Cavalier tank The Tank , Cruiser , Mk VII Cavalier ( A24 ) was an interim design of British cruiser tank during World War II . It was derived from the A15 Crusader tank and was superseded by the A27 Cromwell tank . Development . In mid - 1940 , the British were considering which tank should follow on from the new cruiser tanks then being developed . A specification was drawn up by the Directorate of Tanks and Transport which included the QF 6 pounder gun . This led to General Staff specification A23 for a cruiser version of the A22 Churchill tank from Vauxhall , the A24 from Nuffield Mechanization & Aero Limited based upon their Crusader tank design , and a design from Birmingham Railway Carriage and Wagon Company also based on the Crusader . The Nuffield design used an uprated ( 410 hp ) Liberty engine which was expected to give a top speed of . Armour would be from 63 to 70 mm at the front , and the 6 pounder gun would be in a turret on a 60 inch turret ring . The Tank Board meeting in January 1941 decided that as the tank needed to be in production by early 1942 it should be based upon an existing design to avoid the need for prototypes . Six tanks of the Nuffield design were ordered that month . At the end of 1941 it was decided production of the Nuffield design , by then known as Cromwell , would be by Nuffield and Ruston and Hornsby . The schedule had already slipped due to work on other projects and work to fit the 6 pounder to the Crusader tank and the first tank began trials in March 1942 . The tank was judged unsatisfactory ; the Nuffield order was reduced to 500 tanks and the BRC & W design was looked at again . With no spare production capacity for vehicles , Rolls - Royce ' s design team had got involved in developing a tank engine from one of their existing aero - engines . Working with Leylands engineers they produced by early 1941 from the Merlin , the Meteor which gave a higher output than the Liberty for a similar size . The lead designer had met with BRC & W and they were able to produce a prototype of their design with the Meteor and a new Leyland transmission by the end of January 1942 . However Leyland had doubts about the Meteor and wanted to manufacture the Liberty instead . The General staff specifications now covered three tanks : A24 " Cromwell I " from Nuffield , A27L ( Liberty engine ) " Cromwell II " from Leyland and A27M ( Meteor engine ) " Cromwell III " . To avoid confusion the first two were renamed as " Cavalier " and " Centaur " leaving the A27M as the Cromwell tank Construction . Internally Cavalier was subdivided by bulkheads which also functioned as structural members . The driver and hull gunner were in the front compartment , the fighting compartment was in the centre . The bulkhead behind the fighting compartment was the firewall from the engine , a Liberty Mark IV , and the final bulkead separated the engine from the transmission . Mechanically the Cavalier was similar to the Crusader but the Mark IV engine gave more power . Operation of the steering brakes and gear changing was pneumatic . The Cavalier turret was a six sided boxy structure . The mantlet was internal with a large opening in the front of the turret for the gun barrel , the coaxial Besa machine gun and the aperture of the No . 39 telescopic sight . The gun was of the " free elevation " type ; the gun was balanced such that it could be readily moved by the gunner . This fitted in with British practice of firing on the move . Service history . Those that were built were used in training or auxiliary armoured vehicle roles . At least 12 Cavaliers were provided to France in 1945 , and were operated by the 12th Dragoon Regiment of the French 14th Infantry Division .