After months of maintenance and readiness challenges, the Royal Navy’s attack submarine fleet is back on course with a notable increase in activity, reflecting hard work behind the scenes to get boats to sea.

Currently, the Astute-class HMS Anson and the Trafalgar-class HMS Triumph are both at sea, following HMS Astute’s recent return to Faslane after completing Exercise Strike Warrior.

This renewed presence is a promising sign of the Royal Navy’s commitment to improving submarine availability and addressing prior maintenance backlogs.

Earlier this year, the Royal Navy faced prolonged periods without any of its nuclear-powered attack submarines (SSNs) at sea, underscoring the impact of maintenance delays and a stretched fleet. HMS Astute’s recent deployment and HMS Triumph’s return to sea reflect a marked improvement, demonstrating progress in fleet readiness.

With HMS Anson now at sea, the Royal Navy is fielding one of its most advanced submarines in the world. Meanwhile, HMS Triumph, the last active Trafalgar-class submarine, complements the numbers showing the fleet’s ability to sustain a balanced operational presence even as older vessels near the end of their service.

In recent years, the Royal Navy has started to prioritise significant upgrades to its submarine maintenance infrastructure, undertaking projects aimed at enhancing the operational availability of both the Vanguard and Astute-class submarines. Improvements such as the £200 million refurbishment of Number 9 dry dock at Devonport highlight the Royal Navy’s response to infrastructure bottlenecks that have previously hit fleet readiness. This upgraded facility now allows for more efficient deep maintenance on nuclear-powered submarines, helping reduce downtime and meet pressing operational demands.

We haven’t even mentioned Project Euston.

The Ministry of Defence previously initiated Programme EUSTON, a project designed to strengthen submarine maintenance capabilities at His Majesty’s Naval Base (HMNB) Clyde. This programme aims to establish two new floating dry docks along with supporting infrastructure to meet the demands of the Royal Navy’s submarine fleet.

Launched as part of a broader strategy to enhance operational readiness, Programme EUSTON is currently in the early concept phase, with market engagement underway to shape the project’s procurement approach.

Nevertheless, challenges persist, particularly with the ageing facilities and the limited number of dry docks available to support such complex vessels. Recent maintenance periods, including the extensive work on HMS Victorious, illustrate the scale and intricacy of sustaining the Vanguard-class submarines.

This resurgence in SSN activity highlights the Royal Navy’s efforts to overcome previous maintenance backlogs, ensuring that the UK’s undersea defence capabilities remain robust, responsive, and strategically ready.


At the UK Defence Journal, we aim to deliver accurate and timely news on defence matters. We rely on the support of readers like you to maintain our independence and high-quality journalism. Please consider making a one-off donation to help us continue our work. Click here to donate. Thank you for your support!

George Allison
George has a degree in Cyber Security from Glasgow Caledonian University and has a keen interest in naval and cyber security matters and has appeared on national radio and television to discuss current events. George is on Twitter at @geoallison

96 COMMENTS

  1. Project Euston is an interesting name.

    The 1840’s extension of the London Birmingham railway from Camden to Euston cost £74k. The origional contract survives in The National Archives.

    HS2 could cost £74Bn….

    • I never understood the reason behind HS2. Those mega projects always seem to double in size of the original costings. So is that 74Bn for just the London- Birmingham section? And for what 25 minutes of time saved. That money would have been better spent upgrading our existing rail services and fixing our roads.

          • They’ve already spent so much buying land and agreeing contracts that if they cancelled it now they’d still be down £30bn – and £74bn for not that much is better than 30bn for nothing at all.

          • Land goes up in value and can easily be sold or repurposed. Contracts are another thing depending on the terms.

          • Rule no 1 of project viability. You do not consider sunk costs when determining a projects financial viability.

          • A proven fact in assessing the viability of a projects.
            To continue just throws good money after bad.
            HS2 budget estimates are way off because they didn’t factor in the NIMBY factor and to appease the Tory voters it virtually had to run in a tunnel the entire distance.

