GE AC44C6M

The GE AC44C6M is a rebuilt locomotive rather than a new build: an alternating-current traction, 4,400 horsepower diesel-electric locomotive converted from Dash 9 and some AC4400CW units. The rebuild keeps the 16-cylinder 7FDL prime mover, underframe and engine and radiator compartments of the donor unit but replaces its direct-current traction motors with alternating-current motors, and adds a new hood front section with an inverter cabinet. Rebuilds have been done by GE and later Wabtec, American Motive Power and Norfolk Southern shops, starting in September 2015. Norfolk Southern is the largest operator, converting its Dash 9-40C units first and fitting them with a new wide-nosed cab, while BNSF, Canadian National, Quebec North Shore and Labrador Railway and Fortescue also run them. Wabtec claims better fuel efficiency and reliability, at a cost of roughly half to 60 percent of a new AC locomotive.