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Earth Science

Researchers Experiment With Explosives To Fight Wildfires 80

aesoteric writes: "Australian researchers are a step closer to demonstrating whether explosives — rather than water — can be used to extinguish an out-of-control wildfire. The research uses a blast of air to knock the flame off its fuel source — a technique used in the oil & gas industry for decades. The latest tests were conducted in New Mexico. Firefighters are reported to be quietly optimistic about the research's potential."
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Researchers Experiment With Explosives To Fight Wildfires

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  • Always puts out the fire....

    .....for a while, anyhow.....
    • To paraphrase Homer: To explosions! The cause of, and solution to, all of life's problems.
      • Fires are already on fire, so...

        EXPLOSIONS!

        That's WHY people become researchers: "Now, what can we BURN or DETONATE?"

        • by Cryacin ( 657549 )
          The bushfires... Nuke them from space, it's the only way to be sure.
        • It will only be a matter of time before they try something that includes golf balls. I predict they will eventually freeze a golf ball size mixture of corn starch and water. Pack about a million of them in a c130 and drop them in front of the fire at 200 mph. The frozen objects will collect moisture out of the atmosphere on the way down and rip all the canopy off the trees when they hit. When they melt they will produce a cool fog that will cool down the underbrush.
    • Could it possibly be because fire season is starting in New Mexico, and ending in Oz?
    • Because there's a lot of wildfire expertise, and people pay top dollar to save their mcmansions?

    • Why are Australian firefighters working in New Mexico?

      The researchers are Australian, not the firefighters. In then American Southwest, most firefighters are Mexicans.

      • by Nutria ( 679911 )

        The researchers are Australian, not the firefighters.

        Don't the researchers have any firefighting experience?

    • There aren't many places that have the protocols and skills to handle energetic materials safely.

      • There aren't many places that have the protocols and skills to handle energetic materials safely.

        All they have to do is watches a Mythbuster's marathon and they'd know what not to do.

  • if it doesn't work at first, add more rockets.

    Good advice for any situation.

  • by Anonymous Coward on Wednesday May 21, 2014 @02:32PM (#47059149)

    The reason it works with oil fires is that the oil cools rather FAST once the flame is out.

    Wood... not so much. It is a good insulator and will preserve the heat - thus the vapor from wood will still be there - and HOT. Once the oxygen gets to it, it will flame again.

    • I bet they are; its proven incredibly effective on Sharknados and a wildfire should be a much simpler threat.
    • by Ichijo ( 607641 )

      [Wood] is a good insulator and will preserve the heat - thus the vapor from wood will still be there - and HOT.

      This assumes the wood will still be there and therefore the explosion wasn't quite big enough.

    • "Fire is very fast moving if it gets up into the tree tops. If the fire is still smouldering or burning on the forest floor, it's moving at a fraction of the speed, giving emergency services extra time to come in with water bombing or ground operations," Doig says.

    • by overshoot ( 39700 ) on Wednesday May 21, 2014 @03:31PM (#47059853)
      In NM, as in Oz, a lot of fires start as brushfires -- no wood, no particular heat retention -- stop it even briefly and it doesn't get into the forests.
      • by radtea ( 464814 )

        In NM, as in Oz, a lot of fires start as brushfires -- no wood, no particular heat retention -- stop it even briefly and it doesn't get into the forests.

        Reading between the lines of TFA this appears an extremely optimistic reading of the research, which so far involves blowing a flame off a propane source, and appears in the long term to be directed at separating flame from tree-tops, with the idea that this will slow down the rate of spread, not put the fire out. It will give emergency services more time to respond by quenching the fast-moving tree-top phase of the fire.

        The problem is that there will still be glowing coals on the woody stems, even if they

    • by torkus ( 1133985 )

      Yah, I can only imagine this will be useful in some very very specific situations.

      In an oil or gas flame, the heat of combustion generally ignites the incoming fuel. In a forest fire you have an *immense* amount of latent heat even if you were to completely extinguish the flames for a brief moment. Similar reason to why they keep spraying down after a house fire is technically out.

      • Yah, I can only imagine this will be useful in some very very specific situations.

        In an oil or gas flame, the heat of combustion generally ignites the incoming fuel. In a forest fire you have an *immense* amount of latent heat even if you were to completely extinguish the flames for a brief moment. Similar reason to why they keep spraying down after a house fire is technically out.

        Seems to me this wouldn't be very useful in a groundfire or rootfire, but could be very useful in slowing a firestorm (vortex of flame whirling through the branches). This technique would drive it back down to the ground where they can use chemicals and water to contain it.

      • Yah, I can only imagine this will be useful in some very very specific situations.

        In an oil or gas flame, the heat of combustion generally ignites the incoming fuel. In a forest fire you have an *immense* amount of latent heat even if you were to completely extinguish the flames for a brief moment. Similar reason to why they keep spraying down after a house fire is technically out.

