How about using H2 or He balloons to lift parasails?

I'm thinking a few He balloons (or even gas bag filled with on-board produced H2) could be used to hoist a line aloft even with little wind at sea level and thus get a para-sail up to where there might be decent wind.

From my few kites I flew as a kid I remember the main thing about kites is you gotta run to launch them but once they are a few yards up the wind gets a whole lot stronger.

Many displacement boats might not have enough speed to launch a para-sail up into high stronger wind from slower wind at sea level.

I'm assuming the 'calm at ground level' happens more on land with so many obstructions (but then we got hills making 'wind tunnels'), than on water, but I hear it is still a big factor on water.

Might be a little more Safe and Sane to have a string of balloons up first, then have that line take up a para sail, rather than try to launch a barely flying para-sail from the deck.



Use the compressed He and balloons as back up fire-fighting and back up emergency buoyancy(fill cabin with balloons, or even tied balloons to any handy place on deck).

 

Here in South Florida there is a fishing technique called kite fishing where a kite is used to suspend a live bait on the surface away from the boat.

In calm wind conditions they use helium balloons to "help" the kike stay aloft.

http://www.captharry.com/categories2/KiteFishingSystemsAccessories/48.html


Steve

 

Interesting idea, see comments above.

Porta

 

Yes I have often thought about that too.

You would need a very stable kite, if (once flying) it descended in to the lower wind gradient it would collapse and land in the water.

Perhaps the kite its self could be gas filled?

 

do you have any idea how many balloons you would need to lift a person? - its a hell of alot.

Then with any forward velocity or wind, the entire bunch of balloons acts like a giant spinaker causing massive amounts of drag and downwind pull - so your boat would probably need MORE power to get the parasail flying than with no baloons at all...

Then if anything goes wrong with the balloons during the launch, you drown your punter because the boat doesnt have the power to do it safely and properly. - The tow boat needs enough power and speed to get things flying before any line gets paid out or its UNSAFE...

 

I didn't think he was talking about lifting people, only sails.

If the winds were that light, then its not such a big job, as I would assume that the sail being lifted would not be very heavy.

The BIG drawback is - the cost of, or even the cost of creating, gas for lift, far exceeds the expense of a bit of diesel for the engines to create forward propulsion. Add to that, the weight of the storage of the made gas, with all the extra stuff to control it, would make the whole exercise unviable IMHO.

 

I have a military surplus H2 generation modules used for balloons which was quite cheap and is compact- was available at surplus places. These were made for pilots that went down over water and are considered older technology The hydrogen is made by placing the canister containing calcium hydride in sea water and it inflates up to a 4' balloon, as I recall. Compact electrolysis units can also produce hydrogen from sea water with the power from a small battery to get a sail up. There's still the tangling issue, though....

P.

 

tangling was the 2nd main issue I was hoping to improve on with balloons.

I figure a balloon or even string is going to not tangle because it is pulling up all the time, not like a kite sail you are trying to tease into catching enough air to lift itself.

Once you fill a few balloons give them a 100' or more of line, then you have a tight single line from the boat to the sky.

 

.... and the cost of these units to buy and operate ???

You are talking 100 kilometres of diesel fuel easily, if not more - on the offchance you might strike a day of no wind with a 5knot breeze within say .... 40 feet of the waters surface.

Wheres the dividend ??

 

Kite surfing kites often have an air filled chamber across the top of their kites so if they go into the water they will float in the correct attitude to re launch. I see the problem here with the permeability of the material re these light gases.

 

If there was a way of recharging the gas, permeability would not be a big issue because it would only be needed to assist launch... but you see advertising blimps flying for months. Once flying the kite would be self supporting.
What would be the weight of a kite and lines sufficient to drive say a 40ft displacement hull? Could an efficient kite be designed that would have an internal volume of sufficient bouyancy to lift it?

 

I think you are right...and it may be possible to design a system where the balloons can be pulled back when the kite has been launched

Nick.

 

There are several commercial ventures offering kite assist to shipping, this is just one:

http://www.kiteship.com/marine.php

here's the same concept for a yacht:

http://www.30m-yachts.com/our-range.php

and this has been discussed here several times, below is just one thread, use the search feature for more:

http://www.boatdesign.net/forums/multihulls/rudder-design-shape-high-speed-kite-sailer-41444.html

As for pulling the baloons back: Rifle practice

 

Now this is the ticket!
I've been looking on how to launch a kitesurfing kite off the front tramp of a beach cat. I got to fill the kite anyway. I'd rather not have to use He and all the associated gear, but this might just get the whole development going a bit sooner. get the kite up and sailing, mess with the retrieval system and be then rethinking the launching mode/system.

 

Ha Ha....flare gun might work well too?