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Thread: Requesting comments on a sail canoe rigging/setup concept/design

  1. #1
    Join Date
    Mar 2019
    Location
    Palm Harbor, Florida, USA
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    5

    Default Requesting comments on a sail canoe rigging/setup concept/design

    I could use a bit of design advice.

    Have just acquired, for a song, a well-used, but undamaged very good condition, 30year old 17' fiberglass keelless canoe with 36" beam, with ash gunnels.


    Have also acquired a used free-standing Sunfish mast, spars, and sail.

    I just begun this project and am gathering used materials and components, to reduce cost, and wish to convert it into an 'all-purpose' type craft, and
    plan to use it for solo, inland waterway and light coastal cruising, camping, fishing, and exploring, but no racing or rum-running...

    When broken down (15 minutes?) all components fit inside the hull, and can be hauled in my pick-up truck bed, without need for a trailer.
    Even filled completely with water, I'm adding enough flotation foam to float the boat, me, and my cargo) without sinking. In other words, I would like to be able to either paddle it or sail it, albeit at a snails pace, when filled to the gunnels with sea water.

    With this much sail (7 sq meters)-to-empty weight (60-70 Kilos) ratio, it has promise to be decently swift in 5-12 knot winds, and probably dangerous, if I'm not careful. This seems like a lot of sail, but it is what I have, and plan to use it, if feasible.

    Am a more than a little concerned, about ever letting lee gunnel get below water line...ever...

    A few details:



    • Aluminum mast is 3.1 meters tall from keel to top.
    • Upper and lower spars are 4.0 meters, each.
    • Un-battened Lateen, 3.6 ozs, sail with a (4 meters x 4 meters x 4.36 meters)
    • Also, I want to be able to quickly reset it up for paddling, or for stable rowing (if I can work out an oar to outrigger non-interference scheme). Also, I want to be able to use a 2HP Tohatsu O/B for fishing,


    • 2.4 meter long outriggers on a 2.4 meter beam, to control heel.
    • Maximum passenger and cargo weight 130 kilos.
    • Maximum wind might be in range of 12-15 knots, with wave height below a meter. But would like to sail it in light air down to say, 5 knots.
    • Will add removable fore and aft spray covers/deck 3.4 meters long, each – either thin marine plywood (fiber-glassed), or waterproof 'snap on' membrane, over curved battens.
    • Will install enough flotation foam in hull and outriggers to support 180-200 kilos, which should float rigged boat, me, and rarely used heaviest cargo load
    • Will run main halyard, down haul, topping lift and rudder lines to 'cockpit'.

    I need some advice on my rigging design (see sketch for preliminary dimensions) – in particular:


    • Mast-to-bow relationship to OAL is 25%, initially
    • Mast to leeboard measurements. But am assuming center-lines of lee board and 'center of effort' of sail should be close to same.
    • Leeboard area and effective working depth
    • Not really sure about need for keel.
    • Rudder area and effective depth.
    • AMA beam width
    • AMA vertical positioning as you can see is kind rough as of yet (initially, I' ll make both very adjustable until I can figure it out) Using 2" PVC (heat gun) bending, or pinned 45° and 90° fittings
    • AKA cross section for strength vs. lightness. Will start with 2" PVC.
    • Best way to reef the sail. (Thinking of holding lower spar in place with topping lift, lowering upper spar with main halyard, and adding 3-4 reefing grommets on the imaginary line from Tack to midpoint of Leech.
    • What else?


    Comments, suggestions, ideas, and even guffaws, requested and appreciated...

    Thanks for you kind attention to this request.

    John in Palm Harbor Fl, USA.

    http://s1108.photobucket.com/user/Ni...uc2z2.jpg.html




  2. #2
    Join Date
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    Many of your UK readers will not have seen the Sunfish rig, which I know is triangular, (but not what happens at the front of each spar). Equally, we don't know much about the hull shape either.

