The Royal Navy’s sixth Astute-class attack submarine, HMS Agamemnon, is in the final stages of commissioning and is expected to depart Barrow-in-Furness to begin sea trials by the end of 2026, the Ministry of Defence stated in a written answer to a parliamentary question.
Liberal Democrat MP James MacCleary had asked the Secretary of State for Defence when HMS Agamemnon was expected to be fully operational.
Minister for Defence Readiness and Industry Luke Pollard replied: “HMS Agamemnon is in the final stages of commissioning, and we continue to work closely with industry partners to deliver the submarine by the end of 2026, at which point she is expected to depart Barrow and commence sea trials.” He continued: “For security reasons, we do not disclose specific timelines for full operational capability, which will be dependent on the successful completion of these trials.”
The reluctance to set out a date for full operational capability is consistent with longstanding MoD practice on the submarine fleet. The dates at which individual boats achieve operational status, the work-up patterns that precede them and the patrol patterns that follow are treated as classified information across the Royal Navy’s underwater enterprise.
Pollard’s answer confirms only the broad sequencing from commissioning through departure to sea trials, leaving the period between trials and front-line tasking unstated.
HMS Agamemnon is the sixth of seven Astute class submarines being built by BAE Systems at Barrow-in-Furness for the Royal Navy. The class, designed and built to replace the Trafalgar class boats, provides the Royal Navy’s nuclear-powered attack submarine capability and is configured to carry Spearfish heavyweight torpedoes and Tomahawk Land Attack Missiles. The first five boats, HMS Astute, HMS Ambush, HMS Artful, HMS Audacious and HMS Anson, are now in service, with HMS Achilles, the seventh and final boat of the class, in build behind HMS Agamemnon.
HMS Agamemnon was launched at Barrow in October 2024. The boat’s transition from build through commissioning to sea trials will, on the timeline set out in Pollard’s answer, see it leave the Devonshire Dock Hall by the end of 2026 to begin the long process of trials and work-up that traditionally precedes acceptance into front-line service. For previous boats of the class that process has taken several years.
The Astute class, alongside the four Vanguard class ballistic missile submarines, constitutes the totality of the Royal Navy’s nuclear-powered submarine force. The boats operate from HM Naval Base Clyde at Faslane, alongside the Vanguard force, and are tasked across roles ranging from the protection of the continuous at-sea nuclear deterrent to intelligence collection, strike operations and maritime interdiction.
“In service”? Yeah right….
She was originally due to depart Barrow and commence sea trials etc at the end of March, and ready to join the fleet early 27. So she will be approx 1 year late when she does join the fleet.
Of course, much will depend on how all the trials and work up goes, perhaps time can be saved between the different stages of her trials/work up package given that this is a fairly extensive and known period of time.