http://www.military-today.com/trucks/m911.htm The Oshkosh M911 heavy equipment transporter emerged as a supplement for the previous M746 tractor truck, which proved to be expensive to maintain and operate. In 1976 the US Army issued a requirement for a new tank transporter. The US Army required the new vehicle to have proven commercial background and to have low maintenance costs. In result production contract of 747 vehicles went to Oshkosh Corporation. The new tank transporter was designated as the M911. Production commenced in 1977. Some of these vehicles are still in service.