          • Comparing the navy to hS2 is a non starter.
            HS2 is there to make money the navy is there to defend the country.
            Entirely different criteria

          • Not really. If they can save £44bn, they should. Maybe they should spend £10bn on a vertiport solution instead that would create new industry and exports, and maybe they sell some of the land or use it for something else.

        • Except for the minor problem that it was planned under the Brown governmnet in 2008/9. Never mind… facts do get in the way….

          • The thing is a huge amount of the increased costs relate to unforeseen tunnelling..almost all the unforeseen tunnelling is through Tory strongholds and is all about keeping places pretty and not about any civil engineering requirements…essentially Tory nimbys..they are tunnelling a total of 52.5 km of twin bore tunnels for a total of 104 kms of tunnels, that was never budgeted for. Also pretty much every council area between London and Manchester had some form of planning challenge. Also the government kept changing the specs..as an example they ripped up the Euston station plan and cost an extra 2 billion with that one decision…they added in delays as they looked to shave costs and all the delays in planning and changed decisions finally came up against the Ukriane war and covid…causing a world wide shortage in concrete and putting building materials costs up 30% in one month…

            basically it was a good plan if it had simply been got on with, no one asked for a tunnel because they are special people, no one challenged planning or changed their minds or slowed production for in year savings..and there was not a pandemic or Ukraine war…basically everything that is wrong with this country from an industrial capital project point of view.

            shows what we need to do

            1) remove political interference from projects..politicians decide then they need to Fuxk off and leave it be.
            2) remove the nimby lobbyists from planning, if it needs building for the good of society and it’s not harming your health..Fuxk off and sorry about the view.
            3) in year budgets for government projects need to go..funding should be entirely focused on making it as cheap and efficient as possible across the life of the project..not keeping to an in year budget that will create massive cost increase in future years.

          • The issue of budget bloat was largely tunnelling, mitigations and co struction inflation.

            The initial high cost was down to a daft 250mph running speed. It would have been half the cost at 186mph. And that would have made little difference to journey times.

            For the same money you’d have gone from London to Crewe.

            Another massive cost was the daft route alignment which was part caused by the daft running speed.

          • I bet. Never liked him. Stangely enough I had a chat with Tony Benn when I was in my early twenties and he was a charming man and a true believer in his Christian and socialist views. Bit of a contradiction I know but he wa s sincere.

        • Silly you for blaming Boris. This was actually a labour proposal in 2009. Because they believed we needed to increase the speed. This was 6 years after HS1 first opened. That is if we can blame any government, because it was the DfT that proposed the idea. And through time Tory Liberal coalition they decided on the track and company plus cost. And in 2019 the prime minister ordered a review to see if this was needed. Who was PM in 2019? Under Douglas Oakervee a British civil engineer and non executive chair of HS2 found it was needed. So rather than stop the money already spent. They went on a head. But at no time was this proposal Boris Johnsons. It’s really worth knowing what you say. Remember the Starmer regime has locked up innocent people for wrongful words. Even one person was found dead in jail Peter Lynch. Whether that was suicide or murder we won’t know ever.

      • It was very little to do with 25 mins saved, but the promotors made the mistake of majoring on that trivial advantage, thinking that the public would be impressed. Actually it is all about capacity on the existing west coast mainline, which is becoming critical and results in severely restricted access for freight trains, and long distance expresses being held back by various stopping trains.
        HS2 HAS to be built, but it would have been much better at a lower specification that did not need a continuous reinforced concrete base, rather than conventional granite ballast. Furthermore it is not logical to blame the railway for the ridiculous cost of lengthy tunnels, 10 mile long bat shelters and excessive use of viaducts at the whim of the various green lobbies.

          • bands up how many of you out there have started digging the bomb shelter in the garden now that trump is back again. my wife is complaining about it breaking her nails.

