List of British Rail diesel multiple unit classes
This is a list of British Rail diesel multiple unit classes.
TOPS classes
List of British Rail electric multiple unit classes
This page lists every electric-powered multiple unit allocated a TOPS classification or used on the mainline network since 1948 (i.e. British Railways and post-privatisation). British Rail operated a wide variety of electric multiple units for use on electrified lines.
These use electrical switching devices (thyristors and transistors) and have electronic power control.
The Southern Railway and its successor, the Southern Region of British Rail, used three letter codes to classify their DC EMU fleets, as shown after the TOPS class numbers.
The 500 series classes were reserved for DC (third/fourth rail) EMUs not from the Southern Region. This included the DC (third/fourth rail) lines in North London, Merseyside and Greater Manchester. The DC electric network around Tyneside had been de-electrified by the time TOPS was introduced, and the stock withdrawn or transferred to the Southern Region.
TOPS classes
Pre-TOPS classes
This was a one-off unit, withdrawn before the introduction of TOPS.
List of British Rail departmental multiple unit classes
The 900 series classes were reserved for multiple units in departmental stock, most of which were converted from old passenger units. In broad terms, classes 930-935 were allocated to Southern Region multiple units (ex-200 and 400 series), 936 & 937 to other EMUs (ex-300 and 500 series) and 960 to other DMUs (ex-100 series). In recent years, this has been less rigidly adhered to.
The original use for the Southern Region (SR) classes are included in brackets; these designations have been less rigidly applied in recent years.
British United Traction
British United Traction (BUT) was a joint company owned by the Associated Equipment Company and Leyland Motors which produced railway equipment and trolleybuses.
British Rail Derby Lightweight
The British Rail Derby Lightweight diesel multiple units, were the first such trains to be built en-masse for British Railways. The units were built at BR's Derby Works from 1954 to 1955. The units were built in various formations, including two single car units, 12 power-twin 2-car units, 84 power-trailer 2-car units, and four 4-car units. Contemporaneous with these units was the unique Battery Electric Multiple Unit.
British Rail Metro-Cammell
In 1955, Metropolitan Cammell produced its first lightweight Diesel multiple units, the prototypes of what were to become British Rail's most successful and longest-lived "First Generation" DMU type, the Class 101.
British Rail Railbuses
British Rail produced a variety of Railbuses as a means both of building new rolling stock cheaply, and to provide services on lightly-used lines economically.
GWR railcars
In 1933, the Great Western Railway introduced the first of what was to become a very successful series of railcars, which survived in regular use into the 1960s, when they were replaced with the new British Rail "first generation" type diesel multiple units.
LMS railcars
The London Midland and Scottish Railway (LMS) introduced a number of railcars to service between 1933 and 1939. They were mainly single units but one was a three-car articulated set.
Pacer
Pacer trains are railbuses built by British Rail between 1080 and 1987. There are several classes of them: 140, 141, 142, 143 and 144. They are diesel multiple unit trains, meaning each carriage has its own diesel engine. Pacers were built as a stopgap because British Rail did not have enough normal trains at the time and could not get new ones quickly enough. They were not supposed to be used for more than 20 years, but it actually took nearly 35 years to replace them.
Most Pacer trains were put out of use in 2020. Two things finally made this happen. The first is that it is difficult for people with disabilities to climb onto Pacer trains. The Rail Vehicle Accessibility Regulations require that all public passenger trains must be made easy to use for disabled people by 2020 - but they made an exception for the Pacer trains until the end of 2020. Only one Pacer (the modernised 144e) follows this rule right now. The second is that the Transport Secretary made a decision in 2015 to retire the Pacers by 2020 for the then-new Northern service, arguing that it would be bad for the economy in the north to keep using "these uncomfortable and low-quality vehicles".
At the start of 2020, 138 Pacer units were still being used or stored by three National Rail operators: Northern Trains, Great Western Railway and Transport for Wales. Northern Trains retired its last Pacer unit on 27 November 2020, and so did Great Western Railway in December 2020. Transport for Wales will still use their Class 143s into the first part of 2021.
The Pacer series were made to keep building and running costs low, so all of the Pacer units use:
At the beginning of the 1980s British Rail (BR) needed to make new trains to replace its old first generation diesel multiple units (DMUs) which had been built between the mid-1950s and early-1960s. These old trains had helped replace steam and were popular with the public at the time. But BR did not get much money from the government, so could not get new trains that were just as good as the old ones. BR created two kinds of new second generation trains: the Sprinter series, for use on city and longer-distance services, and the Pacer series as cheap DMUs built using bus parts for short-distance countryside and branch line services. The Pacers were intended as a cheap stopgap solution to the shortage of trains, and were not supposed to be used for more than 20 years. BR set a challenge to several companies to design a cheap, lightweight train similar to railbuses. Since then, 165 Pacer trains (with 340 carriages in total) have been built. By 2015, some of these were over 30 years old.
They also tried to sell Pacers by showing them in the USA, Northern Ireland, Belgium, Sweden, Thailand, Malaysia and Indonesia, but no one bought any there. However, Iran bought leftover Class 141 units, for use on suburban lines around Tehran until 2005.
The Pacer series was the outcome of an idea to try using bus parts to create a diesel multiple unit. The first prototype, known as LEV 1, was made by British Rail Research Division and Leyland Motors working together. It used a bus body that was mounted on a modified freight train underframe (HSFV1). In 1980 they also built a two-car prototype class 140 at British Rail Engineering Limited (BREL)'s Derby Litchurch Lane Works.
Then they built 20 more two-car units, forming the Class 141 fleet that was used mostly for suburban services in Yorkshire. They could carry 94 passengers in each set of two cars. Their two Leyland TL11 engines gave a total of , making for a top speed of .
The 141s were built with Leyland National bus bodies that were so narrow that they could only be fitted with standard bus seats. The later Pacers had widened body panels to allow better seating.
The entire class got a technical upgrade in 1988 at the Hunslet-Barclay works in Kilmarnock.
The units were withdrawn from British Rail in 1997. Many were sold to Islamic Republic of Iran Railways but have been withdrawn and are left in disused sidings in Iran. A few are preserved at museum sites.
The next and largest Pacer class was the Class 142. This again was built by Leyland and BREL, in 1985. The body was based on a Leyland National bus, built at Workington in Cumbria. Many fixtures and fittings of the Leyland National could be found on the units. The new class could carry more passengers: 120 passengers per two-car set. The same engines were used.
The first sets were used on Devon and Cornwall branch lines and on commuter services in the north west. The units from Cornwall were eventually moved to Liverpool and the north east, so the Class 142s were often seen on services across the north of England.