Freight ship passing through the North Channel past a mist shrouded Mull of Kintyre Radharc Images/Alamy

This article, originally published in November 1995, was updated on 10 February 2020. We changed the headline and created a new graphic due to the government’s investigation of a proposed bridge between Scotland and Northern Ireland.

IN the past month, more than 4500 incendiary bombs from the Second World War have washed up on beaches around the west coast of Scotland. They are made of phosphorus, benzene and cellulose, and were designed to ignite on contact with air. Four-year-old Gordon Baillie picked one up while playing in his uncle’s garden near Campbeltown on the Mull of Kintyre. It burnt his hand and leg, and made his clothes smoke.

The phosphorus bombs are the clearest warning so far of the dangers of using the sea as a dump for military waste. The bombs were dropped into the North Channel between Scotland and Northern Ireland fifty years ago, but are now washing up on land and starting to burn. Worryingly, the phosphorus bombs are just a tiny fraction of the 1.15 million tons (1.17 million tonnes) of conventional and chemical weapons known to have been dumped in the sea around Britain since the Second World War. They could be the heralds of more to come.


Discovery of the first phosphorus bombs on 6 October at Saltcoats on the Firth of Clyde prompted a major cleanup operation. Every day for the following two weeks army bomb disposal teams picked up hundreds of them along the length of the Clyde coastline, round the Mull of Kintyre and on the islands of Arran, Islay, Jura and Gigha. Children were told to keep away from the beaches, farmers advised not to gather seaweed for fertiliser, and warning signs appeared on beaches.

At first, the Ministry of Defence insisted that the bombs had no “UK military origin”, and that no evidence existed that they had ever been dumped at sea. But after a cross-party group of Scottish MPs met defence secretary, Michael Portillo, the story changed. On 2 November, the MoD admitted that the devices came from decayed 30 pound (13.6 kilogram) incendiary bombs of a type dropped from British aircraft in the Second World War.

The implication, not yet confirmed by the MoD, is that the bombs had been sent for dumping in Beaufort’s Dyke, an underwater trench 50 kilometres long, 5 kilometres wide and about 250 metres deep, which runs within 10 kilometres of the Scottish coast. Between 1945 and 1976, the MoD dropped about 1 million tons of munitions into and around the trench, making it by far the largest known British military dump.

On 10 February 2020, Boris Johnson said the government has been tasked with investigating two routes for a bridge between Scotland and Northern Ireland. The routes mentioned included Portpatrick to Larne or near Campbeltown to the Antrim coast.

But why should obsolete munitions suddenly start emerging from the dump? The most likely answer is an undersea gas pipeline linking Scotland and Northern Ireland. After consulting the MoD, British Gas decided to divert the pipeline immediately to the north of the designated dumping area around Beaufort’s Dyke. Its contractors began ploughing a 60-centimetre deep trench for the pipeline in the seabed just three days before the phosphorus bombs started to come ashore. Workers quoted anonymously in The Scotsman newspaper blamed the ploughing operation, although this was denied by British Gas. “We have no evidence connecting our operations with the appearance of these munitions,” says a British Gas spokesman.

Scientists at the Scottish Office’s Marine Laboratory in Aberdeen, however, say British Gas is wrong. They say that the crew of the barge which helped to lay the pipeline submitted official reports to the coastguard describing how they had seen objects identical to the phosphorus bombs floating in the sea. Underwater video footage taken by British Gas’s contractors and studied by the scientists also clearly shows the bombs, and a host of other metallic wastes, next to the pipeline.

Beyond reasonable doubt

According to the scientists in Aberdeen, it is now “beyond reasonable doubt” that the phosphorus bombs were dislodged by the ploughing operation. They floated to the surface and were blown north into the Firth of Clyde and round the Mull of Kintyre by the prevailing winds, say the scientists. This week, the Marine Laboratory began an urgent two-week survey of the seabed around Beaufort’s Dyke. It will sample fish and sediment, and scan the seabed using sonar and video cameras.

The survey is likely to confirm what British Gas discovered by accident: that many of the munitions meant for Beaufort’s Dyke never got there. Instead, they were dumped in shallow waters en route to the dyke by ships from Stranraer and Cumbria. Two seamen from Stranraer who sailed on dumping expeditions in the 1940s, John Balfour and Alfie Shingleston, have said that in poor weather, the ships discharged their cargoes no more than a few hundred metres off shore. “There is credible evidence that a significant amount of material never made it to the site,” says one scientist from the Marine Laboratory. He believes that munitions ended up in unauthorised dumps to the north and south of the dyke and possibly in the Solway Firth. “Out of sight, out of mind was the prime criterion at the time,” he says.

