British Rail Class 43 (HST)

The British Rail Class 43 is the classification used for the diesel-electric power cars of the InterCity 125 High Speed Train, which were first classed as Classes 253 and 254 sets. British Rail Engineering Limited built the power cars at Crewe Works between 1975 and 1982, while the matching trailer cars came from its Derby Litchurch Lane Works, to a design by British Railways Board engineers at the Railway Technical Centre in Derby working with the Research Division. Each train has a power car at either end, each carrying a single medium-power diesel engine, a split chosen to hold the axle load to 17.5 tonnes. Two prototype power cars left Crewe in 1972 and production totalled 197 cars. The class is officially the fastest diesel locomotive in the world, with an absolute maximum speed of 148.5 mph against a regular service speed of 125 mph.