By the 1980s, various studies had been carried out into suitable replacements for the ageing frigates OTAGO and TARANAKI whose hulls were now over 20 years old. In 1981 the British Government offered the RNZN two Leander-Class frigates, HMS DIDO and HMS BACCHANTE. As an interim measure the offer was accepted and the ships were commissioned as HMNZS SOUTHLAND and HMNZS WELLINGTON. They replaced TARANAKI which was decommissioned in June 1982 and OTAGO, decommissioned in November 1983. Both Type 12s were subsequently scrapped in Auckland.
This gave the RNZN a combat force of four Leander-Class frigates with the advantages of commonality, but created the problem that all were approximately the same age and would all require replacing in the 1990s. To alleviate this, a comprehensive modernisation and life extension was carried out to WELLINGTON by the Naval Dockyard at Devonport (1983-1987). A similar modernisation of CANTERBURY was completed in September 1990.
SOUTHLAND brought the Ikara anti-submarine weapon system into New Zealand service, but the biggest change for the RNZN was the ADAWS 5 operational computer system. The RNZN established a new branch of software engineers to manage ADAWS and the new NAUTIS command systems that were subsequently installed in WELLINGTON and CANTERBURY. At the same time, the number of Wasp helicopters was increased to seven, allowing flights on all the frigates and, as well, Wasps to be available for MONOWAI and the new ENDEAVOUR.
The museum has a collection of oral histories relating to Leander Naval Combat Force 1982-1997.