When a Vanguard-class submarine returned to Faslane this week after around 205 days at sea, it was a testament to the endurance and dedication. But the more uncomfortable story is what recent record-breaking patrol lengths actually say about the state of Britain’s nuclear enterprise, and it isn’t a flattering one.
Maintenance periods have lengthened significantly, which has forced patrols to extend in order to sustain the Continuous At Sea Deterrent. The arithmetic isn’t complicated: if one boat is stuck in a delayed refit for longer than planned, the boats that are still operational have to stay out longer to cover the gap.
This is partly because ageing submarines become harder and more expensive to maintain, with unplanned defects becoming more frequent and the schedule margin for everyone else getting thinner as a result. For example, HMS Vanguard’s deep maintenance and refuelling overran by four years, which, again according to the Nuclear Information Service, pushed back the planned maintenance of HMS Victorious and generally piled more pressure onto the other boats, cascading through the whole programme.
Alongside this, the force has been dealing with well-documented industrial constraints, including shortages of nuclear-qualified engineers and delays to infrastructure upgrades, all of which reduce the capacity to turn boats around quickly enough. Extended patrols also make it harder to recruit and retain people, so experienced submariners leave after record-length deployments and take years of institutional knowledge with them, which makes the next maintenance period harder still.
What’s being done?
The naval leadership has at least acknowledged the scale of the problem. First Sea Lord General Sir Gwyn Jenkins visited Faslane in January 2026 to launch the Submarine Maintenance Recovery Plan, saying that “submarine maintenance throughput needs to drastically improve” and calling for “a radical engine for change in the middle of our enterprise.” In the short term that’s meant creating deployable engineering workshop space at Clyde using containerised facilities, adding around 90 square metres of additional workshop capacity fairly quickly, alongside further temporary facilities at an undisclosed location elsewhere.
The plan also tries to address a structural problem where multiple teams were working on different parts of the issue without enough authority or resources to actually fix the system as a whole.
Looking further out, the Clyde 2070 infrastructure programme, formally launched in July 2025, is focused on modernising Faslane over the long term to support the Dreadnought class and eventually SSN-AUKUS submarines, with £250 million committed over the first three years of what is expected to be a multi-decade effort.
The Ministry of Defence recently confirmed that the Royal Navy’s long-planned additional fleet docking capability is now formally being delivered through Programme Euston, with the aim of providing new out-of-water engineering capacity at HM Naval Base Clyde in the early 2030s. In a written parliamentary answer, Defence Minister Luke Pollard said Programme Euston is the Navy’s solution to the requirement for additional fleet time docking, a capability seen as increasingly critical to sustaining the UK’s submarine force.
“Programme Euston is the Royal Navy’s solution to Additional Fleet Time Docking Capability,” Pollard said. “The programme aims to deliver a resilient out of water engineering capability at HMNB Clyde by the early 2030s.”
He added that the next major milestone will be the submission of a Programme Business Case in mid-2026, after which timelines will continue to be reviewed through the Ministry of Defence’s major programmes portfolio. The department declined to provide more detailed delivery schedules, citing commercial and operational sensitivities.
The biggest long-term fix is probably the Dreadnought class itself, which is designed from the outset with the lessons of the Vanguard era in mind and is intended to be easier to sustain, with modern infrastructure and a trained workforce ready to support it when it arrives. A new Trident Training Facility Extension opened at Faslane in March 2026, ahead of schedule, which will train up to 130 Royal Navy submariners for each of the new boats, with the first intake expected later this year. Whether the recovery plan delivers improvements quickly enough to meaningfully shorten Vanguard-era patrols before the class retires is probably the critical question hanging over all of this.
The long-term solutions carry their own risks though. According to the excellent Navy Lookout, one of the main causes of the current pressure traces back to a decision made in 2010, when the Cameron government delayed main gate approval for the Successor programme by five years, reportedly saving around £750 million in the short term while adding costs running into billions over the longer run and leaving the submarine force under growing strain throughout the 2020s.
The Clyde Infrastructure Programme itself holds an Amber delivery confidence rating, reflecting ongoing problems with resource availability and inflation, and balancing infrastructure work with live submarine operations at the same site is a significant logistical challenge in itself, as is attracting and keeping people with the right expertise in nuclear operations and project management.
The same workforce and capacity pressures that have pushed patrol lengths to record levels are bearing down on the programmes that are supposed to fix them, and while the recovery effort is real and the investment is substantial the margin for further slippage is pretty thin, but things are on the right track, at least.
All those responsible for this sad state of affairs are probably retired and living a comfortable life without a care now.
Being in maintenance for 4 years seems ridiculous enough to me, but overrunning by 4 years? 7 Years on maintenance? It “only” took 6 years to build!
Once the reactor is hot some things take a lot longer.
There are always growing issues with running boats well beyond their intended lifetimes.
Nuke ships are not like conventional ships. What’s being described above sounds a lot like a USN ‘RCOH’ (Refuelling and Complex Overhaul) period. In this period, they will cut a hole in the boat’s pressure hull to access the reactor vessel. They’ll put a structure above that hole to safely remove the spent fuel. This is not an effort for the faint of heart due to the dangers involved. The reactor must be shut down for a fairly long period of time before you can even START the effort because the fuel is still insanely hot due to latent heat from the reaction. Since the whole ‘replace the fuel’ thing is already taking ages, most services who own nuke boats basically defer a pile of maintenance until its time for the refueling so they can do both at once. A Nimitz class might see the cats completely stripped out and rebuilt during this time. Several have had the entire main mast and portions of the island removed and replaced (major structural work).
So, while a QE can go in and out of maintenance every few months to take care of the little nits that develop, Charles De Gaulle and Nimitz defer those things because they’re going to be laid up and cut open for YEARS anyway doing refueling. Thus, the refueling becomes a cluster of all kinds of structural, electrical, and hydraulic maintenance along with massive systems upgrades. Some of this stuff comes with unforeseen consequences that add delays and unforeseen costs.
The rise of ‘life of ship’ reactor cores should see nuke ships moving closer to the normal maintenance practices, but the Vanguards are still stuck in the past.
Only Vanguard received an additional refuelling which was done as a precaution. However it’s been ascertained that the other three don’t need it for the service life extension fortunately.
Remember Covid? That had a big impact on the speed of refit work. Social distancing, Limited workforce available on site etc.
It seems to me that in this country for the last 30 years since blair we are run by idiots who i wouldnt trust to run a bath !!!!!!
@George one of your best articles.
It really says something that Starmer is greeting each boat as it comes back.
Oddly, it says something about his priorities but it also implicitly states and acknowledges the massive sacrifices the crews are making in less than ideal conditions.
Navy outlook states that the issue with the submarines is being caused because one boat has sat along side for 19 months (it doesn’t say which boat)
Does any know what the issue actually is and what boat it is outside the rotation for so long.
PS I don’t need the usual daily Mail conspiracy crap about swapping spare parts between nuclear submarines being the issue. Just want to know if anyone has any actual information that can be shared legally obviously.
Much respect to the crew and their families, thank you.
Would it not be better for future generations if we could turn the mistakes of previous politicians into morality tales. It would be extremely useful if we couild bring Cameron, Osbourne and Hammond to account and remove any hnours or peerages as punishment for making bad decisons. It would serve to frighten the next generation of politicans into something resembling competence.