    I am a canoeist, and a sailor, but not a canoe sailor. I think the centre of effort might be slightly further forward, but in any case, by using a vang and a bleater, which goes from mast to front end of boom, you could adjust the boom for and aft , and hence move the centre of effort. Also by rotating your lee board (which you would have to raise anyway to come ashore) you could alter the centre of resistance of the hull and out riggers. You are right, mast in front of lee board (you probably only need one, which will only be a leeboard on one tack and a "weather board "on the other) so that vessel has an intrinsic desire to turn into the wind. (a vital safety requirement.) Judging by other sailing canoes on here I would go for shorter, more voluminous outrigger floats to reduce skin friction drag, and fit them on a single outrigger, positioned so that only one is in the water at any one time (again drag). By using shorter, chunkyer outrigger floats you may be able to fit oars further aft and miss the floats. For different reasons the most modern racing shells have a v-shaped rigger, so that, in your case, it would cross the boat in front of your rowing position.

    However, if you were prepared to sit on the gunwhale you would have a righting moment only a little less than a sunfish (and a great deal drier) and hence be able to carry full sail for more of the time. I think it might be wiser to try for two reefs rather than just one. Halving you sail area is a big reduction in power. You might look up "slab reefing" which does away with the need for cringles in the short turn, but not perhaps if you were sailing to Cuba.

    Hope that that helps, but others wiser than me may tell you different.

    Impcanoe

  3. #3
    Join Date
    Mar 2019
    Location
    Palm Harbor, Florida, USA
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    5

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    Impcanoe,

    Excellent ideas!
    Your intelligible post made me glad to have made the effort to join this forum, this afternoon.
    It gives me lots to more to think about, as I fall asleep this evening.

    I like:

    • Two reefs instead of one, maybe 25% less sail, and 50% less sail.
    • Bleater, eh? New one on me. Sounds good for moving 'centre of effort'. However, my sail attaches to top and bottom spars (booms) by 15 rings each, and bottom boom is 'fixed' in position to mast with a bronze 360 swivel. While it can slide up and down mast, it cannot slide fore and aft relative to mast, because the swivel's function is to keep the lower boom tight to mast, at all times, even when boom is on on lee side of mast. In effect, it functions as mid'-boom gooseneck.
    • I like idea of shorter thicker, float (AMA), especially having only one one outrigger arm (AKA), which possibly would address 4 issues: 1. As you say"less friction/drag". - 2. Only one AKA to make. 3. And, I suspect, better more responsive (tighter) tacking radius. with shorter float. 4. Makes setting up oar options much easier. One follow-up question: Since they will be much shorter, that opens up the question of optimal fore/aft positioning for best handling. My instinct is to cheat them aft a bit. Perhaps centered at 1/3rd OAL from stern. Your opinion?

    • My twin lee boards will be mounted on a single swiveling 'axle', and will rotate together, and be spring-loaded or lever cortrolled at side of cockpit, in down position, so when I hit a sand bar, they get kicked back up as needed, without damage. Where i live, sand bars few kilometers out can be only 1/3 meter under water, at low tide. Rocks and such, not much of an issue here. Sometimes, I will sail across broad areas around 1/\3rd meter deep.
    • Yes, one float in water at a time. Even though my drawing did not show it, I had planned on setting the up as such, once I found out how canoe would heel, in a close haul, with various wind and cargo loadings.
    • Yes, "slab reefing". Will experiment with that, once some other issues are resolved. I have slab reefing set up on my WindRider 17, (which is becoming more than I wish to handle at age 77.)


    Many thanks on your generous response!.

    By the way, fyi, my drawing is a 'shrunken' .jpeg of a .DWG file, made at a much larger scale with high degree of accuracy, with McDraft Pro 7 by MicroSpot, Limited, a British company, located in Kent.

