Cruiser Mk VIII Challenger

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.

History
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 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.

Design
The hull machine gun was removed to provide stowage space for the long 17pdr cartridges. It was expected this larger ammunition, together with its stowage forward, would require two loaders and hence a larger turret. To accommodate the large weapon and a second loader, a turret larger than that of the Cromwell was required and the hull had to be lengthened; and an extra road wheel added. This change in length, without a corresponding change in width across the tracks, reduced mobility compared to the Cromwell.

In order to keep the weight under control, compromises had to be made and armouring was reduced. It was not possible to reduce hull armour, so it was reduced on the turret - 63 mm on the front and 40 mm on the side compared to 75 mm and 60 mm on the Cromwell. As the base of the turret was unprotected, a jacking feature was fitted to clear any jam resulting from enemy action.

The first Challenger was completed in 1942. When the second was tested at Lulworth, it was criticized that, although it would be effective at long range against the current best-gunned tank in German service (the Panzer IV "Special" with the long 75 mm gun), at shorter ranges it would be at a disadvantage due to slow firing rate and thin armour. An order for 200 was placed in February 1943. In November of that year it was announced that no more would be ordered.

Service
Unfortunately, due to some short sightedness, no provision had been made for deep wading trunking and the A30 was unable to participate in the Normandy landings; the tank had to wait until ports had been secured and the Mulberry harbours completed. The Challenger, despite its high centre of gravity, was liked by its crews as it was somewhat faster and more agile than the equivalently armed Sherman Firefly. The Firefly design, which had been a backup, proved to be easier to build and production of the Challenger was stopped with about 200 built. Many of the A30s were issued to units using Cromwells, which eased maintenance as they shared many parts.

As well as with British units, the 1st Czechoslovak Armoured Brigade which was supplied by the British, used the Challenger in its operations besieging Dunkirk. After the war ended, the Czechoslovak government purchased 22 Challengers from the brigade wartime inventory, and these vehicles continued to serve in the postwar Czechoslovak army (first with 11th, later with 23rd Tank Brigade and finally they were concentrated into the 13th Independent Tank Battalion) until retired to the reserve in 1951 and finally scrapped in 1959.

The 1st Polish Armoured Division received a few in mid-1945.

Variants
The Avenger or SP 17pdr, A30 (Avenger) was a variant on the Challenger idea with a differently shaped open topped turret to help reduce weight. With priority production at Vauxhall Motors for the Comet tank, those built in 1945 were not ready for use until after the end of the war in Europe. Some 250 were built and these formed part of the BAOR in Germany.

Survivors


Two vehicles survive. One is at the Overloon War Museum in the Netherlands. The other is awaiting restoration at the Isle of Wight Military Museum in the United Kingdom. Once restored, it will be displayed at the Bovington Tank Museum.