The story below is yet another example of the complications involved in the use of road (strike) flares. One flare coming in contact with combustible materials, dry vegetation, leaking flammable liquids or vapors, and in the case of this story...SEWER GAS!!
Think safety...Think EMERGI-SAFE 2020!!
An Ann Arbor police officer learns a hard lesson about the proper placement of road flares
By Rich Kinsey
The nice thing about being a retired cop from the Ann Arbor Police Department is the camaraderie. We often meet for breakfast, catch up, joke and harass each other. Sometimes a good story will also rise up above the bacon n’ eggs and bovine scatology.
The story I'm about to tell came from an officer and friend who chided me that my writing isn't particularly interesting, but he likes the comments that follow and finds them much more interesting. Cops are a tough crowd.
He told us that years ago, there was a fire in the area of Main and Kingsley, and the officers had to re-route traffic. One of the officers at the scene set up a traffic flare line to move traffic in the proper direction.
There's an art to laying traffic flare patterns. Some on the expressway can be very long. Police officers must learn the proper techniques of flare placement. Traffic flares - also known as railroad flares or “fusees” - will burn brightly red and expel acrid sulfur smoke for about 20 minutes. For long flare lines, the experienced officer will lay three or four flares together so one flare will light the next flare and so on.
Wind conditions also must be taken into account. I know from experience that flares will roll in the wind and sometimes light unexpected things on fire. In my case, it was a flare that rolled from my traffic point at State and Stimson the evening the University of Michigan and Michigan State University battled on through several overtimes in the Big House. I wound up having to stamp out a little fire in the leaves and rubber railroad track bed.
According to the breakfast story teller, the flare pattern at Main and Kingsley was well-set - or so it seemed. The scene was wrapping up, and the officers were extinguishing the flares and properly disposing of the spikes attached to the nonburning side of the flare. The officer telling the story spied an anomaly in flare placement.
A flare was still burning, wedged in the hole of a sewer cover. The officer who spotted it thought whoever placed it there didn't have a keen grasp on the fact that sewers are full of methane gas. Amazed that the flare hadn’t caused an explosion, the officer pulled it out of the sewer cover.
It may have been a globule of flame that dropped down the hole or the exact concentration necessary for conflagration - that is almost explosive combustion - but explode it did. The officer must have just gotten his arm out of the way when he saw a huge blue tower of flame and saw the heavy manhole cover blown about 30 feet into the air.
He next realized that what goes up must come down - just about the time the 80 or 90 pound manhole cover was reaching maximum altitude. The officer ran, and the manhole cover came down with a clang and clatter like a massive coin hitting the ground.
The officer was saved by his heavy winter coat, gloves and eyeglasses, but he was still burned on the face, hands, and wrist. He was treated and released with some miracle ointment that healed the burns in a few days.
No one else was injured. And the unscheduled launch of the sewer cover was used as a learning tool for scores of police recruits being instructed about the proper use of flares.