New Age Trawler/Motorsailer; Kite assisted PowerYacht

[Pericles]

http://www.kitelife.com/archives/SEPT98/kite.htm

http://special.lib.gla.ac.uk/exhibns/month/mar2001.html

The first records of man-lifting kites come from China. Their use is mentioned in Sun Tzu's The Art of War as a means of viewing the movements of enemy troops. In a story about the Japanese thief Ishikawa Goemon (1558-1594), he used a man-lifting kite to allow him to steal the golden scales from a pair of ornamental fish images which were mounted on the top of Nagoya Castle. His men manoeuvered him into the air on a trapeze attached to the tail of a giant kite. He flew to the rooftop where he stole the scales, and was then lowered and escaped. In the 17th century, Japanese architect Kawamura Zuiken used kites to lift his workmen during construction. George Pocock, who invented a kite-drawn buggy in 1822, had previously used kites as a method of lifting men to inaccessible cliff tops, but it was not until around the 1880s that there was serious interest in developing man-lifting kites.

http://en.wikipedia.org/wiki/Man-lifting_kite

http://www.dcss.org/speedsl/KiteTugs.html

Good information here.

http://www.aka.kite.org/?traction.html

Polynesians may have used traction kites. They wove their crab claw sails. I am looking for information on fishing kites as well.

http://tobi.gmu.edu/tobithings/fishing/anell1955.pdf

http://www.asiafinest.com/forum/lofi...39391-150.html

http://subvision.net/sky/planetkite/...awesi-muna.htm

Pericles

[Greenseas2]

I've been trackiing this thread with interest and it is one of the VERY INTERESTING threads. Consequently, a few of us decided to hook a sailboard kite to my 30 foot S2 center cockpit sloop and go to sea (to give more maneuvering room). Kites work well and we were sailing under the kite alone at past-hull-speed velocity when the wind shifted 90 degrees. There are 3 pools of yellow water on the cockpit floor where the crew had been sitting and drips all of the way to the bow from the instant change in direction of the kite. Must say that kites are a powerful way to make a boat go. A once in a lifetime experiment.

[kach22i]

Originally Posted by Pericles

Good information here.

http://www.aka.kite.org/?traction.html

Second sentence:
Kites have been used to pull large sailing ships from wind sheltered harbors

The ship I first posted may have operated close to the shore going in between small islands, coves and harbors where a constant wind at sea level would be hard to come by.

...................................................................

Originally Posted by Pericles

http://subvision.net/sky/planetkite/...awesi-muna.htm

Pericles

Wow, cave drawings of kites in use..............freaking me out man.

[kach22i]

Originally Posted by Greenseas2

30 foot ..........we were sailing under the kite alone at past-hull-speed velocity when the wind shifted 90 degrees.

How large was this kite and what was to station it to?

I would imagine that if the line were attached at a point at or below neck level, one could lose their head with an abrupt change in wind direction as described.

[Greenseas2]

Didn't measure the kite but it was of the standard wind surfer design. The experiment was just a fun thing and no serious considerations were taken other than attaching the beast to the boat through the midships blocks and winches designed for a spinnaker. I do admit that it was fun, with the exception on the 90 degree wind change. Suggest that anyone else doing this should attach a "spill line" to either partially dump or totally spill the wind if necessary. A big part of the problem was that we became too complacent with a new device that appeared to work well and should be explored further. There's a lot of great information on this thread, so don't let the actions of a few senior citizens stop you for going further with it.

[kach22i]

I found an old post of mine.................with main sail down that sunflower thing would still give the ship a little push.

http://boatdesign.net/forums/showthr...280#post169280

Originally Posted by kach22i

I wonder if the ancient Greeks knew about the bulb-bow, and that it was more than just something to ram another ship with?

http://www.science.sakhalin.ru/Ship/Vlad_E1.html

[brian eiland]

Originally Posted by kach22i

Since I've hi-jacked this thread and feel ashamed, in an effort to get back on topic I pose a new question.

No problem kach22i, at least you hijacked it with something of intelligence to contribute

[kach22i]

Originally Posted by brian eiland

No problem kach22i, at least you hijacked it with something of intelligence to contribute

Cool, I did get sidetracked on the lighter than air gas thing though.

