Imagine a boat that has two very large kites attached to either end one is rigidly mounted to the boat at the back the other is attached to the front via a 1,000-2,000 foot tether so that it is able to fly at a much higher altitude. Now the theory is that at different altitudes the wind blows at different speeds so by making use of the air speed difference you should be able to fly until one of three things happens the sun goes out (not likely),the wind slows or stops long enough for the kiteship to land or kite failure. Now some bakers may liken this to a glider but it is not, a glider is thermal powered while the kiteship is wind powered so hopefully I've preempted that argument.-- Spaceman Spiff, Feb 26 2008 Sailing submarine Sailing_20submarine [phoenix, Feb 26 2008] Google search for "kite sail" http://www.google.c...tIndex=&startPage=1About 210,000 hits [phoenix, Feb 26 2008] Kite For Sail http://www.kiteforsail.com/The first link from the above search. [phoenix, Feb 26 2008] Kite For Sale http://www.windpowe.../specials/sale.htmlThe first link from the above search. [zeno, Feb 27 2008] MV Beluga http://www.skysails.info/index.php?L=1SkySails freshly-baked kite-powered ship [neutrinos_shadow, Feb 27 2008] Hang on. Do you mean a ship pulled across the sea by kites, or a pair of kites tethered only to eachother to take advantage of differential windspeeds? Both are baked to lesser or greater degrees...-- MaxwellBuchanan, Feb 26 2008 Shirley a sail is a kite, albeit attached to a vehicle.-- phoenix, Feb 26 2008 Kites (in the form of parasails) are indeed the way the shipping industry is going, in bringing back the age of sail (for fuel economy).-- DrCurry, Feb 26 2008 Kite ships are one of those things that aren't widely known because they don't work well yet. But, yeah, "thought of" to death.
The theory behind this particular idea is not good. The kite that is rigidly mounted to the ship is a sail, practically speaking. The kite that is on a @ 2,000 foot line isn't very high, as large traction kites go. Out at sea, the difference in wind direction between sea-level and 1000 feet isn't going to be much.
Which is not to say that a ship equipped with this rig would not move a little. It just isn't better than, or even different from, dozens of kite/ship ideas.-- baconbrain, Feb 26 2008 I just recently saw a demo of this idea. It was being tested by some engineering firm to see if kite sales would help reduce trans island shipping fuel costs...I think the ship was a New Zealand vessel...and quite large as I recall. Can't remember where I saw it...some video on a science news site.-- Blisterbob, Feb 27 2008 So what does the differential in wind speeds at different altitudes have to do with anything?
And before you try shooting down anyone else's argument, straighten something out here: is this a water-borne vessel ("Imagine a boat...") or an aircraft ("... be able to fly until ...")? Let us know if you decide on one or the other.-- lurch, Feb 27 2008 //to see if kite sales would help reduce trans island shipping fuel costs// I think you mean "offset".-- MaxwellBuchanan, Feb 27 2008 Great ship in the sky! I just re-read the description, and with the help of a sleep-deprivation headache, I think I finally see what is intended. (Why is it that *I* understand these lunatic ravings?)
The ship has a BIG kite built onto it (like a wing on an airplane), which functions as a lifting-kite for the entire ship. The whole damn ship flies, up out of the water, like a kite being run with, or a towed glider. The tow is provided by the other kite, up a thousand feet above it, in an air layer where the wind is supposedly blowing in another direction.
I'm pretty sure that's it, anyhow. Thanks, [lurch], for the tip-off.
My earlier objections still stand. There isn't enough wind-difference at sea to power anything. It's been thought of, as something like it can be done with light kites in ideal conditions over land. And this idea is a lot, lot worse than I had thought it was. Now, it gets a fishbone from me.-- baconbrain, Feb 28 2008 Even over a mile? the 1000-2000 ft was arbitrary. the tether could be as long as one wants within tensile limits, 7 miles should be doable. Start out on the ocean fly kite into lower reaches of jet stream then reel oneself up into the air. should be plenty of airspeed difference. I'm sure there are other air currents over the oceans that can be used as well.-- Spaceman Spiff, Feb 28 2008 random, halfbakery