These were built to diagrams 181 and 182. Over the years 13 lots of them were produced, the earliest at Derby in October 1952 and the last lot were constructed at Wolverton in April 1962. The coach was divided roughly into two, with four compartments and a lavatory in one end, followed by the guard's compartment and luggage space at the other end. There were doors both sides, at either end of the passenger section, and two sets of double doors each side giving access into the luggage compartment. The guard also had a private door outside from his compartment and another one across the corridor on the opposite side of the coach.