Tag: Explosives

Live ordnance from both the First and Second World Wars are more likely to detonate as they age, according to a new study published in Royal Society Open Science.

“The munitions are continuously deteriorating, resulting in the release of hazardous materials into the environment, potentially posing environmental and societal risks,” the researchers wrote. “Moreover, as the explosives deteriorate over time, often resulting from inferior storage conditions or the presence of undesired factors such as moisture and certain metals, the munitions may become increasingly sensitive to external stimuli and susceptible to accidental detonation.”

The team studied Amatols, explosive combinations of TNT and ammonium nitrate, extracted from historical ordnance in Norway. Amatols were first cooked up in 1915, when the United Kingdom found itself short on artillery shells during the First World War. For several decades—through the Second World War—Amatols were used as a convenient substitute for pure TNT in explosives.

The ordnance recovered in Norway was live—i.e., set to explode—and was found during explosive ordnance disposal operations designed to avoid that very thing. All the ordnance studied by the team was produced before May 1945 and German-made.

To test the sensitivity of the bombs, the team used a device called a fallhammer apparatus. The contraption is basically what it sounds like: masses are dropped on an explosive substance to determine the amount of force that is required to catalyze a reaction.

Surprisingly, the ordnance was wholesale more sensitive to detonation today than it would have been when it was dropped. In the case of one explosive combination (dubbed “substance B” in the research), the explosive was four times more sensitive than expected.

The team couldn’t determine what made the munitions more sensitive some 80 years after they were dropped. It may be the formation of salts that sensitize the mixture, they posited, or the contamination of the Amatol with metals the substances come into contact with in the ground. It may simple be the bombs losing structural integrity as they’ve sat in the ground over the decades.

Increasingly sensitive bombs in the ground are a problem all over Europe and, frankly, wherever bombs have been dropped. In Germany, over 2,000 tons of munitions are found annually, and in the UK, thousands of explosive objects are found and safely dealt with each year. In Italy, about 60,000 pieces of unexploded ordnance are found each year, according to Atlas Obscura. And in Belgium, excavating explosive relics of the First World War remains a daily struggle. Overall, there are millions of tons of long-forgotten explosive ordnance, the team estimated.

Furthermore, even undisturbed ordnance leaches toxic compounds into the ground as it deteriorates, the team wrote, posing a unique, vexing ecological problem.

The team stressed the importance of getting the historical ordnance out of the ground, and taking even more care than is typical to do so. After all, no one wants to be on the receiving end of a particularly sensitive bombshell.

More: Who Planted a Bomb That Killed Two People at the 1940 New York World’s Fair?