The word you may have never heard before is “bunkering.”
Helps to be as old as the hills, and to actually have “bunkered” a coal furnace in your life, but I’ll explain as we go.
What occasions the discussion today is Thursday’s “one little thing around the house, dear…” That’s what you call an acre of ground with leaves ankle-deep and rain due through the area in three hours.
Our Science of Prepping Fires discussion begins with a review of the three elements needed for any fire: Fuel, oxygen, and a source of ignition.
We also need a project…hmmm…something that would be a fine demonstration of total control over fire, yet won’t require much effort.
We begin by getting out the leaf blower and blowing umpteen bushels of leaves. We observe Chapter 3 (from The Science of Leaf Control) which says a) never attempt leaves on anything but a calm day, b) dry day, and c) always blow leaves down hill, not up. Reread the chapter on “Leaf Laziness to Ure.”
As you can see, this is the pile of leaves, before we set about bunkering the fire as we want it.
The purpose of the “big burn” look is to get a sense of how this material will be burning.
Since you may not have been raised in a Fire Department family, there is a critical dynamic of fires that can only be experienced close-up and personal. I got to see this walking through burned out hotels and the like being instructed by The Chief himself on fine points of fire spread through “transoms” – what used to be doors over windows to help keep old-time hotels cool in the summertime. See related background in the Ozark Hotel Fire in Seattle. Bloody awful mess and one of my first experiences with big killer fires.
Point is, whether you are prepping and just practicing fire control, or whether you find yourself in a survival situation, fire come in three sizes.
1.Small fires: These are fires that smolder a lot. They generate some heat, but they don’t get enough fire-energy going to be real self-sustaining nightmares. Left alone they will mostly just smolder along and sometimes will go out. I can’t count how many smoking-caused fires I covered as a reporter, but many of this kind were smoldering for hours before someone discovered them. Usually victims died of smoke inhalation or the toxic fumes from bedding and the like before the “real fire” got going.
2.Sustaining Fires: This class of fire is a little bigger and it will grow, but not terribly fast. In terms of dynamics, what you are looking as is marginal fuel, mostly. While the fuel might not support combustion on its own, and you can test this by trying to burn one leaf, when there are enough leaves in the pile, the fire becomes self-sustaining. In other words, there’s enough heat generated by the fire to dry more fuel, which generates more heat, which dries more fuel…. Well, you get the idea.
3.The Rip Snorter: This is the kind of fire you want to avoid most of the time. It has enough heat-mass to dry even soggy materials and get it going. Everything that can combust will eventually be burned in a rip-snorter. Transom glass over doors in old hotels will break and on it goes.
Super-size a Rip Snorter and you get a fire storm, see Dresden in WW II for details.
Since this is not a fire forensics discussion, we will press right ahead to “bunkering” the fire.
Coal is where the term came from, when piles of coal were called “bunkers”. Reference to the Titanic here is interesting.
Point is that firemen (on locomotives although to a degree at the firehouse) would often speak of “bunkering your fire.” The mental image that goes with this is of a fireman stoking the fire of a steam engine by throwing his shovelful this way, or that, to proper bunker the fire.
Since our “fire speed” has been figured from lighting one end of our pile, we can now “bunker the fuel source” in just the way we want in order to produce the burn speed we’re after.
Properly “bunkered” and tended just right, we have a very tightly controlled fire. If it starts to look a little weak, we can add fuel. If it gets too ambitious, we can take some fuel out of its path.
Thing is, when burning leaves out in the real Outback, where the fire department is a good 20 minutes away, you want to always be in total control of ALL fire. You do this by testing speed, making sure never to get a rip snorter going, and by adjusting your bunkering so that the fire burns down a line that you have total control over. See the gray ash-trail behind my fire?
This is a prepper skill how?
Well, for one thing, when you go to other parts of the world and see people who have been dislocated, as in the upper Amazon, for example up around Equitos, you will often see people doing controlled (and sometimes not) burns because it really is an easy way to clear land, remove most pests from an area, and put some of the elements leached out of soil by tress back into the ground.
And if gives you a chance to demonstrate your total ownership of fire control.
Something in the, uh, Ure genes, I guess. Fire Art or George makes and ash of himself.
Start with char cloth and a fire steel and a good working sweat to get everything just right and let’s see how good we can get at fire control, shall we? Plenty of leaves to go around this time of the year…
Oh, and if you want to stop global warming, stop burning down Indonesia and the Amazon, right?
Write when you get rich,