Cartopable 3-Person Sailing+Rowing Canoue/Dinghy

Discussion in 'Boat Design' started by feunatz, Jan 9, 2018.

  1. feunatz
    Joined: Nov 2016
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    Location: Austria

    feunatz Junior Member

    The cartoppability of the Trika540 looks fine to me:
    http://www.metzboats.de/htm/designs/multihulls/trika540/trika540_08.jpg

    But overall you're right - I'm getting away from my needs. Maybe someday

    To get back to topic. I did by the amas plans for the Trika540 to use on my build. (3,4m length - 100liter)


    I do plan to use quality epoxy an fillers - peelply - and bagging where possible. I'm still not fully convertet on the need to use marine grade ply. Currently considering the use of lightweight poplar ply since all ply will be fully encased in glas. But maybe this will change until it's time to order the ply.

    So far I'd like to thank all of you for your helpful advice and especially AnthonyW for taking the time and providing all the informations on his build.

    Current component selection:
    Trika540 amas on Aluminum poles(roughly 2800mm x 70mm), for transport the poles will be stored in the main hull. Amas could be transportet in the main hull or attached to it with shorter poles.
    Main hull - still undecided - open top with some sort of transom - seating with one adult as forward as possible and one aft for paddling - child goes in the middle - or on the windward ama ;)
    Sailing Rig - still undecided - something simple and stowable - current fav would be 2 optimist rigs. In line these would need about 4,2m space - so there could be a problem with getting the balance forward enought?
     
  2. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    The glues are part of what make marine ply more valued.

    Yesterday, I bought a sheet of construction grade 5/8 and it sheers on the veneer face when you screw it. Imagine building a boat and later having a poor glue sheer from hydaulics. The boat would be garbage.
     
  3. Richard Woods
    Joined: Jun 2006
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    Location: UK, USA and Canada

    Richard Woods Woods Designs

    If you look at the photos and videos of the Duo rowing with 3 adults and sailing with one you will see that when rowing one crew sits on the foredeck, on top of the mast step, the other sits on the transom, on top of where the tiller/rudder would be.

    My Strike 15 trimaran has outriggers that fold forwards and a mast that is supported by the main hull alone. So it would be possible to row it, using long oars. The standard Optimist rig has a centre mainsheet. Not sure if you have sailed one as an adult (I have) but large people find it challenging to get under the boom. I don't think having two rigs and 3 people will work, especially on a canoe, you would have to be very synchronised and skilful to safely tack and especially gybe (in which case you would probably want a better sailing boat anyway)

    As someone else said, it isn't just a matter of putting sails where they are convenient. They have to go where they work, where sheets can be easily located, where the masts can be supported. And where you can easily balance the boat with leeway preventers

    Richard Woods
     
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  4. feunatz
    Joined: Nov 2016
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    Location: Austria

    feunatz Junior Member

    You're right. I was mostly focusing on the need for water resistant glue. Will try to get some ply samples for testing before ordering the lot.


    You do have a point there - scaling a laser hull to 16ft and placing two optimist rigs made it quite obvious to me. The forward person would have to sit between the forward mast and sheet. Lots of contortion required on every maneuver.

    Using a Laser rig looks a lot more practical an doable. Training(touring) rigs are cheap and available. 2Pcs transportfriendly mast. Maybe there is even a possibility to add a laser pico or other small jib for better upwind performance.

    Another option would be 420rig, but that could be more sailpower than I or the design can handle.

    [​IMG]
     
  5. AnthonyW
    Joined: Oct 2012
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    Location: Cape Town, South Africa

    AnthonyW Senior Member

    Plywood - you could possibly get away with WBP Plywood (water boil proof plywood). This is the same as marine plywood, but is not guarenteed to be void free. Essentially the plywood has to survive being boiled for a period as a test, and this type of plywood is used for external ply in house/building construction where it will face weathering. This reference is more common in this term in Europe than in the US apparently. But given the closeness of the cost, I would just go for Marine ply? Either way, WBP would probably be the minimum if you can get this void free and just want some peace of mind. Give the term a google. And see what the equivalent might be in Austria? Might be common in the building industry.

    Personally I love the idea of two sails like the Osprey. Practically, have never sailed such a narrow boat, I think in practice if this was based on existing more complex rigs then I would be less in love with the idea of a bit more rigging lying around in a narrow hull with a child and wife clambering around. Jib sheets is one thing. Another full mast and vangs, kicking straps etc could make for a busy spot and an irritable wife. And depending on the position of you sheet pulleys, this flapping around on your forward sail in the vicinity of a small child's head might be a concern in a jibe. A simple cat rig might be more hassle free. And the child could sit slightly forward of the mast depending on the arrangement.

