The British Rail Class 117 diesel multiple units (DMUs) were built by Pressed Steel from 1959 to 1961.

[1] A total of 123 Class 117 cars were built by Pressed Steel between 1959 and 1961, delivered as 39 three-car units plus three pairs of spare motor coaches.

The first shake up in ownership occurred in the late 1980s, when the Scottish, Welsh, Cornish and Birmingham based units were transferred to Provincial Services, later Regional Railways, in the sectorisation of British Rail, while the Southall-based units transferred to Network SouthEast.

They were replaced on the lines out of Paddington when the Class 165/1 'Network Turbo' units came into service by 28 November 1992.

An attempt was made to remove them from Cornish work using Class 142 "Skipper/Pacer" railcars, but these fixed wheelbase units proved to be a liability on the tight Cornish branchline curves, increasing rail and wheel wear, and were transferred to the North of England instead.