"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."
No comments:
Post a Comment