Last night I watched the movie “Backdraft,” which by the way isn’t one of the world’s greatest movies, but they did show a hell of a lot of backdraft fires. The only problem is that they never explained what a backdraft fire was.
What, pray tell, is a backdraft?
**Firefighters responding to a confined fire that is late in the steady-state burning phase or in the hot-smoldering phase risk causing a back draft if the science of fire is not considered in opening the structure.**http://roswellfire.com/firebehavior1/tsld033.htm
If the fire has gotten very hot in a confined area and the fire is running out or low on oxygen, opening a door, window will cause a backdraft.
The fire burns in the room. The door and windows are closed so the fire uses up all the oxygen in the air. It dies down but the air pressure inside the room is now lower than outside. When the door is opened, the air outside rushes in. The hot gases in the room ignite and explode…a Flashover.
Spent about 4 years as a full time firefighter. I saw a clear example of a backdraft only once, in a house fire. The house was full of smoke, but very little fire. When we finally broke in the door, the flames erupted almost immediately, blowing part of the roof off the house.
What struck me most about the movie was the remarkable visibility in all their fires. The building fires I remember were smoky and chaotic, people groping around, bumping into each other. It was hard to see much of anything. Of course that would have made for a pretty uninteresting movie.
I dunno… that reminds me of a lot of movies… Dragonslayer and Crouching Tiger/Hidden Dragon spring to mind.
kniz pretty much hit the nail on the head with his backdraft description. Not to be confused with flashover, where everything in the room ignites at once (the simple definition).
MrO, you didn’t notice the 3/4 boots always rolled down (like anyone even uses them now…), the lack of SCBA use, 2 firefighters with an 1.5 handline wandering around a very well-involved industrial building fire, the “dig in, we don’t have any help” line…I could go on forever…