The need for a sealift capability saw the ship modified for service as a fast troop transport, and recommissioned in 1962. "Sydney" was initially used for training and a single supply run in support of Malaysia's defence policy against Indonesia, but in 1965, she sailed on the first voyage to Vũng Tàu, transporting soldiers and equipment to serve in the Vietnam War. 25 voyages to Vietnam were made between 1965 and 1972, earning the ship the nickname "Vung Tau Ferry".