[3] By 1989, the project had selected a proposal by Germany's Blohm + Voss, based on their MEKO 200 design, to be built in Australia by AMECON at Williamstown, Victoria.

The last ship of the class entered service in 2006; by this point, the RAN and RNZN had embarked on separate projects to improve the frigates' capabilities by fitting the additional weapons, along with updates to other systems and equipment.

[6][7] By 1985, various design briefs ranging from 1,200 to 5,000 tonnes (1,200 to 4,900 long tons) displacement were under consideration, with the RAN emphasising anti-ship missile defence, damage control, and ship survivability based on Royal Navy experiences during the Falklands War.

Alternate suggestions, such as reducing the RNZN to a coast guard-type force responsible for coastal and fisheries protection, replacing the frigates with smaller offshore patrol vessels, or reorienting the navy to primarily operate submarines, were made in several venues, but were seen as an unacceptable loss in capability.

[13] In response, the New Zealand government sought to improve ties with Australia; one such avenue was to promote military interoperability between the countries by standardising equipment and procedures where possible.

[8][20] On 14 August 1989, the Australian government announced that AMECON had been awarded the tender for construction of the Anzac class based on modified MEKO 200 design.

[23] The initial proposal – to build an additional six Anzac-class frigates configured for wide-area anti-aircraft warfare – did not go ahead as the Anzac design was too small to effectively host all the required equipment and weapons.

The option of the United States Coast Guard's (USCG) Hamilton-class cutters was seriously considered as an alternative to the order of HMNZS Canterbury in 1968, which was approved under the understanding that New Zealand would hold continued access to the UK market after Britain entered the European Economic Community and was affordable only because it was part of a British deal with the Yarrow shipyard to build seven RN, Chilean and RNZN Leanders at less than the cost to save shipyard jobs in Scotland.

[citation needed] During the late 1970s, proposals for a modified Hamilton-class cutter with less range or the RN Type 21 frigate with similar anti-submarine capability to a Leander but with a smaller crew and with less AW, AA, an AD.

Both these proposals and others for full combat Dutch or American Oliver Hazard Perry-class frigates were rejected by the Muldoon government and in the early 1980s a number of retired naval officers and political scientists like Helen Clark and Robert Miles were seriously debating and writing papers and articles suggesting options such as RN OPVs, the Castle-class and the USCG's WMEC Bear class.

[26] The government's official stance was dedication to maintaining a blue-water navy, primarily in order to defend the nation and contribute to regional security.

[27] Despite this, the government was slow to respond to opponents of the project which included peace campaigners, politicians (from both within and outside the Labour Party, and from both ends of the political spectrum), and military personnel.

[20][28] Most of the concern revolved around the cost of purchasing frigate-type ships, along with the idea that four high-capability warships would be too few and too overspecialised to operate in the roles envisioned for the RNZN.

[29] The primary role foreseen for the RNZN was fisheries protection, particularly following the introduction of a 200-nautical-mile (370 km; 230 mi) exclusive economic zZone by the 1982 United Nations Convention on the Law of the Sea; this was thought to require a minimum of six vessels to effectively police.

[32] One proposal suggested to avoid this was that the New Zealand Anzacs be fitted with inferior engines that would reduce the vessels' top speed and make it impossible to operate with United States Navy fleets.

[33] Two months after tenders for the project closed, the managing director of Svendborg Skibsværft began to campaign for the construction of the Danish IS-86 patrol vessel (later designated the Thetis-class frigate) for the RNZN.

[40] The US Clinton Administration partly discredited the option of a third Anzac by formally offering the RNZN two Oliver Hazard Perry-class frigate shorthulls of 15–17 years age, purportedly armed with SM1 Standard missiles and later 28 F-16 Fighting Falcon aircraft which it had refused to transfer to Pakistan.

These offers were made partly because of US concern that Australia needed more regional defence support to conduct a more robust foreign and economic policy in SE Asia.

[42][43] A year later, the idea was still being debated internally although the proposal had been downgraded to buying one of the active Australian Anzacs second-hand which the RAN could then replace by building an additional ship.

[9][48] The Sea Sparrow is a semi-active radar homing missile, with a 39-kilogram (86 lb) warhead, a range of 14.6 kilometres (9.1 mi), and a top speed of Mach 2.5.

[9] When construction started, both navies were planning for, but had yet to identify, new helicopters to be operated by the frigates; as an interim measure, the RAN used Sikorsky S-70B-2 Seahawks, while the RNZN embarked Westland Wasps.

[48] The Sceptre-A equipment was unable to meet the required performance specifications, and Thales UK (which previously acquired Racal Thorn) was contracted in 2001 to replace the units with the Centaur ESM.

[52] In 2004, Tenix, Saab, and the Department of Defence formed a Private Public Partnership to upgrade the anti-ship missile defence (ASMD) capability of the Anzac class, through the installation of CEA Technologies' CEAFAR and CEAMOUNT active phased array radars, a Vampir NG Infrared Search and Track system, and Sharpeye Navigational Radar Systems.

[57] Additional ballast was required to maintain stability, and the combined weight increase brought the ship's full load displacement to 3,810 tons.

[52] Around the same time, the RAN began to fit all frigates deploying to the Persian Gulf with two M2HB .50 calibre machine guns in Mini Typhoon mounts, installed on the aft corners of the hangar roof.

[78] Propulsion changes are primarily focused on replacing the TB83 diesel engines with the TB93, providing an additional 1.4 megawatts (1,900 hp) and higher speeds during diesel-only sailing.

The Lockheed Martin Combat Management System 330 is also installed on the RNZN frigates,[85] as it increases the eyes on each screen, covering lesser sensors and crew.

[77] In 2002, Te Kaha returned to the Persian Gulf, this time as part of Operation Enduring Freedom, after a four-month flag-showing deployment in Asian waters.

[87] From 2018, the Anzac-class frigates were undergoing their Midlife Capability Assurance Program (AMCAP) upgrade at the Australian Marine Complex, Henderson, Western Australia, a process scheduled to be completed by 2023.

The Prime Minister confirmed that any frigate will be built in Adelaide and incorporate an Australian CEA phased array radar The program is estimated to be worth $35 billion.