The Fremantle-class patrol boats were coastal patrol vessels operated by the Royal Australian Navy (RAN) from 1979 to 2007. Designed by British shipbuilder Brooke Marine and constructed in Australia by NQEA, the Fremantle class were larger, more powerful, and more capable than the preceding , and the two primary patrol boat bases required infrastructure upgrades to support them. Although up to 30 vessels were planned, fifteen were ordered and constructed, with an unexercised option for five more. Their retirement was announced in 2001 and a decommissioning schedule published in 2004. From May 2005 they were replaced by the patrol boats with the last two Fremantles decommissioning in May 2007. Most of the class were scrapped, with two marked for preservation as museum ships. The Fremantle class has also appeared in two drama television series based on the Royal Australian Navy. Planning and development The concept for the Fremantle class began somewhere between 1967 and 1969, as the s entered service, and areas for improvement were observed. In September 1970, the RAN announced the intention to construct ten new patrol boats, which would operate in tandem with the Attack class and replace two general purpose vessels. These new vessels were intended to enter service between 1976 and 1980. The number of vessels to be built fluctuated, peaking at thirty vessels (16 RAN, 4 Royal Australian Naval Reserve, and 10 for the military of Papua New Guinea), and settling at fifteen. Plans of acquisition were announced in April 1975, with eleven shipbuilders submitting tenders, of which two were shortlisted in 1976; Brooke Marine of Eng,and and Lürssen Werft of West Germany. Brooke Marine won the contract to design and produce the lead ship, with NQEA contracted to build the other fourteen vessels. An option for an additional five vessels existed, but they were placed on indefinite hold in 1982. There was a separate acquisition plan for six missile-armed variants, but this was suspended due to the lack of available funding, and the belief that such ships could be constructed on short notice if required. Design and construction The design of the Fremantle class called for ships with improved seakeeping, and newer equipment and weapons than those fitted to the Attack class. The Fremantles had a full load displacement of , were long overall, had a beam of , and a maximum draught of . The Fremantles were 28% longer and 50% heavier