        But the "very very specific situations" might actually be common problems that firefighters encounter. I can imagine several possibilities about how this general idea could be employed to good advantage.

        Fuel structure is critical in determining the intensity of a fire. Consider burning forest or brush - the vertically held trunks and spread lateral limbs of the former, and the branched framework of the later, are perfect ways to hold fuel in place so that it can burn quickly and intensely. If you can blast

        • Clearing fire breaks with explosive is likely to be disappointing, to drop a tree you want to place a 1 pound block of TNT or C4 on the side of the tree you want it to fall in then wrap Det cord [wikipedia.org] around the tree and TNT 10 times, then run the det cord up the tree about 8 feet to a 1 pound kicker charge on the side away from where you want the tree to fall. While I love blowing shit up, a chainsaw is faster and easier.
          Something like a Bangalore torpedo [wikipedia.org] would knock out a short section of brush to 3 or 4 m wi

          • A better example than the Bangalore torpedo would be the mine clearing line charge [wikipedia.org] which is capable of clearing a full width fire break (20 feet [usda.gov]) under many conditions.

            While chain saws, and wrapping trees with C4 is effective, where feasible, there are many situations where it is not (inaccessible, imminent fire danger precludes it, it is already on fire).

            And there is other interesting prior art [buch-der-synergie.de] showing effectiveness on suppressing wild fires.

            And the idea that blast charges can't knock down trees in an ar

            • It's not that you can't knock down trees, it's just that the shape of the trunk (basicaly round) and the wood being wet and more flexable makes it easy to overestimate the effects of a given explosion on trees.

      • Yah, I can only imagine this will be useful in some very very specific situations.

        You mean, like when a fire is crowning? Crown fires are fast and account for most (almost all?) of the firefighter fatalities (including the recent one at Yarnell where someone I used to work with died.) Interrupt that process, even briefly, and you may save some firefighters on the ground.

  • by wjcofkc ( 964165 ) on Wednesday May 21, 2014 @02:33PM (#47059153)
    I have always wondered why this is not standard practice. If you want to extinguish a candle, the established method is to blow it out. After all, we used explosives to put out the Iraqi oil fires. Carpet bomb it, massively. If the fire is already to big for that to be practical, carpet bomb as wide and as much of a perimeter as you can and let it burn itself out.
  • by gurps_npc ( 621217 ) on Wednesday May 21, 2014 @02:35PM (#47059189) Homepage
    Right now the main way fire fighters fight large forest fires is by setting other small fires destroying fuel. (There is never enough water or similar substance to put out a real forest fire.)

    This is basically just a faster way to do that - by removing the oxygen as opposed to the carbon from the carbon+oxygen+heat equation.

    • I'm not so sure this is as good an idea as it sounds. In a controlled situation sure but a wild fire in a heavily wooded area you may end up just spreading it around.

      • In a controlled situation sure but a wild fire in a heavily wooded area you may end up just spreading it around.

        The explosive is not tossed into the center of the fire. It is detonated just in front of the fire's path. So it not only blows out the fire, but it pushes burning wood backwards, into the already scorched area. Then the firefighters rush in to extinguish the remaining smaller flames.

  • by overshoot ( 39700 ) on Wednesday May 21, 2014 @02:36PM (#47059197)
    Do I know some people in NM [nmt.edu] who are going to love this! And the fact that theyr'e next door to the NM firefighters' training academy ain't gonna hurt, either.
    • by plopez ( 54068 )

      They actually have classes in explosives and you can get licensed for their use at NMT.

      • Well, yeah. Not surprising for a school of mines, after all.

        As it happens, one of my kids did take explosives engineering there (as an elective) and I'm in the process of moving to Socorro.

  • by HellYeahAutomaton ( 815542 ) on Wednesday May 21, 2014 @02:47PM (#47059317)

    "After the flames were extinguished, the explosives did nothing but create an avenue for the fires to spread during those first critical hours: Buildings and walls that might have served as firebreaks had been demolished.

    The explosives also raised a dust that choked the lungs and impaired visibility. But perhaps the worst damage was the creation of even more fires as flaming debris ignited ruptured gas lines. Unwilling to admit responsibility for their collective mistakes, the Mayor, the Army, and the Fire Department all pointed fingers at each other, adding fuel to the administrative confusion that reigned during the fire."

    http://mceer.buffalo.edu/1906_... [buffalo.edu]

    • by Thud457 ( 234763 )
      Most wildfires aren't in urban areas. Unless you just had a 500-year earthquake, incendiary bombing, or Godzilla attack.

      But, as others have pointed out, this works better for oil well fires because oil won't sit and smoulder for hours, then reignite.
      • But, as others have pointed out, this works better for oil well fires because oil won't sit and smoulder for hours, then reignite.

        As a precursor to moving in and applying chemicals its sounds like a good idea. After the flames are displaced you could count on fires springing up again from pockets that remain above the autoignition temperature [engineeringtoolbox.com] of the materials but it would probably take awhile, you'd have some clear area and time to move in and quench them.

