British Rail Class 43 (HST)

British Rail Class 43

Powercar 43002 restored to the original Intercity 125 livery in May 2016

Type and origin Power type Diesel Builder British Rail Engineering Limited Crewe Works Build date 1975–1982 Total produced 197

Specifications Configuration Bo-Bo UIC class Bo'Bo' Gauge 1,435 mm (4 ft 8 1⁄2 in) standard gauge Bogies BP10 Wheel diameter 3 ft 4 in (1.016 m) Length 17.79 metres (58.4 ft) Width 2.74 metres (9.0 ft) Loco weight 70.25 tonnes (69.14 long tons; 77.44 short tons) Fuel capacity 990 imp gal (4,500 l; 1,190 US gal) Prime mover Paxman 12VP185 or MTU 16V4000 R41R Originally Paxman Valenta 12RP200L Alternator VP185: Brush Traction BA1001B MTU: Brush Traction BA1001C Traction motors GEC G417AZ (43124-43152) Brush Traction TMH68-46 Both frame mounted, four off. Transmission Engine driven alternator and rectifier supplying DC to traction motors MU working Within class only Train heating Electric Train Heat Train brakes Air

Performance figures Maximum speed in service: 125 mph (201 km/h) Record: 148 mph (238 km/h) Power output Engine: 2,250 hp (1,678 kW) At rail: 1,320 kW (1,770 bhp) Tractive effort Maximum: 17,980 lbf (80.0 kN) Continuous: 10,340 lbf (46.0 kN) @64.5 mph (104 km/h) [1] Loco brakeforce 35 long tons-force (349 kN)

Career Operators Current East Midlands Trains Grand Central CrossCountry Network Rail Virgin Trains East Coast Great Western Railway Previous British Rail GNER Midland Mainline National Express East Coast Virgin CrossCountry East Coast Virgin Trains (West Coast) Cotswold Rail Future Abellio ScotRail Numbers 43002–43198 Axle load class Route availability 5

The British Rail Class 43 (HST) is the TOPS classification used for the InterCity 125 High Speed Train (formerly classes 253 and 254) power cars, built by British Rail Engineering Limited from 1975 to 1982.

The class is officially the fastest diesel locomotive in the world, with an absolute maximum speed of 148 mph (238 km/h), and a regular service speed of 125 mph (201 km/h).

In the early 1970s, the British Railways Board made the decision to replace its main-line express diesel traction. Financial limitations were tight, so mass electrification was not possible. As a result, a new generation of high-speed diesel trains had to be developed.

Experience with the high-speed Class 55 Deltic locomotives had shown that a low axle weight was essential to avoid damage to the track at sustained high speed, and that high-speed engines were the only way to provide a good enough power/weight ratio for diesels. To power the HST at up to 125 mph (201 km/h), each power car had a new diesel engine, the 12-cylinder Paxman Valenta, running at 1,500 rpm and developing 2,250 bhp (1,680 kW). The 70-tonne weight of the power car gave it a 17.5-tonne axle loading.

The prototype set was developed at the Railway Technical Centre, Derby, the power cars having been constructed by BREL Crewe Works and the British Rail Mark 3 passenger cars by BREL at Derby Litchurch Lane Works. The engine used in the prototype power cars was the Paxman 'Valenta' 12RP200L, which developed 2,250 horsepower (1,680 kW). The electrical equipment was supplied by Brush. The power cars had a main driver's position at one aerodynamically shaped end with the other flat and gangwayed end having only an auxiliary driving position for shunting purposes.

The two prototype power cars emerged from the works in June and August 1972 and were initially numbered 41001 and 41002, but after a short period the entire set, including the passenger coaches, became reclassified as a diesel-electric multiple unit: British Rail Class 252. The power cars were given the coaching stock numbers 43000 and 43001. After proving trials on the Eastern Region the prototype High Speed Diesel Train (HSDT) was transferred to the Western Region, where it was deployed on Paddington Bristol/Weston-super-Mare services.