Coupling code: Blue Square
Underframe: 57ft 6in
Engines: Leyland 150hp
These fives sets had one of the most unusual types of construction, the frame being formed from square section steel tube and the skin being alloy. The sets were part of British Railway's scheme to trial units from different builders, the company building vehicles for many other countries. However these sets were not considered successful and two sets were bought back by the builders for re-sale to Trinidad, the last of the other sets were withdrawn in 1971. They had worked exclusively on the ER, mainly on branch lines and local service in East Anglia.
One set saw further use as the ER General Manager's special train, and then preservation.