The Armidale-class patrol boats are 56.8 metres (186 ft) long, with a beam of 9.7 metres (32 ft), a draught of 2.7 metres (8 ft 10 in), and a standard displacement of 270 tons.[1] The semi-displacement vee hull is fabricated from aluminium alloy, and each vessel is built to a combination of Det Norske Veritas standards for high-speed light craft and RAN requirements.[2] The Armidales can travel at a maximum speed of 25 knots (46 km/h; 29 mph), and are driven by two propeller shafts, each connected to an MTU 16V M70 diesel.[3] The ships have a range of 3,000 nautical miles (5,600 km; 3,500 mi) at 12 knots (22 km/h; 14 mph), allowing them to patrol the waters around the distant territories of Australia, and are designed for standard patrols of 21 days, with a maximum endurance of 42 days.[3][2]
The main armament of the Armidale class is a Rafael Typhoon stabilised 25-millimetre (0.98 in) gun mount fitted with an M242 Bushmaster autocannon.[3] Two 12.7-millimetre (0.50 in) machine guns are also carried.[4] Boarding operations are performed by two 7.2-metre (24 ft), waterjet propelled rigid-hulled inflatable boats (RHIBs).[2] Each RHIB is stored in a dedicated cradle and davit, and is capable of operating independently from the patrol boat as it carries its own communications, navigation, and safety equipment.[2][5]
Each patrol boat has a standard ship's company of 21 personnel, with a maximum of 29.[3][2][6] A 20-berth auxiliary accommodation compartment was included in the design for the transportation of soldiers, illegal fishermen, or unauthorised arrivals; in the latter two cases, the compartment could be secured from the outside.[7] However, a malfunction in the sewerage treatment facilities aboard HMAS Maitland in August 2006 pumped hydrogen sulphide and carbon monoxide into the compartment, non-fatally poisoning four sailors working inside, after which use of the compartment for accommodation was banned across the class.[6][7]
Heron, Wesley; Powell, Anthony (2007). "Welcome to the Armidale Class". In Forbes, Andrew; Lovi, Michelle (eds.). Australian Maritime Issues 2006(PDF). Papers in Australian Maritime Affairs. Sea Power Centre – Australia. pp. 129–134. ISBN978-0-642-29644-3. ISSN1327-5658. Archived from the original(PDF) on 13 June 2011. Retrieved 12 May 2010.
The chapter is available separately as Semaphore, Issue 4, 2006 in PDF and HTML formats.