The EMD SD9 is a model of diesel locomotive built by General Motors Electro-Motive Division between January 1954 and June 1959. An EMD 567C 16-cylinder engine generated 1,750 horsepower (1.30 MW). Externally similar to its predecessor, the SD7, the SD9 was built with the improved and much more maintainable 567C engine.
Four hundred and seventy-one SD9s were built for American railroads, while a further 44 were produced for export.
Many SD9s both high and short hood can still be found in service today on shortline railroads and industrial operators. Although most Class 1 roads stopped using these locomotives by the 1970s and 1980s, some remain in rebuilt form on some major Class I railroads, as switcher locomotives.[citation needed]
^Bachand, Jean-Denis. "EMD SD9". The Diesel Shop. Archived from the original on 2022-03-31. Retrieved 18 July 2021.