speed of 70 mph, with slam-doors, and vacuum brakes. The driving motor vehicles were nicknamed "Bubble Cars" by some enthusiasts.
The British Rail Class 122 diesel mechanical multiple units were built by Gloucester RC&W in 1958. Twenty single-car, double-ended driving motor vehicles, nicknamed "Bubble Cars", were built, numbered 55000–55019. These were supplemented by nine single-ended trailer vehicles, numbered 56291–56299.
The British Rail Class 116 diesel multiple units were built by BR Derby from 1957 to 1961. Introduced as part of the British Railways Modernisation Plan in the mid 1950s, as with other first generation DMUs the 116 was intended to replace steam trains and reduce costs across the rail network. Alongside Metro-Cammell, BR Derby had prior experience with DMUs, having developed a Lightweight Unit, and so was awarded a contract for a new design.
The British Rail Class 104 diesel multiple units were built by Birmingham Railway Carriage and Wagon Company from 1957 to 1959.
The British Rail Classes 101 and 102 diesel-mechanical multiple units were built by Metro-Cammell at Washwood Heath in Birmingham, England from 1956 to 1959, following construction of a series of prototype units. These classes proved to be some of the most successful and longest-lived of BR's First Generation DMUs, second in longevity only to the Class 121, with the final five units being withdrawn on 24 December 2003. The oldest set was, by then, just over 47 years old.
The British Rail Class 127 diesel multiple units were built by BR Derby in 1959. Thirty 4-car units were built, formed of two outer driving motor vehicles, sandwiching two intermediate trailers which were classified class 186. The technical description of such as 4-car unit was DMBS + TSL + TS + DMBS.
The Maritime Line is a railway line that runs in the valley of the River Fal from Truro, the county town, to Falmouth on the south coast of Cornwall, England.
The British Rail Class 150 Sprinter is a class of diesel multiple unit passenger trains; they were developed and constructed by British Rail Engineering Limited at York Carriage Works between 1984 and 1987 for use on regional services across the UK. The type is a second-generation design, built to more modern standards and based on BR's Mark 3 body design for longer-distance services. It was developed alongside the lower-cost Pacers, which were built using bus parts, for use on short-distance services. Two prototype units were built, followed by 135 production units in two batches. Subsequently, further members of the Sprinter family were also developed and introduced to service, including the Class 155, Class 156, Class 158 and Class 159.
The Class 168Clubman is a British diesel multiple unit (DMU) passenger train used on Chiltern Line services between London Marylebone and the West Midlands. The trains were built by Adtranz at the Derby Litchurch Lane Works in several batches from 1998.
The British Rail Class 103 diesel multiple units were built by Park Royal Vehicles with diesel engines by British United Traction (BUT). Ordered in the first half of 1955, 20 of these sets were built by Park Royal at the Crossley Motors works in Stockport of the ACV Group. They consisted of a power car and a driving trailer. Standard BUT equipment was fitted, with 'A' type engines.
The British Rail Classes 105 and 106 diesel multiple units were built by Cravens Ltd. of Sheffield from 1956 to 1959. The class were built with a side profile identical to British Railways Mark 1 carriage stock, using the same doors and windows. None were selected for refurbishment. The last passenger car was withdrawn from service in 1988.
The British Rail Class 126 diesel multiple unit was built by BR Swindon Works in 1959/60 to work services from Glasgow to Ayrshire and comprised 22 3-car sets and were a development of the earlier Swindon-built trainsets that had been introduced in 1955 to work the Edinburgh Waverley - Glasgow Queen St services. These vehicles formed the first Inter City service to be operated by diesel units in Great Britain.
The British Rail Class 119 DMUs were used throughout the Western Region and on services in the Midlands sourced by Tyseley Depot. Built by the Gloucester Railway Carriage & Wagon Co. Ltd, the body design was based on the Swindon Cross-Country sets, but with a Derby cab. Sets were normally formed of three cars.
The British Rail Class 124 diesel multiple units were built by BR Swindon Works in 1960.
The British Rail Class 123 was a design of diesel multiple unit built for British Rail in 1963. They were the last first-generation DMUs built for British Railways and were built at Swindon Works. Ten of the four-car sets were built and introduced in 1963. The units bear a visible similarity to the British Rail Class 309; however, there is no 'relation' here as the two types were built by different manufacturers for different markets.
Diesel multiple units and railcars are trains, usually with passenger accommodation, that do not require a locomotive. Railcars can be single cars, while in multiple units cars are marshalled together with a driving position either end. As of December 2010, 23 percent of the rail passenger cars used on Network Rail are part of a diesel multiple unit.
