Blasting caps

A downloaded image shows a number of metallic blasting caps used in industrial settings.

Photo contributed

A Marathon County-based group of demolition experts was summoned to Barron County Saturday, July 25, 2020, after approximately 100 industrial blasting caps were found in a rural Prairie Farm home, according to Barron County dispatch logs.

According to a log entry, a man was cleaning out his father’s home in the 900 block of 2 1/2 Avenue near Prairie Farm, when he came across boxes of DuPont blasting caps, presumably from the 1970s or 80s.

The man reported finding two or three boxes containing about 100 caps.

The caps are explosive devices used to detonate dynamite and other larger explosives.

Dispatchers advised the caller not to move the caps. Later, the Barron County Sheriff’s Department contacted the Marathon County Sheriff’s Department, which has a bomb squad that serves its own county, neighboring Oneida County, and other northern Wisconsin locations.

The squad is certified in the safe disposal of bombs, hazardous materials and weapons of mass destruction.

A demolition expert from Marathon County later arrived to take possession of the blasting caps.

“Blasting caps are inherently dangerous explosives,” said Marathon County Sheriff’s Department Lt. Ryan Weber, head bomb technician for the explosives unit.

“They are sensitive to heat, shock and friction, all of which can detonate them,” he added. “The explosive power doesn’t deteriorate over time. But the older they get, the materials used to manufacture them can corrode and make them more sensitive.”

Blasting caps include a high explosive material that’s more powerful than conventional black powder, Weber added. In some situations, the material is no bigger than a piece of baby aspirin, he said.

“We’ll do demonstrations for patrol deputies or the Transportation Safety Administration, where we’ll embed (a blasting cap) in a watermelon, pumpkin or a raw chicken, to show the effects it can have on human flesh,” Weber said.