British Rail Class 24

British Railways Type 2 British Rail Class 24
Class 24, no. 24065 at Motherwell depot, May 1976
Type and origin Power type Diesel-electric Builder British Railways’ Derby Works, Darlington Works and Crewe Works Build date 1958–1961 Total produced 151
Specifications Configuration: ​  • UIC Bo'Bo'  • Commonwealth Bo-Bo Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Wheel diameter 3 ft 9 in (1.143 m) Minimum curve 4.5 chains (91 m) Wheelbase 36 ft 6 in (11.13 m) Length 50 ft 6 in (15.39 m) Width 8 ft 10 in (2.69 m) Height 12 ft 8 in (3.86 m) Loco weight Class 24/0: 79 long tons (80.3 t; 88.5 short tons) Class 24/1: 73 long tons (74.2 t; 81.8 short tons) Fuel capacity Class 24/0: 546 imp gal (2,480 L; 656 US gal) Class 24/1: 500 imp gal (2,300 L; 600 US gal) Prime mover Sulzer 6LDA28 Generator BTH RTB15656 DC Traction motors BTH 137BY, DC, 4 off Transmission Diesel electric MU working ★ Blue Star Train heating Steam generator Train brakes Vacuum
Performance figures Maximum speed 75 mph (121 km/h) Power output Engine: 1,160 hp (865 kW) At rail: 843 hp (629 kW) Tractive effort Maximum: 42,000 lbf (186.8 kN) Continuous: 21,300 lbf (94.7 kN) Brakeforce 38 long tons-force (380 kN)
Career Operators British Railways Numbers D5000–D5150; later 24001–24047, 24051–24141 Axle load class Class 24/0: RA 7 (6 from 1969) Class 24/1: RA 6 (5 from 1959) Retired 1967–1980 Preserved Four (list)

The British Rail Class 24 diesel locomotives, originally known as the British Railways Type 2, were built from 1958 to 1961. One hundred and fifty-one of these locomotives were built at Derby, Crewe and Darlington. The first twenty locomotives were part of the 1955 British Rail modernisation plan. This class was used as the basis for the more powerful Class 25 locomotives.

The final survivor, no. 24081, was withdrawn from Crewe depot in 1980.