The Government has admitted it is exploring new ways to ensure the wreck of a Second World War bomb ship off the Kent coast remains safe.

In a debate in the House of Lords about the American munitions ship SS Richard Montgomery located off the coast of Sheppey, Baroness (Diana) Barran said: "An advisory group of experts is considering whether monitoring and regular surveying is still the correct course or whether a more proactive intervention should be considered.

"Interventions could include the removal of munitions or some form of containment of the wreck.

"We appreciate there are no risk-free options which is why we are using the most qualified experts we can find."

She was speaking after Labour peer Lord Toby Harris of Haringey, 65, asked for a debate on the stricken ship which sank off Sheerness on the Isle of Sheppey 75 years ago.

He said on Wednesday (July 3): "The Government’s policy appears to be to bury its head in the Sheerness sands, presumably in the hope that the problem will simply go away.

"Every year the wreck disintegrates further. Surveys only look at its external condition. Nothing is known about the contents and their condition.

"Any of the munitions found elsewhere on their own would immediately trigger a major evacuation and an emergency. So why is the Government so relaxed about thousands of such bombs and shells deteriorating together in an unstable environment, unguarded and unprotected?"

He asked: "Why has nothing been done for 75 years? Why is there no plan to make the wreck safe? And who will take responsibility for what happens if it all goes wrong?"

The Maritime and Coastguard Agency says there are 1,400 tonnes of TNT on board.

Lord Harris says the vessel sailed with 35,943 explosive items, of which 13,961 remain. That is estimated to weigh 3,105 tonnes.

He said phosphorus had escaped from the holds and floated to the surface, catching fire on contact with the air.

The Royal Military College of Science warned in 1970 that if the remaining bombs blew up, the force of the explosion would create a 3,000 metre-high column of water and a five metre-high tidal wave would swamp Sheerness and its 11,000 residents and travel up the Thames.

It predicted the tsunami, possibly carrying burning phosphorus, would also reach the petrochemical installation on the Isle of Grain.

But Baroness Barran said the government did not believe a tidal wave would travel up the Thames.

She said: "We believe there would be a sudden displacement and replacement of water, which would impact the immediate vicinity but would not form a travelling wave."

She insisted: "The Government takes its responsibility for the wreck extremely seriously. The Richard Montgomery remains the most surveyed and the most monitored wreck in the country."

Conservative peer Lord (Chris) Patten, 75, the former Governor of Hong Kong, told the House: "We need to keep calm and carry on monitoring."

But Lord (Tony) Berkeley said: "I would not accept that the risk is remote. I am told there is a way of removing most of the cargo from the ship in a safe manner. We have a duty to get the widest possible expert procedure and method statement of how the cargo could be removed.

"The sooner this is done the better because if it breaks up, perhaps the explosives will go over the seabed and perhaps some will come to the surface and cause some very nasty accidents. It is in a pretty built-up area. We owe it to everybody who lives around there to get this sorted as soon as possible."

Lord Greenway said: "Some people have proposed either moving the whole wreck, which would be well-nigh impossible, or just removing the munitions. The latter course has been estimated to cost tens of millions of pounds and would probably involve the evacuation of Sheerness. I tend to follow the line of Lord Patten that we should leave well alone but continue to monitor closely."

Lord Addington said: "It was suggested that if a large amount of sand were to be put over the ship it would further lessen the risk. Another way is just to tell everybody to go nowhere near it."

Lord Rosser, shadow spokesman for Home Affairs and Transport said: "The official view is that the risk of a major explosion is 'believed' to be remote, which is certainly not entirely reassuring.

"Is it considered more dangerous to try to remove the remaining munitions than it is to live with the wreck as it is today with the munitions on board?"

He asked: "What is the cost of the current security and protection arrangements? What would the impact be on surrounding areas and the Thames if the remaining munitions were destroyed in a controlled explosion? And what would be the cost?

"Who will take responsibility if it all goes horribly wrong? My guess is that if it all went horribly wrong, it would result in one of the biggest buck-passing exercises in history."

Near Misses

Lord Harris said: "There are more than 5,000 vessels pass the wreck each year. Until 1978 there were 24 near misses but later figures are not available.

"Perhaps this is because of two potentially catastrophic incidents in May 1980.

"In the first, the MV Fletching grazed one of the marker buoys and came within 15 metres of the wreck.

"Later that week the Danish-registered Mare Altum, a chemical tanker of almost 1,600 gross tonnage carrying low-flashpoint toluene, was on a collision course. Disaster was averted only minutes before it would have hit the wreck.

"The consequences of that would have been unthinkable. How many near misses have there been in the period since then?"

In 2017, a paddle-boarder posted a picture on social media of himself balanced on the wreck.

In 1969 students from Kent University phoned the police as a prank threatening to blow up the wreck, which led to a massive security operation.

A similar operation was mounted during the 2012 Olympics, according to one source, because a speedboat carrying three men and explosives was intercepted nearby.

The ship is designated as a “dangerous wreck” under Section 2 of the Protection of Wrecks Act 1973 and so must be surveyed regularly.

USA

Lord Harris said: "The SS Richard Montgomery is owned by the United States Government. In 1948 and 1967, the US offered to make the wreck safe. Both offers were turned down."

He asked: "What were the last communications with the US on this matter and is the US Government still liable for the damage caused if the wreck explodes?"

Baroness Barron said: "The department is not sure why any offer of help from the USA was rejected. The issue has not been discussed recently."

Background

The SS Richard Montgomery was built in 137 days in 1943 by the St John's River Shipbuilding Company of Jacksonville, Florida. It was one of 82 Liberty ships made to ferry munitions to Britain.

The hull was welded rather than riveted so was more susceptible to cracking and the low-grade steel became brittle in the cold waters of the North Atlantic.

In August 1944 she was loaded with 6,225 tonnes of high-explosive bombs and detonators and arrived in the Thames estuary.

The King’s harbour master, based in Southend, instructed her to moor at Sheerness middle sands in 10 metres of water despite having a draught of 9.45 metres and a full cargo.

On Sunday, August 20, there was a force 8 gale.

The ship dragged her anchor and ran aground. As the tide ebbed, her plates buckled and cracked forcing the captain and crew to abandon ship.

On August 24 one of the holds was breached and two weeks later the ship broke its back.

Extensive salvage efforts took place over the next month and most of the ammunition from two of the five holds was removed until the operation was cancelled because it became too dangerous.

Read: The Government's latest report on the Richard Montgomery

See: Lord Harris in the House of Lords