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Science Technology

Giant Firefighting Blimp 50

Posted by timothy from the sploosh dept.
bgood writes: "MSNBC has an article about a California firm's plans for building a firefighting airship. Wetzone Engineering is working on a prototype and hopes to have a production craft in use within three years." Looks like a great way to water the lawn, too.
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Giant Firefighting Blimp More

Giant Firefighting Blimp

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  • it'll not be able to float over fires - it'll rise up with all the hot air.
  • So what happens when one of these babies crashes in a huge ball of fire? Kinda defeats the whole purpose of the thing, don't ya think?

    • Nobody's used hydrogen in airships since the Hindenburg disaster. Even the Hindenburg was designed to use helium, and would have if it weren't for export restrictions. Helium is too noble [chemicalelements.com] to burst into flame.
    • Well, the fact that the Hindenburg was filled with hydrogen is not what made it explode. What made it explode was the fact that it's skin was literally pained with rocket fuel (This was before they knew what it was, of course. It just looked pretty to them I guess). Do a little googling and you'll see.
      • This "aluminum paint over iron oxide primer" theory seems like something out of "McGyver". That's a potentially explosive mix, but the active chemical components were just thin layers, dilluted in dried paint oils. Not by far as flammable as the big hydrogen filled balloons inside.
  • It had better not be filled with hydrogen.

  • First Pick! (Nitpick that is.) (Score:3, Informative)

    by fm6 ( 162816 ) on Thursday June 20, 2002 @07:45PM (#3740346) Homepage Journal
    A blimp is a nonrigid airship [bartleby.com]. This would be a semirigid airship.
  • But hot air rises, right? So this thing goes over a fire to put it out, and then...FWOOM...it's in orbit!
  • The article says that traditional firefighting aircraft must fly "dangerously low". This implies that this airship is going to be designed to drop the water from higher up. Depending how high up, the effect of the updraft would be lessened.
  • From time to time a story on lighter-than-air craft gets published. Let's face it, blimps and airships are less reliable than heavier-than-air craft. Every single airship that was built in the 1930's crashed or burned. Air has a very low density, being less dense than air means a very fragile construction. Big size + skimpy design == torn apart by winds.
    • Airships can stay up for far longer periods of time than can a heavier-than-air vehicle. Consider that the Hindenburg took three *days* to cross from Berlin to New Jersey. Airships can also hover, and are very stable. There are few limits on size (Hindenburg was 804 feet in length), and can keep sufficient supplies on board for a small crew for days or longer.

      Because they can stay longer than fixed-wing and have more room and carrying capacity than helicopters, they can mount water cannon allowing for more directed targeting.

      As for your assertion on the reliability of the technology, aircraft technology in general was very undeveloped then, and several countries (and even companies) around the world use airships that have been around for a very long time with a very high safety record.
    • Thousands of airplanes built in the 1930, 1940s and 1950s crashed. We're still building the damned things and we're still flying in them, despite the fact that Islamic whackjobs like to drive them into tall buildings. I would love to take a trip across the ocean on a blimp. And
      spending three days to get across the ocean
      to Berlin on a blimp is in my mind better than having to fly through Chicago O'Hare and Frankfurt am Main.
    • Not true
      the hindenburge II
      and the
      Graf Zeppelin
      was scraped for its aluminum during world war 2 and the never crashed. The Graf Zeppelin few longer and farther than any other zeppelin in history even in dangerous places like the arctic
  • Was in a science fiction short, "Bringing down the Iron" or something like that from Analog a few years ago as a way of getting asteroid materials back to the earth's surface

    1) Get a Large Nickle/Ferrous Asteroid
    2) Make a *really* big hollow sphere out of the mined products. Better make it nice and accurate to avoid stress issues
    3) Make it vacuumtite
    4) Get it LEO with reaction jets and begin re-entry
    5) Slowly let air into the sphere to provide a small amount of degree of the rate of descent vs the outside atmosphere density

    Sure, it's made of iron, but a big sphere enclosing a vacuum is a lot lighter as a whole, so it will float.

