The AC44C6M, is a 4,400-horsepower (3,300 kW) diesel locomotive that was rebuilt by GE Transportation Systems, American Motive Power, Inc. and Norfolk Southern's Juniata and Roanoke Shops, starting in September 2015. The AC44C6M is still equipped with the 16-cylinder 7FDL-16 prime mover. It features GE's alternating current 5GEB13B7 traction motors. The AC446CM features the wide cab design found on the later ES44AC model. Externally, there are many differences on the forward section of the locomotive, but the remainder of the locomotive is the same. Internally, AC44C6Ms have new under-floor air conditioner, cab signals, LSL, DPU systems, PTC, and ECP braking ability, a signifiant technological improvement from the Dash 9-40C units.