British Rail DP1

English Electric DELTIC prototype
The nose end of DP1 at Locomotion
Type and origin Power type Diesel-electric Builder English Electric at Dick, Kerr Works, Preston Serial number EE: 2003 Build date 1955
Specifications Configuration: ​  • UIC Co'Co' Gauge 4 ft 8 1⁄2 in (1,435 mm) Wheel diameter 3 ft 7 in (1.09 m) Length 66 ft Loco weight 106 long tons (108 t) Prime mover Napier Deltic D18-25 (2 off) Traction motors EE 526/A, 6 off Cylinders 18 × 2 Transmission Diesel Electric Train heating Stone-Vapor/Clarkson steam generator
Performance figures Top speed 90 mph (140 km/h) 106 mph (171 km/h) from 1956 Power output 3,300 hp (2,500 kW) Tractive effort 90 mph gearing: 60,000 lbf (266.89 kN) 106 mph gearing: 52,500 lbf (233.53 kN)
Career Railroad(s) British Railways Power class Type 5 Number DP1 Official name DELTIC Retired March 1961 Disposition to Science Museum, London, April 1963

DP1, or Prototype Deltic is a demonstrator locomotive built by English Electric in 1955. This locomotive resulted in 22 similar locomotives being ordered by British Rail, which became their Class 55.