  • All Tomorrow's Parties by William Gibson is a pretty good book, and contains an appearance by a firefighting / water-carrying airship.

  • ... they'll be filled with Hydrogen.
  • Setting aside the fact that it would be an incredibaly fragile piece of aircraft (blimps are really only used for those crappy aireal shots of sporting events inside or out---can you say stupid?---right now) for a moment, how much water would they be able to carry? Considering the number of passengers, cargo, and extra utilities that were carried by them in the pre-1940s, the weight isn't that much in comparison to the amount of water that would be needed to fight the fire.

    Even if you could get enough water in the holding tank of the blimp, who's to say that you could easily fill it? From what I've heard and seen about blimps, they aren't the fastest or most manuverable things floating around the sky. In my eyes, the only way they could be effective in fighting fires would be if the fire was VERY close to a river or lake.

    Lastly (bringing the structure of the blimp back into view), if a blimp is highly flamable, and all Blimps built in the 1930s or earlier crashed and burned (as one poster stated earlier), where is the sense in using a blimp to fight the very thing that caused its demise? Ok, ok, I know the materials that make up the structure of the blimp have changed (from wood and canvas to probably steel and a plastic covering), but that still doesn't mean it is immune to fire: the very thing it'd be floating over. Now while it probably wouldn't come into contact with the flame, you have to remember that all of the heat being put off by the fire would be rising rapidly right upto the blimp. Not safe at all in my eyes.

    Just a few things to think about.
  • Just following up on the discussion on bad programming is this headline:

    Californian Blimp makers fill balloon with Hydrogen instead of Helium. It is believed the mistake was due to a programming error.

    mmm... Hydrogen firefighting balloon
  • The key question with this device is: how fast can this thing move? IIRC, current airships really struggle on windy days to get *anywhere*. Funnily enough, major fires almost always occur on windy days. On the same note, if it's as slow as I'm expecting here, it's like to take hours and hours to get these things to a fire. The beauty of fixed-wing aircraft and even firefighting choppersis that you can have one base and have them fighting a fire hundreds of kilometres away in an hour.

    Related to this issue is how manoeuverable this baby is in windy conditions at low altitudes. Fires happen on windy days, and if this baby can't manoeuver into position quickly and safely on a windy day it's going to be useless.

    Their aerial reloading scheme sounds ridiculous. Whilst I have no doubt it can be made to work, technically, it makes no sense to have aircraft that could be dumping water directly on the fire refilling this beastie. The only systems that make sense are either a) hover and suck water out of a lake or river, or b) land and reload.

    Both schemes have their problems - chiefly, how long it takes to descend and climb, which IIRC is really slow compared to other flying machines, and thus increasing the cycle time of the system. For the hover-reload system, you also need to adjust the lift really quickly to compensate for all that mass, which may well be the limiting factor on how fast the system can reload this way. Landing this beast won't be a quick process, either.

    Finally, even given the vastly increased water-carrying capacity of this system, just dumping water in the general direction of fires isn't generally how they get put out. The water needs to be directed precisely. If they have to operate at high altitude, I can't see them being able to direct it precisely enough.

    All in all, I don't see this idea being particularly useful for firefighting, unless it's a heck of a lot faster than what we generally envisiage airships to be.

    • Actually, the Aerial relouding scheme could be the best thing in fire-fighting since water. The problem with conventional, fixed-wing firefighting aircraft is the have to get really low do to the fire because of accuracy problems. The only catch is, often the fires are on mountinous/hilly terrain. When flying in to make a drop, a water bomber pilot is counting heavily on (a) The extra lift caused by the updraft of hot air from the fire and (b) The lift caused by releasing its tonnes of water. If the pilot miscalculates either of these factors or if the water doors jam or open slowly, the plane will likely crash into the hillside. This makes water-bomber flying extremely dangerous and there are many crashes every year because of this.

