I got to see an M728 Combat Engineer Vehicle (CEV) while at the Texas Military Forces Museum.  This vehicle has a dozer blade and a crane boom on it and is built on the chassis of the M60A1 Patton tank. This type of vehicle is used by Combat Engineers; and this model was used during the Vietnam War and the Gulf War. The M728 CEV was produced between 1965 and 1987 and its main armament is an 165mm M135 gun.