The ticking timebomb shipwreck that could damage half of London

Every now and then a newly made discovery of a long-lost shipwreck makes the news with everything from RMS Titanic to the lost ship of Captain Cook and everything in between.

There are a few shipwrecks however that are well known, even visible to us today.  Out of them all, there can’t be any more dangerous than the S.S. Richard Montgomery which since WW2 has lain, partially above water on the mouth of the River Thames.

The S.S. Richard Montgomery was a Liberty ship, from the United States bringing over 9,000 high explosive munitions and one of many reason why one has to be careful when looking for ‘treasures’ on the banks of the Thames as I did in my recent post.

Known semi-affectionately to locals as the “Monty”, the 441ft-long (134m) vessel was a US Liberty ship, a type of cargo ship used during World War II. It arrived off the coast in August 1944 carrying munitions to help the war effort. On 20 August, while waiting to join a convoy across the channel to France, harsh weather caused the ship to drag anchor and founder on a sand bank, of which there are many treacherous examples in the Thames estuary.

As the tide receded the vessel was left stranded. The hull’s welded plates began to crack and buckle under the weight of the explosives on board.  Local dockworkers hurriedly mounted a salvage operation. They managed to empty the rear half of the ship before finally abandoning it on 25 September, when the forward section flooded and the vessel snapped in half.

Since then, no one has been aboard the ship – at least not officially. And without any surviving records of what actually was removed in 1944, it’s impossible to say precisely what cargo remains.


The masts of the S.S. Richard Montgomery

The ship lies just 1.5 miles (2.4km) from shore in the mouth of the bustling Thames estuary. Clearly visible from the land – its rusting masts rising ominously from the water – the sunken vessel contains disturbing cargo: 1,400 tonnes of high explosives which many fear could go off at any time, potentially causing one of the most devastating non-nuclear peace-time explosions ever seen.

It is something that locals near the coast have long worried about whilst millions of Londoners remain blissfully unaware that they are living well withing the shockwaves of a ticking time-bomb.

According to a survey carried out in 2000 by the Maritime and Coastguard Agency (MCA), the ship likely contains a staggering assortment of more than 9,000 US-made explosives.

These include 286 giant 2,000lb ‘blockbuster’ bombs, 4,439 1,000lb devices and – perhaps most worryingly of all – more than 2,500 cluster bombs. Unlike most of the other items on board, cluster bombs would have been transported with their fuses in place, leaving them more prone to detonation.

It seems incredible that such hazardous cargo was abandoned so close to civilisation and in the middle of the one of the UK’s busiest shipping lanes. But in the final stages of the war, the wreck’s recovery wasn’t a priority.

In the decades that followed, authorities considered non-intervention to be the safest course of action. That became particularly true when a 1967 attempt to clear the Kielce – a smaller wrecked munitions vessel almost four miles (6.4km) out to sea – triggered an explosion that measured 4.5 on the Richter scale and damaged property in nearby Folkestone, though no injuries were reported.“Expert advice has always been that the munitions are likely to be stable if left undisturbed,” says the MCA’s Receiver of the Wreck Alison Kentuck, who oversees management of the SS Richard Montgomery, including arranging detailed annual surveys of the site (see box out). “If you go and disturb them, you’re increasing the risk factor.”

“Expert advice has always been that the munitions are likely to be stable if left undisturbed,” says the MCA’s Receiver of the Wreck Alison Kentuck, who oversees management of the SS Richard Montgomery, including arranging detailed annual surveys of the site (see box out). “If you go and disturb them, you’re increasing the risk factor.”

Most agree that the bombs are relatively safe as long as they aren’t exposed to sudden shock, friction or heat. But as happened with the famous wreck of Titanic, recent MCA surveys confirm the wreck is gradually disintegrating. Its deterioration could lead to a sudden collapse that triggers the sympathetic detonation of some, if not all, of the remaining explosives.

If this happened, the consequences could be catastrophic. Some analyses – as reported in the New Scientist in 2004 – suggest that spontaneous detonation of the entire cargo would hurl a column of debris up to 1.8 miles (three kilometres) into the air, send a 40 foot high tsunami sweeping up the Thames and along the Kent coast, cause a shock wave that would damage buildings for miles around, including the liquid gas containers on the nearby Isle of Grain.

It’s a scenario that keeps many, including local historian Colin Harvey, awake at night. “The remit area for the explosion would be from Margate to the centre of London,” he says. “It would level Sheerness, and a 30 or 40ft wave would breach sea defences. Sheppey’s got a population of 25,000 people. Where would they go?”

For those of us who like to put our head in the sands, happily not everyone shares this apocalyptic view.

Dave Welch is a former Royal Navy bomb disposal expert who now runs Ramora UK, an EOD (Explosive Ordnance Disposal) consultancy which carries out a large amount of work on underwater ordnance. Welch, who advised the government on the SS Richard Montgomery’s munitions, says he’s unconvinced by some of the wilder predictions.

“The idea that if one item goes ‘bang’ then everything will is, I think, pretty unlikely,” he says. “Unless you’ve got intimate contact between two munitions subsurface, you’ll rarely cause the other to detonate, because water is a very good mitigator. If you’ve got a 1,000lb bomb two metres from another 1,000lb bomb, the other one won’t go bang. I know that for a fact – I did it last Tuesday..

