Moving the sails in the sky to go around the world

Do you think it could work?

  • No way!

    Votes: 0 0.0%

  • Total voters
    3
Thread starter #1
Hi all!

I am new to the forum - I'm very happy to join

I wanted to ask for your feedback on a concept I am thinking about. :)

I want to start a fun side project to create a boat that can circumnavigate using a kite power system and set a world speed record. I currently have a sailboat captains license (24-meters class) and will soon get open ocean qualifications, yet I am quite a rookie.

As an aerospace engineer it seems obvious there is a much more efficient way of propelling a sailboat, by essentially moving the wings higher up in the atmospeheric boundary layer. Furthermore, circumnavigating with this technology would bring it in the spotlight and could play a role in accelerating its adoption.

As a starting point I was thinking of using a second-hand sailboat (perhaps a Bavaria 30) and large kite (e.g. a 26 sq. m. wing from kitesurfing) to build a proof of concept. The kite would be inflatable and it would be released and retreived from the top of the mast automatically. It would be physically attached to the ship at the base of the mast (to mimise moments) via a single-line dyneema tether. It could also be attached in a less invasive manner perhaps using a towing configuration (https://goo.gl/mCycvE). This line would go to a small control box which essentially would simulate a human operator with several lines going to the kite from the control unit.

I was wondering what are your thoughts on this concept of mine. Do you happen to have any recommendations? Does it sound fun? Would you use such a system on your boat if it turns out to work well?
 

Ghost Rider

Planing into eternity...
#2
Interesting concept, and you're probably not the first to consider it. Circumnavigation would be tricky: the rig would probably work well in latitudes where winds are steady and reliable, but what about the doldrums? Your kite/sail would become a giant sea anchor in no time... then you'd have to fish it out of the water and start over again. On the other hand, a more localized or regional venture might pay off, tackling a large lake or oceanic crossing in the manner of a kitesurfer on steroids, LOL. I think you should make a modest attempt first somewhere near your home town, that way you could work out any bugs in steering, handling, etc., before you attempt a more lengthy and ambitious voyage. :rolleyes:

Hey, I just had a flash of genius, I think I have the solution to your doldrums problem during global circumnavigation: you could place several scumbag politicians on the bow of your boat, their heads swiveled directly toward your kite/sail rig, and the blast of hot air from those tards would help ya bend on the knots, LOL. Downside is, you'd have to equip yourself with some serious hearing protection, otherwise you'll suffer by listening to their bull$h!t, AYE??? Maybe keep 'em in confinement till ya need 'em, then once their usefulness is over you can cap 'em and dump 'em overboard to feed the sharks, LOL. Remember to cap 'em downwind, don't want any of that nasty cr@p on ya... :eek:

GOOD LUCK, AND DON'T RULE OUT A CARTOPPING MODEL FOR VENUES LIKE THE SALTON!!! CHEERS!!! :cool:

P.S. You'd probably have to figure out a way to reduce kite/sail area, or carry a number of kite/sails with ya, like a suit or locker of sails aboard any other boat. And the line you use would have to be bulletproof, so it doesn't snap when the wind starts to howl... :confused:
 

Wavedancer

Upside down?
Staff member
#3
Yes, definitely interesting, at least to Wavedancer.
But I see two issues; how are boats similarly equipped not going to 'strangle' each other with their kites when in close proximity (like in a harbor)?
How to prevent interfering with flying airplanes?
 
#4
Cool idea :cool:.

how are boats similarly equipped not going to 'strangle' each other with their kites when in close proximity
Just ask these guys :D.

Or you could have a small rig for getting in and out of harbor, then fly your wing once your in open waters, which is where this kind of boat would sail anyways.

set a world speed record
If you want speed, I would recommend a planing hull that gets out of the water. The wing that you mention is going to contain a lot of force, something a displacement hull cant take advantage of.

second-hand sailboat (perhaps a Bavaria 30) and large kite (e.g. a 26 sq. m. wing from kitesurfing)
The Bavaria 30 has 37 sq. m. of sail area. The load (of any sailboat) is specifically focused on crucial parts of the hull. The entire boat is designed around high stress areas. The sail you mentioned has 11 sq. m. fewer than the boats specification, however, it may actually soak up a greater force if it is flown higher. The additional force would most likely not be encountered by the hull the same way (as the original sail), and may over stress some areas of the hull. Which is another reason why I recommend a planning hull. At increased speeds (above a hull speed) the force on the hull becomes greater, all the while the speed of the boat decreases. When in a planing hull, greater speeds can be achieved since you are no longer plowing thru the water, your ridding on top of it.

As a proof of concept, it may be beneficial to start small. Try flying a wing on a dinghy and see how it behaves. I suspect that the foils and weight location in the boat is going to be crucial.

Good luck! ;)
 
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Ghost Rider

Planing into eternity...
#5
Good advice, I'm thinking that foils would provide the ultimate boat speed, once the OP figured out where to attach the kite/sail line to the boat... the attachment point would obviously have to be somewhere up forward, aye? The whole concept of streaming the kite/sail from the mast would not work, unless the attachment point were somewhere lower and farther forward, correct? But that would be AWESOME, seeing a hull up out of the water on foils with a kite/sail draggin' that thing along at MAX BOAT SPEED, LOL. :eek:

P.S. That shot of all the kitesurfers reminds me of the gang who would hang out at Silver Strand State Beach in Coronado on windy days... there'd be two dozen of those fooliots out there haulin' @$$ and catchin' air, LOL.
 
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