The military Quad Bike was a British invention with design work going back to 1943. The Standard Ultra Lightweight and Jungle Airborne Buggy were both in final stages of testing when WWII ended and the orders were cancelled. The first Japanese Quad Bikes arrived in 1982 and in the following years began to replace motorcycles in military service. The first Quad Bike ordered by the British army in large numbers were based on the Yamaha 450, fitted with a diesel engine and NATO tow bar. In addition their tires are filled with run-flat sealant, a small winch and infra-red lights are also fitted. In British service the Quad Bike is called a Small ATV (All Terrain Vehicle) and by 2015 over 1,000 had been delivered. It is often used with a small trailer, the Logic SMT 171B or SMT 120B, both with a capacity of 150 kg. The Small ATV's first saw action in Afghanistan were they were used by Special Forces to transport sniper teams and more generally as load carriers. The Small ATV's soon became invaluable, able to get to otherwise impassible areas relatively quietly. The vehicles are easily transportable by helicopter and an aluminum Quad Bike Bridge (QBB) is also in service to aid in mobility. On offensive operations the Small ATV's mount machine guns and grenade launchers. It can also be used in the casualty evacuation role and can carry two stretchers. For rapid transport the Small ATV's are packed into a logistics container, a 20ft Hi-Cube can carry 10 vehicles. The Quad Bike is currently being improved for new roles including battlefield communication and drone control vehicle.