According to a letter sent by the MoD in June to researchers at the University of Liverpool, the MoD dispatched vast amounts of old weapons to Beaufort’s Dyke. The ministry dumped some 14,000 tons of 5-inch artillery rockets filled with poisonous phosgene gas in the trench between July and October 1945. Over the following three years, it consigned 135,000 tons of conventional munitions there, and every year “into the late 1950s” another 20,000 tons ended up in the dyke.

By the early 1970s, the discharges had reduced to about 3000 tons a year, says the MoD. “In most cases” the dumped munitions were defused, although some weapons may still have been live. The MoD thinks the area of Beaufort’s Dyke was “probably” used before 1945, “possibly” as early as 1920. Disposal then may not have been confined to the site defined in 1945, it says. The dyke was last used for “general munitions dumping” in 1973, although the MoD reveals that “one emergency dump of a small number of 40 millimetre shells took place in 1976”.

The phosphorus bombs are not the first objects to return to land. Over the past five years, spring tides have washed up about 700 antitank grenades and other weapons on the Isle of Man and the coast of Northern Ireland. David Long, a marine geologist from the British Geological Survey in Edinburgh, says that this lethal jetsam is carried by strong southeasterly currents that flow from the southern end of Beaufort’s Dyke. Similarly strong currents, reaching 1.5 metres a second, flow north from the dyke’s northern end.

Beaufort’s Dyke is not the only military dump off Scotland’s west coast. Statements from the MoD also reveal that between 1945 and 1957 it scuttled 24 ships packed with 137,000 tons of chemical weapons at two sites in the Atlantic. One is 1600 kilometres southwest of Land’s End, around Hurds Deep, but the other is a large area beginning 100 kilometres northwest of Northern Ireland and southeast of Rockall Deep. Eight of the ships are sitting at depths of less than 2000 metres, and the shallowest is in 500 metres of water. Both sites are also home to thousands of tons of radioactive waste from Britain’s nuclear programme.

Late last month, the armed forces minister Nicholas Soames told Parliament that the material dumped in the Atlantic includes 17,000 tons of captured German bombs filled with the nerve gas tabun. The scientists at the Marine Laboratory in Aberdeen say that another nerve gas, sarin, together with phosgene, tear gas and mustard gas, have also been dumped.

The MoD has always maintained that there is no scientific evidence to suggest any significant harm to human health or the marine environment from its dumps – so long as they remain undisturbed. “The combined effects of dilution, dispersion, hydrolysis and low temperatures act to reduce the toxic potential of munition materials,” says a senior MoD official.

“There is no evidence because no one has looked for any,” says the scientist from the Marine Laboratory in Aberdeen. He says fishermen in the Baltic, another dumping site for Second World War chemical weapons, have been severely burnt by mustard gas. “If canisters were raised from the seabed and leaked, they could kill fishermen,” he warns. Fishermen in the Firth of Clyde and the North Channel say they often find munitions in their nets.

Although phosgene, tabun and sarin should be hydrolysed in seawater into relatively harmless by-products, mustard gas is likely to persist. It is heavier than water and comparatively insoluble, so that when it leaks it tends to form an oily layer on the seabed. According to the Marine Laboratory, it could contaminate fish.

In the postwar years, the MoD chose its dumping zones partly because they were far away from commercial fisheries. Since then, however, declining populations of more easily caught species combined with advances in fishing technology have driven fishermen to further and deeper waters. Prawns are now fished just north of Beaufort’s Dyke and there is a hake fishery in the dyke itself. Farther out to sea, fishermen trawl down to 1800 metres for deep sea species such as the orange roughy.

Fishing bans

Most marine scientists now agree that comprehensive surveys of the dump sites are needed to find out precisely what is in them, and what state the munitions are in. If there are any doubts about the safety of a site, government experts say the most that could be done would be to ban fishing and other underwater activities in the area. In this case, fishing could end up being banned in most of the North Channel and Irish Sea, says Paul Johnston, a marine pollution expert at the University of Exeter. This would be an unacceptable curb on fishermen. “If the weapons are removable, they should be removed as soon as possible otherwise we will end up with a series of problems,” he says.

The phosphorus bombs are straws in the wind, says Johnston. They have come ashore first because they are so buoyant, but he predicts that there could be worse to follow. It is possible, he says, that intact phosgene containers could separate from their rockets and wash ashore. “The effects are inherently unpredictable,” says Johnston, “but there is a very clear risk of personal injury.” (see Map)