Fish kites....................back on to the side topic.

http://www.gombergkites.com/plynn2.html


http://www.goodorient.com/Chinese_Tr...sh_Kite_P21578


Wind Socks
http://www.foreverflying.com/laundry.html


http://www.getoutdoors.com/goblog/in...e-Fishing.html



http://horsesmouth.typepad.com/hm/ki...ing/index.html

[brian eiland]

Another video of a small cat being powered by a kite

http://www.kiteboat.com/kb_videos.html

[masalai]

Thanks folks, nice video & pics, nearly there but not yet for cruisers - particularly us old codgers......

[Greenseas2]

I really enjoyed the video of the cat under kite power, and it appears that there was good control of both boat and kite even though it required two people steering, one for the boat and one for the kite. Somewhere in one of the shipping journals I recently saw some small Japanese freighters using cylindrical sails. The shaft of the cylinder was attached, through a transmission, to the prop drive shaft. With this arrangement wind direction and sail control offers no problems or concerns even though wind force may. The only draw back with the cylindrical sails might be appearance, but it does offer direct drive and free motive power to a vessel.

[eponodyne]

I'm *just* about to order an i550 kit; I plan on powering it with a 12 sq m Cabrinha bow kite I got off Craigslist for a song. I hope to be documenting my build of it on the Woodenboat forum.

I like what Dan Tracy has done. I think it's a huge step forward. I hope to add my mite to the knowledge base of kites and boats. I've been thinking about this for quite some time, and hope to incorporate some ideas that may be useful:

-One pilot, center-mounted with a wheel in front of him. Rudder controlled by pedals.

-Kite lines lead to a car on a track, off-the-shelf Harken. Semicircular in shape, this provides a constant radius for secondary lines leading back to a yoke in front of the helmsman. By using a combination of cams and bellcranks on these lines, I should be able to get enough travel out of the yoke to be able to move the kite around the way it should be. In addition, this zemicircular track will reach from beam to beam, and be gimballed so it can match angles with the kite lines.

-The important thing about this arrangement is that on a reach, the pull of the kite will be coming from the leeward side of the boat. Heelin moment is thus reduced to a minimum. Control of the kite side-to-side on this track will be provided by the lowly rope and 2 cam cleats, with short lines on a spring, or push-pull cables to open them as needed. I don't need to have a 6:1 control system to anchor the car, I just need to let the kite fly from side to side. The whole point is that the kite is controllable.

-No ballast needed, or very minimal ballast just to make the boat less tiddly.

-I intend to build a full-span trim tab into the trailing edge of the daggerboard((s), I may go with tandem boards)). Guys, we been going about the trim-tab idea all wrong, wrong, wrong. Think about it: When you install a moveable trailing edge on a symmetrical foil in a medium as dense as water, anything past just a few degrees of adjustment to the trailing edge, and you don't have a trim tab.

You have a flap. So why not build the wretched thing as a flap? I don't think we need to look at leading-edge slots and Fowler extendible flaps just quite yet. But if you want to work upwind to (say) port, then doesn't it make sense to provide lift to port by "lowering" the flap on the centerboard or daggerboard or whatever, let's say... 20 degrees to starboard? Smell what I'm steppin in here?

I see no reason why this idea won't work. If I am wrong and it doesn't, then some Sunday afternoon I pull the boat out and I center the flap and fair over it, with no real damage done.



Questions, concerns, hints, allegations, things left unsaid?

[masalai]

Please keep us posted on Boatdesign.... We are many who are hanging in the wings... Good luck..

[Greenseas2]

Don't knock the leading edge Krueger flaps (simple leading edge slots) and trailing Fowler flaps. Those devices can help keep your air foil up in very light winds. They're used in the Swiss Helio Courier and Turbo Porter aircraft for ultra slow flight and short field landings/take-off capability. Before that they were use on the German Feisler Storch STOL aircraft for the same reason and are now used on the Slepcev Storch and other STOL aircraft. The steerable parasail device is fairly technical in nature and all design consideration should be taken in to consideration. Who knows? Maybe the parasail design for your boat mightl also have some nuances that potentially could benefit the aviation world as well. Good luck!

[FAST FRED]

Best use we have found for a kite is cruising the Bahamas.

Send the kite up and the slower cruising buddies can tell which lump of similar land you are actually at.

FF