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TheIT
05-31-2007, 10:03 PM
If a small fire is started in a forest clearing, how would a camper put it out?

I've got a scene in my fantasy WIP where a fire is started next to a path in a maple forest. This world is pre-industrial, so no fire trucks or helicopters. In this scene, the fire will get put out by magic once the wizard gets there, so what I'm looking for is how the foresters would attempt to deal with the fire before he arrives. Use shovels to smother it with dirt? Let the area where it started burn and attempt to contain it by digging fire breaks?

Also, after the fire is put out, what needs to be done to make sure the fire doesn't flare up again?

Thanks in advance for all replies.

ETA: Let me add another question here. If you were to create a magical device which could put out a fire, what would it need to do? Remove heat?

Evaine
05-31-2007, 10:35 PM
Any forestry plantation in this area has things like large, flexible shovels left on racks at intervals - also buckets. Before the helicopter comes with the huge amount of water, people still need to stand there and physically beat the fire until it goes out - and then beat some more so it doesn't catch again.

waylander
05-31-2007, 11:25 PM
P#ss on it, if it is only a small one

All your magical device needs to do is exclude air from the immediate area of the fire, so some kind of barrier spell would do it.

Maryn
06-01-2007, 01:09 AM
Fire needs heat, fuel, and air, so if the magic removes any one of these things, voila!

I suspect a fire break takes quite a while to make wide enough that sparks and embers can't make the jump. I like the idea of peeing on it, if it's really small, then shoveling dirt on it while attempting to kick fuel (dried leaves or needles, grasses, fallen twigs) farther from it.

Maryn, hardly an expert

Leva
06-01-2007, 01:18 AM
You scrape the vegetation away with a shovel or -- preferably -- a hoe down to bare dirt to make a firebreak around the fire, then let the fire burn itself out. Expect to have to put out spot fires caused by flying embers. Once you have a fire break, you start shoveling dirt over any areas that are burning hard.

If it's more than a few feet in diameter or there's any wind, one person is not going to be able to put it out.

And it is absolutely *amazing* how much heat a brush fire can put out. I've seen plastic (garbage cans, siding, etc.) melt a hundred feet away from a good one and I've singed the hair off my arms and melted the soles of my shoes walking up to within a few feet of a fire burning in ankle high rice grass. A couple inches of dry grass will put up flames several feet high in the right conditions, too.

I live in a community where grass fires happen occasionally ... the general reaction of the locals is to show up with shovels, hoes, and the odd tractor or water trailer (we haul water here) because it can take hours before the pros show up ... about two years ago we had a really good grass fire get going with a 20mph wind behind it (fire travels as fast as the wind) ... it burned a few hundred acres of grass and desert but we saved every house. I had to have a haircut (singed my hair letting a dog loose from a burning tree he was tied to) and ruined a pair of hiking boots doing it and I kept tasting smoke for days. And I blistered and burned the heck out of my hands ... heavy leather gloves are recommended, and a heavy (non-melting) jacket and pants.

A heavy hoe is the most useful tool for cutting a firebreak.

Oh, and if there's a barb wire fence in a just-burned area? Really not a good idea to grab the barb wire to push it down so you can squeeze through it. It took a good year for the burn scars to fade on the palm of my hand ...

Except for a pile of burning tires and a couple burning 55gallon drums of mystery chemicals, we had the fire almost out by the time the "real" firefighters showed up. We let them deal with the mystery chemicals and made a point of staying well away ...!!!!

Leva

TheIT
06-01-2007, 04:27 AM
Thanks, this helps. In my story, the fire starts because an incendiary magical trap goes off next to the path and sets the undergrowth on fire. It'll be at least ten to fifteen minutes before anyone reaches the fire. Any ideas on how fast a brush fire can spread? How much area would be affected?

theengel
06-01-2007, 04:47 AM
Actually, all you need to do is remove the oxygen...the rest of the air can stay. When I was a kid they used to have this aerosal can that you would spray on any fire. The liquid would evaporate real quick like liquid air would, so it took all the heat. Whatever chemical process it was going through also stole all the oxygen from the air. I'm not sure why they were outlawed...they worked well.

Puma
06-01-2007, 06:01 AM
Hi TheIt - What are your other parameters - wet or dry conditions, what kind of brush, what season of the year, etc.? In dry situations with fuel like dried grasses, dead pine needles, or even old wood (twigs and branches) on the ground a fire can spread pretty fast. If it's a damp Spring with brush with a lot of sap in it (or dew on it) it's not going to flame up quickly - it might smoulder for a while and then burst into flames when enough of the surrounding fuel reaches the combustion point. Maple is not going to be a fast burner unless in some way a lot of it is brought to the combustion point quickly.

