By the end of the First World War in November 1918, the concept of the tank had been fully vindicated as an indispensable weapon of war. The tank was a British invention, and at the war’s end Britain led the field in tank design and tactics, with France coming a very close second with innovative designs like the Renault FT. 17, one of the best-selling tanks of the interwar years.
The British Centurion tank – a magnificent fighting vehicle that finally proved that Britain’s tank designers were capable of getting things right after years of producing tanks that were at best barely adequate and at worst disastrous – traced its lineage back to a change of armoured warfare doctrine that came about in the early 1930s, when the British Army, which had previously concentrated on developing dual-role medium tanks, took the decision to develop two separate types of armoured fighting vehicle, one an infantry tank to operate in support of ground forces and the other a `cruiser’ tank whose role was to break through enemy defences and then exploit the breakthrough by making surprise attacks on command and communications behind the forward battle area.
The British Army’s armoured warfare doctrine was based on these two different types of tank. The first, the so-called `cruiser tank’, was fast and lightly armoured, its purpose being to break through enemy defences or bypass them. The second type, the so-called `infantry tank’, more heavily armoured and with a speed slow enough to enable dismounted infantry to keep up, would then exploit the success of the cruiser tanks, which by now would be roaming around the enemy’s rear areas and causing as much disruption as possible. This doctrine, which was sound enough in principle, was refined in 1919 by a senior officer of the Royal Tank Corps, Colonel J. F. C. Fuller, who produced a plan that envisaged a large-scale armoured offensive designed to achieve multiple armoured penetrations of an enemy’s forward defences and totally disrupt his command and control system in the rear. The plan was virtually ignored by the British War Office but enthusiastically adopted by a reborn German Army, whose tank commanders used it to excellent effect in the Blitzkrieg of 1940.
The revised doctrine was influenced by various considerations, some technical, others political. The main political consideration reflected the need to police the more remote parts of the British Empire in the Middle East and Northwest India, where the disintegration of other pre-war empires had resulted in a rise of nationalism and its accompanying unrest. To achieve this, armoured cars were ideal, often working in cooperation with aircraft, whereas tanks were useless in the terrain where most of the problems arose. In the 1920s the production of armoured cars assumed priority over the development of other armoured vehicles, and it was not until the rise of Nazi Germany and its emphasis on the development of a strong Panzer force that production of new types of tank in Britain was accelerated.
The technical considerations involved the choice of armour, armament and motive power. One bold decision of the 1930s was to provide the new generation of cruiser tanks with a 40mm (2-pounder) main gun in addition to a secondary armament of one or more machine guns; the main gun, with armour-piercing shells, would be more than adequate to cope with the Panzer I and II tanks under development in Germany, armed respectively with machine guns (Panzer I) or a 20mm cannon (Panzer II). The problem here was a lack of foresight; British tanks were still using the 2-pounder gun well into the Second World War, by which time the Germans were deploying the Panzer III and IV armed with a main gun of up to 75mm calibre. One senior British officer, General Percy Hobart, Deputy Director of Staff Duties (Armoured Fighting Vehicles) persistently called for British tanks to be armed with a 57mm 6-pounder gun in 1938, but no formal requirement for such a weapon was issued until after the fall of France in the summer of 1940.
Armour protection for the new generation of British cruiser tanks was also sacrificed to reduce weight, it was decided that vehicles would be powered by modified petrol engines of the type being produced for existing commercial vehicles.
The first cruiser tank, designed by Vickers in 1934, was the Mk I (A9), which entered production in 1937, albeit on a fairly limited scale. Its turret was power-traversed and the vehicle carried a six-man crew. Its main armament was a 40mm 2- pounder gun, supplemented by three machine guns, two of which were mounted in small subsidiary turrets. Production of the Mk I ended with the 125th vehicle, the early model seeing service in France and North Africa. It was followed by the Heavy Cruiser Tank Mk II, which had begun life as the A10 Infantry Tank based on the A9, but with thicker armour and other refinements, including the deletion of the subsidiary turrets.
The next cruiser tank design, the A13 Cruiser Tank Mk III, was the product of Nuffield Mechanizations Ltd and represented an important step forward in British tank development, as it used a suspension system based on that devised in the United States by J. Walter Christie. A prototype made its appearance in 1937 and proved to have an excellent performance, the Christie suspension making a huge difference. (The Christie system was also adopted by the Russian BT series of tanks, culminating in the excellent T-34.)
