British Rail Class D2/12

British Railways class D2/12
D2511, preserved at the Keighley and Worth Valley Railway
Type and origin Power type Diesel-mechanical Builder Hudswell Clarke Serial number D1201–D1210 Build date 1961 Total produced 10
Specifications Configuration: ​  • Whyte 0-6-0 DM Gauge 4 ft 8+1⁄2 in (1,435 mm) standard gauge Wheel diameter 3 ft 6 in (1.067 m) Loco weight 34.20 long tons (34.75 t; 38.30 short tons) Prime mover Gardner 8L3 Transmission fluid coupling and Bostock & Bramley four-speed Power-flow SSS synchro-self-shifting gearbox[1] MU working Not fitted Train heating None
Performance figures Maximum speed 24 mph (39 km/h) Power output Engine: 204 bhp (152 kW) Tractive effort 16,100 lbf (71.6 kN)
Career Operators British Railways Class D2/12; later 2/14A; no TOPS class Numbers D2510–D2519 Axle load class Route availability 4 Retired 1967 Disposition 6 scrapped, 4 sold NCB (3 scrapped, 1 preserved)

British Rail Class D2/12 was a class of ten locomotives commissioned by British Railways in England. They were diesel powered locomotives in the pre-TOPS period built by Hudswell Clarke with a Gardner engine. The mechanical transmission, using a scoop control fluid coupling and four-speed Power-flow SSS (synchro-self-shifting) gearbox,^[1] was a Hudswell Clarke speciality.

The D2/12 was mechanically similar to the earlier British Rail Class D2/7 but was of more modern appearance. The engine casing was lower, giving much better all-round visibility.