See main article: Fremantle-class patrol boat. Starting in the late 1960s, planning began for a new class of patrol boat to replace the, with designs calling for improved seakeeping capability, and updated weapons and equipment.[1] The Fremantles had a full load displacement of, were long overall, had a beam of, and a maximum draught of .[2] Main propulsion machinery consisted of two MTU series 538 diesel engines, which supplied to the two propeller shafts.[2] Exhaust was not expelled through a funnel, like most ships, but through vents below the waterline. The patrol boat could reach a maximum speed of, and had a maximum range of at .[2] The ship's company consisted of 22 personnel.[2] Each patrol boat was armed with a single Bofors 40mm gun as main armament, supplemented by two .50 cal Browning machineguns and an 81-mm mortar,[2] although the mortar was removed from all ships sometime after 1988. The main weapon was originally to be two 30-mm guns on a twin-mount, but the reconditioned Bofors were selected to keep costs down; provision was made to install an updated weapon later in the class' service life, but this did not eventuate.[3] [4]
Dubbo was laid down by NQEA in Cairns, Queensland on 9 August 1982, launched on 21 January 1984 in the presence of Thomas Arthur Slattery and Joan Slattery, then Mayor and Mayoress of Dubbo, and commissioned into the RAN on 10 March 1984.[5]
Dubbo was decommissioned at on 2 February 2007, and was the last ship of her class to be stationed at Coonawarra.[6] The patrol boat was broken up for scrap in Darwin during 2006 and 2007, at a cost of $450,000 to the Australian government.