Coupling code: Blue Square
Underframe: 57ft 6in
Engines: AEC 150hp
Although commonly known as Park Royal sets, they were ordered from B.U.T. and built at the Crossley Motor works in Stockport (part of the ACV group). The 20 two-car sets each had seating for 16 first class and 100 second class. They were intended for the Birmingham Part 2 scheme, and operated mainly on the LMR in the Chester area but also on the St Albans / Watford branches after the demise of the ACV/BUT railcars, and some latterly on the WR in the Cardiff / Reading areas.
The last vehicle was withdrawal from passenger use in 1983, some saw further departmental use and a few were preserved.