In the 1990s, Clyde Engineering developed the GT46C heavy freight locomotive using prime mover, generator and traction motors from EMD. 24 of these were built, which were only delivered after Clyde Engineering had been bought by EDi Rail. Since the installation of three-phase traction equipment would have exceeded the permitted weight, the newly developed GT46C ACe was introduced in 2007. This uses traction motors from Siemens and electronics from Mitsubishi, among others. Thanks to the three-phase AC technology and a slightly more powerful prime mover, the starting tractive effort increased from 408 to 600 kN. By 2023, 94 locomotives have already been delivered and there are already orders for 36 more. Some of the production is carried out in the USA by EMD (today Progress Rail). Aurizon is a major operator of both generations and Pacific National operates a total of 40 GT46C ACe locomotives.