The Commonwealth Railway's GM Class displaced steam on the desert stretch of the Nullarbor Plains but by 1999 their use on the transcontinental main was quite rare. Now owned by the Australian Railroad Group, GM.43, GM.46 and GM.40 prepare to leave Parkeston on the western edge of the desert for the limestone quarry at Loongana, out on the Plains with No.4236 empty, right on a clear Eastern Goldfield's sunset.