T14 Heavy Tank
The Assault Tank T14 was a joint project between the United States and the United Kingdom with the goal being to produce a universal infantry tank.
The T14 project never came to fruition, as a pilot model was not delivered to the UK until 1944 by which time the British Churchill tank had been in service for two years and greatly improved over its initial model. US efforts working on a similarly well-armoured tank but with a higher speed for use other than in infantry support led to the T20 Medium Tank.
Only two were built; one tested in the US and the other sent to Britain. The example sent to Britain survives in The Tank Museum, Bovington. The British had developed the Heavy Assault Tank A33 “Excelsior” design to the same specification as the T14 but this did not go into service either.