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Re: Other: Solar Powered kayak
By:Paul G. Jacobson
Date: 11/29/2007, 5:31 pm
In Response To: Re: Other: Solar Powered kayak (Chris Ostlind)

: Aside from the gentle sarcasm, (which I enjoyed, by the way)... perhaps you
: can share with us how this outrigger device can provide static buoyancy
: while at the same time still performing its task as principal propulsion
: device?

Not being an engineer, but simply by looking at the device I can see that the bouyancy is obviously derived from the displacement of the outrigger being greater than the weight of it. If the outrigger (when totally submerged) would displace 100 pounds of water, and the weight of the battery, solar cells and motor comes to jsut 50 pounds, then you have an additional 50 pounds of flotation holding up your kayak.

Stability is greatly increased by the weight of the outrigger and the leverage afforded by mouting it away from the kayak. The greater the distance, the greater the stability-but a modest separation does a very good job. On any kayak or canoe, if you sit off-center (to left or right) the boat will tilt in the direction you move. Your live body, shifting around is changing the center of mass in the boat, and the boat hull rebalances itself. With an outrigger attached, a move by the paddler toward the outrigger puts downward pressure on the outrigger. As the pressure increases the outrigger goes deeper into the water, and finds a state of equilibrium when it has displaced enough water to equal that pressure. If the paddler leans away from the outrigger, then their action tends to lift the outrigger out of the water. As the outrigger rises, less of its weight is supported by the water it displaces, and more is supported by the kayak's rotation. The length of the bar between the outrigger and the kayak enhances this effect, much as a small weight osliding on the beam of a balance scale can be shifted to indicate the weight of some product.

: More specifically: When employed in the outrigger function, how do you
: generate thrust on the off side of the craft at the same time?

What off side of the craft? You now have two hulls of different length and different drag, with a motor mounted between them. If the two hulls were identical you'ld want that motor spced dead center between them. Since they are not identical, you slide the motor toward, or away from the center so that it gives you the best use of its power when going straight forward. The location of the motor is a fulcrum, and the different drags of the two hulls would be balanced around that point. For fine tuning a rudder would be nice.

: Even more
: specific, how much static buoyancy does the device provide? Is it enough
: to statically resist capsize, or must it be employed in a dynamic fashion
: to do so?

I can't give you figures on that --and you'd probably need some fairly close estimates at measurements of the outrigger and the particular kayak to get anything meaningful from whatever math an engineer would use. However: We can get the amount of force it takes to rotate a given kayak hull so many degrees. this comes from a lot of the hull design programs. We can also do some fairly simple physics, along the lines of that balance scale I mentioned, to show that the effect would be pretty dramatic. Some thoughts for you: I'll assume the deep cycle battery in this thing is roughly the size of an auto battery--about 35 pounds, and that the entire outrigger pod is maybe another 15 pounds. That 50 pounds is located about 2 feet from the centerline of the the kayak. So, it would take about 100 footpounds of force to pull the thing out of the water. Most paddlers could easily stand up in their kayaks without being able to exert that much force on the far side of the boat. On the other hand, if that outrigger displaces 100 pounds, it would take 200 footpounds on the appropriate side of the boat to force it under water. sol to be on the safe side--if you are going to stand in your kayak, you'd keep your weight on the outrigger side for greater stability. The further away from the center line you put the outrigger (say 3 feet instead of 2) the more force you would need to exert to capsize the kayak. Should the craft capsize from the paddler jumping around like this, the paddler will fall off, the craft will right itself, and the paddler can use the platform betweent he outrigger and the kayak as a nice support when re-entering their boat.

: It's that pesky design spiral loophole again, no? The one where you give some
: to get some?

I thought that was the reciprocity theory of Xmas gift giving :)

PGJ

Messages In This Thread

Other: Solar Powered kayak *LINK*
Jesper B -- 11/27/2007, 9:17 am
Re: Other Jet Powered kayak *LINK* *Pic*
Paul G. Jacobson -- 11/30/2007, 2:14 pm
Re: Other: Solar Powered kayak
Robert N Pruden -- 11/29/2007, 12:24 am
Re: Other: Solar Powered kayak
Kris Buttermore -- 11/28/2007, 2:15 pm
Re: Other: Solar Powered kayak
Mike Scarborough -- 11/28/2007, 10:59 am
Re: Other: Solar Powered kayak
Bill Hamm -- 11/28/2007, 1:58 am
You gonna build one?
Paul G. Jacobson -- 11/29/2007, 6:21 pm
Re: You gonna build one?
Bill Hamm -- 11/30/2007, 10:50 am
Solar Powered kayak
Dave ( of Calif.) -- 11/27/2007, 5:43 pm
Re: Other: Solar Powered kayak
Mike Savage -- 11/27/2007, 1:39 pm
Re: Other: Solar Powered kayak
Chris Ostlind -- 11/28/2007, 10:12 am
Re: Other: Solar Powered kayak
Mike Savage -- 11/28/2007, 11:03 am
Re: Other: Solar Powered kayak *LINK* *Pic*
Chris Ostlind -- 11/28/2007, 12:08 pm
Re: Other: Solar Powered kayak
Mike Savage -- 11/28/2007, 4:38 pm
Re: Other: Solar Powered kayak
Chris Ostlind -- 11/28/2007, 5:22 pm
Re: Other: Solar Powered kayak *Pic*
Kris Buttermore -- 11/29/2007, 12:36 pm
Re: Other: Solar Powered kayak
Bryan Hansel -- 11/29/2007, 6:30 pm
Re: Other: Solar Powered kayak
Chris Ostlind -- 11/29/2007, 6:44 pm
Re: Other: Solar Powered kayak
Kris Buttermore -- 11/30/2007, 1:05 pm
Re: Other: Solar Powered kayak
Bryan Hansel -- 11/30/2007, 8:33 pm
Re: Other: Solar Powered kayak
Kris Buttermore -- 12/3/2007, 2:24 pm
Re: Other: Solar Powered kayak
Bryan Hansel -- 12/3/2007, 3:32 pm
Re: Other: Solar Powered kayak
Bill Hamm -- 11/30/2007, 10:47 am
Re: Other: Solar Powered kayak
Bryan Hansel -- 11/29/2007, 11:23 pm
Re: Other: Solar Powered kayak
Chris Ostlind -- 11/29/2007, 1:11 pm
Re: Other: Solar Powered kayak
Kris Buttermore -- 11/30/2007, 1:03 pm
Re: Other: Solar Powered kayak *LINK*
Kris Buttermore -- 11/29/2007, 1:07 pm
Re: Other: Solar Powered kayak
Chris Ostlind -- 11/29/2007, 1:26 pm
Re: Other: Solar Powered kayak
Paul G. Jacobson -- 11/29/2007, 5:31 pm
Re: Other: Solar Powered kayak
Kris Buttermore -- 11/30/2007, 12:19 pm
Re: Other: Solar Powered kayak
Mike Savage -- 11/28/2007, 8:02 pm
Solar Powered kayak
Dave ( of Calif.) -- 11/29/2007, 12:29 pm
Re: Other: Solar Powered kayak
TOM RAYMOND -- 11/28/2007, 1:14 pm