By the 1970s, first-generation diesels on the nation’s railroads were approaching the end of their service lives. Instead of purchasing new locomotives for switching and low-speed local work, major Class I railroads such as the Illinois Central, Southern Pacific, Seaboard Coast Line, and many others chose to rebuild their EMD GP7 and GP9 locomotives from the ground up with new or modernized components. The resulting units promised improved reliability to serve at least another decade or more — all this for a fraction of the cost of a new locomotive. Sensing lost business, the Electro-Motive Division of General Motors (EMD) proposed an alternative solution — the GP15-1 locomotive. This new model would utilize the trucks, traction motors, and other components from trade-in GP7s and GP9s fully reconditioned and reinstalled into a completely new locomotive chassis with a 1,500 hp non-turbocharged 12-cylinder 645-series prime mover and a compact version of the “tunnel motor” radiator cooling section seen first on SD45T-2s.
To save costs, the GP15-1 retains DC electrical components, unlike its Dash-2 sisters that utilized AC-driven components. 310 GP15-1s were built between 1976 and 1979, with 30 additional GP15ACs delivered in 1982. Chessie System and Apalachicola Northern both ordered GP15Ts powered by a turbocharged 8-cylinder 645 prime mover instead of the normally aspirated 16-cylinder 645.
For 2025, Athearn has delivered a new production of its GP15-1 and GP15T locomotives. Our first review sample is Athearn’s rendition of Missouri Pacific 1562 — an EMD GP15-1 finished in MP’s classic “Jenks Blue.” This latest run of MoPac GP15s features numerous detail improvements and corrections over prior MoPac GP15-1 releases, including corrected artwork and entirely new front and rear handrails that depict the units in their as-delivered configuration with solid front railings instead of a chain over the front personnel walkway between units. All MoPac units in this release are modeled after specific units from the first group of twenty GP15-1s delivered to Missouri Pacific and Chicago & Eastern Illinois beginning in June 1976.
Representing the pinnacle of Athearn’s product offerings, this depiction bristles with a maximum level of detail throughout, especially under the side sills and on each pilot face. For the prototypical paint schemes, each unit is detailed and decorated to match a specific road number. If one looks closely for distinctions between these MoPac GP15s, one will find different striping variations across the front pilot, and either Blomberg-B or Blomberg-M trucks depending upon the road number chosen.
Details atop the cab and long hood of the MP Geep include a Leslie S-3 airhorn, “firecracker”-style radio antenna, dual Super “Non-Lifting” spark arrestors, and a pair of etched metal radiator grilles over the “tunnel” radiator section. Along the sides of the long hood are a pair of vertically mounted airfoils meant to reduce the amount of exhaust particulates entering the intake filters behind the cab, along with see-through corrugated etched metal screens above the rear truck…
