of Ikara. The British launcher also differed, covered by a zareba (breakwater) when not in use to prevent icing in northern waters, and extremely accurate in training in bearing. It was also notoriously noisy. Ikara-fitted ships Ikara was fitted to all of the Royal Australian Navy (RAN) frigates/destroyer escorts and guided-missile destroyers. There were three main variants of the system fitted to RAN ships; F1, F2, and F3. The F1 system, using an analogue computer, a single launcher and without a data link, was fitted to HMA Ships and only. The F3 system, with a digital computer, digital display, single launcher and a digital data link, was fitted to the other four River class ships. HMAS Stuart and Derwent were fitted with F3/0 systems during Half-life refits during the 1980s. The F2 system, using a digital computer, digital display, two launchers and with a digital data link, was fitted to the three Perth-class destroyers. The digital computer used by the RAN was the AN/UYK-1 NTDS (Naval Tactical Data System) (Bunker Ramo 133). The Ikara missile was withdrawn from service by the RAN in 1991. Ikara was also operated by the Brazilian Navy, Royal Navy, and Royal New Zealand Navy. It was phased out in the early 1990s due to the obsolescence of the Mk 44 torpedo and inability to carry the newer and heavier Mk 46 or Stingray. The British purchased Ikara to fit to the two new CVA-01 aircraft carriers planned (and later cancelled) in the 1960s, and their escorts, the Type 82 destroyers, of which only one, was built. With the cancellation of the remaining escorts, the British were left with purchased Ikara missiles in storage, and opted to fit them into eight existing Batch 1 Leander-class frigates in need of modernisation: HM ships , , , , , , and . Operators Former operators Royal Australian Navy Brazilian Navy Chilean Navy Royal New Zealand Navy Royal Navy Notes References External links Middle Watch: Ikara AdAstra: IKARA and ADASTRA Destroyers.org: The Anti-Submarine Rocket Gyrodyne Helicopters.com: Asroc Anti-submarine missiles of Australia Naval weapons of Australia Naval weapons of the United Kingdom Guided missiles of the Cold War Cold War military equipment of Australia Military equipment introduced in the 1960s