EMD GP15

The EMD GP15 is a 4-axle diesel-electric locomotive built by General Motors Electro-Motive Division between June 1976 and April 1983. Intended to provide an alternative to the rebuilding programs that many railroads were applying to their early road switchers, it is generally employed as a yard switcher or light road switcher. There were 3 variants made: the GP15-1, the GP15T, and the GP15AC. The GP15-1 and GP15AC are powered by a 12-cylinder EMD 645E engine, which generates 1,500 hp (1,119 kW). The GP15T differs in that it uses a turbo charged 8-cylinder instead of the roots blown 12-cylinder to generate the same horsepower. The GP15AC differs from the others as it uses an AC alternator connected to the engine instead of a DC generator to drive the traction motors. The radiator section is similar to those found on the EMD SD40T-2 and EMD SD45T-2 "tunnel motors," leading some observers to incorrectly identify the units as such or as GP15Ts, and giving them the nickname "baby tunnel motors". A number of GP15-1s remain in service today for yard work and light road duty.