Ticking time bomb? Could a sunken WW2 munitions ship bring disaster to the Kent Coast?

SS Richard Montgomery

The American ship SS Richard Montgomery sank and split in two off the coast of Sheerness in August 1944 with around 1,400 tonnes of explosives on board. The munitions were never removed meaning that they could still potentially explode. If that were to happen, Sheerness and much of coastal Medway would be devastated.

By Angus Wright

During World War Two several battles broke out at sea with thousands of allied and enemy ships being sunk around the world. By the end of the war, the British Navy had lost 278 major warships and over 1,000 smaller vessels. With the encroachment of the naval battlefront approaching the UK, many ships were sunk in British waters.

One such ship was the SS Richard Montgomery, a US Liberty ship. The ship was built in 1943 – in Jacksonville, Florida – by St. John’s River Shipbuilding Company.  It was built to be an ammunition ship which would carry supplies for the war to allied troops.

In August 1944, the SS Richard Montgomery was loaded with 7000 tonnes of munitions and sent to the UK. There it would wait for a convoy which would proceed across the English Channel and on to Cherbourg in Norway.

Upon arrival in UK waters, the ship was instructed to anchor in the Great Nore anchorage off the coast of Sheerness in Kent. Unfortunately, the ship would never leave here again. While many ships were sunk in battle, the SS Richard Montgomery fell foul to environmental issues. While anchored in Great Nore, the ships anchor dragged causing it to drift into shallow water and in turn run aground on a sand bank.

At the time of the incident, efforts were made to remove the supplies on board. During the removal process, water started to fill the hull causing the operation to be abandoned with only half of the cargo being taken from the ship. The influx of water caused the ship to sink, halting any further progress of the removal of any more cargo.

The wreck of the SS Richard Montgomery sits at the mouth of the Thames estuary on the same sand bank it sank on nearly 80 years ago. While the wreck is submerged, its masts are still visible and protrude above the water. There have been talks of removing the masts as they may be causing excess pressure on the wreck which still contains more than 1400 tonnes of explosives.

The SS Richard Montgomery is reported to have a variety of explosive devices on board including:

  • 286 × 2,000 lb (910 kg) high explosive bombs
  • 4,439 × 1,000 lb (450 kg) bombs of various types
  • 1,925 × 500 lb (230 kg) bombs
  • 2,815 fragmentation bombs and bomb clusters
  • Various explosive booster charges
  • Various smoke bombs, including white phosphorus bombs

Various pyrotechnic signals There are varying theories as to how much damage would be caused if the munitions on board were to explode. An analysis published in New Scientist in 2004 estimated that if all devices on board were to explode it would crate a column of debris reaching 1.8 miles into the air. Not only this but it would cause a tsunami which would travel up the Thames and a shockwave that would be felt for several miles and cause damage to houses in the affected area. An incident of this size would be devastating for the town of Sheerness, not to mention the countless residential and business properties lining the Thames.

This extreme scenario painted by New Scientist has been contested by many. One person who disagrees with this is Dave Welch, a former Royal Navy bomb disposal expert. He claims that it is highly unlikely that the detonation of one device would cause others in the vicinity to explode and cause a chain reaction the size of the explosion discussed in the New Scientist report. Welch claims that the water acts as a mitigator and will prevent the munitions from making contact with each other.

While the outcome is contested, it is agreed that it could be more dangerous leaving the wreck as it is than intervening. The difficulty of moving the ship and its contents is tremendous. The MCAS Receiver of the Wreck, Alison Kentuck, is the overseer of the management of the wreck and thinks that the ammunition is likely to be stable if left alone, the wreck itself could collapse from corrosion and trigger an explosion of, as discussed, indeterminate size.

There are a few solutions being discussed, however, they all have their own challenges. The most obvious is to remove the explosives from the wreck and leave the ship to degrade, however, there are the risks to personnel involved that either the explosives could detonate or the ship could collapse with the movement.

Another option for the disposal of the wreck and it’s contents would be to tow the ship out to deeper waters to allow the safe disposal of the munitions or natural degradation, however, this still holds the risk of accidental detonation being triggered. The other solution being proposed is the creation of a giant structure to cover the wreck and protect the surrounding area. The issue here would be the structure itself; the ship is 135 metres long with a 17-metre beam (width for those not nautically inclined) meaning the structure created would have to be gigantic.

While options for the fate of the SS Richard Montgomery are still being weighed up, there is a daily risk outside of the degradation and stability of the ship and its contents. The ship is in an extremely busy shipping lane which carries the risk of the wreck being struck by a wayward vessel. To mitigate this, an 875-yard exclusion zone has been put in place which is monitored 24-hours a day to help avoid any potential disaster.

While the SS Richard Montgomery wasn’t a conventional naval casualty of WWII and never made it to battle, it still presents both a very real threat to us today but also a reminder of what our predecessors dealt with out-with many of our lifetimes. Here’s hoping that in the coming years a solution is found to protect both the local area from disaster and also preserve this monument to one of the biggest global conflicts in history.

Photo Credit – Clem Rutter, Rochester, Kent