        • No expert – but couldn’t we go to double decker trains like the continent? Would it cost anywhere near £44bn to alter bridges / stations etc?

          • Bridges, stations and most expensively tunnels. You can spend loads of money on that and at the end of the day you’ve still got a victorian railway with bigger tunnels. Overall you get a better return on investment if you build new wide tunnels with a new shiny high speed railway going through them, because then you still have a victorian railway in addition to that which is perfectly adequate for carrying freight and local services. HS2 was originally specced for European sized trains so could handle double decker trains if the extra capacity is required in the future.

      • We needed a Jumbo not a Concord.
        Sadly MPs are rarely on the button and no major £billon +project has ever come in under budget

      • Much of the reason is that the cost at the start of the project are based on current costs while much of the final spending will have up to 30 years inflation. If projects run over budget which is normal the only way to fund them is to slow them down and use future years funding which inflates the nominal cost. Cross rail for instance started at £7 billion and ended up at £20 billion but it wasn’t three times over budget.

      • HS2 was never about saving time, it was always about capacity. By making HS2 high speed it is able to relive three main lines at the same time. A lower speed rail line couldn’t do this so you would have to either upgrade or build three new mainlines.

        As an example the sections of the East Coast mainline between Leeds and London are at capacity.

        The West Coast mainline is not near Leeds.

        By making a high speed line down the West Coast with a branch to Leeds you take traffic off the East Coast mainline as even though it’s further to travel the high speeds drive traffic to the new line.

        Also existing high speed trains on mainlines take up massive capacity.

        When they took Eurostar trains away from Waterloo and on to HS1 it increased rail capacity by 40% into Waterloo.

        HS2 would do the same for London as well as Birmingham and Manchester.

        All the cost overruns on HS2 can be explained by the Tory’s trying to placate NIMBYs in the South East.

        They should have put it down the M40 corridor and told every that wanted a tunnel to f**k off.

        • Spot on (as ever) Jim, and thanks for elaborating my point. Items of essential national infrastructure should have precedence over all other considerations. Those directly affected should be compensated fairly but no more.

      • As someone in the rail industry, HS2 has nothing to do with cutting journey times. That’s just the clickbait headlines that the media wanted to get out of it. It’s obviously a bonus, but HS2 is really about increasing capacity, specifically (and ironically now it’s been cut) between Birmingham and Manchester (or even just between Birmingham and Crewe). This section is currently a massive bottleneck.This goes for cargo and passenger rail services. The roads and railways work side by side, it isn’t some left vs right wing thing. If you don’t increase the capacity of the rail network, then you have to increase the capacity of the road network between those areas. The railway can be used to take many cars or many truckloads of cargo off of the roads. This will directly have a positive impact on drivers. Maybe you want to increase the lanes on the motorway instead, I personally disagree that that should be the priority due to reasons I won’t go into here, but either way some capacity expansion should be invested in.

        The governments we’ve had for the last x amount of years have been allergic to long term thinking/investment, whether that’s in transport, defence, education you name it. They think about what’s best for their time in power and then screw over the party that replaces them.

        As for the cost of the projects, the amount of money we spend on consulting/investigating for the most niche things that even the most left wing European countries don’t put the effort into plays a part. For a project to be successful in this country billions needs to be spent to ensure that not a blade of grass is trampled. Then the extortionate property prices and land values… And the nimbyism delaying everything…Oh and the difficult geotechnical conditions we have compared to somewhere like Spain… I could go on and on. Anyway… HS2 is a good idea that is worth the long term investment. It should have started in the North so that it wouldn’t be scrapped halfway through (and I’m a Southerner saying that).

      • Completely agree, capacity and consistency should have been the focus..it would have been so much cheaper to have created extra normal speed rail capability..high speed has to go straight,which is more engineering work and greater cost around land purchases add in the Conservative Party nimby lobby insisting every Tory seat was tunnelled under and it was always going to be a disaster..

