[David_Hayward (RIP)]

Thanks! You guys might like to know this snippet of info about the connection between GM Limited in Southampton and GM:

... An Admiralty file of 1940 relates to the testing of GM two-stroke diesel engines by the Admiralty that GM Limited were proposing. Limited submitted a marine version of the three-cylinder Detroit-Diesel 3-71 design to the Admiralty for type tests. However the success of the trials came to the attention of the War Office post-Dunkirk as there was concern by July 1940 to ensure an uninterrupted supply of power units for the Vickers ‘Valentine’ Infantry Tank Mk. IIIA, orders for which had been placed in Canada. The Valentine was a 1938 design that initially used AEC petrol or diesel engines. The W.O. became interested in the Detroit-Diesel design in its six-cylinder form as an alternative power unit and so Limited worked with the Detroit Technical Staff in procuring a 6-71 engine which was then redesigned for the tank and to be interchangeable with British power units. Field tests carried on by the W.O. and presumably Ministry of Supply in collaboration with GM Overseas Operations and Limited resulted in the first application of GM Diesel engines to tank usage, as the Model 6-71S. This was later superseded by the more powerful 6-71A. The alterations and design called for the changing of the fuel, water and exhaust connections, mounting brackets and clutch and gear controls. The MofS forwarded complete drawings of the modifications to GM Overseas Operations in New York in order to determine whether GM would supply the 6-71 in quantity. Negotiations then took place over five months between GMOO, the Detroit-Diesel Division, Canadian Pacific Railroad who had been commissioned to build the Canadian Valentines, and British officials. This culminated in an initial order from the British Purchasing Commission on 27th September 1940 for 250 engines. The GMC 6004 diesels were used it seems in production Mks IV, V, VII-XI.

It seems that twin 6-71s were fitted in the M3A3 (Lee IV/Lee V) as well but none would have come here.