The A9 design was originally designed by Vickers to be a medium tank in 1934. However, it was re-designated a Cruiser tank for service with the armoured divisions as the Cruiser Tank Mark I, A9. A total of 125 were built. The A9 Cruiser Mk I saw some action in France in 1940 and again during the early desert battles in 1940 and 1941.
One of its best design features was its suspension, which was later adopted for the Valentine Infantry tank. Part of the new technology develops during the creation of the A9 was to make a new type of rubber that could withstand the heat and pressure of a 16-ton tank moving at 15 mph. The new rubber and improved variations played an important part of further British tank development.
The main armament of the Cruiser Tank Mk I was the 2 pdr. The Close Support (CS) version mounted a 3.7" howitzer in place of the 2 pdr main gun. It was also fitted with two hull-turret Vickers machine-guns.
