New Nuclear Attack Submarine Joints the British Royal Navy: How Capable is HMS Agamemnon?

The British Royal Navy has commissioned a new nuclear powered attack submarine, HMS Agamemnon, into service, which represents the sixth of seven vessels of the class planned to join the fleet. Unusually, the commissioning warrant was read by the head of state King Charles III, rather than the Fleet Commander, which was seen to reflect the growing perceived importance of the Armed Forces in civilian life at a time when the United Kingdom is actively involved in hostilities with Russia in the Ukrainain theatre. Commenting on the strategic significance of the attack submarine fleet, First Sea Lord General Sir Gwyn Jenkins stated at the commissioning ceremony: “The commissioning of the sixth Astute class submarine, HMS Agamemnon and the steel cut for the fourth Dreadnought class [strategic misslie] submarine, HMS King George VI, mark significant milestones in the Royal Navy’s enduring commitment to safeguarding our nation.” He further noted that the submarine fleet remains “respected by allies, feared by enemies and the pride of our island nation.”

Although the standings of the British defence sector and the armed forces have declined significantly over the past half century, the state of the submarine fleet and industry have drawn a sharp contrast to the highly problematic surface fleet. Costing approximately $2 billion each, the ships integrate a range of cutting edge technologies, including the use of 39,000 anti-acoustic tiles. With a crew of 98, Astute class ships can operate at depths of up to 390 meters and travel at 32 knot speeds when fully submerged. The 7,400 ton ships utilise two primary classes of armaments, namely Tomahawk cruise missiles and Spearfish torpedoes.

The lack of supersonic missiles or any kind of anti-ship cruise missiles remains a serious limitation of the Astute class, contrasting sharply to Chinese and Russian submarines which deploy both supersonic and hypersonic missiles for anti-ship and land attack role such as the YJ-21, the new YJ-19, and the Russian Zircon. Each submarine carries up to 38 missiles and torpedoes, unlike most submarine classes that use separate missile launch cells and torpedo tubes. Russian Yasen class attack submarines, for example, carry 32 cruise missiles and separately up to 30 torpedoes. In June 2025 it was revealed that the British Ministry of Defence was planning to finance an expansion of the nuclear-powered attack submarine fleet to close to double its current size, as part of the latest Strategic Defence Review. The Review prioritised both medium and long term preparations for possible conflict with Russia.