gun systems", which may bear a superficial resemblance to tank destroyers, but are employed as direct fire support units typically providing support in low intensity operations such as Iraq and Afghanistan. These have the advantage of easier deployment, as only the largest air transports can carry a main battle tank, and their smaller size makes them more effective in urban combat. Many forces' IFVs carry anti-tank missiles in every infantry platoon, and attack helicopters have also added anti-tank capability to the modern battlefield. But there are still dedicated anti-tank vehicles with very heavy long-range missiles, or intended for airborne use. There have also been dedicated anti-tank vehicles built on ordinary armoured personnel carrier or armoured car chassis. Examples include the U.S. M901 ITV (Improved TOW Vehicle) and the Norwegian NM142, both on an M113 chassis, several Soviet ATGM launchers based on the BRDM scout car, the British FV438 Swingfire and FV102 Striker and the German Raketenjagdpanzer series built on the chassis of the HS 30 and Mardar IFVs. Armoured train An armoured train is a railway train protected with armour. They are usually equipped with rail cars armed with artillery, autocannons, machine guns, tank turrets and anti-aircraft guns. They were mostly used during the late 19th to mid-20th century, when they offered an innovative way to quickly move large amounts of firepower. Their use was discontinued in most countries when road vehicles became much more powerful and offered more flexibility, and because armoured trains were too vulnerable to track sabotage and attacks from the air. However, the Russian Federation used improvised armoured trains in the Second Chechen War in the late 1990s and 2000s. Armoured trains carrying ballistic missiles have also been used. The rail cars on an armoured train were designed for many tasks, such as carrying artillery and machine guns, infantry units, anti-tank and anti-aircraft guns. During World War II, the Germans would sometimes put a Fremdgerät (captured AFVs such as the French Somua S-35 or Czech PzKpfw 38(t)), or obsolescent Panzer II light tanks on a flatbed rail car, which could quickly be offloaded by means of a ramp and used away from the railway line to chase down enemy partisans. Different types of armour were used to protect armoured trains from attack. In addition to various metal plates, concrete and sandbags were used in some cases on armoured trains. Armoured trains were sometimes escorted by a