An EMD SD38AC is a 6-axle diesel-electric locomotive built by General Motors Electro-Motive Division between June and October 1971. This model is an SD38 with an AR10 alternating current alternator instead of the SD38's normal direct current generator. It produces from a 16-cylinder EMD 645E roots blown prime mover. It came equipped with or without dynamic brakes. This locomotive shares a common frame with the SD38, SD39, SD40 and SD45. The SD38AC was a transition between the SD38 and its successor, the SD38-2. 15 examples of this model were built; 6 for B&amp;LE, 8 for DMIR and one for BC Hydro.