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Hot air balloon harpoon

A safe way of landing hot air baloons.
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Hot air baloons can be tricky to land; they tend to drag their baskets along the ground.

The proposal is for a large downward pointing harpoon attached to a reel of thin cable. The harpoon is propelled by a recoilless rocket.

On reaching the upwind boundary of the proposed landing site, the rocket is fired, embedding the harpoon deeply in the ground. The baloon comes to a stop in the air with the line taught. The occupants then carfully vent hot air (or let the envelope cool) unti they descend to ground level.

On landing, a further harpoon, on a very short line, could be fired to tether the basket.

The harpoons can be retrieved from the ground by pressing a catch on the rear of the shaft which lets the barbs hinge forward when the shaft is pulled.

The harpoon could also be used to execute an "emergency stop" if approaching power lines, etc.

8th of 7, Jun 17 2002

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       Two L's in 'balloon'. Why not have a winch to pull oneself down, rather than releasing air?
StarChaser, Jun 17 2002
  

       StarChaser: Well, you could have a hand winch. A power winch would have a weight penalty. But as you pull the balloon down, you pull it into cooler, denser air, and the lift increases slightly, hence increasing the tension on the cable and the force on the grapnel. Wind force would already be applying tension, you don't want to needlesly add more. Venting hot air employs a system which already exists in the balloon and gives a gentle descent if done propely. You need to reduce the buoyancy anyway to make a good landing.   

       Sorry about the missing "l" - our spellchecker has got confused ....
8th of 7, Jun 17 2002
  

       Whale safaris with these balloons would be popular with the Norwegians and Japanese.
FarmerJohn, Jun 17 2002
  

       It seems like what you are proposing is similar to the anchors that boats have, only this is a projectile sharp object that could, theoretically, poke more than just your eye out.
polartomato, Jun 17 2002
  

       Polartomato: Anchors drag along the ground until they snag something, possibly doing a lot of damage in the process. At least the harpoon can be aimed; and the projectile is tethered. The world is full of things that are dangerous or lethal if misused. One has to hope that the CAA only issue balloon pilot licences to those individuals who do not demonstrate a propensity for harpooning other people's cows. Maybe there could be a question about that on the written exam, like "Do you want a balloon pilot's licence just so you can go fishing for livestock ?". If the candidate answered "YES" then they would not get a licence. Simple, eh ?   

       Then we would all be quite safe. After all, it's the Government giving out the licenses, and we know they are wise, kindly people who have only our best interests at heart.
8th of 7, Jun 17 2002
  

       You're from the UK, I presume?
polartomato, Jun 17 2002
  

       We sometimes land in the UK. Where We come from is a different question ....
8th of 7, Jun 18 2002
  

       UnaBubba: Meat needs to be hung a few days before it's cooked for the flavour to develop. You couldn't carry enough gas to stay up that long ..... unless you speared many cows in succession and used their intestinal gas for refuelling, and just retained the edible bits from the first cow. Also if you used the main burner, the fat would drip on you during the cooking process. Special clothing would be needed.   

       Of course if it was a helium baloon it wouldn't be a problem. You could drift around for months, spearing anything useful that you drifted over on your travels.
8th of 7, Jun 18 2002
  

       I'm finding it hard to imagine a more humourously dangerous way of hunting whales
stupop, Jun 18 2002
  

       ...or a more entertaining way of hunting balloons.
DrBob, Jun 18 2002
  

       All very nice, and all (I hope) leading to a rapidly deployed bob with fusee-mounted land gripping anchors. There are too many problems I see with chucking a lance into the ground, including misfires.
reensure, Jun 20 2002
  

       Reensure: If you were high enough, you could let the harpoon free-fall until a ripcord tripped off the rocket motor, rather than launching it from a vertical tube like a Carl Gustav 84mm rocket (which was what i originally had in mind). That would reduce the risk from misfires....   

       The problem with just dropping an anchor or a grapnel is that it could catch on anything, and then be a pain to retreive (like the upper branches of a tree). Besides, you want to pull yourself down to terra firma, not the top of some farmer's barn.
8th of 7, Jun 20 2002
  

       blissmiss: That'll be your guilty conscience constantly haunted by images of Sparki avenging herself on you.
pottedstu, Jun 20 2002
  

       ARRRR Thar she blows - THE WHITE WHALE!   

       Landed a balloon/airship recently?   

       If it's a balloon, the problem is uncontrolled descent. That's misjudging your rate of descent until there's not enough time to correct. There's a resulting <thud> <crack> <bounce> <thud> <crack>. Somewhere in the middle of this you lose the champers, the wife screams and, if you some serious cross-wind, the basket tips over. The HB solution could be inflatable cushioning, low balast positioning, or similar.   

       If it's an airship, the problem is more likely manoevuring on the airfield in a strong wind. Your ground crew is frantically chasing your lines and there's not enough lateral authority or thrust to position over the teather. The HB solution is better/ more powerful/ more flexible thrust.   

       Of course, this is far less fun than a 8ft 150lb rocket propelled death stick. Kudos and a croissantto you, 8th.   

       PS how about an electro-magnet? Should weigh about the same as a lightweight harpoon, and you could stick to cars, and hitch lifts from one underpass/ bridge to another.
FloridaManatee, Jan 06 2003
  

       What about four or even eight harpoons around the circumference of the basket. The guns are synchronized to fire simultaneously. Better to divide the tensile stresses across multiple lines.   

       Also, I like the electromagnet idea; it could be powered by an advanced form of a plastic battery (experimental plastic battery being being developed by Johns Hopkins University) which lines the outside of the balloon skin instead of a big heavy battery.
carsten, Mar 04 2003
  

       I agree with DrBob. What a disappointment to discover that the harpoon is meant to be mounted on the balloon iteself rather than on a large, nearby kite...
cloudface, Dec 21 2007
  

       Life is full of little disappointments.
8th of 7, Dec 21 2007
  
      
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