The Tank, Cruiser, Challenger (A30) was a British tank of World War II. It mounted the 17 Pounder gun on a chassis derived from the Cromwell tank to add heavier anti-tank firepower to the cruiser tank units. The design compromises made in fitting the large gun onto the Cromwell chassis resulted in a tank with a powerful weapon, but with less armour. The extemporised Sherman Firefly conversion of the US-supplied Sherman to take the 17 pounder was easier to produce and, combined with delays in production, meant that only 200 Challengers were built. However, it was able to keep up with the fast Cromwell tank and was used alongside them. The driving force in the development of Challenger was Roy Robotham. Robotham had been a Rolls-Royce executive in the car division who, with no work to do, had led a team to develop a tank powerplant from the Rolls-Royce Merlin aircraft engine. The Rolls-Royce Meteor gave the British a powerful reliable engine, which would power the A27M Cruiser Mk VIII Cromwell tank. Robotham's contributions gained him a place in the Ministry of Supply and on the Tank Board, despite his lack of experience in tank design. Initially, Vickers had been working on a "High Velocity" 75 mm (3.0 in) gun to be fitted to the Cromwell, but it was realised that the Cromwell's turret ring was too small to mount it. There were longer term plans to develop improved tanks to replace the Cromwell - this would deliver the interim Comet tank and, at the end of the war, the Centurion tank. The General Staff brought forward specification A29 for a 17 pounder armed cruiser tank. This was passed over for the alternate specification, A30 for a 17 pounder armed tank. In 1942, an order for a 17 pounder gun armed tank was placed with Birmingham Carriage & Waggon expecting it to be based on the A27M components. Turret and gun mounting was in the hands of Stothert & Pitt. Birmingham Carriage had to modify the Cromwell hull to take a bigger turret.

• published: 05 Nov 2013
• views: 0