  4. #4
    Join Date
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    Ok, you are clearly keen on this project. Here is some more research for you. There is a very knowledgeable man, dealing with boats with interesting rigs (and hulls and appendages) called Michael Storer. He designed a very clever boat called the Goat Island Skiff. More importantly for you, he brought together a lot of ideas for controlling and refining gaff rigged mainsails. (hence "bleater") If you were to control where your boom crosses the mast with a bleater, you could throw away you scaffold pole joint and have a more flexible rig. For fun you could look up his design Oz racer, basically an enlarged kitchen drawer with a rig on it, and look as pictures of it sailing.

    But for serious research just go through the canoe sailing threads on here.

    I am a little older than you, and have recently decided, philosophically, to live to be a hundred. Makes all those "should I ,shouldn't I" do something when I'm so old. Of course I should, I've got another 20 years of doing it to go.

    Good luck

    Petert
    Impcanoe

  5. #5
    Join Date
    Dec 2012
    Location
    Pennsylavania USA and Ontario Canada
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    Hello John,

    Today I am at Cedar Key, leaving tomorrow. I understand the waters you describe. (Am having trouble logging in on my tablet, so may be out of touch for some days if I can't fix that.)

    The Sunfish rig is huge (75 sq ft) and heavy by canoe standards. It doesn't reef very conveniently. A 17 ft canoe might more typically use a lateen of about 55 sq ft with the lightest possible spars. To use it, I'd be thinking of making a full-on trimaran with large enough ama volume to carry some routine load. You show a pair--I'd extend them much further forward as both forward and heeling forces on the sails can try to 'pitchpole' the hull if there isn't some countervailing buoyancy up there and the Sunfish sail is rather tall by canoe standards.

    (The Sunfish, for those who don't know it, is rather like a Laser with a lateen sail. It is about 4 feet wide and just under 14 feet long, and has a foot well for the sailor's (1 or 2) knees--you sit on the deck and often need to hike (sit) out to keep it upright. Sunfish sailors expect to capsize periodically and the hull facilitates self righting. It is a rather stiff boat for it's size. The mast is sturdy and heavy by canoe standards while the yard and boom are aluminum tubing 1 1/2 in diameter and 13'8" long. The sail is hauled to the masthead through a plastic fitting while the boom is held to the mast by means of a pivoting gooseneck that clamps to the boom and can slide up and down the mast. There are rules restrictions for the class that can be ignored in this case. Here is an info link:

    https://sailboatdata.com/sailboat/sunfish)

    The Sunfish daggerboard gives a good hint as to the size of leeboard that will be wanted.

    You can also make a good initial guess as to leeboard position by looking at the diagram in that link. Few sailors today use dual leeboards, preferring one somewhat longer one on one side.

    You might look to some of Gary Dierking's designs for some hints on setup, amas, akas, etc.

    Enough for now--I'll try to keep in the loop while traveling this week.

    Bob
    Last edited by Bob Cavenagh; 31st-March-2019 at 04:42 PM.

  6. #6
    Join Date
    Mar 2019
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    Palm Harbor, Florida, USA
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    Bob,

    Thanks!

    Your recommendations make very good sense.

    Have already decided to increase AMA diameter to 6"(152mm) x 8' (2.8meters) long. on an 8' (2.4meter) beam (thinwall PVC sewer pipe) This should provide about 115 lbs (50 Kilos) of buoyancy, per AMA.
    Will look at best way to move them forward, as you suggest.

    Have solved reefing issue by lowering top spar with main halyard (at either 25% or 50%) while holding boom (lower spar) in place with topping lift.

    Initially, I'll make the mast step mounting thwart assembly, the AKA mounting thwarts, as well as the lee board mounting thwart as 'temporary prototypes', which will be fore/aft movable, thus enabling me to tweak' until I get what I want.

    Additionally, my goal is to have no single 'breakdown' component weighing more than 50 lbs, with qwik connections' for everything, since lifting/'muscling' is not on my agenda these days, nor is a trailer. All will fit in my pickup bed.

