My thoughts exactly, I use my TI to get me where I want to go at the speeds I would like to go, with the destination in mind, regardless of the wind conditions and direction. I'm no athlete by any stretch of the imagination, and simply don't have the physical endurance to do something like the everglades challenge the old fashion way. But my thinking is why not just think it thru and develop your boat to accomplish what you need it to do (basically cheat by any means possible), working around your own physical limitations. Basically I have a pedal boat, why not make every ounce of energy I expend with my legs count for something regardless of conditions. If I could make the 300 mile EC trek averaging 8-10 mph (vs 2-3mph in very light winds)) regardless of the conditions and actual wind direction (or no wind at all), why not. With my TI the whole 300 mile EC trip would take between 3-4 gallons of fuel, which I can easily stow on board (under 25 lbs of fuel). One of the things on my bucket list is to travel the Mississippi, knowing my own physical limitations that would not be practical for me. With my current TI configuration I could easily average 8-10 mph for the whole expedition, traveling 100 to 120 miles per day vs 30-40 miles per day on a standard TI or kayak. I would think expedition guys would be all over this stuff, but their not.....
To build my wing sail I read and researched everything I could find on the subject for about 2 yrs before ever trying to make anything. I just looked back at all my research and documents, and can't make heads or tails of what the heck I have, though I still have every dimension of every aspect memorized (my curse), but how I came up with what I have I have no clue.
I did however find a couple articles that I had saved that must have been important to me at the time (but make no sense to me now LOL).
Here is one from a very bright guy named Paul Bogataj http://www.uk.northsails.com/RADUploads ... s-Work.pdf
Another guy who seems to know a lot about the subject is Tom Speers here is his home page http://tspeer.com/
Here is some of the dimensions of my wing jib:
Basically their are 18 spars on the sail, what I did was measure the length needed at each spar position (because the sail is a triangle, each spar length is different). I made the widest point 12% back from the front, and the width at the widest point is 12% of the length. From there you just connect the dots across the control points. When in neutral (as shown in the pic above the wing creates no lift and almost no drag whatsoever, and just follow the wind just like a weathervane. Because of the air intake slits in the front the inside fills up with air and puffs out very rigid (like a balloon), you can press in on the outsides and they feel like an inflated balloon because of the pressure inside. To test the sail with the sail in neutral I went out and pedaled figure 8's out in the water in 25 mph winds, the wing didn't affect my steering ability hardly at all. Because the sail is rigid it can't flutter and flap like a flag even in 25-30 mph winds.
Here is a good pic of my TI with the wing mounted as a kayak sail (you can see all the crazy spars).
Here is a video I made during development showing kind of how the jib works.https://www.youtube.com/watch?v=1-lucLodTQM
Here is a link to charts and a nice article showing the performance expectations from different sail designshttp://smalltridesign.com/masts/rig-mast_options.html
Of course since I have a fixed mast on my main, and the jib with the mast fixed in front of it I can only get something similar to configuration F upwind only (with both sails deployed). That's mostly what my boat is configured for (upwind performance in lower winds). My boat averages between 8-10 mph upwind in 5-8 mph winds with the wind anywhere between 10 deg to 30 degrees off the bow (everything was designed around that). Of course I have to supply supplemental power (ie... pedal drives, and/or motors) to create the forward motion that makes the chain reaction occur. The wing works no differently than the wing on a piper cub, basically on a plane your prop creates the forward motion, once the forward motion reaches a minimum apparent wind (in my case 6-7 mph apparent wind) then the wing begins to create lift (in the case of the piper cub, the plane lifts off the ground), in my case this lift creates a vacuum in front of the boat that sucks the boat forward, at a greater velocity than if it were not there at all (basically the wing works as an amplifier (like an air conditioner works (taking existing energy and amplifying it)). With the piper cub, if your engine quits you fall out of the sky, with my setup, you just stop (the boat rounds into the wind and stalls if you stop pedaling).
