British Rail Class 45

Derby Type 4 British Rail Class 45
A Class 45 south of Loughborough in July 1975
Type and origin Power type Diesel-electric Builder British Railways' Derby Works and Crewe Works Build date 1960–1962 Total produced 127
Specifications Configuration: ​  • UIC (1′Co)(Co1′)  • Commonwealth 1Co-Co1 Wheel diameter 3 ft 9 in (1.143 m) Minimum curve 5 chains (100 m) Wheelbase 59 ft 8 in (18.19 m) Length 67 ft 11 in (20.70 m) Width 8 ft 10+1⁄2 in (2.71 m) Height 12 ft 10 in (3.91 m) Loco weight 133 long tons (135 t; 149 short tons) Fuel capacity 840 imp gal (3,800 L; 1,010 US gal) Prime mover Sulzer 12LDA28-B Engine type four stroke 12 cylinder double bank Displacement 12× 22 litres (1,300 cu in) per cylinder, or 264 litres (16,100 cu in) total Generator Crompton Parkinson Traction motors Crompton Parkinson Cylinders 12 Cylinder size 280 mm × 360 mm (11.024 in × 14.173 in), bore × stroke MU working ★ Blue Star Train heating 45/0: Steam 45/1: Electric Train Heat Loco brake Air Train brakes Vacuum and Air
Performance figures Maximum speed 90 mph (145 km/h) Power output Engine: 2,500 bhp (1,864 kW) At rail: 2,000 hp (1,491 kW) Tractive effort Maximum: 55,000 lbf (245 kN) Brakeforce 63 long tons-force (628 kN)
Career Operators British Railways Numbers D11–D137; later 45001–45077, 45101–45150 Nicknames Peak Axle load class Route availability 7 Withdrawn 1981-1989 Disposition Eleven preserved, remainder scrapped

The British Rail Class 45 or Sulzer Type 4 are diesel locomotives built by British Railways' Derby and Crewe Works between 1960 and 1962. Along with the similar Class 44 and 46 locomotives, they became known as Peaks.