Hello. It looks like you�re using an ad blocker that may prevent our website from working properly. To receive the best Tortoise experience possible, please make sure any blockers are switched off and refresh the page.

If you have any questions or need help, let us know at memberhelp@tortoisemedia.com

HMS Victorious photographed in the Clyde estuary whilst on transit to the Clyde Submarine Base Faslane.
All at sea – the UK’s nuclear submarines

All at sea – the UK’s nuclear submarines

HMS Victorious photographed in the Clyde estuary whilst on transit to the Clyde Submarine Base Faslane.

Britain’s nuclear deterrent submarines are breaking records for the longest continuous patrol at sea. That’s a problem.

On 11 September a British nuclear submarine returned to base in Faslane, Scotland, its exterior coloured sludge-green by algae and barnacles. It was welcomed home by the UK’s deputy prime minister and the head of the Royal Navy.

So what? Neither of those things was normal. The Vanguard-class ballistic submarine is believed to have been on continuous patrol at sea for 196 days – more than six months; hence the VIP welcome home. 

The average patrol is now around five months, up from three in recent decades, with the record a reported 207 days underwater. 

This near-doubling of patrol lengths tests crew morale and equipment on the ageing submarines – with replacements for the Vanguard-class submarines still a decade away. 

That has raised fears of serious accidents that will be reinforced by reports – not denied by the Ministry of Defence – that a Vanguard recently dived towards crush depth without its crew being aware because of an instrument failure.

By the numbers

4 – Vanguard-class nuclear-powered ballistic missile submarines (HMS Vanguard, Victorious, Vigilant and Vengeance), each armed with…

48 – Trident 2 D5 nuclear warheads.

55 – years at least one British nuclear-armed submarine has been on patrol at all times to maintain a continuous at sea deterrent.

25 – original design lifespan (in years) of Vanguard-class submarines, under which…

3 – of the four submarines should have retired by now, starting in 2017.

Nuclear MOT. One reason for the lengthening patrols is that the Navy has been operating with only three or sometimes two fully operational deterrent submarines.

  • HMS Vanguard is currently undergoing sea trials after a seven-year refit (originally scheduled for three) finished in May;
  • HMS Victorious went into Plymouth’s Devonport facility in June for a long-planned multi-million refit – after also reportedly suffering a fire on board last year.

The existing deterrent submarines are due to be replaced by four Dreadnought-class submarines from the early 2030s as part of a £31 billion programme – but construction work is slow, says Pete Sandeman, a naval analyst and director of website Navy Lookout.

“It’s partly a political choice to spread out the cost but it’s also a capacity issue in terms of the engineers and people and facilities we have available,” he said.

Silent service. The First Sea Lord, Admiral Sir Ben Key, told a House of Commons defence committee last week that the pressure of the long deployments on the 130-strong crew and their families “keeps me awake at night”.

As crew members spend longer underwater, concerns are being raised about

  • Morale. The Navy “looks after its people as best it possibly can” says Sandeman, but the crew still face up to half the year in a metal tube without seeing daylight. Food becomes a big part of the day; fresh food runs out quickly. Once on board, crew members are allowed one 120-word message a week from their families – and it’s one way, says Ryan Ramsey, a former commander on a Trafalgar-class attack submarine. They can’t write back.
  • Discipline. “I think the longer the patrols get, the higher the psychological stress on the people serving on those submarines. And I think the higher the risk that something could go wrong,” said Marion Messmer, a senior research fellow in the International Security Programme at Chatham House. The Royal Navy opened an inquiry last year after reports said women were sexually harassed – one whistleblower described being named on a “crush depth rape list”.
  • Retention. “To my knowledge… there is nothing in place to enable the transition back to being a father, a brother, a sister,” Ramsey said. “We are asking way beyond what people join the submarine service to do.” He added that submariners could start to “vote with their feet”. The total Royal Navy workforce shrank by 4.1 per cent in the year to July 2023.

Nuclear risk. “The chances of a serious incident at sea… or some other misstep increase with each year that passes,” said Rob Forsyth, a former executive officer on Resolution-class submarines, which preceded the Vanguard-class.

A Royal Navy spokesperson would not comment on the reports of a depth gauge failure. When asked about the length of submarine patrols, they said: “We acknowledge the commitment and dedication of submariners and their loved ones, whose service keeps us safe from the most extreme threats to our national security and way of life.”

Facing Putin in the east and the risk of another Nato-sceptic Trump presidency in the US, it’s unlikely Britain’s politicians will reopen arguments against an independent nuclear deterrent any time soon. The question is how the Vanguard submarines – and their crews – can be stretched into the next decade.

Thanks for reading. Please tell your friends to sign up, send us ideas and tell us what you think. Email sensemaker@tortoisemedia.com.

Choose which Tortoise newsletters you receive

NEW from tortoise