In 1981, the Maryland Department of Transportation took delivery of five rebuilt F7A’s from Morrison-Knudsen. Four of the units were essentially in-kind rebuilds of the original configuration, but one lost its prime mover and traction motors in favor of a 6-cylinder Cummins engine and an HEP generator. Classified as an All Purpose Cab Unit (APCU), the one-of-a-kind unit served MDOT, and later MARC, off and on for another 29 years, after which it was donated to the B&O railroad museum.
