Sydney enlisted on 12 May 1941 and was posted to Australian Army Service Corps Section, Sparrow Force. He joined the unit on Timor as a driver from the Australian Army Service Corps, after the fall of Koepang, approx March 1942. He was one of the former Koepang men, who moved to the village of Mape for intensive commando training and on 8 May 1942, they were formed into a new Platoon, “D” Platoon under the command of Lieutenant Turton and later under Lt Doig.
After the campaign on Timor, he embarked with the unit, for Australia aboard the Royal Dutch destroyer “Tjerk Hiddes” on either 11 Dec 1942 or 16 Dec 1942, as the embarkation rolls do not differentiate.
He was discharged on 17 Apr 1944.