A7 medium tank

The A7 Medium Tank, (or Medium Tank A7), was a British experimental medium tank design of the period between the two World Wars.

The A7, known as the "14-tonner" was intended as a cheaper design to previous tanks, including the A6 Medium Tank, by not using separate machine gun turrets.

They were designed under the Chief Superintendent of Design at the Royal Ordnance Factory, Woolwich who built three prototypes. A7E1 and A7E2 were complete by end of 1929. They differed in the gearbox used; E1 had a 4-speed gearbox as used on the Medium Mk III the E2 a Wilson planetary gearbox. Both used epicyclic steering. In 1934 work was started on A7E3 which was required to be a "fast" tank and needed a more powerful powerplant. The A7 never went into production as all prototypes proved mechanically unreliable. The turret design, altered to take a 2-pounder (40mm) gun was carried forward onto the A9 (Cruiser Mk I) and A10 (Cruiser Mk II) specification tanks, the E3 engine design was used for the Matilda II infantry tank.