Historic shipwreck still holds explosives

An American cargo ship, the SS Richard Montgomery, sank in 1944 near Sheerness in the Thames estuary and remains at the riverbed with about 1,400 tonnes of unexploded ordnance still on board.

Masts removed to reduce risks

Between mid-September and late September, seven diver-engineers from the company Resolve completed a careful operation to remove the three masts that had been sticking out of the ship's wreck. The effort, which cost 9.5 million pounds and was supported by the British Department for Transport, aimed to reduce navigation risks but did not involve the ship's explosive cargo.

Shipwreck’s history and cargo

The SS Richard Montgomery was a Liberty ship built in Florida and launched in 1943. It ran aground on August 20, 1944, off Sheerness, and sank 19 days later while waiting to join a convoy heading to Cherbourg with a cargo of ordnance. Rescue teams recovered part of the ordnance before the ship disintegrated, but a significant amount remained trapped in the flooded holds.

Wreck’s current state and survey findings

A survey in 2008 confirmed that the ship's hull now rests at a depth of about 15 meters, tilted to starboard. The operation to remove the masts, which involved cutting underwater metal structures up to 25 meters high, was carried out using the Neptune crane barge. The recovered masts are now being studied and preserved at the Historic Dockyard Chatham.

Remaining ordnance and safety measures

The initial cargo was estimated to be around 6,000 to 7,000 tonnes of ordnance, with about a fifth remaining today. The maritime exclusion zone remains in effect, and no boat can approach the wreck freely. British experts consider an accidental explosion unlikely but potentially serious due to the proximity of Sheerness and the maritime traffic in the estuary.