HMS Vengeance, one of the UK's four nuclear-armed Vanguard-class submarines, has returned to its base at Faslane in Scotland after a record 217 days submerged, surpassing the previous 205-day record set by HMS Vanguard. The seven-month deployment has prompted questions about the toll on the crew and the reliability of the ageing boats.
HMS Vengeance began its patrol on 12 April and remained underwater until Sunday. It was still carrying Prime Minister Keir Starmer’s letter to the captain. The next boat on rotation will carry instructions from his successor, Andy Burnham.
The Vanguard-class submarines, brought into service in the 1990s, were designed to carry three to four months of food for crews of about 140. Missions now start with tinned food crammed into corridors. The long patrols have raised concerns about the psychological impact on crew members, who cannot message out and whose submarines cannot be resupplied.
"Patrols are getting longer and longer," said David Cullen, a nuclear expert at the Basic thinktank. "The fleet was designed around three-month tours, and that was considered to be a long time to be stuck underwater in a metal box with no contact with the outside world."
The increase in time at sea reflects the slow pace of submarine maintenance. Labour has blamed spending cuts implemented by the Conservatives. Naval chiefs insist there is a plan for improvement. In July, Labour announced a £26 billion, 10-year plan to invest in the navy’s three main bases, including Faslane. The head of the Royal Navy, Gen Sir Gwyn Jenkins, said he had “nothing but tremendous respect” for Trident sailors but added that the UK needed to “improve our submarine maintenance” to allow faster turnaround.
The Royal Navy is struggling to recruit new personnel. The submarine service has also contended with allegations of sexual abuse and harassment during deployments. In October 2024, the then first sea lord apologised to women who suffered “misogyny, bullying and other unacceptable behaviours” in the submarine service. The navy conducted an inquiry after a whistleblower complained of a “constant campaign of sexual bullying”.
The first replacement for the Vanguard class, HMS Dreadnought, is not expected to be ready until about 2032, meaning the current boats must operate for at least five more years. “The inherent risks of operating submarines are being pushed by them being run as they are,” Cullen said. “At the end of the submarines’ design life they should be run gently, not as hard as they are.”
Analysis
Why This Matters
- The record patrol tests the limits of the UK's continuous-at-sea deterrent, which depends on the physical and mental endurance of submarine crews and the reliability of aging vessels.
- Crew welfare and allegations of harassment complicate recruitment and retention in a navy already struggling to find new personnel.
- Extended deployments and maintenance delays raise strategic questions about the credibility of the UK's nuclear deterrent until the Dreadnought class arrives.
Background
The UK has maintained a continuous at-sea nuclear deterrent since the 1960s. The four Vanguard-class submarines, armed with Trident missiles, entered service in the 1990s. A replacement class, the Dreadnought, has been under development for years but will not be ready until the 2030s, forcing the old boats to serve longer than originally planned. The maintenance process has been slow, leading to longer patrols.
Key Perspectives
Labour government: blames the record patrol length on maintenance delays caused by spending cuts under the previous Conservative government.
Royal Navy chief Gen Sir Gwyn Jenkins: acknowledges the need to improve submarine maintenance and speed turnaround, but insists there is a plan for improvement.
David Cullen, nuclear expert at the Basic thinktank: warns that pushing the submarines hard at the end of their design life increases operational risks.
What to Watch
- Whether the Ministry of Defence can reduce patrol lengths back to three to four months as maintenance improves.
- The progress of the Dreadnought programme and any announcements about its timetable.
- Any further reports or investigations into crew welfare and the handling of harassment allegations.
Checked
12 claims in this story checked against 1 source: 12 supported.
Show each claim
- SupportedHMS Vengeance ended a record 217-day patrol.World news | The Guardian: “HMS Vengeance began its patrol on 12 April and spent 217 days submerged before returning on Sunday”
- SupportedThe record patrol raises concerns about crew welfare and the ageing fleet’s reliability.World news | The Guardian: “has raised questions about the strains placed on sailors and the reliability of ageing submarines sent on the extended missions.”
- SupportedHMS Vengeance returned to Faslane in Scotland after the patrol.World news | The Guardian: “returning to the Faslane naval base in Scotland”
- SupportedThe patrol surpassed the previous 205-day record set by HMS Vanguard.World news | The Guardian: “Its tour underwater surpasses the old 205-day record, set by HMS Vanguard”
- SupportedHMS Vengeance began its patrol on 12 April and remained submerged until Sunday.World news | The Guardian: “HMS Vengeance began its patrol on 12 April and spent 217 days submerged before returning on Sunday”
- SupportedCullen said, “Patrols are getting longer and longer.”World news | The Guardian: ““Patrols are getting longer and longer,” said David Cullen, a nuclear expert with the Basic thinktank.”
- SupportedCullen said the fleet was designed around three-month tours, considered a long time to be underwater without contact with the outside world.World news | The Guardian: ““The fleet was designed around three-month tours, and that was considered to be a long time to be stuck underwater in a metal box with no contact with the outside world.””
- SupportedThe increase in time at sea reflects the slow pace of submarine maintenance.World news | The Guardian: “The increase in the time spent at sea reflects the slow pace of submarine maintenance”
- SupportedIn July, Labour announced a £26 billion, 10-year plan to invest in the navy’s three main bases, including Faslane.World news | The Guardian: “In July, Labour announced a £26bn, 10-year plan to invest in Britain’s three main naval bases, at Faslane, the operational home of the Trident submarines, Devonport and Portsmouth”
- SupportedGen Sir Gwyn Jenkins said he had “nothing but tremendous respect” for Trident sailors and that the UK needed to “improve our submarine maintenance”.World news | The Guardian: “Gen Sir Gwyn Jenkins, said he had “nothing but tremendous respect” for the Trident sailors, but added that the UK needed to “improve our submarine maintenance” to allow faster turnaround.”
- SupportedHMS Dreadnought is not expected to be ready until about 2032, leaving the current boats with at least five more years in service.World news | The Guardian: “HMS Dreadnought, is not expected to be ready until about 2032, meaning that the old boats have at least five more years to remain in service.”
- SupportedCullen said the risks of operating submarines were being pushed by how they were run, and that they should be run gently at the end of their design life.World news | The Guardian: ““The inherent risks of operating submarines are being pushed by them being run as they are. At the end of the submarines’ design life they should be run gently, not as hard as they are,” Cullen said.”