The 56 m all-aluminium monohull “Armidale”, first of the Royal Australian Navy’s twelve Armidale Class Patrol Boats, has completed all trials. Based in the ports of Darwin and Cairns, the Armidale Class fleet will operate within Australia’s Marine Jurisdictional Zones and on the high seas in latitudes not exceeding 50 degrees, primarily carrying out surveillance, interception, investigation, apprehension and the escort to port of vessels suspected of illegal fisheries, quarantine, customs or immigration offences.

The hard-chine, semi-planing hull minimizes resistance and was conceived to provide superior seakeeping performance. Detailed comparisons between equivalent steel and aluminium hulls established that there is only a minor difference in overall construction cost between the two alternatives. However, the aluminium patrol boat offers major savings in operating and through-life support costs. Tank testing and calculations showed that the aluminium vessel achieved the same performance with less power, resulting in a reduction in fuel consumption of over 20 per cent. The new boats have been designed to operate without re-supply for up to six weeks but are equipped for replenishment at sea. This includes transferring personnel and light cargo between the boat and helicopters and provision for refuelling from a supply vessel.

The onboard fuel capacity provides a steaming range in excess of 3,000 nautical miles, which is a 20 per cent increase over the RAN’s existing patrol vessels. The bridge has been located as low as possible in the midship to minimise the lateral motions. Based around proven commercial solutions, the bridge arrangement allows for all round vision from the control station. In addition to a command position and two navigating helm stations, the bridge features dedicated consoles for engineering, communications and weapons plus bridge wing stations. The vessels have been designed to operate with a complement of 29, comprising seven officers, four senior sailors and 18 junior sailors.

The 12 patrol boats will be delivered at regular intervals over the next two-and-a-half years and the Australian Government has indicated its intention to order a further two vessels. These would operate out of either Dampier or Port Hedland and be specifically tasked with patrolling the waters around offshore oil and gas facilities in the north-west of Western Australia.