One important factor about wing sails that is significant on small boats like the TI is the heel moment (the force trying to tip you over) on a wing sail is less that 1/4 of the heeling force on a standard sail, basically what this means is even with the wing sail fully engaged in higher winds, it can't possibly tip the boat over (as long as you don't stall the wing, then it's like holding a piece of cardboard sideways to the wind, we all know the result of that). Actually in high winds what I often do is put my main away (furl it), then just sail using the 33 sq ft jib, which provides 'almost' equal propulsion in 12-15 mph winds to the mainsail alone (basically I can sail about the same speed with either sail up, but there is no risk of capsizing with the wing (I know I've tried LOL). Bottom line wing sails are about 30%-50% more efficient than conventional sails, so you can provide equal propulsion with a smaller sail, or more preferred you can put a much larger wing sail on a TI (~ 140 sq ft) and still not bury your AMA's (heeling moment). That 140 sq ft wing would be equal in power generation to a 225 sq ft conventional sail (disclaimer, the mast holder, mast, and hull on a TI can't support much more than about 100-120 sq ft. of conventional sail area without breaking, also the heeling moment would be greater than the AMA's can withstand (you would tip over)).
Of course the wing sails on the AC 72's probably cost between $3-$5 million dollars each, which is a little beyond my budget of about $100 dollars (what it cost in materials to make my wing jib). Yes it took a couple weekends of my time to actually make it in my garage with no special tools, just a layout table, scissors, and a my wife's sewing machine (without her permission LOL). Dreaming, reading, and learning everything I could about the subject cost me nothing at all, actually the design you see was my first pass, I'm dumbfounded beyond belief that it actually works ( LOL). By far the coolest aspect of the whole thing is even if there is no wind whatsoever (as is the case of most weekends when I go out), the dang thing still works like a champ since it creates it's own wind to work with, a totally un-anticipated bonus, that I didn't expect.
I don't consider my boat a sail boat, it's a human hybrid powered pedal boat, the sails are there only to amplify every pedal stroke I take into useful power, If I had two strong peddlers, I could eliminate the gas engines altogether, however we get pooped out after a half mile or so.
Of course at any time I can tilt the motors up, stop pedaling and just sail the old fashion way (6000 yr old tech (LOL)). But I much prefer traveling 8-10 mph vs 3-4 mph in light winds (in Florida it's 90 deg out there in the sun and with no breeze on your face, it's brutal out there baking in my big yellow fry pan).
What does all this mean, I have no idea, I just have a lot of fun using my boat, to be honest I don't do much on the boat anymore, basically just use it. I really have no future plans to do any more, though I have the designs done for replacing my main sail with a type 'F' wing main sail (from the link above), I just don't feel like spending the $150 bucks or so in materials, or waste the time making it, I doubt very much I will ever build it.
Currently what I have fulfills all my wants and needs and gets me out to where we want to go to go snorkeling and scuba diving, and allows us to travel at more than a snails pace in the very typical light winds we have where I sail every weekend (more often than not the winds are typically 4-8 mph). If the winds are higher, then the sea get too rough and visibility for diving goes down to zero, so we don't even bother to take the boat out if the winds are over 8 mph. I'm admittedly not a sailer, and don't aspire to be one. If I can go out all day spending about a dollar in fuel for the day, I'm good with that, I have an absolute blast with my boat everytime I go out. Here is a video my daughter made when we were down at our Key West place snorkeling on the 3rd biggest coral reef in the world (we live for this kind of stuff), and my boat is the means to get us there. (previously posted)https://www.youtube.com/watch?v=K9NMZmFMTU4
Here is another video of us a couple months ago scuba diving in a big fishbowl (you can fit spaceship earth at Disney Epcot center into this aquarium and still have room to spare, we had the time of our lives). (previously posted)https://www.youtube.com/watch?v=bwhuR250bdY
This is what we do.