Thames Wreck Cleanup: Masts Gone, But the Bombs Remain

The rusting spars that loomed over the Thames Estuary for eight decades are finally gone.

Officials confirm that a delicate operation to remove the three masts from the SS Richard Montgomery has been completed. The ship, a U.S. vessel that broke apart in 1944, still holds an estimated 1,500 tons of World War II explosives. While the tall structures have been cut away, the munitions inside the hull remain exactly where they have been since the ship sank.

The Montgomery was one of roughly 2,700 ships built in the United States to aid the Allied war effort. It grounded on a sandbar near Sheerness, about 40 miles from London, in August 1944. The vessel was transporting supplies for the forces after the D-Day landings. During salvage attempts, the ship fractured and settled into the estuary. For years, the masts served as a local landmark, but recent inspections revealed that the structure was deteriorating.

Concerns grew that the decaying masts could collapse onto the cargo, triggering a chain reaction. Nolan Conway, a naval architect with Resolve Marine Group, explained that the ship had begun to lean. He noted that some of the munitions likely contain pressure fuses. An impact from the falling masts could have set these fuses off, leading to a detonation.

The primary difficulty was cutting the masts without shaking the wreck. Conway’s team constructed a custom lifting frame to hoist each mast without causing it to swing. They also employed a remotely operated underwater diamond-wire saw. This device clamps onto the mast with hydraulic arms and cuts through it, eliminating the need for divers to enter the water.

U.K. maritime minister Keir Mather addressed the House of Commons this week. He stated that the complex project finished ahead of schedule and within budget. The total cost was just under $13 million. Mather argued that the masts placed significant load on the structure. Removing them reduces that stress and aids the long-term safe management of the site.

The explosives are staying in place because extracting them would pose considerable risks. Experts disagree on the severity of a potential explosion. Conway noted that estimates range from minor shoreline damage to a tidal wave moving up the Thames, or a smaller event that might only close a shipping channel. He summarized the situation by saying there is a large range of impacts, but none of them are really good. Officials currently judge the overall chance of an explosion to be low.

A government exclusion zone continues to surround the wreck, which sits about 1.5 miles off the coast. Mather confirmed that the site will remain under continuous monitoring and control. The removed masts are not being scrapped. They have been moved to the Historic Dockyard Chatham museum for display, honoring the ship's role in the war. The Montgomery will now rest entirely out of sight, but it is far from forgotten.