Snelson’s Canoe
These concepts are so cool. I don’t think you need to seek anything more from the sail than this - it’s a good design that suits the concept.
I want mine in hot pink!
I’m still pondering a battened cambered version, but I"m having a hard time getting it to balance.
If all you want is good sail shape without a highly tensioned stay, you can keep everything you have and just insert a bunch of Bierig Camberspars. Think of half a wishbone boom inserted into the sail and rotating around an axis between luff and leach. You have a rigid spar that keeps luff and leach apart, but you also get camber because the spar can flip to either side. You can keep the boom you have now.
I tried that in a model-scale junk sail, shown below. It worked just fine. When I tried it on a sailing canoe, it didn’t work, but Nils Myklebust here in Trondheim made it work on his motorsailor. I do have a picture of that, but the file size is too large to attach and from the perspective from which I took the picture, the camber is not apparent anyway.
Or you can have a lens-shaped planform, with 20% in front of the pivot axis and a junk-style sheetlet to the end of each spar.
Either it goes up and down on the forestay
In your present design, how do you raise the sail? What keeps the mast up when the sail is down? Or would you have to raise them together? Anyway, whatever you do, I don’t think the addition of rigid battens will make a difference to that. Actually, if you were to go with the lens-shaped planform, you could have a loose stay to lee that keeps the mast up when the boat is just sitting on the beach without sail, you hank the sail onto that, raise it under full control instead of wildly flogging about, then take all the load onto the sail.
Maybe the sail splits along the pivot axis so that the forward half of the panel acts like a jib to the back half. Has that been investigated by anybody?
That would be a balestron rig hung on a wire instead of a mast. I have seen that in a 1970s book on multihulls as a suggestion for an aerodynamically clean rig. The proposal was illustrated with a picture of a model yacht which had that rig.
Regards
Robert Biegler
I tried that in a model-scale junk sail, shown below. It worked just fine. When I tried it on a sailing canoe, it didn’t work, but Nils Myklebust here in Trondheim made it work on his motorsailor. I do have a picture of that, but the file size is too large to attach and from the perspective from which I took the picture, the camber is not apparent anyway.
Robert, what was the problem with the canoe sized version?
Thanks,
Skip
In your present design, how do you raise the sail? What keeps the mast up when the sail is down? Or would you have to raise them together?
The club jib is just that, a jib. It hanks on and is raised with a halyard. The boom is suspended by a forestay and a backstay which are attached to swivels top and bottom. Because the forestay and backstay form an acute angle up by the masthead, it restricts how full the roach can be if it is fully battened. A partially battened jib, with a nice full roach, can slip behind the backstay, just like it would on a keelboat with a backstay. Its the same reason you can’t have a square headed main on a boat with a backstay. Does that make sense?
Here’s Snelson’s Walap—a futuristic rig on a classic canoe.
More eye candy. In my grandiose fantasies, this is the kind of thing that Uffa Fox might have come up with in an alternate universe. And then sailed it to Copenhagen.
As usual, I’d love to see some pics of your doodling, however crude or camelish.
And you’ve inspired me to bang out another drawing this weekend….
Chris
OK here are my current musings about using your rig on current and possible future projects.
For the broomstick, geometry’s not all that elegant but should work to compare with the biaxial sail.
Nomad on the other hand kinda warms my heart. First cut’s got a little more area than I’d probably use (96 s.f. / sail) but the general configuration is pretty clean, just have to do the calcs to see if the mast are going to be light enough to stab into place. If that’s the case there’s a lot of goodness to the approach.
Skip
Oops, the stay between the mastheads got clipped off in plotting from Autocad to raster.
I’m loving the schooner. I bet she looks mighty fine beating to windward with sails overlapping.
Are you worried about your CE being so far to leeward? Your current designs (and traditional proas) seem to do okay with that configuration. And it sure is nice to have everything tied to the vaka.
chris
I’m loving the schooner. I bet she looks mighty fine beating to windward with sails overlapping.
Are you worried about your CE being so far to leeward? Your current designs (and traditional proas) seem to do okay with that configuration. And it sure is nice to have everything tied to the vaka.
chris
More worried about the lack of a lifting vector to the rig. By and large what I’ve played with so far has always had some lifting component to the rig (as do most traditional rigs). The vertical schooner type rig is going to have a little more bow down component. The main issue may well be downwind, Upwind and reaching most of these do fine (or better) downwind sucks unless something is done to balance out the forces. Either something switches over to the normal windward side or something is added (flying staysail?) to balance things out.