How to fight a brush fire - when I was a kid (before we had fire trucks closer than 20 miles away) we fought fires with wet gunny sacks (or even bedsheets soaked in water) and shovels to smack out the fire (not to dig dirt and throw on it which would have taken a long time). We lost a whole field of young pine trees one summer with everyone in the family (six of us) out beating out the flames with everything we could find (there was a lot of old dry grass that helped the fire spread). Puma

TheIT
06-01-2007, 06:12 AM
Thanks, Puma, I knew I forgot to mention something. The scene is set in a maple forest in early summer (San Francisco, CA climate). The trap which starts the fire was intended to immolate the person carrying the item, and when it goes off the item is buried under a pile of leaves next to the dirt and gravel path. So think lots of very hot flame.

I've been asking about brush fires because of the magical parameters. This forest is magical, so the trees teleport away from the fire and won't get burned. The fire's fuel would be whatever's left on the forest floor: leaves, undergrowth, twigs, other? What I'm trying to have happen is that a large circle gets burned, perhaps fifty feet across, maybe more, so that my mage can step in and save the day by putting out the fire. Until he gets there, the foresters would be trying to tackle the blaze.

Puma
06-02-2007, 04:13 PM
Hi TheIt - Methinks you've got a situation that isn't going to be believable so far.

1. In a dry maple woods, the ground cover would be dead leaves that would be fairly highly flammable if it's fall. But, after leaves have been down for a while and gotten wet they don't burn so well. Having your device land under a pile of leaves might or might not start a fire depending on how incendiary your device is. If you want a conflagration to start, you've got to have brush and small trees that're pretty dry or burn very easily - pine, creosote?, sage, grasses, etc. would help your idea.

2. You said maple woods in San Francisco type climate - are there any maple trees around San Francisco (except ones planted in yards)? Make sure your vegetation really does match your setting/climate.

3. How many "foresters" are fighting the fire? A fifty foot diameter ring of grass burning isn't that big especially if the grass is not tall (which it wouldn't be in a maple woods). A fifty foot ring is hardly a "save the day" type of situation. You probably have, but if you haven't, do some googling on forest fires.

4. Where did the foresters come from and how long did it take them to get there? There usually aren't Smokey Bears standing every fifity feet along paths through woods. How did they discover the fire? You've got a time element involved that's going to help determine how big your fire is by the time your Wizard arrives.

4. Your incendiary device - since you said it was supposed to immolate the carrier, I'm assuming he threw it away from him and survived. What type of material are you using? Is it explosive as well as incendiary? If it's explosive, the bits of fire would be thrown farther and cause more than one fire to start which would be harder for one or several people to fight.

Hope all these questions and thoughts help you. Puma

Cav Guy
06-03-2007, 01:28 AM
If it's a magical incendiary you have a slightly different set of things to consider before you move on to the fire part.

Some magic systems define magic fire as being created from bits of magical energy, essence, whatever, and don't remain to catch things on fire after the duration or impact of the spell (unless it has especially spectacular results). I'll assume that you have this part worked out.

As Puma pointed out, dead leaves and the like in a forest in early summer/late spring aren't really going to be that dry. In most cases (unless someone goes out and cleans up every fall) there's going to be a layer of rather dank mulch under the first layer of leaves, and that stuff doesn't burn readily. You're not going to have as much deadfall in a maple forest as you would in a pine forest, so there might not be that much burnable on the forest floor (once you take into account the mulching effect of fallen leaves and so on). You'd find grass and the like in clearings, but most likely not in the forest proper.

Tsu Dho Nimh
06-03-2007, 07:23 AM
What time of year? How big is the fire?

Firefighting is low-tech for the most part.

An effective weapon against smaller fires is wet burlap bags or wool blankets or sheepskins with the wool on them. Soak them and beat the heck out of the flames. Even green leafy branches can be used.

The strategy with a low-burning fire, like a grass fire, is to break the line of fire into segments ... 1/2, then 1/4 , 1/8ths because it has less heat than a solid line of advance.

If the fire is "creeping" through short brush, you can clear an effective break fairly quickly by hacking the brush down and throwing it away from the fire, then plowing a strip to expose bare dirt. If all you have is manual labor, a line of peasants with pickaxes and mattocks can clear a narrow trench almost as fast as they can walk.
http://www.sfgate.com/c/pictures/2006/07/09/ba_smokejumpers_250.jpg

The post-fire part is called "overhaul", where you rake over the burned area looking for stumps and roots that are smoldering, and soak them.

TheIT
06-05-2007, 02:48 AM
Thanks, everyone, you've given me a lot to think about, and right now my thought is that I need to rethink my scenario. :D

A couple clarifications:

Yes, I'm putting a maple forest in a San Francisco-like area which is unusual, but I'm also using up a lot of my "bolognium" quotient for this story on the forest. The trees are very magical: they sing (hum), they teleport, and they have a deeper purpose which will be revealed by the end of this story. If a fire starts in the forest, they'll scream and teleport away from the flames, so the humans will immediately know there's something wrong. This forest is actually in a very large walled estate inside a city.

