The model of the first successful American diesel locomotive was the EMD FT.
Built by Electro-Motive Corporation, later General Motors Electro-Motive Division, the FT emerged in 1939 as a high-power diesel-electric freight locomotive. Its demonstrator set, led by FT 103, toured American railroads and showed that diesel power could handle demanding main-line freight without the crews, fuel handling, water stops, and maintenance associated with steam.
The first customer units went to the Atchison, Topeka and Santa Fe Railway in 1941. An FT A unit produced 1,350 horsepower, while a standard A-B pair provided 2,700 horsepower under one control system. Its 16-cylinder EMD 567 two-stroke engine, electric traction motors, and rugged Blomberg trucks made the design practical as well as powerful.
The FT is sometimes confused with earlier diesel switchers or EMD’s passenger E-units. Those locomotives were important, but the FT’s breakthrough was dependable, mass-produced road-freight service. EMD built 555 A units and 541 B units before production ended in 1945, helping launch the rapid replacement of steam on American railroads.