British Rail Class 140

British Rail Class 140 Pacer
Class 140 (right) at Landore TMD, Swansea, in 1982
In service	1981 – c. 1986
Manufacturer	British Rail Engineering Limited Leyland Vehicles Limited[1]
Order no.	30962[2]
Built at	Derby Litchurch Lane Works[2]
Family name	Pacer
Constructed	1979–1981[3]
Number built	1
Number preserved	1
Formation	2 vehicles: DMSL-DMS
Diagram	DMSL vehicle: DP222 DMS vehicle: DP223[1]
Fleet numbers	Unit: 140001 Vehicles: 55500 and 55501[2]
Capacity	102 seats[2]
Operators	British Rail
Depots	Neville Hill (Leeds)[2]
Specifications
Car body construction	Steel[1]
Car length	15.878 m (52 ft 1.1 in)[1]
Width	Over body: 2.468 m (8 ft 1.2 in) Over treadplates: 2.744 m (9 ft 0 in)[1]
Height	3.906 m (12 ft 9.8 in)[1]
Floor height	1.215 m (3 ft 11.8 in)[1]
Doors	3 per side
Wheel diameter	840 mm (2 ft 9 in)[1]
Wheelbase	9.000 m (29 ft 6.3 in)[1]
Maximum speed	75 mph (121 km/h)
Weight	DMSL vehicle: 23.2 t (22.8 long tons; 25.6 short tons) DMS vehicle: 23.0 t (22.6 long tons; 25.4 short tons)[2]
Prime mover(s)	2 × Leyland TL11 (one per vehicle)[1]
Engine type	Inline-6 4-stroke turbo-diesel[4]
Displacement	11.1 L (680 cu in) per engine[4]
Power output	153 kW (205 hp) per engine[2]
Transmission	SCG R.500 (4-sp. epicyclic)[5]
Minimum turning radius	70 m (230 ft)[1]
Braking system(s)	Electro-pneumatic (tread) ('Westcode')
Safety system(s)	AWS
Coupling system	Tightlock[1]
Multiple working	Not fitted[1]
Track gauge	1,435 mm (4 ft 8+1⁄2 in) standard gauge

The British Rail Class 140 was the prototype of the Pacer diesel multiple unit.

It was constructed between 1979 and 1981 in response to a desire within British Rail to develop a capable railbus for its smaller branch line services. Much of the bodywork was constructed using Leyland National bus components, with the exception of the cabs. Based on the single car railbus prototypes, the Class 140 was built to BR's then stringent regulations regarding crashworthiness and resistance to end loading; as such, much of its intention lightweight 'bus on a wagon' look was lost, becoming a more substantial vehicle. Throughout the 1980s, the sole member of the class functioned as a trials and demonstration unit, acting as a herald to the closely related Class 141. Since its withdrawal, the unit has been preserved at the Keith and Dufftown Railway.