        If it was going to be high speed, they needed to hold to their guns and refuse to tunnel unless it was an engineering requirement.

      • The main point of HS2 was never supposed to be improved journey time, that was intended just to be a nice side effect. The main aim was / is increased capacity both in terms of passengers but also in terms of freeing up the existing network for more freight carriage. One of the main causes for the increased costs was all the nimbys who resulted in an unreasonable amount of tunelling being mandated by government. Continuous government interference is a theme many on this site will be familiar with. As it stands, the North-West economy is effectively being strangled by connectivity issues, for which the only real solutions are a) build a big railway or b) build a massive new motorway. If the North-West economy is going to grow, and thus contribute to wider national growth, money needs to be invested in new infrastructure. Over time, a completed HS2 even at £74Bn will pay for itself several times over in terms of growth, and will thus also eventually pay for new defence spending, schools, hospitals etc.

    • Yes, increasing capacity was a key reason for the work and absent a complete shift to home working would be needed in future decades regardless. Any decrease in journey times was and is a complete red herring.

      The escalating costs of the programme are a different matter though – this could have been done for so much cheaper. There are lots of lessons to be learnt there.

      Why were the Victorians able and willing to build things that would last for generations and we, the inheritors of their work, so reluctant? Probably lots of reasons for that but we don’t appear to have any interest in leaving a lasting legacy for those that come after us.

    • Not quite correct -the main reason for HS2 was for relieving pressure on the West Coast Mainline, you can’t increase capacity on it.

      • It would be possible to increase capacity on the west coast main line by slowing trains down to say 75 miles per hour to match fast freight trains. You can only do that though by finding a new route for fast trains hence HS2.

        With current pendolino services running at 125 to 140 mph you need a lot of space behind a freight train and a following freight train creates a lot of space as it follows a fast passenger service.

        You could possibly already separate services where there are four tracks but there is quite a a bit which isn’t, or where there are crossings of other lines which are not segregated. Even where there are 4 tracks you can’t get long distance trains running at 125/140 mph, other passenger trains at 100/110mph and freight at 75mph. That requires 6 tracks. Almost nowhere is that possible without extensive widening works as there are only four tracks maximum on the most of the route. Widening would be very expensive going through towns and cities.

        Building for 300km per hour specification would have been much cheaper and may well be what gets built north of Birmingham in years to come.

        • How about increasing the speed of fast freight trains to passenger train speeds and taking slow freight trains off the west coast main line altogether?

          • Gauge corner cracking is part of the reason not to.

            Moving very heavy axel loads fast causes huge amounts of wear. The current rolling stock isn’t competent for higher running speeds.

            Stopping distances will exceed the block lengths so you would need multiple blocks so the problem gets worse not better for marginal increases in speed.

          • That would make sense if I was suggesting simply transportoing the same feight in the same rolling stock as now. However, not all freight is “very heavy” and I wasn’t suggesting using the current rolling stock. I’m suggesting fast freight only using brand new rolling stock, including more axels and better brakes if necessary. If all trains on the WCML ran at the same high speed, the density of trains could increase significantly (think of underground trains), which means the weight of freight per train could also decrease.

            The heavy stuff would go slowly on routes other than the WCML. It has to be cheaper to increase slow freight capacity than high speed passenger capacity.

        • Frieghts go on the Up, Down slow where the line is quadrupled, which is in many areas.
          It’s not just about speed. As a Signalman, I know trains go in paths, and slowing trains to 75 to me just means the signalling system is on restrictive aspects for longer as trains going slower take longer to clear the section, creating backlog in the rear and thus no new pathways.

          You either reduce the service, or create extra capacity, which HS2 was meant to do.

        • It is surprising how little of the journey is done at more than 110mph – very little 125mph running occurs. The upgrade to 140mph was never done as the costs had spun out of control when moving block signalling didn’t pass the safety case.

