be retaining eleven four-carriage sets for increasing capacity on local and regional services between Cardiff Central, Bristol Temple Meads, Taunton, , Plymouth and Penzance, with one set spare. With twelve sets total, 48 Mark 3 coaches with sliding doors and 24 Class 43 powercars will be kept to form these sets, with the new addition of toilet retention tanks and a passenger information system. The first set for GWR entered service in March 2018. They are due to be withdrawn from service by December 2023. Named powercars With the sets being known as Castle sets, GWR announced that most powercars in the fleet would be receiving a nameplate based on a traditional castle from the south-west. From July 2022 more names were attached and some powercars with non-castle plates lost them. Formation The vehicle types used to form High Speed Trains are listed below: The 197 power cars produced are numbered 43002-43198. The two prototype power cars, were originally numbered 41001 and 41002, latterly becoming 43000 and 43001. Accidents and incidents On 29 November 1979, 254028 was derailed at , North Yorkshire. References Further reading External links 253 253 Diesel electric multiple units Train-related introductions in 1976