The GT46C ACe is a model of Australian diesel electric locomotive designed and built by Downer Rail at its Cardiff Locomotive Workshops using Electro-Motive Diesel components between 2007 and 2019. The first units were built as the SCT class for freight operator SCT Logistics from 2007 followed by the LDP class and TT class for Pacific National, the GWA class and GWB class for Genesee and Wyoming Australia (later One Rail Australia which was sold to Aurizon in July 2022) the WH class for Whitehaven Coal, and the SSR class for Southern Shorthaul Railroad.