FV4401 Contentious Tank Destroyer
Designed as an air transportable tank destroyer, the FV4401 Contentious was based on the chassis of the Comet tank (although it had four road wheels instead of five). Initially armed with the 84mm 20 pounder gun, this was later upgraded to the L7 105 mm gun.
In order to maintain a low weight to be air transportable and minimize its profile height, it did not have a turret. Instead, the gun was mounted on an open hull with an autoloader. The gun had a limited transverse, with aim being by steering the tank. Elevation was achieved by raising the road wheels with a hydraulic system. Each wheel could be moved independently to move the elevation up or down.
The only prototype produced was constructed of boiler plate, to evaluate the vehicles layout. No production of the Contentious was undertaken.
More photos here