Cruiser Mk IV - Design and Development

Design and Development

Britain became interested in fast tanks after observing the Soviet BT tanks during the 1936 Red Army manoeuvres. The BT was based on the revolutionary designs of American J. Walter Christie, and so a team from Morris Motors was sent to the United States to purchase one of Christie's tanks, and also the rights to build more. The tank purchased became known as the A13E1, and this was delivered in late 1936. However, the hull was too small and this led to a second British-built prototype being constructed.

The A13E2 was built to mount the turret of the Vickers designed Cruiser Tank MkI (A9). This carried a 40 mm 2-pounder anti-tank gun and co-axial .303 water-cooled Vickers machine gun. The drive train was also revised, with the road wheels no longer powered - as a result the tank could not be driven on its wheels alone. Better tracks were used, with rear-mounted drive sprockets; on trials over 40 mph was attained on these tracks, but later the speed was governed to 30 mph. The armour basis of the A13E2 was 15 mm, in line with other pre-war fast tank designs.

The A13E3 was the final trials model; this led to the production tank, the A13 MkI, Cruiser Tank Mk III, which entered production in 1939 at Nuffield Mechanization & Aero Limited, a munitions subsidiary of Morris Motors. An order for 65 tanks was placed; and at least 30 tanks completed when the War Office decided to build a new model with thicker armour. The A13 MkII, Cruiser Tank Mk IV, had a maximum armour thickness of 30 mm, and faceted armour was mounted on the original turret's sides and rear. This gave the tank a far more modern appearance. Some Mk III tanks were re-built to Mk IV standard while at the factory.

In service, the .303 Vickers machine gun gave constant trouble, and so the British Army decided to replace it with the 7.92 mm BESA. All British tanks were to have their designs modified to mount the new weapon from early 1940. This led to the main production version, the A13 MkIIA, Cruiser Tank MkIVA. A few examples of this model were sent with the BEF to France, along with most of the earlier A13's so far produced. It is not known how many A13 MkIVA tanks were produced; numbers depending on source. Between the Cruiser Mark III and Cruiser Mark IV, 665 were produced when production ended in 1941. English Electric, Leyland, and LMS Railway were also involved in A13 production.

In France the A13 did not do well; this was mainly due to poor training as a result of its being rushed into service. Many tanks shipped to France were in poor condition, some so new they had vital parts not yet installed. However, the A13 did much better in the deserts of North Africa, and coped with the conditions better than some other designs. It was fast, and its 2-pounder gun was a fine weapon against Italian and German tanks of this period. It stayed in contention as a battle tank until late 1941, when newer models of the Panzer III and Panzer IV appeared with thicker armour and larger guns. In North Africa it was the anti-tank gun which claimed the vast majority of British tanks lost in battle; German tanks accounted for few British losses, contrary to popular belief.

The A13 MkIII, Cruiser Tank Mk V was a radical departure from the original A13 design and constituted a new tank. Both hull and turret were redesigned, and it used a new flat-12 Meadows engine with radiators mounted in the front hull. Named the Covenanter, it was built in large numbers, but was not battleworthy and was used only for training. The A13 MkIIA was replaced by the A15 Crusader tank, which was similar to the Covenanter but used the original A13 engine.