From the https://www.express.co.uk By James Murray. 10 January 2022.

The WW2 pub trip that set a time-bomb ticking in the Thames.

AS THE MoD plans a £4m clean-up operation, the Express reveals how a sea captain's night ashore 78 years ago put the estuary at risk of a huge explosion and devastating tsunami.

Thames Estuary and shipwreck masts.

The SS Montgomery could cause a tsunami that would 'flood London'.

Settling down for a night in the "Jolly Sailor" pub, Captain Charles Wilkie could not shift a nagging worry about his ship, the SS Richard Montgomery, which he had left anchored little more than a mile away off the Kent coast in the Thames estuary. It was August 1944, just 11 weeks after D-Day, and as history has shown, he had good reason to be concerned.

The US-built cargo vessel was carrying 6,862 tonnes of bombs and waiting to join a convoy of ships heading to Cherbourg, France, to replenish Allied supplies. But a storm was already whipping up the waters of the Thames estuary.

Wilkie, an American, had been directed to drop anchors by Royal Navy Lieutenant Richard Wilsley but, concerned he could become grounded on a sandbank, he and his boatman had gone ashore to seek a second opinion from the local expert at Sheerness dockyard. Shipping controller Reginald Coward agreed it would be safer to anchor where the estuary had been deep-dredged and there were three solidly-anchored buoys to fasten to.

But fate was already conspiring against Wilkie: the gathering storm made it unsafe to risk a return journey in a small boat at night.

That is how J C Wilkie and his boatman came to sign in as guests at the "Jolly Sailor" while his ship and crew were left under the command of his first officer, according to historian Colin Harvey.

The SS Richard Montgomery in her prime. (Image: Colin Harvey).

Even as the captain slept in a room above the pub, in the Blue Town area of Sheerness, a calamity was unfolding at sea.

The ship, buffeted by strong winds, was dragging its anchors easily across the muddy seabed. By the time the skipper returned to his vessel on the morning of August 20, she was firmly stuck on a sandbank, with no chance of being refloated.

Now, 78 years on, the catalogue of clangers still haunts the people living on the Isle of Sheppey, Kent, and those eight miles across the estuary in Southend, Essex. For the wreck of the SS Richard Montgomery, or Monty as locals call her, remains laden with submerged bombs equivalent to 1,400 tonnes of TNT.

A leaked MoD report says a blast could produce a 16ft tsunami, which would threaten lives - along with vital gas and oil installations on the Kent coastline. An explosion "would throw a 300 metre-wide column of water and debris nearly 3,000 metres into the air and generate a wave five metres high". And historian Mr Harvey, 79, from nearby Sittingbourne, Kent, is deeply concerned about the likelihood of such a disaster as the wreck becomes more unstable.

The ship's three metal masts protrude above the water from the submerged and crumbling deck, and are corroding badly below the waterline. If they collapse into the munitions, they could trigger a huge explosion and subsequent tsunami.

The pub’s August 1944 guest book showing Captain Wilkie ’s name. (Image: Colin Harvey).

"Sheerness, the largest town on the Isle of Sheppey, is below sea level, so you can imagine how much damage a 16ft tsunami would cause," says Mr Harvey.

"When you look at the history, all this could have been avoided. The ship was directed to anchor at a place where she could have rested on the sea bed at low tide. She should never have been there in the first place. Coward was absolutely right to suggest the captain move her, but it was too late. If only Wilkie and Coward had put the plan into action immediately, disaster would have been avoided."

He explains: "After spending the night at the "Jolly Sailor," Captain Wilkie returned to his vessel the following morning to see she had moved position on to a large sandbank called Sheerness Middle Sand. She was stuck there.

"A few days later the ship started to crack under the immense strain, but the captain and crew stayed on board. They did manage to get some munitions off-loaded but she broke in two and the last of the US civilian crew abandoned ship.

"Stevedores remained on board for a few more weeks to get more munitions off but then it became too dangerous. A list of what was taken off has been destroyed so nobody actually has an inventory of that. Some munitions were taken to Chatham and Sheerness but it is not clear what happened to them then."

Local historian Colin Harvey with wreck in the background. (Image: Colin Harvey).

An inquiry into the grounding was rushed, claims Mr Harvey. It heard that nearby vessels reported seeing the ship moving in darkness but that the first officer, who was on duty that night, was at a loss to explain why he didn't wake up the captain.

The historian suspects the first officer could not tell the inquiry why he did not wake the captain because Wilkie was at the "Jolly Sailor" pub - and not aboard his vessel as he should have been.

"You have to remember this happened at a critical time in World War Two when everyone was working under pressure," he says.

"This was a problem to come back to once the war was over, but it was never properly resolved. All the munitions should have been taken off soon after the war but it was ruled too costly and probably too dangerous.

"However, the situation is not any better now than it was then. In fact, it's probably a lot worse. Monty has been hit once by a vessel and there have been more than 20 near misses. It is right by a busy shipping lane. There are cracks and holes in the hull now, so munitions could eventually escape.

A montage of sonar images of Monty on the Thames riverbed. (Image: Colin Harvey).

"To safely remove the munitions now would cost about £300 million and would involve building a massive enclosed structure around the wreck, draining off the sea water and air, then pumping inert gas into the enclosure to reduce the risk of explosion. It would be a massive operation."

As part of his inquiries, Mr Harvey discovered a baffling, erroneous, letter sent to Sheerness Council in 1962 from the office of the Commander in Chief of the US Naval Forces in Europe, denying the existence of the wreck.

Signed by a Lieutenant J S Cohune, the letter states: "On 20 August 1944 she [The SS Richard Montgomery] went aground at the bottom of the Thames River Anchorage. Since only her superstructure remained visible, she was declared a maritime wreck. She was raised and scrapped in April 1948 and sold to Phillip's Craft and Fisher Company on 28 April 1948. Perhaps you can keep this office posted as to the progress you are making in solving the riddle."

Partly because of that letter, some locals in Sheerness jokingly refer to Monty as the "ghost ship".

Others talk ominously of Monty's Revenge if she does blow, sending a 16ft tsunami into Kent, Essex and up the Thames.

In a partial fix, Briggs Marine, based in Fife, Scotland, will begin dismantling the masts this June, supported by Royal Navy experts and 29 Ordnance Disposal Group in a £4.6million operation lasting two months.

"It will be extremely dangerous and I worry for those carrying out this work. I also think they'll have to evacuate thousands of people from Sheerness and Southend while it takes place," says Mr Harvey, who gives talks on the world's most treacherous wreck. He understands the masts will be held in place by cranes on salvage vessels but they will almost certainly have to be cut off the deck area below the waterline, possibly with divers using oxy-acetylene torches.

"This MoD report has highlighted the risk of a masts collapse causing an explosion."

It is the combination of munitions on the SS Richard Montgomery that alarms salvage experts, with white phosphorus smoke bombs along with high explosives.

Munitions consultant Andrew Crawford conducted a risk assessment in 2009 and described 2,600 cluster bombs as armed.

INSIDE each bomb is a stainless steel tube with a stainless steel ball at the top, held in place by a spring with a Mazak (zinc aluminium alloy) pin. Although stainless steel does not corrode, Mazak dissolves over time. This means the ball would roll down the tube, arming the bomb.