GE ET44AC

The ET44AC, for Evolution Series Tier 4, is the 4,400 horsepower alternating current locomotive that replaced the ES44AC. Nearly every Class I freight railroad owned the type, the exceptions being BNSF Railway and Canadian Pacific, although BNSF ordered ET44ACH units in late 2023 and Canadian Pacific ordered ET44ACs only in late 2024, after the CPKC merger of April 2023. Union Pacific and CSX designate their units ET44AH, and Union Pacific also calls them C45AH. BNSF calls its units ET44ACH because they are ballasted to 436,320 pounds. The ET44AC shares the GE GEVO engine of the rest of the Evolution Series.