The EMD SD50 is a 3,500-horsepower (2,610 kW) diesel-electric locomotive built by General Motors Electro-Motive Division. It was introduced in May 1981 as part of EMD's "50 Series"; production ceased in January 1986. The SD50 was a transitional model between EMD's Dash 2 series which was produced throughout the 1970s and the microprocessor-equipped SD60 and SD70 locomotives. A total of 431 were built.

The EMD SD60 is a 3,800 horsepower (2,800 kW), six-axle diesel-electric locomotive built by General Motors Electro-Motive Division, intended for heavy-duty drag freight or medium-speed freight service. It was introduced in 1984, and production ran until 1995.