to give them the required speed, cruiser designs sacrificed armour and armament compared to the infantry tanks. Pure British cruisers were generally replaced by more capable medium tanks such as the US Sherman and, to a lesser extent, the Cromwell by 1943. The Soviet fast tank (bistrokhodniy tank, or BT tank) classification also came out of the infantry/cavalry concept of armoured warfare and formed the basis for the British cruisers after 1936. The T-34 was a development of this line of tanks as well, though their armament, armour, and all-round capability places them firmly in the medium tank category. Armoured car The armoured car is a wheeled, often lightly armoured, vehicle adapted as a fighting machine. Its earliest form consisted of a motorised ironside chassis fitted with firing ports. By World War I, this had evolved into a mobile fortress equipped with command equipment, searchlights, and machine guns for self-defence. It was soon proposed that the requirements for the armament and layout of armoured cars be somewhat similar to those on naval craft, resulting in turreted vehicles. The first example carried a single revolving cupola with a Vickers gun; modern armoured cars may boast heavier armament – ranging from twin machine guns to large calibre cannon. Some multi-axled wheeled fighting vehicles can be quite heavy, and superior to older or smaller tanks in terms of armour and armament. Others are often used in military marches and processions, or for the escorting of important figures. Under peacetime conditions, they form an essential part of most standing armies. Armoured car units can move without the assistance of transporters and cover great distances with fewer logistical problems than tracked vehicles. During World War II, armoured cars were used for reconnaissance alongside scout cars. Their guns were suitable for some defence if they encountered enemy armoured fighting vehicles, but they were not intended to engage enemy tanks. Armoured cars have since been used in the offensive role against tanks with varying degrees of success, most notably during the South African Border War, Toyota War, the Invasion of Kuwait, and other lower-intensity conflicts. Aerosani An aerosani (, literally 'aerosled') is a type of propeller-driven snowmobile, running on skis, used for communications, mail deliveries, medical aid, emergency recovery and border patrolling in northern Russia, as well as for recreation. Aerosanis were used by the Soviet Red Army during the Winter War and World War II. The