Design Intended role “The Type 23 class frigate was conceived in the late 1970s as a light anti-submarine frigate whose primary role was to meet the then Soviet nuclear submarine threat in the North Atlantic. This new class was intended to replace the Leander class frigate, which was developed in the 1950s and the Type 21 class frigate, developed in the 1960s, as the backbone of the Royal Navy’s surface ship anti-submarine force. The Type 23 class frigate was not procured as a replacement for the Type 22 frigate.” Though with the reductions in the size of the Navy as a result of the 1998 Strategic Defence Review the last of the Type 23s, the St Albans did replace a Type 22, the Coventry. The ships were to carry a towed array sonar to detect Soviet submarines in the North Atlantic and carry a Westland Lynx or EHI Merlin helicopter to attack them. It was initially proposed that the frigates would not mount defensive armament. Instead the Sea Wolf missile system was to be carried by Fort Victoria class replenishment oilers, one of which was to support typically four Type 23s. The Forts would also provide servicing facilities for the force’s helicopters; the Type 23 would have facilities only for rearming and refuelling them. Evolution As a result of lessons learned from the Falklands War, the design grew in size and complexity to encompass the Vertical Launch Sea Wolf (VLS) system with an extra tracking system as a defence against low-flying aircraft and sea-skimming anti-ship missiles such as Exocet. With the addition of Harpoon surface-to-surface missiles and a medium calibre gun for naval gunfire support, the Type 23 had evolved into a more complex and balanced vessel optimised for general warfare, which introduced a host of new technologies and concepts to the Royal Navy. These included extensive radar cross section reduction design measures, automation to substantially reduce crew size, a CODLAG (Combined Diesel-electric and Gas) propulsion system providing very quiet running for anti-submarine operations along with excellent range, vertical launch missile technology and a fully-distributed combat management system. The Vertical Launch Sea Wolf surface-to-air missile system was designed for and first deployed on the Type 23. Unlike conventional Sea Wolf, the missile is boosted vertically until it clears the ship’s super-structure and then turns to fly directly to the target. Consequently, the ship’s structure does not cause no-fire zones that would delay or inhibit missile firing in a conventionally launched system. HMS Norfolk was the first of the class to enter service, commissioned into the Fleet on 1 June 1990 at a cost of 135.449 million GBP, later vessels cost 60-96 million GBP. Nomenclature Although the Type 23 is officially the “Duke” class, and includes such famous names as HMS Iron Duke, (which had been the name of the battleship HMS Iron Duke, Admiral Jellicoe’s flagship at the Battle of Jutland), five of the names had previously been used on classes known as the ‘County class’: Kent and Norfolk were names given both to 1960s guided missile destroyers and Second World War-era heavy cruisers, while Monmouth, Lancaster, Kent and Argyll revived names carried by First World War-era armoured cruisers. This use of Ducal and County names broke a tradition of alphabetical names for escort ships which had run in two – not unbroken – cycles from the L-class destroyers of 1913 to the Daring-class destroyers of 1950; this progression was revived with the Amazon-class Type 21 frigates of 1972-75, and continued with B and C names for most of the Type 22 frigates of 1976-89. However, the D names have since been used for the new Type 45 Daring-class destroyers now entering service from 2009. Specifications Type 23 propeller, specially designed to reduce underwater noise. Weapon Systems 2 x quadruple Harpoon missile launchers 32 x Vertical Launch Sea Wolf Surface-to-air missiles (VLS GWS 26 Mod 1 Block 2 system) 1 x 114 mm (4.5 in) Vickers Mark 8 gun (all ships being upgraded to Mod 1 standard) 2 x Oerlikon 30 mm L/75 KCB guns on single Laurence Scott DS-30B mounts. Being upgraded to remote control with electro-optic director 4 x Cray Marine 324 mm (2 twin) fixed torpedo tubes, Marconi Sting Ray NATO Seagnat, Type 182 and DLF3 countermeasures launchers Aircraft: Westland Lynx HM.8 or AgustaWestland Merlin HM.1 helicopter and Cougar AS532 Chilean Navy Armament: Sea Skua missiles (Lynx only) Sting Ray torpedoes depth charges AM-39 Exocet (Chilean Navy Cougars) Electronic Systems Search: BAE Systems Radar Type 996 Mod 1, 3D surveillance Navigation: Kelvin Hughes Radar Type 1007 and Racal Decca Type 1008 Fire control: 2 x GEC Marconi Type 911 Sea Wolf systems Sperry Sea Archer 30 optronic surveillance / director Bow sonar: Thales Underwater Systems Type 2050 Towed sonar: Ultra Electronics Type 2031Z, being replaced by Type 2087 in eight ships Combat Management System: BAE Systems Command System DNA(1) Note: Type 23′s Search Radar will be replaced by BAE Systems Insyte Artisan 3D Radar. The radar also equips Albion Class & HMS Ocean Assault Ships, and will be on the two future Queen Elizabeth class aircraft carriers. The project was worth 100 Million and the contract announced in 4 August, 2008. Command system The first few Type 23 frigates entered service without a computerised command system, so the Secretary of State for Defence was asked “what ability those type 23 frigates not fitted with an automated command and control system will possess to identify aircraft as either friendly or hostile.” The reply given was that: “The classification of an aircraft as friendly or hostile is based on information from a variety of sources including the ships identification friend or foe (IFF) system and other sensors. In T23 frigates not fitted with a command system this information will be available but will not be correlated automatically.” Crew size “When first commissioned the complement of crew carried by Type 23 frigates was 173. The current [February 1998] complement is 171.” “There are no plans to reduce the complement of Type 23 frigates by [...]