British Rail Class 151

British Rail Class 151 Sprinter
A class 151 at Derby in 1987
In service	1985–1989
Manufacturer	Metro-Cammell
Order no.	30987 (DMSL) 30988 (DMS) 30989 (MS)[1]
Built at	Washwood Heath, Birmingham
Family name	Sprinter
Replaced	BR First-Generation DMUs
Constructed	1985[1]
Entered service	1985[2]
Scrapped	2004[2]
Number built	2
Number scrapped	2
Formation	3 cars per unit: DMSL-MS-DMS[3]
Diagram	DMSL vehicles: DP233 MS vehicles: DR204 DMS vehicles: DP232[1]
Fleet numbers	As built: 151001–151002 Post-1987: 151003–151004[2]
Capacity	232 (total) 68 (DMSL) 84 (MS) 80 (DMS)[1]
Operators	Regional Railways
Depots	Etches Park (Derby)[1]
Specifications
Car body construction	Aluminium[3]
Car length	DMS vehicles: 19.975 m (65 ft 6.4 in)[4] MS vehicles: 19.600 m (64 ft 3.7 in)[3]
Width	2.810 m (9 ft 2.6 in)[4]
Height	3.845 m (12 ft 7.4 in)[4]
Floor height	1.156 m (3 ft 9.5 in)[4]
Doors	Double-leaf pocket sliding[3]
Wheelbase	Bogies: 2.300 m (7 ft 6.6 in) Bogie centres: 14.040 m (46 ft 0.8 in)[4]
Maximum speed	75 mph (121 km/h)[3]
Weight	DM vehicles: 32.4 tonnes (31.9 long tons; 35.7 short tons) MS vehicles: 32.1 tonnes (31.6 long tons; 35.4 short tons) Total: 96.9 tonnes (95.4 long tons; 106.8 short tons)[3]
Prime mover(s)	3 × Cummins NT855-R5 (one per vehicle)[1]
Engine type	Inline-6 4-stroke turbo-diesel[5]
Displacement	14 L (855 cu in) per engine[5]
Power output	638 kW (855 hp) total[3]
Transmission	Twin Disc 1330
UIC classification	2′B′+2′B′+B′2′
Bogies	Metro-Cammell[3]
Braking system(s)	Electro-pneumatic[3]
Coupling system	BSI[1]
Multiple working	Within class, and with Classes 14x and 15x[3]
Track gauge	1,435 mm (4 ft 8+1⁄2 in) standard gauge

The British Rail Class 151 was a prototype class of diesel multiple unit (DMU) developed and constructed by the British railway equipment manufacturer Metro Cammell. It was designed primarily to serve as a successor to the earlier first-generation "Heritage" DMUs operated by the British Rail (BR).

Development of the Class 151 commenced during 1983 in response to a specification issued by BR calling for a new generation of DMU with which to equip its fleet. Both Metro Cammell and British Rail Engineering Limited (BREL) were selected to produce prototypes of their design submissions. Accordingly, a pair of 3-car units were constructed, which entered trial service with BR during 1985. If it had emerged successful, the Class 151 would have likely become the basis of Sprinter family of DMUs that were produced during the 1980s. However, following a competitive evaluation against the rival Class 150, the type did not secure a production contract, having lost out to its BREL-built rival. Both units were withdrawn during 1989 and, despite multiple vendors planning to restore them for service, they were ultimately scrapped.