      Helicopters are not susceptible to the above problem for obvious reasons, however, they are slower (important when the water source is further away from a fire), they can't carry very much, and they are extremely expensive to operate. That is why you still see water-bombers in use despite the high risks involven in their operation.

      A blimp like this would be incredibly useful because the water bombers could then be operated from a safe altitude and their runs could be made very quickly. As for the accuracy altitude, this would not be a problem for the blimp because, as mentioned on the site, rather than just providing general spray coverage to the area, it can have high-pressure water cannons mounted on it. These are only effective from relatively motionless platform which is why they can't be used on planes. As you mentioned, they are used for targeting hotspots identified by ground-based firefighters.

      IMHO, if they can overcome the wind problem you mentioned, a single one of the airships could could greatly improve the effectiveness of any aerial firefighting operation.

      FWIW, I happen to think that their reforestation plans for post-fire use are complete bullshit. Those have so far had a very low success rate in forestry industry tests. Mostly it seems like a gimmick to entice investors.
  • Convection: if hot air made things rise as fast as most posters seem to think, slashdot would have reached low earth orbit by now. Airships aren't hot air balloons, they do have active altitude control.

    Flammability: Modern airships use non-flammable helium (the manufacturers don't appear to state what they plan to use in this case). The Hindenberg only burned strongly because of the flammable metals in her skin; the hydrogen vanished, literally, in a flash. Even then, more than half of the passangers and crew survived:
    http://www.dwv-info.de/pm/hindbg/hbe.htm

    Speed: Airships can manage up to 80 knots
    http://www.airship.demon.co.uk/whatis.html

    Weight / lift capability: 'just under' 1 million litres of water weighs 'just under' 1 thousand tonnes. Guess what? The air-buoyancy of a helium airship this size is 'just under' 1 thousand tonnes (I won't bore you all with the math).

    The only scary thing about this airship is the fact of 1000 tonnes of *anything* flying around overhead (Although a fully laden Boeing 747 has a max take-off weight up to 400 tonnes:
    http://www.aerospaceweb.org/aircraft/jetliner/b747 ).

    If it did crash, however, it'd be the world's biggest water baloon.

  • Such an airship is nearly impossible to build.
    In Germany the company Cargolifter [cargolifter.com] tried to build an simmilar airship - now they are blanc.

    Some Problems:
    - If they stand in air with 1000000 litres of water, they will rocket upwards after they have deployed all their water. Same problem at refill.

    - If they use helium, the airship had to be larger than 300metres. Cargolifter (260metres) shouldt only carry 160tons. If they use hydrogen, they would not get al lizense to fly such a beast.

    Maybe it's possible if they spend $1000000000 over 5-10 years of development.
  • have to get drunk before piloting it? *ducks*
  • Unfortunately, there are more problems than the obvious (and easily addressed) "weight changes and hydrogen burns" problems.

    Earlier, convection was brought up, with a heat rising, Zeppelin rising scenerio. The whole deal with convection isn't that hotter air will sweep things up with it, but that the hydrogen (or more likely helium) will be cooler than the rising hot air and... the airship will drop, into the flames, like a proverbial rock. Eckener, the famed Zeppelin pilot, when passing over a large desert in his famous trip around the world, had a similiar problem ; The rising hot air threatened to sink him. Truly, this may be the largest hurdle that Yoyodine Airship Co. will need to scramble over.

    On a postitive note, not every Zeppelin went up in a ball of flame. Dozens were used to bomb britain in WWI, and the Graf Zeppelin used for the first around the world trip by air, had made 590 flights (144 across the ocean) and spent 17,177 hours (about 2 years) in the air, and no-one had been hurt in it. Only a handful of the rigid-body dirigibles (out of an admitted few), crashed in a horrendous and messy ink-black and halloween orange gout of fiery plasma, so everyone better lay off the airships, alright?

    For more information about Eckener and the Zeppelins, take a look at "Dr. Eckeners Dream Machine" by Douglas Botting. Exciting stuff, especially if you have a penchant for airships (as I do). Thanks for watching Reading Rainbow.

    -Avery

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