Cruiser tank
The cruiser tank (also called cavalry tank or fast tank) was a British tank design concept of the inter-war period. This concept was the driving force behind several tank designs which saw action during the Second World War.
Like the ships of the same name, cruiser tanks were fast and mobile, and were designed to operate independently of the slow-moving infantry and their heavier Infantry tanks.
Once gaps had been punched in the enemy front by the infantry tanks, the cruisers were intended to penetrate to the rear, attacking lines of supply and communication in accordance with the theories of Hobart and Liddell-Hart. Speed was therefore a critical factor, and to achieve this the early cruiser designs were lightly armoured and armed. This emphasis on speed unbalanced the British designs; insufficient attention was paid to armour protection. At the time it was not well understood that lightly-armoured vehicles would not survive on the modern battlefield. An even bigger problem for most cruiser tanks was the small calibre of their main gun. Most cruisers were armed with the two-pounder (40 mm) gun. This gun had good armour penetration (the best at the time), but was never issued high explosive ammunition. This made the cruisers vulnerable to towed Anti-tank guns. However, as fighting enemy tanks was part of the projected role of the Cruiser tanks they were the first to be upgraded to the heavier 6 pounder (57 mm) gun when it became available, and a great deal of effort was put into developing (admittedly unsuccessful) Cruiser tanks armed with the 17 pounder QF (76 mm) gun. Ironically, given the emphasis on high mobility, most cruisers were plagued by mechanical unreliability. This problem was usually caused by insufficient development as most of the early Cruiser tank designs were ordered "off the drawing board" and was not fully solved until the debut of the Cromwell in 1944, with its powerful, reliable Rolls-Royce Meteor engine.
Inter-war cruisers included the A-9, A-10, A-13 Mk I and A-13 Mk II, which were used in the French, Greek, and North African Desert campaigns. The A-13 (Mk I and Mk II) was the first British cruiser to be fitted with Christie suspension, after British officers observed Soviet high-speed BT tanks on manoeuvres. During early WW2, the Crusader was probably the best-known cruiser, being used in large numbers in the Western Desert Campaign. Other WW2 cruisers include the Covenanter, Centaur, Cromwell, and Comet. The Centaur and Cromwell saw action from Normandy onwards, while the Comet was fielded in the beginning of 1945. By this point in the war, the firepower and armour protection of the cruisers made them indistinguishable from medium tanks.
In the course of the war, technological improvements enabled heavier tanks to approximate the speed of the cruisers, and the concept became obsolete. The last of their line was the Centurion. The Centurion was designed to satisfy the "Heavy Cruiser" criteria by combining the mobility of a Cruiser tank and armour of an Infantry tank into one chassis. This idea - and the Centurion along with it - then evolved into the "Universal tank" concept, a single design that could "do it all." Ultimately the Centurion tank transcended its cruiser tank origins and become the first modern main battle tank.
The cruiser-tank concept was also employed by the Soviet Union in the 1930s, as exemplified by the BT tank series ([bystrokhodniy tank] Error: {{Lang-xx}}: text has italic markup (help), "fast tank").