Fresh warnings of Russian undersea sabotage risk as UK’s 1,400-tonne explosive ‘doomsday’ ship raises security fears
Britain’s ‘doomsday wreck’ could unleash 7km blast as experts warn of growing undersea sabotage threat
Britain’s most dangerous shipwreck could trigger a devastating blast stretching for miles if detonated, as fresh warnings emerge over Russia’s growing undersea activity and the UK’s vulnerability to sabotage.
Listen to this article
The concern comes as the exclusion zone around the SS Richard Montgomery has been expanded, forcing shipping to give the explosive-laden wreck an even wider berth off the Kent coast.
The Second World War vessel still holds around 1,400 tonnes of munitions, raising fears of catastrophic consequences if it were ever triggered.
Speaking exclusively to LBC, Joakim Sjöblom, CEO and founder of SWEBAL, said the scale of destruction would be enormous.
“If 1,400 tonnes of munitions were to detonate on land it would create a blast radius of almost 7km,” he said.
As LBC reported last year, the Montgomery has long been described as a “sitting duck” for sabotage, lying close to busy shipping lanes and guarded only by buoys and warning markers.
Now, the wider threat picture is becoming more acute. One senior defence source told LBC it was "ludicrously dangerous” that the wreck remained under the control of the DfT and not “a department better equipped to protect this national security risk, laying off the coast.”
A flying restriction order remains in place above the area, with pilots and drone operators warned to stay away.
Defence Secretary John Healey has revealed that British and allied forces recently spent a month tracking a group of Russian submarines operating in the North Atlantic, including an Akula-class nuclear-powered attack submarine and two specialist deep-sea vessels linked to Russia’s GUGI programme.
A Royal Navy warship and RAF P8 surveillance aircraft were deployed alongside allies to monitor the vessels around the clock before they eventually withdrew.
Healey said the operation was intended to “track and deter any malign activity”, adding that Russian attempts to operate covertly had been exposed.
Security analysts say the presence of GUGI-linked submarines is particularly significant, given their known role in deep-sea operations targeting cables and other critical infrastructure.
Verineia Codrean, chief strategy officer at undersea drone firm EUROATLAS, warned the seabed is rapidly becoming a frontline in modern conflict.
“The seabed is becoming an active domain of conflict, but it remains difficult to monitor and protect,” she told LBC.
“What makes undersea threats effective is ambiguity. Disruption to cables or pipelines can have immediate economic impact, yet remain hard to attribute. That limits response options and allows repeated activity below the threshold of open conflict.”
She warned that without continuous monitoring and faster verification, critical infrastructure, including cables, pipelines and hazardous wrecks, remains exposed.
“The sea is one of the areas of conflict in which we are most exposed,” she added.
Russia has allegedly been mapping undersea infrastructure, including with vessels such as the Yantar, while the UK government has reported a sharp rise in suspicious activity in British waters.
Officials say there has been a 30% increase in Russian vessels posing a potential threat over the past two years, alongside growing evidence that Moscow has invested heavily in undersea drone capabilities.
Security experts also warn that so-called “shadow fleet” vessels could be used to deploy those systems covertly.
Taken together, analysts say, the ingredients for a grey zone attack are already in place.
However, a Government spokesperson told LBC: “Our priority will always be to maintain the safety of the public and to reduce the risk posed by the SS Richard Montgomery. The wreck is rigorously monitored 24/7 to ensure that the site remains stable and the exclusion zone is not breached.
“We are in the process of awarding a contract to Resolve Marine Group to remove the ship’s masts to minimise risk. We are also delivering the largest sustained increase in defence spending since the Cold War, with the Royal Navy receiving new capabilities including increasing surveillance, detecting threats, and deterring adversaries at sea.”
Speaking exclusively to LBC last year, Professor David Alexander, an expert in emergency planning and risk management, described the Montgomery as a “ready-made target” in the context of undersea sabotage and asymmetric warfare.
“This is a national security threat hiding in plain sight,” he warned.
The SS Richard Montgomery, laden with unstable munitions and sitting in a strategically sensitive location, is seen as a particularly attractive target: high impact, low cost, and plausibly deniable.
With Royal Navy resources stretched and attention often focused on crises elsewhere, including the Middle East, there are fears domestic vulnerabilities are being overlooked.
“All of this means that the threat of some kind of underwater incursion is high,” Codrean said.
“Russia has the information and the capability to carry out grey zone warfare and sabotage attacks like the one being warned about here.”
Earlier this month, the exclusion zone around the wreck was expanded to allow for survey work on both the vessel and the surrounding seabed, reinforcing concerns about its stability and the risks it poses.
The works, carried out by the vessel Maplin between March 23 and April 5, required ships to give the site an even wider berth.
Despite decades of warnings, the wreck is still sitting there, its ageing explosives becoming more unstable, and in today’s climate, increasingly seen not as a relic of the past, but a genuine national security risk.