Class 159

Class 159
Name	Class 159
Service	1990–present
Manufacturer	British Rail Engineering Limited
Yearconstruction	1989–1993
Numberbuilt	30 sets (90 vehicles)
Formation	3-car sets
Operator	British Rail; ScotRail; Transport for Wales; Avanti West Coast; West Midlands Trains
Carbody	Steel
Maxspeed	90 mph (145 km/h)
Gauge	1,435 mm (standard gauge)

Class 159 is a diesel multiple unit passenger train introduced into service in the United Kingdom between 1989 and 1993. Built by British Rail Engineering Limited for regional and intercity services, the type was deployed primarily on routes radiating from Bristol Temple Meads, Birmingham New Street, and Manchester Piccadilly. The fleet has been operated by a succession of train operators including British Rail, First Great Western, ScotRail, and Transport for Wales, and has undergone multiple refurbishments to extend service life and improve passenger amenities.

Background and Development

Development of the Class 159 followed a need identified during the late 1980s for faster diesel traction on the West of England Main Line, the Bristol–Exeter line, and the Cross Country Route. British Rail sought replacements for ageing Sprinter units and to provide improved performance comparable with InterCity 125 services on non-electrified routes. The project drew on design experience from the Class 158 family and from work by British Rail Engineering Limited at the Crewe Works and York Works facilities. Political and economic contexts such as the Transport Act 1985 and the lead-up to Railway privatisation influenced procurement timelines and set the stage for later operator changes like FirstGroup and Stagecoach Group franchises.

Design and Technical Specifications

The Class 159 is a three-car diesel multiple unit with steel car bodies derived from the Mark 3 design ethos and mechanical components related to the Sprinter family. Power is provided by diesel engines coupled to hydraulic transmissions, enabling a maximum speed of 90 mph suitable for regional express workings. Bogie design and wheelsets incorporate standards used elsewhere on the national network overseen by Network Rail and formerly by Railtrack; braking systems comply with Railway Group Standards. Passenger accommodation originally featured both first and standard class seating, air conditioning retrofits, wheelchair-accessible toilets, and on-board catering provision for longer-distance services linking hubs such as Plymouth railway station, Exeter St Davids, and Taunton railway station.

Variants and Subclasses

While the main production batch shared a common three-car formation, small variations existed between early and later builds reflecting different interior layouts and wiring schematics. Units operated by ScotRail underwent modifications to cope with Scottish route conditions and timetable patterns centered on Glasgow Queen Street and Edinburgh Waverley. Some sets saw compatibility work for multiple working with other types like Class 150 and Class 156 units managed under depot allocations such as Cardiff Canton TMD, Bristol Bath Road Depot, and Birmingham Barton Depot.

Operational History

Class 159 units entered traffic replacing older DMUs on key regional express routes linking Bristol Temple Meads to London Paddington, as well as cross-regional services touching Oxford, Cheltenham Spa, and Swansea. Under British Rail and subsequent private operators including First Great Western and Arriva Trains Wales, the fleet was integral to timetable expansions, rolling stock cascades, and franchise bids. Performance over the decades reflected the influence of infrastructure upgrades such as the Great Western Main Line electrification programme and pathing changes at major junctions like Birmingham New Street and Reading station.

Refurbishments and Modifications

Several refurbishment programmes were carried out by operators and contractors such as Wabtec and Bombardier Transportation to update interiors, install new passenger information systems, and retrofit CCTV and accessible features in line with the Persons with Reduced Mobility Technical Specification for Interoperability. Modifications included replacement seating, LED lighting, toilet refurbishments, and HVAC overhauls to meet modern standards demanded by franchises won by companies including FirstGroup and Abellio.

Incidents and Accidents

Over its operational lifetime, units have been involved in a number of incidents recorded by the Rail Accident Investigation Branch and reported in industry sources. Events ranged from minor collisions during depot movements at locations such as Manchester Victoria to more serious derailments and points failures near junctions including Bristol Parkway; investigations typically led to recommendations about maintenance regimes, signalling interfaces at interlockings, and improved driver training under policies traced back to Office of Rail and Road oversight.

Fleet Allocation and Operators

Originally ordered by British Rail for the Regional Railways sector, the fleet passed to operators including First Great Western (later Great Western Railway), ScotRail, and regional operators such as Transport for Wales following Railway privatisation. Depot allocations have included Cardiff Canton TMD, Exeter depots, Scotland’s Inverness depot, and Birmingham New Street stabling points. As of recent timetables, sets continue to serve regional intercity corridors alongside newer rolling stock from manufacturers such as Siemens and Hitachi.

Category:British Rail diesel multiple units