Australian light destroyer project The Australian light destroyer project aimed to build a class of small destroyer s for the Royal Australian Navy ( RAN ) . The project began in 1966 with the goal of developing simple light destroyers ( DDL ) to support patrol boat operations . The project was rescoped in 1969 when the Navy decided to use the ships to replace other destroyers as they retired , leading to an increase in the design ' s size and complexity . Concerns over the ships ' cost and technological risk led the government to cancel the DDL project in 1973 on the RAN ' s advice , and a variant of the United States ' was procured instead . Requirement . From 1963 to 1966 , RAN warships took part in the Indonesian Confrontation . During this period , Australian minesweepers and frigate s patrolled Malaysia ' s coastline to counter Indonesian infiltration parties traveling in small craft . These ships also bombarded Indonesian positions in East Kalimantan near the border with Malaysia on several occasions . The RAN ' s experiences during this conflict led it to perceive a need for light destroyers and patrol boat s tailored to confrontation - type tasks . When the DDL project began in 1966 , the ships ' role was to support patrol boat s during anti - infiltration operations and complement the Navy ' s existing destroyer force . The intenion was that the DDLs would be fast , simply armed and smaller than conventional destroyers . It was also hoped that a common DDL hull design could be used to produce variants optimised for different roles . The RAN and British Royal Navy ( RN ) held discussions in 1967 on jointly developing DDLs , but the RN withdrew from the project when the Australians insisted on arming the ships with United States - designed weapons . The DDL design evolved during the late 1960s . As a result of planning conducted during 1967 and 1968 , it gradually became clear that the ships would replace rather than complement the Navy ' s three " Daring " class destroyers and four early s . Accordingly , it was specified in 1969 that the DDLs would be more capable and flexible than originally intended , allowing the RAN to maintain its capabilities as the older destroyers retired . The intended roles for the DDLs ' were set in 1970 by an agreement between the RAN and Department of Defence , which specified that the ships were to be capable of destroying equivalent surface warships , carrying out maritime interdiction duties , commanding groups of patrol boats and aircraft , have reasonable anti - aircraft and anti - submarine capabilities and be able to provide naval gunfire support to land forces . The RAN originally intended to order up to ten DDLs . All the ships were to be built in Australia to maintain local shipbuilding capabilities , and Australian industry was to be involved to the greatest possible extent . Production of the ships was to be evenly split between Cockatoo Island Dockyard in Sydney and Williamstown Naval Dockyard in Melbourne . Design . The DDL design changed considerably over the life of the project . The initial specification was for a 1 , 000 - ton escort vessel and in an early design the class was to have a single gun as its primary armament and carry a helicopter . When the Navy Office later prepared an initial sketch design it was for a 2 , 100 - ton ship with a length of , a beam of and a maximum speed . These DDLs were to be armed with two five - inch guns and operate a single light helicopter . After preparing its initial sketch design , the Navy contracted Yarrow Admiralty Research Division ( Y - ARD ) in July 1970 to complete preliminary designs for the DDLs . As an initial stage , Y - ARD was required to develop sketch designs for six different armament configurations using a common hull . Requests for tender for studies on major sub - components were also issued in 1970 , and these were completed by mid - 1971 . The RAN conducted armament effectiveness studies of each of the six DDL variants in parallel with Y - ARD ' s development of the designs . These studies found that including an area air defence capability and an ability to operate two helicopters greatly improved the DDL ' s effectiveness . As a result , these features were included in the Navy ' s specification for the DDL design which was issued in late 1970 . By this time the design had evolved to specify a general - purpose destroyer of 4 , 200 tons , armed with a five - inch gun and a Tartar missile launcher , and capable of operating two helicopters . The changes increased the cost of building the ships , and the number planned was reduced to three . Nevertheless , the DDL design was considered likely to result in very capable ships , with the 1972 – 73 edition of " Jane ' s Fighting Ships " commenting favourably . The changes to the DDL design reflected shifting requirements and poor project management by the Navy . The development of an Australian - designed ship customised for Australian conditions caused naval officers to include requirements beyond those which were essential . These changes were made without regard for costs , as the team tasked with developing the specifications was not also responsible for the ships ' final price and delivery schedule . The Navy ' s failure to maintain control of the design requirements and make cost - performance trade - offs may have been due to its limited experience in overseeing the design of new warships . Cancellation . Despite the changes to the design and its growing costs , construction of three DDLs was approved by the Liberal Party McMahon Government in August 1972 . At this time , the total project cost was estimated at A $ 355 million . All three ships were to be built at Williamstown Dockyard , with construction of the first ship beginning in 1975 , followed by the other ships at two - yearly intervals . The initial DDL was to be commissioned in 1980 , and the third in 1984 . Further DDLs may also have been ordered . The DDL design was not supported by the Australian Labor Party ( ALP ) opposition , which believed that the ships would be too large and expensive for escort , patrol and surveillance duties . Increasing costs and concerns over the ships ' design led to the cancellation of the DDL project . The Department of Defence observed that the DDL ' s costs were escalating and it was unable to finalise the design . The Navy also reviewed the project and found that it was unduly expensive , and a Joint Parliamentary committee concluded that a unique Australian design entailed significant technological risks . As a result , the Navy recommended to the ALP Whitlam Government that the DDL project be cancelled , and this took place in August 1973 . The cost of the project to the Navy had been A $ 1 . 7 million , most of which was spent on design investigations and management consultancies . The DDL project ' s problems harmed the Australian shipbuilding industry . The cancellation of both the DDLs and another project to develop an Australian fast combat support ship design led to a perception that technical risks needed to be minimised when selecting new warships , and it was preferable to rely on proven foreign designs . Australian industry was also left with a bad impression as companies involved in the project had devoted considerable resources to preparing tenders for the DDL . Despite cancelling the DDL project , the government endorsed the RAN ' s requirement for new destroyer - type warships and requested a review of existing foreign designs to find a replacement . The two designs subsequently considered by the Navy were the United States ' s and a variant of the British Type 42 destroyer armed with SM - 1 surface to air missiles . The project team found that the Type 42 was the only design capable of meeting the Navy ' s requirement , and stated that the " Oliver Hazard Perry " class was " a second rate escort that falls short of the DDL requirements on virtually every respect " . Despite this , there were serious concerns over whether it would be possible to fit SM - 1 missiles to the Type 42 , and this led the government to approve the purchase of two " Oliver Hazard Perry " ships from the United States in April 1974 . The DDL project was reviewed again when the Liberal Fraser Government came into office in late 1975 , but a firm order for two " Oliver Hazard Perry " frigates was placed in February 1976 and a third was ordered in late 1977 . Six of these frigates , which were designated the , were eventually ordered , and the final two were built in Australia at Williamstown .