British Rail Class 44

Derby Type 4 British Rail Class 44
44 010 "Tryfan" heads a freight train on the Birmingham-Peterborough line, in Leicestershire, April 1976.
Type and origin Power type Diesel-electric Builder British Railways’ Derby Works Build date 1959–1960 Total produced 10
Specifications Configuration: ​  • UIC (1′Co)(Co1′)  • Commonwealth 1Co-Co1 Gauge 4 ft 8+1⁄2 in (1,435 mm) standard gauge 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-A Engine type Diesel Generator Crompton Parkinson GC426-A1 Traction motors Six Crompton Parkinson C171-B1 MU working ★ Blue Star Train heating Steam Train brakes Vacuum
Performance figures Maximum speed 90 mph (145 km/h) Power output Engine: 2,300 bhp (1,715 kW) At rail: 1,800 hp (1,342 kW) Tractive effort Maximum: 50,000 lbf (222 kN) Brakeforce 63 long tons-force (628 kN)
Career Operators British Railways Numbers D1–D10; later 44 001–44 010 Nicknames Peak Axle load class Route availability 7 Withdrawn 1976-1980 Disposition Two preserved, remainder scrapped

The British Rail Class 44 or Sulzer Type 4 diesel locomotives were built by British Railways' Derby Works between 1959 and 1960, intended for express passenger services. They were originally numbered D1-D10 and named after mountains in England and Wales, and, along with the similar Class 45 and 46 locomotives, they became known as Peaks.