Ordered in the first half of 1955, 20 of these sets were built by Park Royal at the Crossley Motors works in Stockport of the ACV Group.

They were allocated new to the London Midland Region of British Railways, spending most of their time at Chester.

Although considered non-standard, owing to their bodywork construction, their use of standard BUT equipment and blue square coupling code allowed them to operate with other classes.

They spent some time in the Watford area, working the St Albans and Belmont branches after the demise of the ACV/BUT "flying brick" railcars.

They were delivered in Brunswick green with cream lining, red bufferbeam and pale grey roof.