The Type 22 frigates were designed principally as anti-submarine warfare vessels, to replace the aging Leander Class frigates, but the large ocean going ships were also fitted out to undertake general purpose operations.  The following the Royal Navy convention of naming frigates in alphabetical sequence the first eight Type 22 ships were given names starting with the letter ‘B’ and the Batch 3 ships were given names starting with the letter 'C'. While the Type 22 shared the same basic hull design as the Leander Class ships it also shared features with the Type 42 destroyers such as the same power plants and auxiliary machinery. However, despite the similarities, the Type 22 also heralded many firsts for the Royal Navy such as being the first warships completed to a metric specification and the first warships to not be fitted with a main gun although after the lessons of the Falklands War the Batch 3 ships were fitted with a 4.5 inch main gun. In terms of weaponry these vessels were more than capable of general-purpose operations: air defence was provided by the Sea Wolf missile, while four exocet launchers provided defence against surface threats. The Ikara missile, which had been fitted on some Leander Class Frigates, was rejected in favour of anti-submarine torpedo tubes. The Batch 3 ships are armed with the McDonnell Douglas Harpoon surface-to-surface missile system, for anti-ship operations, the British Aerospace Sea Wolf surface-to-air missile system, for anti-aircraft and anti-missile defence, and two triple Stingray torpedo launchers. In addition, as noted, they are also equipped with a Vickers 4.5 inch gun for Naval Gunfire Support (NSG), as well as a Goalkeeper 30 mm CIWS and 2 DES/MSI 30 mm anti-aircraft weapons and a variety of countermeasures. The Batch 3 ships are fitted with a flight deck capable of supporting the Sea King HAS 5 or the Merlin EH101 helicopter although each ship normally carries a Westland Lynx helicopter for anti-submarine warfare. They are also capable of acting as command ships for a Flag Officer and his staff. Batch 3 ships are powered by two Rolls-Royce Tyne gas turbines which provide a cruising speed of 18 knots. In addition they are equipped with two Rolls-Royce Spey gas turbines which allow the ship to "sprint" at up to 30 knots for short periods. The Type 22 frigates have served with distinction for many years from the Falklands War in 1982 through to the Gulf War in 1991, when HMS London led the British Task Force, and continue to provide a vital contribution today.