Light Tank Mk VII (A17) “Tetrarch”
Following the Light Tank Mk VI, Vickers designed a larger type of light tank in 1937 capable of mounting a 15mm Besa gun in place of the machine guns which were mounted in previous Vickers light tanks. For the Mk VII Vickers adopted a novel type of suspension incorporating large road wheels. As with some earlier Vickers designs, however, steering was achieved by flexing the tracks. The Mk VII was offered to the War Office in 1938 (unofficially as the “Purdah”) and the vehicle, designated A17, was tested for possible future adoption as a “light cruiser” tank, since War Office light tank requirements were already being met by Mk VI production. An order for 120 vehicles was placed at the end of 1938, when war seemed inevitable, and Vickers were asked to transfer production to Metropolitan-Cammell to be free to do other work.
Tetrarch I CS: some vehicles were converted for the close support role, with 76,2 mm (3 inch) howitzer.
Tetrarch DD: 1 tank was fitted and tested with a propeller drive and canvas collapsible flotation screens.
Tetrarch with Littlejohn adaptor: fitted to increase muzzle velocity.
Light Tank Mk. VII Tetrarch – Peter Chamberlain, Chris Ellis, Armour in Profile Number 11
British and American Tanks of World War Two: The Complete Illustrated History of British, American and Commonwealth Tanks, 1939-45 – Peter Chamberlain, Chris Ellis
The Great Tank Scandal: British Armour in the Second World War Part 1 – David Fletcher