Masts removed from WWII wreck SS Richard Montgomery to reduce explosion risk

Removal of masts from Thames estuary wreck completed ahead of schedule and under budget, says minister

By LineZotpaper

Published20 October 2026

Updated20 October 2026

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Sources2 outlets

Engineers have removed the masts of the SS Richard Montgomery, a Second World War cargo ship sunk in the Thames estuary with 1,400 tonnes of unexploded bombs, in an effort to prevent a potential catastrophic explosion that could devastate the Kent coast and send a tidal wave towards London.

A sunken US wartime ship in the Thames estuary holding enough unexploded bombs to devastate a Kent coastal town and send a tidal wave through London has been made slightly safer, ministers have announced. The SS Richard Montgomery sank in 1944 with approximately 1,400 tonnes of munitions onboard. The masts, which had remained visible above water near Sheerness, were removed due to concerns that they could collapse in on the deadly cargo and trigger an explosion.

The potential effects of an explosion have divided expert opinion. Some believe it could cause a small tsunami, throw debris three kilometres into the air, and level Sheerness, according to a 2004 New Scientist report. A government report in 2000 said it was widely accepted that an explosion would put property and the local population at risk.

Maritime minister Keir Mather told the Commons on Monday that the work was completed ahead of schedule and under the estimated cost of £9.5 million. All three masts were successfully removed in a "complex project requiring specialist programme, engineering and risk management expertise". Mather said the masts had put "significant load on the structure and their removal has reduced that risk and supports the long-term safe management of the site."

The masts have been delivered to the Historic Dockyard Chatham, a maritime museum, "in recognition of the historic significance of the SS Richard Montgomery and its role in supporting the allied forces' efforts during world war two", according to Mather.

The wreck will continue to be monitored via an established exclusion zone. A shipping exclusion zone has long been in place, and since 2025 a no-fly zone has been added. Although the risk of an accidental major explosion is now deemed remote, local people have been alarmed by incidents in recent years, including the occasional close proximity of cargo shipping and a paddleboarder who uploaded pictures of himself leaning on the protruding masts.

Analysis

Why This Matters

The SS Richard Montgomery contains an estimated 300 2,000lb blockbuster bombs and more than 2,000 cluster bombs. An accidental explosion could threaten the population of Sheerness and potentially send a tidal wave towards London.
The successful removal of the masts reduces the immediate structural risk to the wreck, but the long-term danger remains. Continuous monitoring will be required.
This project demonstrates government investment in managing hazardous wartime legacies, with implications for public safety and maritime security.

Background

The SS Richard Montgomery was an American Liberty ship that sank in the Thames estuary in August 1944 while carrying munitions for the Allied war effort. It ran aground on a sandbank and broke its back. The exact contents of its three holds remain unknown, but defence agency reports indicate the presence of large quantities of high-explosive and cluster bombs. The wreck has been under constant surveillance and an exclusion zone enforced for decades. In 2025 a no-fly zone was implemented following concerns about the structural integrity of the masts.

Key Perspectives

Government and maritime authorities: The mast removal has reduced risk and supports safe long-term management. Monitoring and exclusion zones continue. Local residents and community: There is ongoing concern about the wreck, heightened by recent incidents such as cargo vessels passing close to the exclusion zone and unauthorised access by a paddleboarder. Expert opinion: Views are divided on the likely scale of destruction from an explosion. Some models predict a small tsunami and debris thrown three kilometres high, while others consider an accidental explosion extremely remote.

What to Watch

Continued monitoring reports and any further structural assessments of the wreck.
Any changes to exclusion zones or additional safety measures.
Potential historical or archaeological interest in the remaining cargo.

Sources

Masts removed from bomb-laden WWII ship in Thames in bid to avoid explosion · UK news | The Guardian
Masts removed from bomb-laden WWII ship in Thames in bid to avoid explosion · World news | The Guardian

Checked

8 claims in this story checked against 1 source: 6 supported.

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SupportedHeadline: the masts were removed from the SS Richard Montgomery wreck to reduce explosion risk.UK news | The Guardian: “The work was carried out because of concerns that the masts, which had remained visible above the water near Sheerness, could collapse in on the deadly cargo and blow up the ship.”
Partly supportedThe wreck holds "1,400 tonnes of unexploded bombs" (opening paragraph).UK news | The Guardian: “a second world war cargo ship that sank in 1944 with approximately 1,400 tonnes of munitions onboard”
Partly supportedThe explosion could devastate the Kent coast and send a tidal wave towards London (opening paragraph).UK news | The Guardian: “holding enough unexploded bombs to devastate a Kent coastal town and send a tidal wave through London”
SupportedWork was completed ahead of schedule and under the estimated cost of £9.5 million (summary and body).UK news | The Guardian: “He said work was completed ahead of schedule and below forecast costs, an estimated £9.5m.”
SupportedMather told the Commons on Monday that all three masts had been successfully removed.UK news | The Guardian: “Keir Mather, the maritime minister, told the Commons on Monday that work had now been completed, with all three masts successfully removed”
SupportedMather described the project as a "complex project requiring specialist programme, engineering and risk management expertise".UK news | The Guardian: “complex project requiring specialist programme, engineering and risk management expertise”
SupportedMather said the masts had put "significant load on the structure" and their removal reduced that risk.UK news | The Guardian: “Mather said that the masts had put "significant load on the structure and their removal has reduced that risk and supports the long-term safe management of the site."”
SupportedA 2004 New Scientist report says an explosion could cause a small tsunami, throw debris three kilometres into the air and level Sheerness.UK news | The Guardian: “Some believe it could cause a small tsunami, throw debris 3km into the air, and “level Sheerness”, according to a New Scientist report in 2004.”