The Royal Navy’s newest nuclear-powered attack submarine, HMS Agamemnon, has successfully submerged for the first time during trials at BAE Systems’ Barrow-in-Furness shipyard, according to the company.
The three-day “trim dive” in Devonshire Dock tested the 7,400-tonne vessel’s stability, buoyancy, and watertight integrity ahead of its departure from Barrow to join the Royal Navy’s fleet at His Majesty’s Naval Base Clyde.
The milestone follows the recent commissioning of the submarine by King Charles III.
Pete Tumelty, Astute Programme Director at BAE Systems’ Submarines business, said in the press release: “This trim dive is the culmination of months of hard work. I’d like to thank all teams involved for their commitment and professionalism. We’re incredibly proud of the contribution we’re making to the nation’s security and Barrow’s long and distinguished heritage as the home of UK submarine design and build.”
Commander David “Bing” Crosby, HMS Agamemnon’s Commanding Officer, said: “The trim and basin dive is a key step in the commissioning of HMS Agamemnon. This period enables us to set the boat’s internal weight, prove her water-tight integrity, test sensors and put some of our systems through their paces ahead of sailing for the first time. It takes a great deal of planning and preparation to achieve this key step and all involved should be very proud of the part they have played.”
HMS Agamemnon is the sixth of seven Astute-class submarines built by BAE Systems. Alongside the Astute programme, the company is constructing four Dreadnought-class boats, which will replace the Vanguard-class submarines currently maintaining the UK’s Continuous At Sea Deterrent.
Henry Musgrave, Head of the Astute Delivery Team at the Submarine Delivery Agency, said: “The successful completion of HMS Agamemnon’s trim dive marks a pivotal milestone in our mission to safely deliver available and capable submarines to the Royal Navy in defence of our nation. This achievement reflects the exceptional collaboration between the SDA and our partners across the Defence Nuclear Enterprise.”
BAE Systems noted that design work is continuing on the future AUKUS-class submarines, developed in partnership with the United States and Australia. The company’s submarine workforce has grown from 10,700 in 2023 to 15,000 today, with projections of reaching 17,000 in the coming years.
By far the most potent tools in the RN – I’ve heard them compared to a particularly quiet later LA-class boat in terms of the noise they produce, whilst having a sonar suite rivalled only by the American equivalent. Anecdotally, they’re usually talked about in the same conversation as the Russian Yassen and American Virginias, likely on the lower end of that scale, but at such fine margins that the difference is negligible in reality.
Twelve new submarines to replace them is a good idea – assuming roughly 4-8 active at anyone time, that gives you a minimum of one with the CSG, two in the North Atlantic/UK and 1 in the Pacifc, with the potential to surge out significantly more boats if needed.
I thought they were meant to be quieter than the LA-class, but how would anyone know?
A future increase from 7 Astute boats to 12 successors? I’ll believe it when I see it.
My comments came from a former American submariner I was talking to a while back. He said he couldn’t give me exact statistics, but he also said to bear in mind that the condition of a boat makes a big difference to its acoustic signature. A ship fresh out of the dock and with a top crew (as RN crews generally are) will sound much quieter than a more worn submarine. He was also referencing the later models of the LA-class in that comparison, which were arguably closer to the early Virginia-class boats than the first of their class.
Again though, in actual combat, these differences are so minute that any alterations to the situation at sea could negate them altogether.
12 boats is definitely going to be tricky to pull off, but we’ll see. Given the RAN should also be buying five, the costs of various subsystems will drop as more are ordered (thinking reactors, VL systemsm, et cetera). The thing is, you could probably still achieve the same ‘4 boats at sea’ position I mentioned above with just 8-10 new submarines.
I remember when these were first “Imagined”.
35 years ago.
But just one more to go now.
Does anyone know how many are out on patrol at the moment?
Yes they do.
Astute has just gone into refit, and I think the others are alongside for maintenance right now, with the exception of Anson potentially?
I’m thinking one at the maximum, more likely none. 🙁
Yes there is currently one SSN and one SSBN out
Thanks.