Fire Behaviour

Obviously I've never seen anything like the firebombing of Dresden, but fires can create their own "wind". Basically fire needs oxygen to survive, just like we do. So when a fire sucks in air like that, it is doing so to boost its oxygen supply which is needed for combustion.

I've seen this hundreds of times on a smaller scale. If a house is on fire, often times the fire will be "sucking" air into the house. You can see this by a reverse smoke flow. Instead of smoke coming out of the door or window, it is being sucked back in. That can also be a sign of backdraft potential, but that is a different matter entirely.

From my limited knowledge of the Dresden bombing, I too have heard of people actually being sucked into the fire. I believe what you had was a "tornado" of fire. Kind of scary. The fire volume was so high that is was pulling in all the available air to replace the oxygen which was depleted.

Also, a fire like that can actually suffocate someone by using up the oxygen, even if there is no smoke in the vicinity. Superheated air when inhaled and char the lungs and actually cause a person to drop dead instantly. One such case of this is the Our Lady of the Angels school fire in Chicago. A firefighter was on a ladder trying to pull kids out of one of the windows when a burst of superheated air killed a dozen or so children right in front of him. He used the word "wilted" to describe it.

Anyway, I will check my texts at the house tomorrow and PM you with a more scientific answer if one is to be found. Good luck!

Brady H.

Os,

Something else just ocurred to me too. I'm not sure how the fire at Dresden "behaved" but one thing that I always stress to people is that fire is a living thing, just like us. As people, we need food, water, and oxygen to survive. Fire also needs food (fuel source) and oxygen. Instead of water, it needs heat. There also has to be a chemical reaction which causes combustion. The Fire Triangle (fuel, oxygen, heat) has now been replaced by the Fire Tetrahedron (fuel, oxygen, heat, chemical reaction). These must be present in order to have a fire. That is something that the smallest and the largest fires have in common. You put a fire out by taking away one or more of the elements.

As far as behavior goes, I am not refering to the scientific fire behavior (burn patterns, etc), but rather a "personality" if you will. It has been my experience that fires can take on a life of their own. They are sneaky and quite dangerous. A fire will run from you, sometimes it will try to arc over your head and get between you and the exit, it will draw back from you and then charge (for lack of a better word) and it can look at you. Though Backdraft the movie has numerous errors, the part where the arsonist asks "Did the fire look at you?" is very true.

Anyway, just thought I would share that too.

BLH

If there is a policy against posting links, feel free to delete this. If not, here is a link to some Wildfire Videos

www.firestormvideos.com

That is a good place to start. The phenomenon is visible in large wildfires. However, we do not get those where I am so I have never seen anything on that scale. If you do a search for fire videos or wildfire videos you will get hits to other sites as well. All of them are good. I just posted the link to the people I am familiar with.

Brady H.

Chemical fires

BradyH1861 said:

Though Backdraft the movie has numerous errors, the part where the arsonist asks "Did the fire look at you?" is very true. Anyway, just thought I would share that too. BLH

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Thanks for the excellent feedback. You guys are awesome.

I've had some experience with chemical fires, since I worked at a refinery and a plastics research plant for quite a few years. My experience was mainly due to some idiot setting off a blaze nearby, and me having to get the hell out while the firefighter pros were on their way.

One of the worst I've ever seen was from a "tickle-three" explosion. "Tickle-three" is the slang term for titanium trichloride. It must be kept under oil or other non-water liquids, or kept sealed in a tank. It burns in the air (literally bursts into flame), and explodes if you try to put water on it -- it "burns" the water as a accellerant fuel. If you get any on your skin it will burn straight thru to the bone and leave a nasty scar. Oh, yeah -- it can also generate chlorine gas as a byproduct of its ignition. Real fun stuff.

It took out one side of a lab building one afternoon. The fire crews just sat back and watched and kept it from spreading until it had mostly used itself up, then they sprayed what was left with a specialized retardant foam.

As far as a simple explosion, ethylene gas is a monster. I was on vacation one day when it took 5 firefighters. The building where the leak began was evacuated, and then all the ethylene was shut off from outside (or so it was thought).

Then the fire crew went inside, and someone must have struck a spark -- nobody knows what happened exactly -- but the entire 4-story building was essentially vaporized in a huge explosion -- I was home and I could hear it from miles away.

Chemical plant fires can be real baddies.

oswann said:

Brady, I am also curious as to your experience with lack of oxygen causing disorientation. Firefighters have spoken to me about beginners mistakes of overestimating their own capacities in physical exertion and holding their breath. By trying to leave a smoke filled building where visibility is low and by not breathing correctly firefighters themselves have become disoriented and have panicked. One person even spoke of losing his sense of up and down, like being under water and kicking to what you think is the surface and hitting your head on the bottom.
Os.

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There is a trick to breathing with the SCBA that is only acheived with practice I think. Prior to their use, firefighters who entered burning buildings would be low to the ground with their mouths almost touching the floor. They developed "leather lungs" to help them deal with the smoke. Disorientation is a key factor of oxygen deprivation. The problem is if you panic, you instinctively breath harder, thus draining your pack even faster. But you can easily get lightheaded, dizzy, and completely turned around. In fact, the dangers involved are one of the prime reasons for the "two in two out" rules where you always have at least one partner. I would definitely concur with the underwater scenario. I was deep in a burning building once and lost my air and in a very short amount of time I had no idea where I was or how to get out. Luckily, the team on the second hose line got to me. It did sort of feel like how I imagine drowning would feel.

Brady H.

oswann said:

Thanks for the info again Brady.

You are a great example of the spirit of these boards. Polite, professional and a fantastic source of information and motivation for any writer. (Maybe I should write blurbs.)

Thanks again and be careful on the job.

Os.

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If I ever finish my novel, I"ll take you up on that!

I know a bit about New York City--grew up there. I spent 33 years (now retired) in the NYC Transit System, which included Directorships in Labor Relations, Budget, Production Planning, Human Resources, and New Car (subway) Engineering.

What I don't know about the system can be had by phoning anybody from the guy who runs the subway system to a subway Car Cleaner at Coney Island's Stillwell Avenue Station.

Fishing: fresh water bass--the only fresh water species where I could give Frank a run for his money. Salt water species: blues, stripers, fluke, flounder, blackfish, and quahogs. Sharks, tuna, etc. require going where you can't see land--not my cup of grog.

Invoke the sound. A fire, regardless of what it is burning, is very loud.
I've been caught, forest fire-fighting, and I'll never forget the sight and sound of the roar overhead, as it reversed and crowned through the top of the trees. With the smoke from the burnt underbrush, it was a wild moment.