British Rail Class 12

The British Rail Class 12 is a diesel locomotive built mainly for shunting duties.

British Rail Class 12
Type and origin Power type Diesel-electric Builder British Railways’ Ashford Works Order number SR 3413 (15), 3537 (11) Build date 1949–1952 Total produced 26
Specifications Configuration: ​  • Whyte 0-6-0  • UIC C Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Wheel diameter 4 ft 6 in (1.372 m) Wheelbase 11 ft 6 in (3.51 m) Length 29 ft 5+1⁄2 in (8.98 m) Width 9 ft 0 in (2.74 m) Height 12 ft 8+1⁄2 in (3.87 m) Loco weight 48 long tons (48.8 t) Fuel capacity 660 imp gal (3,000 L; 790 US gal) Prime mover English Electric 6KT Traction motors English Electric 506A, 2 off Transmission DC generator, DC traction motors, double reduction gearing MU working Not fitted Train heating None Train brakes None; 15230–15232 Air from 1970
Performance figures Top speed 27.5 mph (44.3 km/h) Power output Engine: 350 hp (261 kW) Tractive effort Maximum: 24,600 lbf (109.4 kN)
Career Railroad(s) British Railways Number 15211–15236 Axle load class RA 5

This was the second batch of standard Southern Railway shunters based on the English Electric 6KT 35 hp (260kW) diesel engine. These locomotives (BR numbers 15201-15203) were built by the SR in 1937 and were later classified D3/12.

The Class 12 locomotives were built at the BR Ashford Works over the period 1949–1952. They were numbered 15211–15236 and became Class 12. No locomotives survived long enough to acquire Class 12 TOPS numbers though.