Green’s Dictionary of Slang

(Aus.) the train that runs from Adelaide to Perth across the Nullarbor Plain; also attrib.

1918		Dly News (Perth) 5 Aug. 5/6: [headline] Passengers on the Trans.
1921		Mirror (Perth) 19 Nov. 4/3: Taken specially for ‘The Mirror’ on the Nullabor Plain during the Trans journey across to the West.
1924		Sun. Times (Perth) 16 Mar. 17/7: At Karonie the Trans pulled up and cameras came out to snap the scene.
1943		Baker Popular Dict. Aus. Sl. (2nd edn).