British Rail Class 231
The Class 231 "FLIRT" are a class of diesel-electric multiple unit which are being built for Transport for Wales by Swiss rolling stock manufacturer Stadler Rail. A total of eleven four-car units are to be built. History. The previous Wales & Borders rail franchise operator, KeolisAmey Wales, commenced on 14 October 2018. Although KeolisAmey was removed as the franchise operator and replaced by an operator of last resort Transport for Wales Rail owned by the Welsh Government, the scheduled full fleet replacement will still commence, with a batch of eleven brand new diesel-electric multiple  units set to join the fleet in 2022. The units began testing in Switzerland in July 2021 and in November 2021 the first two units were delivered to Cardiff Canton depot. Operators. Transport for Wales. When built, Transport for Wales' Class 231 units will operate services between and as well as and Ebbw Vale.