Type 23 frigate (Duke Class)

The Type 23 frigate is a warship class of the Royal Navy also known as the Duke class. Sixteen of this class have been built, with the final vessel, HMS St Albans (F83) launched in May 2000. These vessels currently comprise around half of the entire surface escort fleet of the Royal Navy.

The frigate was initially designed as a light anti-submarine warfare platform, with a Lynx or EH-101 Merlin active dipping sonar helicopter, to replace the frigates of the Leander class. The frigates, with no anti-air armament and which would operate primarily in the North Atlantic, would be resupplied by a large force of Fort class replenishment ships. These supply ships were to be fitted with the Sea Wolf missile system for protection of the frigates. Constraints on the navy and the experiences of the Falklands War led to a redesign of the frigates with the addition of a main gun, and a reduced radar signature. The frigate's role was further expanded to cover all forms of naval operations with the addition of Harpoon and Sea Wolf missile systems.