The EMD GP15-1 is a 4-axle diesel locomotive built by General Motors Electro-Motive Division between June, 1976 and March, 1982. Intended as a replacement for the EMD GP7, GP9, and GP18 models, it is generally employed as a yard switcher or light road switcher. This locomotive is powered by a 12-cylinder EMD 645E engine, which generates 1,500 horsepower (1,119 kW). The GP15-1 shares a frame with many other early EMD GP series locomotives, giving it an overall length of 56 feet 2 inches. A total of 310 units were built for American railroads. The Missouri Pacific Railroad purchased more units than the other three buyers combined. For spotting purposes, the MP models have a number of visually-distinguishing features, though not all were applied consistently to the MP units: The MP units have a grab iron ladder mounted on both sides of the long hood end; MP's initial order of GP15-1s rode on Blomberg M trucks rather than the more common Blomberg B (all subsequent units were delivered with Blomberg B trucks) — and, while the standard Blomberg B truck carries two brake shoes per wheel, many MP units were equipped with only a single brake shoe per wheel; #1555–#1574 were outfitted with the standard 81" nose, while the remaining units (all built in December, 1976 or later) came with an 88" nose; and 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. A number of GP15-1s remain in service today.