Thames Wreck Masts Removed in $13 Million Job, 1,500 Tons of Bombs Remain

The three rusting masts of the SS Richard Montgomery are gone, officials confirmed this week. The U.S. maritime minister stated that the complex project concluded ahead of schedule and within budget. The cost of the operation was just under $13 million.

The removal addresses a specific structural risk. Nolan Conway, a naval architect with Resolve Marine Group, explained that the vessel had begun to lean. He noted that the masts posed a threat to the cargo below. Conway said the fear was that the masts could fall onto the explosives and cause a detonation. Some of the munitions are believed to have pressure fuses, making them sensitive to impact.

The engineering team used specialized equipment to minimize disturbance. They built a custom lifting frame to raise each mast without swinging or swaying. For the underwater cuts, they employed a remotely operated diamond-wire saw. This tool clamps around the mast with hydraulic arms and passes the saw through, eliminating the need for divers in the water.

The SS Richard Montgomery ran aground in August 1944, roughly 40 miles from London. It was one of about 2,700 ships built in the United States to support the Allied war effort. The ship broke apart during salvage efforts and sank with an estimated 1,500 tons of explosives in its holds. The munitions were intended to support Allied forces after the D-Day landings.

The explosives remain on the seabed because removing them carries considerable risks. Experts disagree on the potential impact of a detonation. Conway described estimates ranging from shoreline effects to a tidal wave traveling up the Thames. He also noted that a minor event might only close a nearby shipping channel. He summarized the situation by saying, "There's a large range of impacts, but none of them are really good." Officials still judge the overall chance of an explosion to be low.

The government maintains an exclusion zone around the wreck, which lies about 1.5 miles off the Sheerness coast. Minister Keir Mather told the House of Commons that the site will continue to be subject to continuous monitoring and control through that zone. He said taking the masts off reduces the risk to the structure and supports the long-term safe management of the site.

The removed masts are now at the Historic Dockyard Chatham museum. Mather said they will be displayed in recognition of the ship's historic significance and its role in supporting Allied forces during the war. The SS Richard Montgomery and its cargo will stay where they came to rest, now entirely out of sight.