  2. Wow…an SSN article has become a Rail Forum!
    As a railwayman myself, I agree on the capacity issues around WCML and HS2.
    Pity about the route.
    On money, does building a gigantic concrete dry dock really cost 200 million?
    How is that possible please? Is MoD being fleeced again?

    • It’s actually modifying an existing drydock. But the nuclear nature of the subs makes for very strict requirements and in turn cost.

      • We have to rate our dry docks for strong earthquakes now in the UK if they have nuclear boats. Didn’t have to do that back in the day.

      • Yep, was aware it was already there, which to me makes it worse. Ok, the nuke side point taken. How does that run Into that amount? Cables? Power? What does an SSN have when it sits alongside that an escort does not? High security, and?

    • The US and Australia are paying billions for dry docks. Everything cost a fortune now a days. Probably even more reason to keep facilities like H&W.

      • Yes, You!!!! I looked back out of curiosity to see what sparked it.
        Just a simple observation from your good self. 😆
        There are some spotter anoraks on here beneath the military side that’s for sure.
        I’m only an anorak for the military side, and I work on the railway.

          • From the south west to sunny sussex…Exeter…Salisbury…Portsmouth /southhampton…Brighton..it was a slog get to the station for 5.40 and arrived at work for 10.00..then leave at six and get home for 22.30 anu delay days would be a hotel. Did that for 18 months..luckily my boss let me work at home one day a week ( it was a time well before covid and home working ).

    • Some topics immediately seem to go viral, doubt that railways would command that level of attention in the Colonies (except for a). However, passenger rail is of significance in select corridors. 😳😉😁🇬🇧

      From all reports the RN SSN maintenance backlog will be resolved relatively quickly. Wish the same could be stated for the corresponding USN issue. 🤔😳🙄

      • Medium term it might be worth the US using British facilities for maintenance. We conducted submarine maintenance for the US submarines for a number of years in the Cold War and labour cost in the UK are lower in dollar terms.

        US defence contractors seem to eye gouge the pentagon for almost everything. Perhaps with potential competition from Australian and British yards this could lead to better overall outcomes.

        • Did not realize before today that the UK maintained USN SSNs during CW I.
          Routine maintenance or complex refits?
          Thought offloading some USN SSN maintenance/refits to updated British yards was an inspired, original idea. Should have realized that there are no/few new things under the sun. 😎

          (Relatively) open competition (as much as practicable, given security requirements) is a fundamental tenet of a capitalist, free-market system. Those who bring lower cost, higher quality goods and services to market should reap the rewards. May the better shipyard(s) prosper. There may be greater opportunities once SSN-A program reaches IOC (greater compatability w/ Virginia class). Believe the real issue for British shipyards will be monitoring the progress and capabilities of the Australian shipyard(s). They will have the most modern infrastructure, and w/ the exception of PWR-3 maintenance, may underbid both UK and US yards for maintenance/refit contracts. 🤔😉🇭🇲🇬🇧

  3. Anyone know if it’s possible to extend the service life of the last Trafalgar class SSN?
    I’m hoping we get knees soon of either more Astute class bring ordered as an interim stop gap measure to return critical mass to the RN attack sub fleet before Aukus comes into service or that Aukus programme has moved to the left and is coming 5 years sooner.
    It might be useful to retain the last 2 Trafalgar class as a reserve force for special forces deployment, reconnaissance and as a reserve in case of a war with a peer enemy like Russia or China

    • Only 1 trafalgar left and it’s got no refit facility to go to so it will be retired soon. No more astutes as their reactors are out of production.

      Unless facilities are expanded any new Aukus subs will be post 2030, probably at least mid 2030s once dreadnoughts are finished.

      • Vast majority of articles on the topic state a RN SSN-A IOC late 2030s. Presume that date could be advanced, given unlimited funding.

  4. Hi folks hope all is well.
    Well that’s good news despite their initial low numbers we have to deploy at any given time.
    Whilst here, I appear to have trouble been able to be on this site. It takes ages to load and despite all other sites opening as normal, this one is slow. Anybody else noticed this recent
    issue?
    Cheers
    George

    • Evening, George, good to hear from you. DM and I, and others, have also commented on the same problem, in the past.

