Development of the equipment can be traced back to 1965, when the Federal Republic of Germany and the United States decided to design a so called heavy equipment transport (HET) tank truck, used to carry both countries main battle tanks. The tractor's main contractor is the US Chrysler Corporation and the Federal Republic of Germany Fawn company, while the responsibility of the Federal Republic of Germany's trailer Krupp companies.The US in 1970 withdrew the MBT-70 and heavy equipment transport development program. Federal Republic of Germany continued successful development called SLT50-2 tractor, also known as formula elefant tractor. The Army ordered 328 to Fawn, the last in 1980 delivery. The truck and semi-trailer can carry Army Leopard 2 main battle tanks and equipment, including any armoured vehicles.