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 launched in May 2000.

The frigate was 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. 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.

HMS Norfolk was the first of the class to enter service, commissioned on June 1, 1990 at a cost of £135.449 million. Later vessels cost £60-96 million. The annual costs of running a Type 23 is around £16 million.

Characteristics

  • Length: 133 metres/436 feet
  • Beam: 16.1 metres/52.9 feet
  • Displacement: 4,900 tonnes
  • Crew: 185
  • Power: CODLAG (Combined Diesel, Electric and Gas). Two Rolls Royce Spey 34,000 hp gas turbines; two Alstom 1.5 MW electric motors.
  • Speed: 28 knots maximum. 12,500 km at 15 knots
  • Weapons:
    • 2 x quad Harpoon missile launchers
    • VLS Sea Wolf SAM system
    • 4.5-inch (114mm) Vickers Mk 8 gun (some ships being upgraded with the Mk 1)
    • 2 x Oerlikon 20mm guns
    • 2 x magazine launched 324 mm torpedo tubes
    • NATO Seagnat, Type 182 and DLF3 decoy launchers
  • Aircraft: Lynx Mk 8 helicopter
    • Armament:
      • Sea Skua missiles
      • Stingray torpedoes
      • depth charges
  • Sensors:
    • BAe Type 996 search radar Kelvin-Hughes navigation radar
    • BAe Type 911 fire control radar; Thales Type 2050 active sonar
    • Thales Type 2031Z towed array sonar