    Off topic:
    (Once I get this rig working the way I need/want, I'm selling my WindRider 17, which has a big 'screacher' sail, alum. hakas, mid-boom sheeting, boomvang, windshield, halyard-to-cockpit routing, mast-raising system, factory motor mount, topping lift, slug-gate, and forward cockpit sheeting and tiller control.
    Am also selling an ancient Sunfish hull, which, while seaworthy, is in desperate need of a total re-glassing.)


    John

  7. #7
    Join Date
    Dec 2012
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    Pennsylavania USA and Ontario Canada
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    [Have solved reefing issue by lowering top spar with main halyard (at either 25% or 50%) while holding boom (lower spar) in place with topping lift. ]

    You will need some way to keep the yard against the mast. Look up 'Jens rig' for Sunfish.

    You will need to gather and secure the portion of the sail that drops to the bottom to keep it from filling. Look up SLAB reefing....

    [Initially, I'll make the mast step mounting thwart assembly, the AKA mounting thwarts, as well as the lee board mounting thwart as 'temporary prototypes', which will be fore/aft movable, thus enabling me to tweak' until I get what I want.]

    Both the mast step and mast thwart will need to be very sturdy as that sail will generate great lateral and forward thrust against them, (and also to the rear if you get backwinded). The leeboards will produce much lifting and downward thrust, not too much fore and aft, so different fastening methods can be used.

    This beast may prove as big a handful as your Windrider 17. I like those things. Might be easier overall to put a reduced rig on it. But they are harder to transport.

    You wrote about using a pair of leeboards locked together. While that is intriguing, it isn't common as two boards can increase overall drag. But given your chosen waters, you might think of two independent boards, a deep one for deep water, and a broad shallow one for the skinny places. I have done that for here at Cedar key. If you have a Sunfish daggerboard you could add a handle and just use if as the deeper one.

  8. #8
    Join Date
    Mar 2019
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    Palm Harbor, Florida, USA
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    Bob.

    Am considering very strong combo 'thwart deck' about 60"-66" long, which would serve mast, lee boards, and forward AKA. It would be a 'drop-in", slide forward, until; it wedges in two axis, port hull to strbrd hull, and bottom of gunnels to inside of bottom of hull, and tool-lessly clamp it in position in 5 places. 3-5 minute install or removal, if I go with Sunfish sail.

    Yes...a beast... and am still thinking about that, issue. I know I'm pushing a limit with that 75sf SF sail on a 17' canoe.

    However, I haven't discarded a sloop or fractional sloop. I also have 10' tall x 8' wide, (40sf) sail with mast, rings, and boom, ready to go, that would work, which could easily be 4-way stayed with some pretty small Dyneema. With a 8' tall x 4' wide (16sf) jib, which I a can make on a friend's HD sewing machine. I'd be close to that 55 SF, total number, which 'makes more sense'... more running/standing rigging, but more control, smaller AKAs and AMAs, smaller lee board, smaller rudder, and smaller associated thwarts/braces.

    Discretion vs. zeal....hmm...

    Thanks for your comments.

  9. #9
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    >Am considering very strong combo 'thwart deck' about 60"-66" long, which would serve mast, lee boards, and forward AKA. It would be a 'drop-in", slide forward, until; it wedges in two axis, port hull to strbrd hull, and bottom of gunnels to inside of bottom of hull, and tool-lessly clamp it in position in 5 places. 3-5 minute install or removal, if I go with Sunfish sail.<

    There is nothing wrong with that deck idea if you have multiple sub-location options for mast or leeboards, so you can adjust. But I'd want at least a couple of screws into the gunwales on either side to lock it's fore and aft position even further.

    Bob

  10. #10
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    yes, the first ' thwart deck' would be plain old used exterior ply, so i could drill many re-do 'adjustment' holes for aka, mast, lee board mounts, all of which would be separate from deck, made of same materials, but temp mounted on it....until i get it right. Once I think I have what I think I need, I'd make a new deck with integral mounts out of the good stuff.

    I like to do my concept/first design routines with lots of 'wiggle room'...then, instead of calling them mistakes, I see them as 'design evolution steps'...

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