Each had 40 third class seats arranged 2+2 either side of a central gangway[1] and were powered by a 95 hp (71 kW) diesel engine.
After trials between Preston and Carlisle they worked from Blackburn to Spring Vale and Clitheroe and subsequently at Hamilton Central in Lanarkshire.
This was a three-car articulated railcar built to LMS diagram D1996 and outshopped from Derby Carriage and Wagon Works in 1939.
Under each coach were two vertically mounted Leyland 125 bhp (93 kW) diesel engines driving the inner axle of each bogie through a Lysholm-Smith torque converter.
The whole unit weighed 73 long tons, so this yielded a power/weight ratio of slightly more than 10 bhp/ton which provided a main line standard of performance with a maximum speed of 75 mph (121 km/h).
The other coach was converted into staff accommodation with lockers, cooking, washing facilities and a WC, and 12 seats with tables as a mess saloon.
An Armstrong Whitworth diesel-electric railcar operated a luxury 12-seat express service on the LMS for two weeks in 1933 between London and Castle Bromwich near Birmingham in connection with a British Industries Fair.
This car, with body work by Cravens which incorporated a kitchen, was powered by a standard Armstrong-Saurer 250 bhp engine.
Between 1936 and 1937, the LMS trialled two experimental railcars built by Armstrong Siddeley to a French design, which had Michelin pneumatic tyres.