British Rail Class 50

British Rail Class 50

50015 Valiant, as preserved at the East Lancashire Railway in 2008.

Type and origin Power type Diesel-electric Builder English Electric at Vulcan Foundry Build date 1967–1968 Total produced 50

Specifications Configuration Co-Co UIC class Co'Co' Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Wheel diameter 3 ft 7 in (1.092 m) Wheelbase 56 ft 2 in (17.12 m) Length 68 ft 6 in (20.88 m) Width 8 ft 10 in (2.69 m) Height 12 ft 9 in (3.89 m) Axle load 19 long tons 10 hundredweight (19.8 t; 21.8 short tons) Loco weight 115 long tons (117 t; 129 short tons) Fuel capacity 1,540 imp gal (7,000 l; 1,850 US gal) Prime mover English Electric 16 CSVT Engine type 16 cyl, 246 litres (15,000 cu in) Diesel engine Traction motors 6 English Electric type 538/5A axle-hung nose-suspended 400 hp (300 kW) traction motors MU working ■ Orange Square Train heating Electric Train Heat Train brakes Dual (Air and Vacuum)

Performance figures Maximum speed 100 mph (160 km/h) Power output Engine: 2,700 bhp (2,010 kW) Tractive effort Maximum: 48,500 lbf (216 kN) Continuous: 33,000 lbf (147,000 N)@ 23.5 mph (37.8 km/h)

Career Operators British Rail Numbers D400–D449; later 50001–50050 Nicknames Hoovers Axle load class Route availability 6 Disposition 18 still in existence, remainder scrapped

The British Rail (BR) Class 50 was a class of 50 diesel locomotives designed to haul express passenger trains at 100mph. Built by English Electric at their Vulcan Foundry in Newton-le-Willows between 1967 and 1968, the Class 50's were initially on a 10-year lease from English Electric Leasing, and were employed hauling express passenger trains on the, then non-electrified, section of the West Coast Main Line between Crewe and Scotland. Initially numbered D400 - D449 and known as English Electric Type 4s, the locomotives were purchased outright by BR at the end of the lease and became Class 50 in the TOPS renumbering of 1973. The class were nicknamed "Hoovers" (sometimes shortened to "Vacs") by rail enthusiasts because of the distinctive sound made by the cooling fan mechanism. Once the electrification from Crewe to Glasgow was completed the locomotives were moved to the South West of England to allow the retirement of the remaining Diesel-Hydraulic locomotives then in use. As these trains steadily moved to HSTs operation from 1976, the Class 50's moved to hauling trains between London Waterloo and Exeter, and also trains from London Paddington to Hereford and Worcester via Oxford. The class was steadily retired from service in the late 1980s and early 1990s as their services moved to operation by second-generation DMUs.

The origins of the Class 50 lie in an invitation from the British Transport Commission (BTC) to manufacturers to produce a design for a Diesel locomotive with a gross power output of at least 2500hp. In order to produce a prototype quickly, English Electric based their design on that for their Deltic locomotives which were then in production. Other parts related to another current design, the Class 37s were also used. The result was DP2, a 2700hp Diesel-electric locomotive weighing 107 tons and with a top speed of 100mph. The prototype was delivered to British Rail in May 1962