The Mk III’s armament comprised one 40mm gun and a single machine gun, which made it possible to dispense with two crew members. Its big drawback was its inadequate armour, which led to substantial losses when it encountered German Panzer IIIs in France and the Western Desert, and this deficiency led to the development of the Cruiser Tank Mk IV (A13 Mk II) in which the thickness of the armour was increased to 20 or 30mm (0.79 or 1.18in). This was still not very substantial, and the vehicle was fast but very vulnerable. Nevertheless, it acquitted itself well against Italian AFVs in the Western Desert, where it saw considerable action. The next British cruiser tank in the series was the Cruiser Tank Mk V (A13 Mk III), which had a redesigned turret, better armour and a higher top speed. However, it was still armed with the puny 2-pounder gun, which had weaker armour penetration and could not fire high-explosive rounds. The Mk V was known as the Covenanter.
The next cruiser tank, also designed and built by Nuffield, was the A15 Mark VI Crusader, which played an important part in the desert war, despite being outclassed by its German opponents. The Crusader I entered service in 1941 and it was immediately apparent that its 40mm (2-pounder) main armament was inadequate, so plans were made to replace it with the new 57mm (2.24in) 6-pounder. It was this version, designated Crusader III that became the most important tank in the desert battles, first seeing action at the Second Battle of Alamein in October 1942. As more effective tanks such as the Churchill and the American M4 Sherman became available, the Crusader was gradually relegated to secondary duties and specialist roles. Yet even the Churchill – the most important British-designed tank of the Second World War – was plagued by many shortcomings in its early service, being underpowered and fitted with the same weak 2-pounder gun that had been fitted to the earlier cruiser tanks. The appearance of the Churchill Mk III, armed with a 6-pounder gun, finally resulted in an effective fighting vehicle that was to prove its worth in the last battles of the desert war in Tunisia, the invasion of Normandy and the advance across northwest Europe.
Meanwhile, the War Office persevered in its efforts to develop a British-designed cruiser tank that would be operationally acceptable and reliable. Vauxhall’s offering was the A23, a scaled-down version of the A22 Churchill infantry tank with the same suspension. It would have frontal armour of 75mm (3in) thickness, be powered by a twelve-cylinder Bedford engine and carry a crew of five. Nuffield submitted the A24, heavily based on the Crusader design and powered by a version of the V-12 Liberty engine, a powerplant dating back to the latter days of the First World War and by now thoroughly outdated; its only advantage was that it could be put into production quickly, as it used many of the Crusader’s components. The final entry was submitted by Leyland, whose design was similar to Nuffield’s but with different suspension and tracks. All these designs were intended to mount the Quick-Firing (QF) 6-pounder gun.
The design competition was won by Nuffield’s A24 in January 1941. It was expected to be in service by the end of 1942, but there was a snag. The War Office, at last recognizing the obsolescence of the Liberty engine, now insisted that the tank be reengined with the Rolls-Royce Meteor, a version of the excellent Merlin Mk III. Refitting the A24 with the new engine was beyond the capacity of Nuffield, so the job was assigned to Leyland, working with the Birmingham Railway Carriage and Wagon (BRC&W) company. The new tank would emerge as the A27M Cromwell. In fact, the name Cromwell had already been allocated to Nuffield’s Liberty-engined A24; originally designated Cromwell I, it was later known as the Cavalier. The A27L Cromwell II was another variant to bear the name. Based on the Cavalier chassis, it was armed with a 95mm howitzer and, renamed Mk IV Centaur, was deployed in time to support the Allied landings in Normandy in June 1944.
The closing stages of the Second World War saw the emergence of the A34 Comet cruiser tank, a final attempt to rectify the deficiencies that had been revealed in the design of earlier cruiser tanks during combat in the Western Desert and Italy. The first attempt at redesign resulted in the Challenger, comprising a 17-pounder anti-tank gun mounted on a Cromwell chassis. The mounting of this larger gun carried its share of penalties, the biggest of which was that there had to be a reduction in armour protection, so ultimately the Challenger was not a success. In the Comet design, the gun was a 77mm version of the 17-pounder, with a lower muzzle velocity; the engine was uprated and the armour welded rather than riveted. The prototype Comet was rolled out in February 1944 and the first examples were delivered in September, in time to take part in the British XXX Corps’ dash to the Rhine at Arnhem. The Comet went on to see action during the crossing of the Rhine at Wesel in March 1945. Production by the end of the war totalled 1,200 units, some of which were supplied to foreign armies.
The real solution to the British Army’s tank design headaches, however, lay in a decision to combine the requirements of the infantry and cruiser tank and merge them into the design of a single vehicle, a so-called `universal’ tank. In 1943 the War Office, conscious of the vulnerability of existing cruiser tank designs to the formidable German 88mm anti-tank gun and a new generation of German tanks – in particular the heavy Tiger and the Panzer V Panther – instructed the Directorate of Tank Design led by Sir Claude Gibb to come up with a proposal for a new heavy cruiser tank under the General Staff designation A41. It would be known as the Centurion.