Bernoulli's Principle Applied to Firefighting – Box Alarm Training
boxalarmtraining.com
boxalarmtraining.com
You have agencies like NIST and NFPA doing studies and science, but they also get often a bad rap from firefighters for being "overly" safety conscious. Ironic, considering that they did solid foundational work that saved firefighter lives (now, though, more die due to PTSD and mental illness and accumulated cancers than do in the line of duty).
I exaggerate not, I saw an ad for lateral firefighters to come work somewhere in the south:
> Are you tired of being a firefighter in an OSHA state? Does your bunker gear smell of pallets and sadness? Do you really need someone to supervise you throwing a ladder? Come work for XYZ FD.
In this case, it's the concept of "flow path" that is outdated. Firefighters believe(d) that by controlling the entrance of air/oxygen and where it exits the structure or such, that you can create "flow paths" that the fire will follow, bypassing rooms and going down hallways for example, until it all defenestrates through a window or your vent hole. It does no such thing - it's not lava flowing downhill with gravity.
There's a lot of knowledge you gain on the job, often from the senior people. I tell new recruits that Fire Academy doesn't teach you how to be a fireman, it teaches you how not to kill yourself and your brothers on the fireground.
Also there's tons of discussion and practice around controlling doors and always keeping them closed to suffocate and contain the fire as much as possible. I've been pretty pleased with seeing that taught, although a lot of places haven't seemed to adopt these new recommended methods.
Instead, we tend to stay low and manage the overpressure layer with gas cooling. Short bursts from firefighting nozzles that use a spinning element to atomise the spray. These rapidly turn to steam, pulling heat out of the room with the expansion. Precision is very important as too much water or insufficient atomisation will create a sauna, lowering the survivability of the compartment.
To my sister comment, this is more of the same, things we know or think we do. I actually don't know which is true, but we were taught the same, even with a fog nozzle into the overhead. "Careful that you don't lobster yourself, your partner, or the victim!"
Now it's "people will survive that, just get it cool and get the smoke out".
Respectfully disagree. At the central FL fire dept I worked for (2006 - 2020) ventilation during initial attack was practiced and expected. The command to ventilate is given by the hose team once water is on the fire.
For my dept, breaking a window was probably the most used because a couple of reasons: 1) most houses are single story and 2) usually not enough people for roof ops, initially at least. First due is a 3 man engine, 2 man rescue (ambulance) and a district chief, with at least the same complement for second due.
2-in / 2-out rule kept crews off the roof but the 2-out could, and would, break a window.
Once additional crews arrive on scene, roof ops would be started if needed.
But, each dept and type of fires for the area are different. At our dept, single family homes, room and contents fire were the bread and butter, so roof ops weren't usually needed, but, breaking a window in a coordinated effort and in a strategic position was almost always done.
To be clear, not trying to say one is superior to the other. I don’t have any experience with, or specific training in, the US method.