Live Burn in Vienna, August 17, 2013

This morning, field training staff of the Fairfax County Fire and Rescue Academy conducted live fire training for the volunteer fire fighters in the county. I was lucky to be able to participate.

Training was about fire behavior, using real fire in an acquired structure, and carefully controlled ventilation to show how common fire department tactics, such as breaking windows or opening doors, can significantly impact the size and growth rate of fire, heat production in the burning building etc.

This training represents a long overdue sea change in attitudes towards these tactics. The days of "break all the windows, and leave the door wide open", have fallen away in the fact of a better understanding of fire behavior. Modern lightweight construction has made these lessons all the more critical.

I learned a lot just by observing the smoke and fire. Although this was all stuff I've seen in lectures over and over, the ability to observe the fire in a real world setting crystalized those lessons for me in terms of how they impact tactical decisions on the fire ground.

Even the lack of fire behavior can be important -- we observed the different behavior of the fire before and after the window of the fire room was broken open. While the window was intact, the instructor was able to control the size of the fire by controlling the front door. Even though the fire was in the back of the structure, the size of the fire was directly related to how far open the front door was, as long as that door was the fire's only source of air. Once the fire "self vented" (that is, broke the window in the fire room due to heat), the fire no longer responded to changes in the front door. This is an important lesson for the fire ground -- if closing the door doesn't change the fire's behavior, it means that there is a window broken (perhaps through self venting, perhaps by a "well meaning" firefighter).

Some changes in tactics that were covered:

  • "Penciling", that is putting water into smoke in short controlled bursts, something that was once taught with skepticism and suspicion, is now considered an essential tactic. This is largely due to changes in the furnishings in modern homes, which produce massive amounts of highly flammable smoke.
  • Although it is impossible to close the door completely while your hose line is running through it, it should be kept closed as much as possible. This Controls the amount of air that gets to the fire (unless there is another opening, as discussed above).
  • Something I have always preached at the fire academy -- there is no need to advance into the fire room to extinguish the fire. Instead, the nozzle firefighter should hit the fire from the door way. My rule "if you can see the fire, hit the fire", seems to now be the new gospel.

    There is much more to learn, of course, and I look forward to the next opportunity.

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