HST Paxman Diesel locomotive power car, VP185 43081, 8,000th engine preserved at Crewe Heritage Centre, Cheshire, England, UK, CW1 2DB

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, and in service in the UK since 1976. The class is officially the fastest diesel locomotive in the world, with an absolute maximum speed of 148.5 mph (239.0 km/h), and a regular service speed of 125 mph (201 km/h). The record run was led by 43102 (43302) and trailed by 43159 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. Angel Trains donated 43018 to Crewe Heritage Centre following its use as a spares donor for Abellio ScotRail. Porterbrook also donated 43081, the 8, 000th locomotive built at Crewe, to the museum in 2021. Porterbrook donated 43048 and 43089 to the 125 Group. Both moved to the group when their lease ended with East Midlands Railway. The group later purchased 43044 from Porterbrook in 2021, with 43159 being donated in June that year Porterbrook is a British rolling stock company (ROSCO), created as part of the privatisation of British Rail. Together with Angel Trains and Eversholt Rail Group, it is one of the three original ROSCOs.