Published Sunday, January 1, 2012
| From the January 2012 Issue of FireRescue
Dear Nozzlehead … or should I say, G’day Nozzlehead? I’m writing in response to your October article, “Can You ‘Push’ Fire?” p. 22. I read your response and decided to look at the UL study you cited, which I found very interesting.
I understand that fire itself can’t be pushed around a structure, as the introduction of a fog stream will cool the smoke and reduce the heat, but the entrainment of air, as a result of a fog stream, will increase the pressure inside the structure, and this will cause smoke and heat to be forced out of any ventilation openings.
Perhaps you can comment on a video of a recent fire in a residential block in central Brisbane. Around the 55-second mark, the aerial appliance introduces a fog stream into the bedroom window via its onboard monitor, and instantaneously a large volume of smoke and fire is blown out of the adjacent windows, which forms part of the balcony. It’s only for a short period of time, but it’s a dramatic increase of smoke, heat and fire at that ventilation opening that was not present before the fog stream. We see the fire, which had two ventilation openings, now reduced to a single opening. Is this not pushing smoke, heat and fire out onto the balcony as it has nowhere else to go? (Note: To watch the video, visit http://news.ninemsn.com.au/video.aspx?tab=7. In the video search field, search for “Toowong Fire.” The video is named “Woman dies in apartment blaze.”)
—Alex “Fire Pusher” Australia
Beer. Or as you say, “Beee-uh.” OK, now that I have your attention and focus, let’s yabber, mate. I reviewed the video and also spoke with Steve Kerber, the lead researcher on the UL study (www.ul.com/fireservice). He’s a veteran urban fire command officer, a fire protection engineer, can say “dingo” and has eaten at Outback Steakhouse. We discussed it and agree—it is really hard to compare the video to pushing fire for several reasons:
- It was a master stream on a full fog pattern, which probably moves as much air as a PPV fan. We normally don’t recommend using a fog pattern on a master stream to knock down the bulk of a fire.
- There was already fire in that room, so just because it flashed out of the window briefly does not mean that fire was pushed. We would define “pushing fire” as forcing fire into a room that did not have fire in it already—not a brief flash as seen in the video.
- We don’t know what the temperatures were inside all the rooms so, in reality, everything may have gotten better in that apartment once the stream was directed into the window—and we would bet some shrimp on the barbie that it did.
Did fire/smoke puff out of the window briefly? Yes. But did fire get pushed? Not in our opinion. If a firefighter was trapped in that apartment, things would have gotten better for that firefighter. If the master stream was a straight stream, things would have been that much better, as displayed in the wind-driven fire research done by NIST.
Reach out to the fire science organizations in Australia, and have them reach out to Steve for more information. As tough as it has been for me to accept the study conclusions, if you remove the emotion and look strictly at fireground behaviors, it’s easier to understand how we can use science to improve fire operations. I hope that helps, even if you live in Woop Woop.
Nozzlehead’s Favorite Training Resources
John Norman’s Fire Officer Handbook (3rd Edition): This handbook covers basic, solid and proven fire operations and tactics. If there’s any part of this book that EVERY firefighter should read, it’s the part about engine company operations and the importance of getting water on the fire.
Blue Card Command (www.bluecardcommand.com): Blue Card Command teaches fire officers how to run day-to-day fire ops in dwellings, multi-family and commercial structures, etc. It’s a 50-hour online program, plus a 24-hour hands-on classroom and simulator testing process that helps prepare officers to command fires. It’s no BS, and it isn’t something people will “fly through”; this is serious training that can be applied at your next fire.
The Art of Reading Smoke (books, video, classes): Dave Dodson has made an incredible difference in educating all of us on “what THAT smoke means.” These resources are a can’t-miss aspect of any firefighter’s career.
FireTactics (www.firetactics.com): This is truly a fire science site that helps firefighters of all ranks and status understand things like flashover, smoke explosions, backdraft and more.
Got a fire service question or complaint?
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