Type 23 Frigates Still in Service: Why Only Five Remain

The Royal Navy has been left with only five Type 23 frigates fitted with the Sonar 2087 towed array, against a stated requirement for eight, a shortfall that a parliamentary inquiry has described as a serious anti-submarine warfare gap at a time when Russia is seeking to project naval power deeper into the North Atlantic. The finding came in the House of Commons Defence Committee’s report on defence in the High North, published on October 22, which noted that the Ministry of Defence itself had accepted the gap. The committee warned that the number of towed array frigates could remain as low as five for the next three years. The shortfall highlights how little margin a fleet built around a small number of highly capable escorts retains when older hulls are retired before their replacements arrive.

The towed array fleet fell from seven ships to five in mid-2026 when HMS Richmond and HMS Iron Duke were decommissioned, with a planned towed array conversion for Iron Duke having been cancelled and the ship withdrawn less than three years after a £103 million life extension refit. The remaining ships are HMS Kent, which has been in refit for more than two years, HMS Portland, HMS Somerset, HMS St Albans and HMS Sutherland. Against a requirement for 13 frigates and six destroyers set in 2010, the service now fields 11 escorts in total, the five Type 23s and six Type 45 destroyers, or roughly 58 percent of its own stated need. The specialist outlet Navy Lookout reported on October 23 that industry sources expected two more of the five frigates to be declared unseaworthy within months, with the class being retired by corrosion of its light hull steel rather than by the age of its combat systems.

Relief depends on the Type 26 class frigate, eight of which have been ordered from BAE Systems, with the lead ship HMS Glasgow scheduled to enter service in 2028. The program has been considerably complicated by Norway’s decision in August 2025 to buy five Type 26s, with Norwegian deliveries due to begin in 2030 and build slots between the two countries still under negotiation. According to the committee’s report, if two hulls being built for the Royal Navy were diverted to Norway to meet that deadline, the British fleet would not return to eight towed array frigates until 2037. The committee stated: “Export success must not come at the expense of the Royal Navy’s own Type 26 frigate delivery timelines.” It recommended that no further towed array Type 23 leave service until replaced one for one by a Type 26.

The inquiry also found that Britain has allowed the under-ice capability of its Astute class nuclear-powered submarines to lapse, and asked to be briefed on progress towards restoring it, as retreating ice exposes Russian Arctic bases that were once largely inaccessible and as Nordic neighbours rearm, with Finland buying one million landmines and Denmark ordering long-range strike missiles. The frigates and attack submarines are also tasked with protecting the Vanguard class ballistic missile submarines as they enter and leave Faslane in Scotland. In evidence to the inquiry the Ministry of Defence described anti-submarine warfare as a core strength of the British armed forces, and the government is expected to deliver its formal response to the report within two months.