Don’t have the answer yet to a lot of this but look forward to finding out. The whole idea is to end up with an easily trailered and set up rig to carry two comfortably for a long weekend or more. Easily solo’d. Fast, quick, low stress fun. Doesn’t have to be the fastest thing on the water but should be a lot of bang for the buck.
To that end.
Simple
Lightweight
Low inertia
And all the other stuff I forgot 😉
Skip
Robert, what was the problem with the canoe sized version?
I remembered the battens as having a tendency to hang in a pretty much vertical plane, and therefore the sail being too flat. On re-examining the pictures, it doesn’t look so bad. In the first picture, when I tested reefing, all the battens went the wrong way, but at least they were not in the vertical plane. In another picture, they do their job (the picture is too big to attach, have to reduce the size on another machine where I have the software). However, with the deepest camber so far forward (comes from bending the tubes by putting them between two fence posts), the luff would have to be much closer to the mast for the flipping to work reliably on the other tack.
Nils dealt with the flipping by having narrow batten pockets that inhibited flipping, then adding a line that made the battens flip.
Regards
Robert Biegler
Robert, Thanks for the answer, I really appreciate your outlook and efforts, they have helped develop my own.
Chris, I feel like I’ve been high jacking your thread with Nomad stuff so here’s the last bit.
I’ve diddled a little bit with the rig geometry cleaning it up, 80 s.f./sail. Can go wing and wing downwind if needed. If trials with the broomstick work out, this will probably be the direction.
Thanks to all,
Skip
Hijack away, Skip. Its really cool stuff! Collaboration and stealing ideas is what we are all here for!
I wonder two things, looking at your set up.
1. Does it make sense to cant the masts to windward a bit? It might move your center of effort over a little.
2. Does it make sense to have some kind of a smallish “gaff” at the top of the rig? It would be between the forestay and backstay of the pivoting rig, just like the boom does now, but it would make room for some more sail up top. The pointy topped sails don’t look right to me. It might require a small “crane” at the top of the mast to move the axis of the rig back a little.
just a couple of thoughts.
best,
chris
1. Does it make sense to cant the masts to windward a bit? It might move your center of effort over a little.
2. Does it make sense to have some kind of a smallish “gaff” at the top of the rig? It would be between the forestay and backstay of the pivoting rig, just like the boom does now, but it would make room for some more sail up top. The pointy topped sails don’t look right to me. It might require a small “crane” at the top of the mast to move the axis of the rig back a little.
1. Maybe, the more vertical sail comes from an early appreciation that a sail canted to windward was “unstable” in the sense that area and moment arm increased as the float lifted. Probably a secondary effect and not of great value, trialing with Broomstick might give an answer.
2. The pointy top sails reminiscent of a Chesapeake skipjack, but that’s kind of an apple and orange thing. OTOH LFH had little gaff tops on his Meadow Lark design which I greatly admire. In the fullness of time such a thing might happen, particularly if I can cut a little off the mast height and not introduce much bending moment in the “crane”.
All of this is going to coast along for a while, need to finish the broomstick and check out a number of these things with rudders and rig(s). Once these things are quantified a bit it is back to finalize Nomad’s configuration and get on with building a boat I really want.
cheers,
Skip
Here’s an idea for rudders.
Since this is a lagoon racer, the rudders need to kick up when you hit stuff. The sensible thing to do would be to have dagger rudders on the windward side of the vaka, with kick up via a bungee cord, like Gary Dierking’s. But nothing is particularly sensible about this canoe.
The rudders on the lee side keep the spray to lee. There is a push/pull rod running inside the tube to turn the rudder (the mechanism for which is still half-imagined). There’s some kind of friction brake on the tube controls kick up. To shunt, you ease the sheet, release the kick up brake, fold up the old rudder, release and lower the new rudder and sheet in. Sure, the old tiller sticks up, but with a dagger rudder, you have the foil sticking up. I’m imagining hiking sticks on the tillers that are not shown.
A dagger rudder would allow it to sail in thinner water too…but that’s so sensible. I’ll do sensible next time…
one more…
More of the same…