Class 158

Class 158
Alex Noble · CC0 · source
Name	Class 158
Service	1989–present
Manufacturer	British Rail Engineering Limited; Leyland Bus (subcontractor)
Family	Sprinter family
Yearconstruction	1989–1992
Numberbuilt	182
Formation	2 cars per unit
Operator	British Rail; East Midlands Railway; ScotRail; TransPennine Express; Northern Trains; Greater Anglia; West Midlands Trains; Scotrail
Depots	Doncaster depot; Heaton TMD; Leeds Neville Hill depot
Lines	West Coast Main Line; East Coast Main Line; Caledonian Sleeper
Maxspeed	90 mph (145 km/h)
Engine	Cummins diesel engines
Gauge	1,435 mm (standard gauge)

Class 158 The Class 158 is a British two-car diesel multiple-unit built for regional and inter-urban services during the late 1980s and early 1990s. Designed by British Rail Engineering Limited as part of the Sprinter family, the type sought to replace older units like the Class 101 and Class 117 and improve passenger comfort on routes such as the Settle–Carlisle line and services linking Manchester with Scotland. Operators have included successors to British Rail such as ScotRail and East Midlands Railway, with many units undergoing multiple refurbishments across the fleets of Northern Trains and Greater Anglia.

Design and development

The 158 emerged from British Rail's late-1980s franchise-era initiative to modernise regional rolling stock, alongside designs like the Class 150 and Class 156. Stemming from requirements formulated by the InterCity and Regional Railways sectors, the project focused on reducing journey times on routes managed from centres including York and Crewe. Built by British Rail Engineering Limited with involvement from subcontractors such as Leyland Bus, the design incorporated features seen on contemporary vehicles like the Class 155 and Class 159, while aiming to meet specifications influenced by operating regions including Scotland and Wales under control of offices in Cardiff and Edinburgh.

Technical specifications

Each two-car set used lightweight aluminium alloy bodies with maximum speeds of 90 mph, powered by Cummins diesel engines driving hydraulic transmissions supplied by firms similar to Voith. Bogies and suspension arrangements reflected practices from earlier designs by BREL and maintenance standards from depots such as Heaton TMD. Passenger amenities included air-conditioning options, accessible toilets compliant with standards promoted by agencies like Department for Transport in later refurbishments, and onboard systems that would later be integrated with signalling upgrades on corridors such as the West Coast Main Line and East Coast Main Line.

Construction and operators

Production ran between 1989 and 1992, yielding 182 two-car units constructed at works operated by British Rail Engineering Limited. Following the 1994–1997 privatisation period that created companies such as FirstGroup and Stagecoach Group, units were transferred among operators including ScotRail (pre- and post-privatisation), Northern Trains (successor of Northern Rail), East Midlands Railway (successor of East Midlands Trains), Greater Anglia (successor of National Express East Anglia), and regional franchises with custodianship by entities tied to Transport Scotland and the Department for Transport. Maintenance and stabling were performed at depots like Doncaster depot and Leeds Neville Hill depot.

Service history

Initial deployment concentrated on secondary and regional expresses replacing first-generation DMUs on routes linking Manchester with Leeds, services radiating from Birmingham New Street, and inter-regional flows to Scotland via the Settle–Carlisle line. Over the 1990s and 2000s, units formed backbone services for franchises run by companies including Arriva and National Express, adapting to timetable changes from bodies such as Network Rail and responding to passenger demand shaped by commuting patterns in urban centres like Sheffield and Glasgow. Several units remained in frontline use into the 2010s and 2020s despite the introduction of newer trains like the Class 170 and Class 185.

Modifications and refurbishments

Throughout their operational lives, units underwent multiple refurbishments overseen by operators and contractors including Bombardier Transportation and in-house teams at depots such as Heaton. Interior upgrades introduced new seating, LED lighting, and passenger information systems compatible with onboard equipment used by companies like Stagecoach Group and FirstGroup. Accessibility improvements were made to comply with regulations driven by the Department for Transport and government initiatives, while reliability works included engine overhauls by suppliers related to Cummins and renewal of safety equipment to interface with signalling projects managed by Network Rail.

Accidents and incidents

The fleet has been involved in a number of incidents investigated by bodies such as the Rail Accident Investigation Branch and reported to the Office of Rail and Road. Notable events included derailments and collisions on regional routes, with enquiries referencing infrastructure factors on lines like the Settle–Carlisle line and operational contexts involving franchises run by Northern Rail and ScotRail. Lessons from these incidents influenced subsequent safety measures adopted across fleets operated by companies including East Midlands Railway and maintenance regimes at depots like Doncaster depot.

Category:British diesel multiple units