The Anzac class (also identified as the ANZAC class and the MEKO 200 ANZ type) is a ship class of ten frigates; eight operated by the Royal Australian Navy (RAN) and two operated by the Royal New Zealand Navy (RNZN). During the 1980s, the RAN began plans to replace the River-class destroyer escorts (based on the British Leander Class) with a mid-capability patrol frigate and settled on the idea of modifying a proven German design for Australian conditions. Around the same time, the RNZN was seeking to replace their Leander-class frigates while maintaining blue-water capabilities. A souring of relations between New Zealand and the United States of America in relation to New Zealand's nuclear-free zone and the ANZUS security treaty prompted New Zealand to seek improved ties with other nations, particularly Australia. As both nations were seeking warships of similar capabilities, the decision was made in 1987 to collaborate on their acquisition. The project name (and later, the class name) is taken from the Australian and New Zealand Army Corps of the First World War. Twelve ship designs were tendered in 1986. 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 modular design of the frigates allowed sections to be constructed at Whangarei, New Zealand and Newcastle, New South Wales in addition to Williamstown. The RAN ordered eight ships, while the RNZN ordered two and had the option to add two more. The frigate acquisition was controversial and widely opposed in New Zealand, and as a result, the additional ships were not ordered. In 1992, work started on the frigates; ships capable of a top speed, and a range of at . The armament initially consisted of a single 5-inch gun and a point-defence missile system, supported by a missile-armed helicopter. In addition, the ships were fitted for but not with a torpedo system, anti-ship missiles, and a close-in weapons system. 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. Since entering service, Anzac-class frigates have made multiple deployments outside local waters, including involvement in the INTERFET multi-national deployment to East Timor, and multiple operational periods in the