SS Richard Montgomery Masts Lifted

Resolve Marine Group has finished removing the three masts from the SS Richard Montgomery. The vessel lies off the coast of Sheerness in the Thames Estuary, approximately 40 miles from London. The operation cost just under $13 million and was completed ahead of schedule. The ship, a U.S. vessel built during World War II, remains on the seabed with its cargo of munitions intact.

The Montgomery ran aground on a sandbar in August 1944. It was carrying supplies intended for Allied forces after the D-Day landings. During salvage attempts, the ship broke apart and sank. It retained an estimated 1,500 tons of explosives in its cargo holds. For decades, the three masts protruded from the water, visible to local residents and passing ships.

Recent surveys indicated the structure was deteriorating. Concerns grew that the masts might collapse and strike the cargo. Nolan Conway, a naval architect with Resolve Marine Group, explained that the vessel had begun to lean. He noted that if the masts fell onto the cargo, they could cause a detonation. Some of the munitions are believed to have pressure fuses, making them sensitive to impact.

The primary engineering challenge was cutting the masts without disturbing the wreck. The team constructed a custom lifting frame to raise each mast without swinging. They used a remotely operated underwater diamond-wire saw to cut the masts at the base. This device clamps around the mast with hydraulic arms and passes the saw through. The method allowed workers to avoid entering the water entirely.

U.K. maritime minister Keir Mather addressed the House of Commons this week. He stated that the complex project was finished on budget. Mather said the masts placed a significant load on the structure. Their removal reduces that risk and supports the long-term safe management of the site. The masts will be preserved and displayed at the Historic Dockyard Chatham museum.

The explosives remain in place because removing them carries considerable risks. Experts disagree on the potential consequences of a detonation. Conway said estimates range from effects on the shoreline to a tidal wave traveling up the Thames. Other assessments suggest a minor event that might only close a nearby shipping channel. He described the range of impacts as large, though none are positive. Officials still judge the overall chance of an explosion to be low.

The government maintains an exclusion zone around the wreck, which sits about 1.5 miles off the Sheerness coast. Mather said the site will continue to be subject to continuous monitoring and control through that zone. The masts are no longer visible above the waterline. The ship and its cargo will remain where they came to rest, now entirely out of sight.