OWOSSO TWP. — If you want to know how dangerous a “flashover” can be, talk to Owosso Township Assistant Fire Chief Michael Thornburg about a house fire he helped battle in 1979.
The ceiling crashed down on the fire crew, and the air itself burned red.
“The gases were burning red,” Thornburg explained. When they ignited all at once, “I jumped out of a closed window.”
Thornburg’s hands were so badly burned he spent two months in a burn unit. Doctors had to graft 72 inches of skin from his legs onto his hands.
He said his injuries might have been avoided if he had been trained to recognize a flashover: the near-simultaneous ignition of combustible material in an enclosed area when it heats to 1,128 degrees Fahrenheit.
Over the course of the day Saturday, 46 firefighters from across Shiawassee County received flashover training at the Owosso Township Fire Department’s Station One. Six men at a time were enclosed in the lower level of a trailer (called the classroom) in which wood was burned to the flashover point.
The trainers were a team of pros from the fire engineering division at Oakland Community College.
The exercise cost $3,400 and may one day save a life.
“Let’s say our guys respond to a fire and open the front door,” Owosso Township Fire Chief Dave Johnson said. “If there are super-heated gases — carbon monoxide — inside, then exposing the gases to oxygen by opening the door will cause a flashover that can kill or injure our firemen.”
The biggest challenge is being able to recognize the signs of a flashover, so firefighters know that’s what they’re facing and can work out a strategy to deal with it.
The lead trainer, Ken Chestnut, said: “The biggest thing the firefighters get out of this is they get to experience this in a controlled classroom. They learn how to understand their environment.”
Telltale signs that a flashover is imminent include the color of smoke darkening, the degree of heat (which firefighters can test with thermal imaging cameras) and “fingers” of flashing light.
A precautionary step to avoid a flashover, depending on the circumstances, is to ventilate the roof by making a hole in it, allowing the super-heated gases to escape.
During the training exercise, firefighters see the flashover signs, safely experience a flashover and then take turns with the fire hose, dowsing the flames indirectly, by pointing the hose at the ceiling and letting the water fall on the combusted gases.
New firefighters, after participating in one of Saturday’s exercises wearing their protective gear, said they were mesmerized and fascinated by the experience.
As the heat increased inside the trailer, some felt a little nervous.
“It is scary,” Johnson said. “All of a sudden, you go from a very dark room to a very well-lit one. There’s a lot of heat.”
Every fire department in the county was invited to the training session. Participating departments included Owosso Township, Ovid-Middlebury, Corunna-Caledonia, and Vernon, Venice and Shiawassee townships.
The Vernon Township Fire Department hosted a similar training session a few years ago, Johnson said.
“For Owosso Township to set this up, that’s quite an endeavor,” Chestnut said. “But to pay for this without a grant, that’s going way above and beyond.”
Johnson said his department paid the up-front cost and other departments will be making financial contributions.