Thames Wreck Masts Cut Down in $13M Job

The three masts of the SS Richard Montgomery are no longer above the waterline in the Thames Estuary.

The vessel, a U.S. Liberty ship, ran aground off Sheerness in August 1944. It was carrying munitions to support Allied forces after the D-Day landings. The ship broke apart during salvage attempts and sank with its cargo intact. Estimates place the weight of the explosives in its holds at 1,500 tons.

For decades, the masts remained visible to sailors and residents. Recent engineering surveys indicated the structure was deteriorating. Officials feared the masts could collapse and strike the cargo, triggering a detonation. Nolan Conway, a naval architect with Resolve Marine Group, noted that the vessel had begun to lean. He explained that some munitions use pressure fuses, making impact a key risk factor.

Resolve Marine Group was hired to execute the removal. The firm constructed a custom lifting frame to raise each mast without swaying. They utilized a remotely operated diamond-wire saw to cut the masts free. This method eliminated the need for divers to enter the water. The operation concluded this week, coming in under the projected budget. The total cost was just under $13 million.

Keir Mather, the U.K. maritime minister, announced the completion to the House of Commons. He described the project as complex but successful. Mather stated that the masts had placed a significant load on the structure. Their removal reduces that risk and aids the long-term management of the site. The masts are now at the Historic Dockyard Chatham museum for display.

The explosives themselves have not been moved. Officials determined that removing the cargo would carry considerable risks. Conway noted that experts disagree on the potential impact of a detonation. Estimates range from minor shoreline damage to a tidal wave moving up the Thames. He added that the range of impacts is wide, though none are favorable. The government maintains that the overall probability of an explosion remains low.

A government exclusion zone remains in place around the wreck, which sits 1.5 miles off the coast. Mather confirmed that the site will continue to undergo continuous monitoring. The Montgomery and its cargo will stay where they came to rest, now entirely out of sight.