The Adelaide class of six guided missile frigates was constructed in Australia and the United States for service in the Royal Australian Navy. Two were later sold to the Chilean Navy. The Adelaide class was based on the United States Navy's s, but modified for Australian requirements. The first four vessels were built in the United States, and the final two were constructed in Australia. The first ship entered service in November 1980.
Canberra and Adelaide were paid off in 2005 and 2008, respectively, and later sunk as dive wrecks. Their decommissioning offset the cost of a A$1 billion weapons and equipment upgrade to the remaining four ships. As the air-warfare destroyers entered service beginning in 2016, the remaining Adelaide-class ships were progressively decommissioned beginning with Sydney in 2015. Darwin followed in 2017, and Newcastle and Melbourne went last in 2019. The final two were sold to Chile in 2020.
Construction and acquisition
Following the cancellation of the Australian light destroyer project in 1973, the British Type 42 destroyer and the American were identified as alternatives. Although the Type 42 met the Royal Australian Navy (RAN)'s requirements as a replacement for the cancelled light destroyers and the s, fitting the ship with the SM-1 missile would have been difficult. On the other hand, the Oliver Hazard Perry class was still at the design stage; a design that was described by assessment project staff as "a second rate escort that falls short of the DDL [light destroyer] requirements on virtually every respect". Despite this, the Australian government approved the purchase of two US-built Oliver Hazard Perry-class ships in 1974.
The risk of acquiring an unproven design was seen as acceptable because of the success of the United States Navy (USN)'s (of which the RAN operated three ships as the ), when compared to the equivalent British ships the RAN would have purchased. Final government approval to order two ships was granted in 1976, with a third ship ordered in 1977. The order was expanded in April 1980 with the order of a fourth unit. These four ships were built by Todd Pacific Shipyards of Seattle, Washington, as part of the USN's shipbuilding program, and were assigned USN hull numbers during construction, which were replaced with RAN pennant numbers upon entering service. The first, HMAS Adelaide (USN hull number FFG-17, RAN pennant number FFG 01) was built to the Flight I design, while Canberra (FFG-18/FFG 02) and Sydney (FFG-35/FFG 03) were the first and last ships of the Flight II design, respectively. The final American-built ship was Darwin (FFG-44/FFG 04); constructed to the Flight III design. In 1980, two more ships (Melbourne and Newcastle) were ordered, but were built in Australia by AMECON of Williamstown, Victoria, and did not receive USN numbers.
Armament
From the withdrawal of the Perth-class destroyers in 2001 until the introduction of the in 2017, these ships were the RAN's primary air defence vessels, armed with a Mark 13 missile launcher for SM-2 missiles. They also have significant anti-surface capability, being armed with a Mk 75 gun and the Harpoon anti-ship missile (also fired by the Mark 13 launcher), and a pair of triple torpedo tubes for anti-submarine warfare (ASW). In addition, two S-70B Seahawk helicopters are carried.
From 2005 onwards, all RAN frigates deploying to the Persian Gulf are fitted with two M2HB .50-calibre machine guns in Mini Typhoon mounts, installed on the aft corners of the hangar roof. Two TopLite EO directors are used with the guns.
The Australian frigates were originally fitted with American Mark 46 ASW torpedoes, but by 2008, they had been replaced with the European MU90 Impact torpedo in three of the four frigates as part of the FFG Upgrade, with the conversion of Newcastle underway at that point.
Upgrades
There have been two major upgrades distinguishing the Adelaide class from the American Oliver Hazard Perry-class frigates.
Lengthening
The first three ships were constructed to the Oliver Hazard Perry class' 'short' hull design (Flight I and II), with an identical length for both the main deck and the keel. Ships from FFG-36 onwards (including Darwin) were built with an increase in overall length—achieved by angling the transom (the section between the fantail and the keel) to increase the area of the flight deck and allow the operation of Seahawk helicopters. Adelaide, Canberra, and Sydney were later upgraded to match the slightly larger ships, and were fitted with the updated sonars and ESM systems of the Flight III design.