guns such as the German Gepard or the Soviet 9K22 Tunguska, short and medium-range surface-to-air missile systems such as the SA-6, SA-8 and SA-11, or combine both on the same vehicle (the Tunguska for example can also host SA-19 SAM missiles). The usage of anti-aircraft rounds fired from the main gun of a tank has been increasing over the years. An example is the HE-FRAG round from the T-90 which can be detonated at a set distance as determined by its laser range finder. Engineering support Armoured warfare is mechanically and logistically intensive and requires extensive support mechanisms. Armoured fighting vehicles require armoured vehicles capable of working in the same terrain to support them. These are operated by the appropriate branches of the army, e.g. recovery and maintenance vehicles by the REME and combat engineering vehicles by the RE in the British Army. These include: Armoured recovery vehicles (ARV)—many of these are based on the chassis for the vehicle they support. E.g. the ARV for the UK Challenger tank is a Challenger hull onto which a winch is added. Armoured supply vehicles Combat engineering vehicles (CEV), e.g. bulldozers For transporting tracked AFVs over highways, heavy transporters are used, since AFVs are prone to malfunction and their tracks also ruin the highways. Light tanks and tank destroyers While tanks are integral to armoured warfare, when power projection is required, the inability to perform rapid deployment has always been a limit of heavy main battle tanks. It takes a few weeks to transfer tanks and their supporting equipment by air or sea. Some tanks and armoured vehicles can be dropped by parachute, or carried by cargo airplanes or helicopters. The largest transports can only carry one or two main battle tanks. Smaller transports can only carry or air drop light tanks and APCs such as the M113. The desire to create air-portable armoured vehicles that can still take on conventional MBTs has usually resulted in ATGM-armed light vehicles or in self-propelled gun style vehicles. The lack of armour protection is offset by the provision of a first-look/first-hit/first-kill capability through the mating of a powerful gun to superior targeting electronics, a concept similar to that of the US tank destroyers of World War II. Vehicles which have put such considerations into practice include the Stingray light tank, AMX 10 RC and B1 Centauro. Most such US projects to create such vehicles have been