British Rail Class 144

British Rail Class 144
*Pacer*
British Rail Class 144; Pacer
	A Northern Rail Class 144 at Lancaster (2012)
	Northern Rail refurbished Class 144 saloon
In service	1986–2020
Manufacturers	British Rail Engineering Limited; Walter Alexander Coachbuilders;
Order nos.	31015 (DMS vehicles); 31016 (DMSL vehicles); 31037 (MS vehicles);
Family name	Pacer
Constructed	1986–1987
Refurbished	2002–2004; 2010;
Number built	23; (13 × 2-car, 10 × 3-car)
Number preserved	19
Number scrapped	4
Formation	2 or 3 cars per unit: DMS-DMSL; DMS-MS-DMSL;
Diagram	DMS vehicles: DP240; MS vehicles: DR205; DMSL vehicles: DP241;
Fleet numbers	144001–144013 (2-car units); 144014–144023 (3-car units);
Capacity	In 2-abreast configuration:; 104 or 162 seats; In 3-abreast configuration:; 122 or 195 seats;
Owner	Porterbrook
Operators	Arriva Rail North; Arriva Trains Northern; British Rail; Network Rail; Northern Rail; Northern Trains; Regional Railways;
Depot	Neville Hill (Leeds)
Lines served	Airedale Line; Caldervale Line; Hallam Line; Harrogate Line; Huddersfield Line; Penistone Line; Pontefract Line; Wakefield Line; York and Selby Lines;
Specifications
Car body construction	Steel underframe, aluminium alloy body and roof
Car length	DM vehs.: 15.093 m (49 ft 6.2 in); MS vehs.: 15.186 m (49 ft 9.9 in);
Width	2.695 m (8 ft 10.1 in)
Height	3.725 m (12 ft 2.7 in)
Floor height	1.288 m (4 ft 2.7 in)
Doors	Double-leaf folding (3 or 5 per side)
Wheelbase	9.000 m (29 ft 6.3 in)
Maximum speed	75 mph (121 km/h)
Weight	As built;; DMS vehs.: 24.17 t (23.79 long tons; 26.64 short tons); MS vehs.: 23.50 t (23.13 long tons; 25.90 short tons); DMSL vehs.:25.04 t (24.64 long tons; 27.60 short tons);
Axle load	Route Availability 1
Prime movers	As built:; 2 or 3 × Leyland TL11; After upgrade:; 2 or 3 × Cummins LTA10-R; (one per vehicle);
Engine type	Inline-6 4-stroke turbo-diesel
Displacement	Leyland: 11.1 L (680 cu in); Cummins: 10.0 L (610 cu in); (per engine);
Power output	Leyland: 149 kW (200 hp); Cummins: 168 kW (225 hp); (per engine);
Transmission	As built:; SCG RRE5 (4-sp. epicyclic); After upgrade:; Voith T 211 r (hydrokinetic);
Minimum turning radius	70 m (230 ft)
Braking system	Electro-pneumatic (tread)
Safety systems	AWS; TPWS;
Coupling system	BSI
Multiple working	Within class and with Classes 14x, 15x and 170
Track gauge	1,435 mm (4 ft 8+1⁄2 in) standard gauge
Notes/references
	Specifications as at December 1987 except where otherwise noted.

The British Rail Class 144 Pacer is a retired class of diesel multiple unit (DMU) passenger trains built at Derby between 1986 and 1987. British Rail, seeking to procure improved derivatives of the earlier Class 141, placed an order with the manufacturers British Rail Engineering Limited (BREL) and Walter Alexander to construct their own variant, the Class 144. A total of 23 units were constructed. All units were retired from main line service by 2020, though the majority of the units have been acquired for preservation on heritage railways and for other uses. As of December 2022, 19 units have been purchased following withdrawal, of which 14 are in operational condition.