Today’s example of a revision to a prior firefighting “rule”, inspired by the new perspectives provided by fire dynamics research, regards the direction of our fire attack. It is a phrase I first saw used by Lieutenant Sean Gray of Cobb County (GA) Fire and Emergency Services in a November, 2011 article in Fire Engineering, http://www.fireengineering.com/articles/print/volume-164/issue-11/f.... Despite being yet another change from prior teachings, it actually represents a simplification, in that the seat of the fire has been recognized (reaffirmed) as the primary target, while the previous concerns about the need to carefully align the direction of water flow, uninvolved portion of the building, and fire itself have been dismissed.
By now, everyone in the fire service has heard how full-scale live-fire experiments failed to demonstrate the long-taught phenomena of water flow "pushing fire", at least when using solid or straight streams, thereby allowing (resuming) the use of streams directed from outside a burning structure. Partially lost in the “noise” from the ensuing interior vs. exterior water flow argument is that this finding removed some of the self-imposed restrictions and requirements we had placed on our direction of fire attack, which often resulted in a roundabout route to extinguish even a fire that was blowing out of a window or door directly ahead. That is, while we now know we don’t need to worry about hose streams pushing fire deeper into a building, we also don’t need to go to the trouble of aiming them so as to push it out. (See “MFA #18: Like Herding Bees with a Whip - Why you shouldn’t even try to push fire” at http://community.fireengineering.com/profiles/blog/show?id=1219672%...)
This has actually provided an area of potential agreement between those who still hold to traditional tactics and those who have embraced the modern methods, in the following concept:
Efficient fire control requires extinguishing its seat as soon as possible.
(The continuing disagreements will involve when to best begin to cool a fire in a compartment - before or after entry - but let us avoid that debate for now.) With this as an agreed-upon goal, then the questions, for every fire, become simply:
Where is the seat of the fire?
How do we get water there fastest?
When considering extinguishment, the location of the burning material and how best to reach it with water, rather than the direction of its application, is key. If the blaze began on the exterior of a structure, then the ideal path is usually and simply via the exterior. (In fact, UL researchers have shown that a fire burning on the outside of a building must be extinguished before an interior attack can be successful, even if extension into the interior has already occurred, but that’s a topic for another post.) If the base of the fire is inside the structure, then a hoseline must be stretched to where it can be played into the involved room(s). This may be via an interior passageway, but could also be through a window, or even a wall (using a piercing nozzle).
Regardless of the initial site of water flow, we still need to do everything else we ever had to control a fire, including entering the structure for search and completing, or performing, fire extinguishment, so no one is saying “we don’t go inside anymore”. (And, if there is someone out there espousing such nonsense, other than the mythical cowardly firefighter boogeyman that is so often referenced, then please send me a link or contact information. I’d love to talk to them.) While it had previously been believed and taught that the ability of hose streams to induce or reduce fire spread was a primary consideration when choosing our path to the fire, we now have learned that we merely need take the most direct route, and that accomplishing rapid cooling is more important than any induced convection.
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