GE ES44C4

The ES44C4 is a 4,400 horsepower Evolution Series locomotive introduced in 2009 and built until 2020. Although it resembles the ES44AC, each truck has two traction motors instead of three, giving an A1A-A1A wheel arrangement with an unpowered center axle, and no ES44C4 was built with direct current traction. Air cylinders and linkages on the truck sideframes let the computer vary the weight on the drive axles as grade, traction and wheel slip change. BNSF Railway was the launch customer with an initial batch of 25 units numbered 6600 to 6624, and the type was at first built only for BNSF. Florida East Coast Railway later bought 24 for heavy haul and intermodal service, all delivered in 2014.