I'm hoping the magical nature of the trees will counter-balance a reader saying "hey, maples don't belong in this sort of climate"; it's also possible that I'm not putting in enough for a reader to know it's a SF-like climate. Story description so far is that it's summertime and they're in a city on a hill next to an ocean.

Thinking about it, given where the fire starts, it's unlikely any of the foresters would arrive before the mage. Even if they did, they'll only have a couple of minutes tops before he gets there, so they wouldn't have much chance to try to put the fire out. The information you've given me is useful, though, and I'm sure I can use it somewhere else.

Storywise, the trapped item was intentionally hidden in the leaves next to the trail by the person who was carrying it. She didn't know it was trapped, she just knew she couldn't take the item into the manor. The trap goes off later, possibly when someone else walks near it, but the trap fails in that it doesn't kill the intended victim. No one actually gets hurt.

What I need storywise is some way for my other characters to find the item. Sure, someone could just spot it next to the trail, but that's boring, so I'm thinking the trap should get triggered. I'm trying to work out the parameters of the trap. I like the idea of something spectacular like fire for several reasons: it shows the person who set the trap is playing for keeps, it demonstrates the magic of the forest, it demonstrates the mage's power and his reaction to his power, etc. I'd originally been thinking the magical trap would set off a normal fire, but given the probable lack of fuel, the resulting fire sounds like it would be easy to control. Instead, I could make the trap start a magical fire, in which case I can change the rules. Time to put on the thinking cap again....

Tsu Dho Nimh
06-05-2007, 02:56 AM
NOTE: You will not get a "ring" of fire unless there is absolute calm air.

A tiny breeze will move the fire downwind easily.

TheIT
06-05-2007, 02:58 AM
NOTE: You will not get a "ring" of fire unless there is absolute calm air.

A tiny breeze will move the fire downwind easily.

So a fire will move in the direction the wind is blowing (as long as there's fuel in that direction)?

Puma
06-05-2007, 04:19 AM
TheIt - You've got a very good attitude. You're going to be able to pull this off (I can see the wheels turning.) Puma

TheIT
06-05-2007, 04:33 AM
Thanks, Puma. Yep, wheels are turning, and so far no smoke is coming out of my ears. ;)

It's the software designer in me. It's much simpler to stamp out possible bugs in the design phase before they multiply in the implementation phase. I'll be hitting this section in about two scenes, so I wanted to make sure I had some understanding before I tried writing it. At the moment, I think I'm still going to make the trap a fire trap, but I can see I'll need to add some more details to make the scene plausible.

Thanks for all the replies, everyone!

Tsu Dho Nimh
06-06-2007, 07:26 PM
So a fire will move in the direction the wind is blowing (as long as there's fuel in that direction)?

Yes. With no wind it will creep out in all directions, fairly slowly. As the wind picks up, the upwind side slows down and the other side moves faster.

A fire with a strong wind behind it can come roaring uphill at 40+ MPH, hurling embers hundreds of yards ahead of the flames. They roar, they growl, trees explode, they howl ... it's scary.

http://www.missico.com/personal/tidbits/bitterroot_national_forest_fire.htm

To fight fire, you have to get in front of it, and remove the fuel by plowing, trenching, wetting the fuel, bulldozing the trees to keep it out of the crowns (http://forestfire.nau.edu/) where it will be able to move even faster. And as you do, you have to keep an eye on your escape route.

(your wizard could call up a small downpour and soak it, or make all the breezes blow inward to slow it down and hold it in place while the forestry crew stamps it out)

asorum
06-06-2007, 07:33 PM
Just a thought on your fire control question. There is a fourth part to the fire equation. An uncontrolled chemical chain reaction. This why agents like Halon work in part. Halon displaces oxygen, but it also interferes with the chemical chain reaction that allows the fire to continue. Your magical fire suppression agent could be similar to Halon.

TheIT
06-07-2007, 10:16 PM
Thanks for the links! Those look useful.

My mage can manipulate energy, i.e. temperature. I figure he can drain the heat from the area surrounding himself and therefore put out fire. It'll require him to walk into the burning area and put himself at risk. After he walks through an area, the ground will be cold. I'm also trying to figure out if he needs to do anything with the heat he's pulling away from the flames. He might need to use up the excess energy somehow.

Feathers
06-14-2007, 11:26 PM
I'm trying to think here. We have alot of maple-forests around where I live, and most of what would be burnt is dead leaves and some fallen sticks. Leaves don't burn very well unless they are very dry, mostly smoldering, so I don't think the fire would get terribly out of hand. On a realistic side, all you would probably need to do is stamp on it while another person shoves aside other flammabile matieral. You could also dump water or sand on it, as well as beating it with wet/dry coats. But thats kinda extreme.

With the extra energy...just a random thought here...could he just duck in a stream and release all this 'heat' energy, or is it a bit more complex than that?

Hope I helped.