The

British Rail British Railways (BR), which from 1965 traded as British Rail, was a state-owned company that operated most of the overground rail transport in Great Britain from 1948 to 1997. It was formed from the nationalisation of the Big Four British rai ...

Class 129 was a class of single car

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. Diesel-powered single-unit railcars are also ...

s (DMU) built in 1955 for British Rail. Only three were built by Cravens and were introduced in 1958. The class was built for parcels traffic like the Class 128. One unit (55997) survived into departmental service being named 'Hydra'. The driving ends of a Class 129 car bore a visible similarity to that of the Class 105, also built by Cravens.

Fleet list

Departmental Usage

One unit, M55997, was converted as a test bed for hydrostatic drive in 1980, was renumbered RDB 975385, and named ''Laboratory 9 ‘Hydra’''. It was fitted

hydrostatic transmission A continuously variable transmission (CVT) is an automatic transmission that can change seamlessly through a continuous range of gear ratios. This contrasts with other transmissions that provide a limited number of gear ratios in fixed steps. T ...

having the normal Leyland Motors 680 six-cylinder engine driving two

Bosch Rexroth Bosch Rexroth AG is an engineering firm based in Lohr am Main in Germany. It is the result of a merger on 1 May 2001 between Mannesmann Rexroth AG and the Automation Technology Business Unit of Robert Bosch GmbH, and is a wholly owned subsidiar ...

Hydramatic Hydramatic (also known as Hydra-Matic) is an automatic transmission developed by both General Motors' Cadillac and Oldsmobile divisions. Introduced in 1939 for the 1940 model year vehicles, the ''Hydramatic'' was the first mass-produced fully-a ...

axial piston pump An axial piston pump is a positive displacement pump that has a number of pistons in a circular array within a ''cylinder block''. It can be used as a stand-alone pump, a hydraulic motor or an automotive air conditioning compressor. Description ...

s. Each pump supplied fluid to a Volvo fixed displacement compact axle-end motor which drove the axle directly. The maximum system pressure was in the order of . This arrangement was only fitted to one bogie, the other one retaining its normal drive but with the cardan shaft disconnected. The unit was finally withdrawn in January 1986 and scrapped in August that year by

Vic Berry Vic Berry's Scrapyard was a large railway scrapyard situated in the former Great Central Railway Braunstone Gate goods yard in Leicester. Operations Vic Berry established his Leicester scrapyard in 1973 on the site of what had been the fo ...

at Leicester.

References

129 Cravens multiple units Non-passenger multiple units Train-related introductions in 1958 {{England-rail-transport-stub