GP38 Diesel Locomotive

Prototype Information

The GP38 first appeared in January 1966. It utilized a 16-645 prime mover and a D32 direct current generator. This setup matched previous EMD locomotive designs. The demand for higher horsepower eventually required larger generators. These larger units created space constraints within the locomotive body.

EMD solved this problem in 1971 by introducing an AR10 alternating current alternator. This smaller component provided the same electrical capacity as the bulkier generator. This innovation created the GP38AC model. These units look identical to the standard GP38 on the exterior.

The GP38 filled a specific niche for light-duty work and secondary trackage. Many shortlines and industrial users purchased the model for non-mainline service. Major Class I railroads also bought many units to handle extensive branch line operations.