The wreck is surveyed annually. Although in the past, the process could take up to a month, advances in subsea surveying technology mean that it now takes as little as a couple of days. Two key techniques are used: laser scanning and multi-beam sonar. Laser scanning examine the sections of the ship above the water, while sonar images the subsea sections. These two data sets are knitted together to create an overall image that gives a detailed view of the exterior of the wreck, as well as the surrounding seabed.


A scan showing Monty in two parts.

He suggests that a more likely – albeit only marginally less terrifying – scenario is the detonation of a large item initiating a ripple effect through the vessel, which would send munitions flying through the air and scatter hazardous items over a wide area.

And while the likeliest trigger for such an event is the natural disintegration of the vessel, that’s not the only potential cause.

One concern is that the vessel could be struck by one of the many boats that pass close by every day. And although the wreck is surrounded by an 875-yard (800m) exclusion zone and monitored 24 hours a day by the Medway Ports authority, there are concerns that it’s not as well protected as the authorities claim. Indeed, Harvey says there have been at least 22 near-misses over the last few decades.

Perhaps the most serious incident occurred back in May 1980, a Danish fuel tanker strayed off course in poor weather and had to take last-minute evasive action to avoid hitting the wreck.

More recently, an idiotic paddle-boarder provoked an outcry when he posted a photo of himself on Facebook leaning against one of the vessel’s masts.

Perhaps more worryingly is that it could prove to be a tempting target for terrorists that could relatively easily attack the shipwreck to cause the biggest explosion of the 21st century.   In fact during the London 2012 Olympics the ship was under armed protection.

But the biggest risk factor is undoubtedly the state of the ship itself. “The items aren’t the ticking time bomb, the wreck is,” says Welch. “It’s the fact that they’re inside a ship which is slowly decaying that could have the potential of causing enough energy going in them to cause them to detonate.”



Warning buoy marking the wreck of the SS Richard Montgomery photo by Gill Edwards


So what are the options?

Over the years, a variety of suggestions have been made, ranging from the clumsily dangerous option of simply towing the vessel to deeper water to more complex civil engineering solutions involving entombing the wreck in some kind of giant sarcophagus.

The project would, Welch says, cost tens of millions of pounds. “There are lots of examples of wrecks being emptied,” he says. “The thing that makes this different is that it’s a much larger payload and the vessel is slowly crumbling away. What makes it very difficult is where it is.”

Still, Welch and a number of other operators are confident that they could safely clear the wreck site. But there are few signs that anyone will be given the go-ahead any time soon.

One thing that might hasten a solution would be a major infrastructure project, like the former London Mayor Boris Johnson’s proposal for a new airport in the Thames Estuary: the Airport Commission said that before it could be built, the wreck would have to be moved. But with ‘Boris Island’ looking increasingly unlikely, at least for now, we could be in for a long wait – and most seem to agree that the longer the vessel is left, the harder it will be to deal with.

However the wreck is dealt with, it seems unlikely that inaction is going to be a tenable course of action and that sometime in the next 10 years a very difficult decision to make and the sooner it is made then the easier and cheaper it will be.

As decision makers more distant sit on their hands, there is always the horrific possibility that the people of coastal towns such as Sheerness will see an unprecedented disaster which is 80 years in the waiting.

About Stephen Liddell

I am a writer and traveller with a penchant for history and getting off the beaten track. With several books to my name including several #1 sellers. I also write environmental, travel and history articles for magazines as well as freelance work. I run my private tours company with one tour stated by the leading travel website as being with the #1 authentic London Experience. Recently I've appeared on BBC Radio and Bloomberg TV and am waiting on the filming of a ghost story on British TV. I run my own private UK tours company (Ye Olde England Tours) with small, private and totally customisable guided tours run by myself!
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7 Responses to The ticking timebomb shipwreck that could damage half of London

  1. Ankur Mithal says:

    You really bring out forgotten and hidden information in a way that stokes curiosity and interest. Yes, it does seem like such a folly to leave it so close to civilisation.

    Liked by 1 person

    • Thank-you. Obviously no-one wants to start a procedure that might cause damage for 100 miles and possibly injuries or death but it seems that if it happened accidentally at 2am during a stormy winter night or 8am during the commuting rush-hours then more people would be killed. I am sure if it were to happen now, it would be resolved instantly so why take the risk with an old one? It is the London version of Vesuvius and Pompeii.

      Liked by 1 person

  2. Marilyn Liddell Hall (maiden name) Allan says:

    This is very scarey sounding to me!! I am surprised nothing has been done about it! Have divers been in it to look inside?


  3. sed30 says:

    Reblogged this on sed30's Blog and commented:
    😮fascinating but scary stuff

    Liked by 1 person

  4. Contractions of Fate says:

    This is crazy! If they emptied the back half of the ship in 1944, why not finish the job after it snapped in half? Wouldn’t that have been safer then leaving it to rust for 80 years? Even if they had no scuba equipment, they had deep sea diving suits?



  5. Pingback: HMT Bedfordshire – The Royal Navy ship sank defending the United States. | Stephen Liddell

  6. Pingback: London’s Biggest Explosion. Silvertown 1917 | Stephen Liddell

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