In 1964 and 1965, Swindon Works built 56 diesel-hydraulic locomotives for transfer work and short-distance freight service. Unlike all other type 1 locomotives, they had only three axles which were mounted in the main frames. They had one cab that was mounted slightly off-centre between two hoods. The longer hood housed a six-cylinder Paxman Ventura with Napier turbocharger that delivered 650 hp. It transferred its power via a Voith hydraulic transmission and Hunslet final drive onto a jackshaft and coupling rods. 

They were numbered D9500 to D9555 and were originally allocated to depots in the Western Region. Due to the Beeching cuts, their service life was very short since many lines on which they operated were closed. Although they were designated TOPS class 14, all were withdrawn between 1968 and 1970. A total of 19 were preserved in Britain and are nicknamed “Teddy Bears”. One even helped in the construction of the High Speed 1 line from 2005. In 1975, two had been exported to Belgium and in 1982, three more were exported to Spain.