In a muddy field in Flanders, in Belgium, there are signs of a recent harvest along its edge — raw potatoes here and there.
But toward the back of the field, members of DOVO, the Belgian military’s bomb disposal unit, inspect something else yielded by the harvest — an artillery shell that is more than a century old.
“By sight alone, we know what it is. It’s a German one,” 1st Sgt. Sanders Poelmans said. A German, 15-centimeter, high-explosive shell produced in 1914, to be precise.
“It’s still possible to explode,” he added.
And they still do.
“We have two to three cases every year where a farmer hits a shell with his farming equipment, and the shell blows up,” Poelmans said. “So, the farmers are sometimes hurt.”
From 1914 to 1918, this farmland surrounding the city of Ieper witnessed some of the heaviest artillery shelling and highest casualties of World War I.
Shells like the German one found in this field, along with hand grenades and bombs dropped by planes, are found across Belgium on a daily basis. Every year, the unit removes over 150 metric tons of unexploded ordnance on average.
“Normally, we can go to 20, 30 places a day, when it’s in autumn,” the 28-year-old Poelmans said.
“And when all the farmers start harvesting, we have a lot of places to visit.”
So frequent is this corroded, old ammunition found that the routine of clearing it from farmland has been dubbed the “iron harvest.”
About a third of the explosive ammunition fired during the war didn’t go off, in many cases due to the low quality of the mass-produced fuses, Poelmans said. In other cases, it’s because the shell was never quite fired.
The team recovered a 6-pound British artillery at another farm that day.
“The shell is fired with its safety on, so the fuse cannot be armed,” he said.
He speculated that it might have been an inexperienced soldier who forgot about it under extreme stress on the battlefield.
The unit is trained to identify over 600 different types of unexploded ordnance. They’ve cataloged 3,000 unique explosive objects from WWI for further reference.
And with each new find, Poelmans’ team follows the same procedure: Using a brush and small hammer, they carefully remove decades of rust and dirt caked on to shells, to see whether it was fired and thus primed to explode, or if it might have been armed with a chemical agent, like phosgene or mustard gas.
“Most of the shells are filled with high explosive or with the toxic load,” in other words, it’s a chemical weapon, “and it’s not possible to tell on the outside,” Poelmans said.
So whenever they find a shell, they approach it as a chemical weapon still hazardous to their health. Mustard gas can still cause skin blisters and burns, as well as temporary blindness. Chlorine or Phosgene can be lethal, especially if it gets inhaled.
The possibility of finding such chemical weapons in the fields of Flanders is unique to World War I battlefields — a conflict in which both sides tested new, cruel means to break a costly stalemate.
Jacques Callebaut, a member of the bomb disposal unit with nearly four decades of experience, said that suffocating agents and blister agents were frequently used in World War I.
“In fact, the danger for ourselves is bigger when dealing with First World War ammunition than with Second World War ammunition” because of the risk posed by chemical weapons.
After identifying the type of explosive ordnance, the team places it carefully in a box full of sand so it stays secure on the truck.
Sometimes, they will blow it up on location if it’s unsafe to transport to a base — in that case, they will set off a controlled detonation where they found it.
Others are brought back to barracks where they get inspected again before later being destroyed.
If an X-ray reveals chemical traces, they have two options: a static detonation chamber (basically, a huge oven), or a contained detonation chamber, used only when there are a high amount of explosives.
Callebaut said there’s no clear end date for removing all the unexploded ordnance from the area.
“After the First World War, they thought it would be over by 2025, but we are still dealing with it,” he said.
“Cambodia, Laos and Vietnam they’re also still dealing with ammunition which was found, the same with Afghanistan.”
Wherever there is a conflict, there is this threat, he said.