      Now, I’ve used Firefox as my web browser for years. This evening, after getting the same problem with UKDJ access, I switched to Microsoft Edge, to see what happens and – bingo, no problems at all.

      Are you using Firefox? Try Edge (or another browser) and let me know how you get on.

      Cheers to yourself!

      Crab

  5. The RN simply needs more boats.

    7 Astutes is insufficient for UK defence requirements, while the follow-on AUKUS submarines programme is constrained by the ineptitude of many in government, present and past, incl. the MoD, to have the single submarine construction facility at Barrow.

    There is clearly a need for a second yard, I’d go so far as to say in the south too, with the flexibility of concurrently building SSKs and Hunter-Killers; and it would augment the maintenance facilities too. For the SSK, consideration of an off-the-shelf design like the A26 would be an option, if the Upholder plans cannot be dusted off and refreshed in a reasonable time frame.

    This would be a boost for the UK economy, even more so if it were a BAE competitor.

    All it would take is a government with a set, committed to proper defence 🤔

    • Building Nukes is very complex; we’re only ever going to have one yard with that capability.
      It might be good to build a few (4 to 6) AIP SSKs in another yard for duties such as sweeping the Clyde estuary thus freeing the SSNs to go further afield as ‘attack’ boats as our American allies would describe them.

      • Yes, building Hunter Killers is a complex programme and worked up to now; however the issue is the necessity to expand fleet numbers and that is something the present facility (and company) are not able to deliver upon.

        A new facility, in the south, could lever off old dock facilities, long under utilised and wasted, for the new build and maintenance facilities near a large population base for the workforce.

        Thinking small (numbers) delivers small results. In the past 15 Oberon class were to be replaced with 12 Upholders; likewise the Hunter Killers got to 15, all again for the russian (no respect lowercase intedended) threat. Now you have to factor in the chinese too, so fleet numbers well north of those operated (or even planned) in the past are necessary, unless you a. learn russian, b. learn chinese, or c, have a burial plot somewhere.

  6. I’m a little puzzled. Anson is new and just returned from trials? Doesn’t surprise me that it was ready to return to sea at any point. Astute wandered out a little while ago and we now know why and Triumph still has a little umph in her so she is back out to sea.

    So really we still had a little flexibility dispite everyone saying our attack submarine force was as good as dead. Perhaps we should have a little more faith.

    Let’s hope we see the work progress on the other Astutes (most of which are probably perfectly servicable) get underway quickly and we have a large proportion of Astutes across the globe doing their job whilst in the interim the crew get some rest..

    • No the 3 outliers, Ambush, Artful and Audacious have not been at sea for years. Audacious we know is stuck in devenoport waiting for a refit, the other 2 are unclear but have either defects or lack of crew.

  7. Good morning, having just read the above mentioned subject regarding our nations (Dolphins) Silent Service,I seemed to have been transported to another place,time and bizarrely totally different subject regarding Westminster’s (Tory)which incidentally loosely translated from Scots Gaelic meaning Pirates/apologies/their Grand transformation of our creaking (Victorian railway system) wonderful at the time/to be HS2 ,we’re on earth or the for that matter which universe/planet/platform have I arrived on??
    Confused.com

  8. In Flanders fields the poppies blow
    Between the crosses, row on row,
    That mark our place; and in the sky
    The larks, still bravely singing, fly
    Scarce heard amid the guns below.

    We are the Dead. Short days ago
    We lived, felt dawn, saw sunset glow,
    Loved and were loved, and now we lie
    In Flanders fields.

    Take up our quarrel with the foe:
    To you from failing hands we throw
    The torch; be yours to hold it high.
    If ye break faith with us who die
    We shall not sleep, though poppies grow
    In Flanders fields.

    Wear Your Poppy With Pride

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