Advertisement

  Stock Sponsor
Click here for full stock listings


Published: November 8, 2009 3:00 a.m.

BOOM! Explosives set him off

Susan Kinzie
Washington Post
Thumbnail

Washington Post

John Conkling teaches the chemistry of pyrotechnics and explosives at Washington College in Chestertown, Md.

Advertisement

Sparks are flying. And things are sizzling and flaring up, sending out acrid chemical smells and huge plumes of thick, dark smoke bubbling up like mushrooms. Every now and then, a huge boom makes students jump.

You never realize just how many things blow up until you go to John Conkling’s seminar, the Chemistry of Pyrotechnics and Explosives, held every year at Washington College in Chestertown, Md., for the past 27 years. He’s one of the country’s few scholars specializing in pyrotechnics, and every summer he offers a crash course in the chemistry behind the explosions.

It’s for the people who regulate, control, invent or use volatile materials, including police officers, soldiers and technicians who design fireworks displays.

In the lab, students see how to make flames white, red, yellow, blue, even such subtle shades as peach and honeydew melon. They learn how to create thick smoke, ash that squirms and writhes and coils up like a snake, or a quick, brilliant burst of light.

Conkling got into this by accident. He was doing research in organic chemistry at Washington College, where he now teaches, then at Johns Hopkins University, when he realized that studying pyrotechnics could be a lot more fun.

Conkling has studied propellants and explosives, but most of his work has been in pyrotechnics, in which the reactions are designed to produce colored lights, smoke and other effects, either for entertainment such as fireworks, or for defense purposes such as flares.

And his specialty has been sensitivity – what sets off a reaction, which could be anything from a heavy impact such as a blow from a hammer to the slightest tap of a finger, or friction or flame, depending on the chemicals involved. His findings have often been used to make the manufacture, transport and use of the materials safer.

“I don’t think anyone sets out to get into pyrotechnics, he said. “It’s not taught at colleges and universities, it’s not something most people have exposure to. Other scientists looking at the field may think ... it’s not the same as trying to find a cure for cancer.

“But to me, I thought there was a real compelling need for more safety information in the field.”

The field has changed dramatically since Conkling, 65, began studying it in the 1960s. Many of the chemicals used then are better understood now – including the ways they break down over time and can affect people’s health – and are no longer allowed in the U.S.

And after terrorist attacks such as the Oklahoma City bombing and Sept. 11, 2001, there has been far greater concern about security and access to chemicals. At the same time, the Internet has made information instantly available to anyone who looks for it.

“That concerns me a lot, that people would try and do some of this at home,” he said. “If you spark them, hit them, rub them the wrong way, friction can ignite these materials. That’s not common knowledge.”

In some cases, just a tiny buzz of static electricity from a person is enough to touch off an explosion.

At one point in class, he explained what the ratings on the materials really mean. “ ‘Negative’ means there’s less probability,” he told the students. “It certainly doesn’t mean never. There have been explosions of all of these materials. ... You could get just the right amount, and it goes boom.”

It was easy to see how unpredictable it is in the lab, where things sputtered and went dark, burned bluish instead of greenish, or lighted with a wallop that made students gasp.

Much of his research starts by chance, when the phone rings and someone asks a question.

For example, the Army asked him to solve a problem it was having with grenades used to protect armored vehicles. The grenades, designed to produce enough smoke to hide the vehicles from heat-seeking weapons, weren’t igniting. Conkling analyzed the system used to set them off and realized that “it was shattering the chemicals, so they were not burning.” The Army fixed it right away, he said.

Although many of his discoveries have made people safer, the research continually builds on past findings. He has never had a big stop-everything breakthrough moment, he said.

Then he laughs. “Surprises are not something you like to get, in this business.”