        There is a good demonstration of dynamite quenching a flaming oil well here in The Fires of Kuwait [youtube.com] ... rewind and check out this whole mesmerizing documentary!

    • To be fair, that was over 100 years ago and a completely different setting for wildfires. I would be the science behind this technique may have improved since then. But it does provide precedent for not fighting urban fires with explosives, which is hard to label as bad find.
    • by T.E.D. ( 34228 )

      , the Mayor, the Army, and the Fire Department all pointed fingers at each other, adding fuel to the administrative confusion that reigned during the fire

      Quick note to the folks at buffalo.edu: As a matter of English sentence design, perhaps it isn't the best idea to use a fire metaphor smack dab in the middle of a sentence talking about real-life fires. Unless what they mean was that the Mayor, the Army, and the Fire Department all burned to death in the fire while they were arguing.

      In which case, well done. Carry on.

  • Combining burning things with blowing them up? I'm surprised there aren't more volunteers to conduct this experiment! Where's Johnny Knoxville when you need him?
  • by Spy Handler ( 822350 ) on Wednesday May 21, 2014 @03:04PM (#47059475) Homepage Journal

    Watch an old nuclear weapon test footage with trees in it. First you see the flash of light, and instantaneously the trees erupt in flames due to the intense radiation. Then a few seconds later, the shockwave (basically a strong air current) arrives and it puts the fire out.

    You can substitute nuclear with a fuel-air bomb, which has the added benefit of sucking away all the oxygen in the area.

    • "Nuke it from orbit" was my first thought too.
      But seriously, you'll need a lot of explosives to knock out a wildfire. Unless you detect it right after it ignited, it'll be at least acres in size and everything will be ready to re-ignite so you have to blow it out all at once.

  • sounds good (Score:3, Funny)

    by Connie_Lingus ( 317691 ) on Wednesday May 21, 2014 @03:23PM (#47059725) Homepage

    what could possibly go wrong?

  • by steveha ( 103154 ) on Wednesday May 21, 2014 @03:25PM (#47059747) Homepage

    In the movie Fires of Kuwait [wikipedia.org], my favorite part showed a modified tank called "Big Wind".

    Instead of a cannon, "Big Wind" has two jet engines from a MiG fighter plane, and it uses those to blow out fires the same way you might blow out a candle on a birthday cake, only at epic scale.

    http://www.caranddriver.com/features/stilling-the-fires-of-war [caranddriver.com]

    It's probably more practical, for wildfires, to use a helicopter to deliver explosive devices rather than drive a tank around. Setting up the water reservoirs in advance would be a problem also. The tank worked very well in Kuwait, though!

    • by MattGWU ( 86623 )

      I feel like that worked because the source of the fire is more or less a point (the wellhead) so you could point it at the fire *right there* and put it out. A wildfire spread over acres? No one real spot to point at, and when you move to blow out another spot, the fire has spread back to the spot you just extinguished. Why I'm skeptical of this explosives thing, unless they're talking about something that covers a very large area like a fuel air explosive somebody mentioned further up.

  • Any basic firefighting course will teach you there are two components to fire: oxygen and heat. If you remove either you will put out the fire. However, if there's enough heat left fire will reignite. That's why firefighters keep pouring water long after flames have been extinguished.

    So an explosion will not stop the fire unless it also creates enough airflow to cool down whatever was burning. That will work for some materials but not for everything. Just remember how easily blowing at the barbecue charcoal

    • by Anonymous Coward

      Any basic firefighting course will teach you there are two components to fire: oxygen and heat.

      Two... I thought the fire triangle was three sided, oxygen, heat and FUEL. Fighting forest fires generally deals with the FUEL part because when dealing with large areas on fire, there is no way to smother it (remove the oxygen), and never enough water to cool it, so the only real solution you have is to limit the available fuel. Which, by the way, is why forest fires are so hard to fight, well that and they are usually in areas where it's difficult to get men and equipment in and out....

  • Nice slogan. What's next, Nuke The Whales?
  • I can think of a couple of of important differences off the bat...

    1) spewing oil wells very quickly displace hot oil with cool oil, while a forest fire fuel just sits there, remaining hot

    2) burning oil gushers are very compact, while forest fires are generally spread out

  • Deprive the fire of oxygen, that is, after you try flooding the viper launch bays with boroton.

  • "Our reporter is live at the scene of the forest fire"

    KABOOM

    "Oops, not any more."

  • Discovered and researched by rednecks?

  • Oil well fires are stationary points of flame a few tens of meters wide - lots of pressure behind them, but not much territory, and a single point of combustion where the fuel is coming out of the pipe. You can surround them.

    Wildfires have flame fronts that are hundreds to thousands of meters wide, irregularly shaped, with a wall of flames and fuel sources that may be 5 to 30 meters high (or higher), and can be moving 60kph or more.

    Look at this picture: http://media2.abc15.com//photo... [abc15.com]

    Tell me where you wil

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