An EMD SD40T-2 is a 6-axle diesel locomotive built by General Motors Electro-Motive Division. Power is provided by a 16-cylinder EMD 645E3 diesel engine capable of producing 3,000 horsepower. This locomotive features a 4,400 gallon fuel tank and is 70 feet 8 inches long. 312 examples of this locomotive were built for North American railroads between April 1974 and July 1980. This locomotive, along with the SD45T-2, are called tunnel motors, because they were specifically designed to be more effective when operating in tunnels. The major differences between this locomotive and its non-tunnel motor cousin, the SD40-2, are the radiator intakes and radiator fan grills located at the rear of the locomotive. This locomotive model was purchased by the Southern Pacific Railroad, its subsidiary Cotton Belt, and the Denver and Rio Grande Western Railroad. At one point Southern Pacific and then later Union Pacific Railroad owned every SD40T-2. As of 2005 most of these units are in service on the Union Pacific or various leasing companies.