    Just a thought on the lazer rig - in excess wind the boat can heel and shed some load off the mast. In a trimaran format this won't be that easy. Would the mast cater for these stresses? You might need to sleave it in more fibre (excuse the terminology, bit late here - brain fade....).

    Another place to browse for nice ideas is a wonderful website at Small Trimarans | The first online community for enthusiasts of trailerable (and cartopable) trimarans http://smalltrimarans.com/blog/


    Lots of DIY trimarans on this site by amateur builders. Its a nice website.
     
    Last edited: Jan 23, 2018
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  6. AnthonyW
    Joined: Oct 2012
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    Location: Cape Town, South Africa

    AnthonyW Senior Member

    This is moving out of the car toppable range, but the Cross 18 and the Discovery 20 are two interesting small open trimarans. And Seaclipper 16 and W17. But having these row in single hull format might need lots of modification? So this is straying from your brief. But it might add to your collective thought or tip you change your brief, or move back closer to it.

    Going back to my last post, do look around all the posts on the smalltrimarans.com blog. You might find something there that is very close to what you are trying to articulate but have not yet fully gestated in your mind. (Terrible late night metaphor....) All kinds of interesting ideas on the site. Some likely to be fairly frowned upon by formal naval architects in terms of efficiency and design, but no doubt have proved plenty of fun for the builders and those that sail them. A good few have youtube videos which demonstrate how they practically sailed. The site is run by a chap called Joe who is very friendly and passionate about such small craft.
     
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  7. AnthonyW
    Joined: Oct 2012
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    Location: Cape Town, South Africa

    AnthonyW Senior Member

    Final thought (as I don't have much more I can add) - the Selway-Fisher 15' outboard motor canoe I think might tick all the boxes. The main hull would weigh about 40 kgs with rowlocks. Easily car toppable. Some reasonable outriggers for stability, with plans from Paul, or borrow ideas from others on their construction. It takes a light motor. And add a sail from a sailing canoe or the like, Paul does comment it can take a sail. Leeboards, and tiller and related components you could borrow from an 'repair project' on the local classifieds that is really just spare parts. (Motor might have to sit slightly to one side).

    You could have a nice rowing boat, a nice little motor boat for pottering around, and a nice sailing boat. It might not be perfect at all three, but it might be the best blend. For limited construction fuss, it has pretty nice lines. 6mm ply would be plenty strong for these roles. There are some pics of some on Paul's website.

    To quote from the design specs/description on the website
    "Normally a 1/2—2 hp engine would be used but she could take bigger units and she can be rowed or paddled—and like her smaller sister, a sail rig could be used."

    This seems to tick all your boxes. And if it doesn't you would have a nice motor canoe your could resell to get a small portion of your cash back.

    I am beginning to wonder if this isn't the route I should have taken rather Windrush. But having come so far the latter is very pleasing.

    All best. Once you get building, do post some pictures of the build and boat, or pop them on the SmallTrimaran blog site.

    Quite envious - Austria must have some lovely spots for sailing. From what I have seen it is quite beautiful.
     
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  8. feunatz
    Joined: Nov 2016
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    Location: Austria

    feunatz Junior Member

    Thanks again for your valued input, greatly appreciated.

    On the Ply situation. There is some ply in AW100(boilproof) locally available - but only in pine with is a bit heavy. Today i got some quotes for okume marine plywood shipped from germany ~90€ per 6mm board shipped. So I'm quite confident I'll get the wood situation sorted come build time. I do plan to start in march since my building space is unheated and temps are to low here for epoxy until then.

    I did look around on Smalltrimarans - even found one utilizing a laser rig:
    E15 Trimaran Launched In France | Small Trimarans http://smalltrimarans.com/blog/e15-trimaran-launched-in-france/
    He wrote about the same idea of adding a jib, but on a 2015 picture i managed to find it looks like he changed his mind and went for a proa approach:
    Outrigger Sailing Canoes: e15 Tacking Outrigger http://outriggersailingcanoes.blogspot.co.at/2015/02/e15-tacking-outrigger.html

    Mast stability is/was a concern, but since my floats are rather low buoyancy(100l) they should allow the boat to shed at least some wind. And if the mast breaks a replacement would be very easy and cheap to get.

    In the next days I'll build a scale model to get a better look at my idea and make it easier to finalize the desired beam and other things.
    I allready did do some quick calculations on the aluminum outrigger poles. Using 70mm x 3mm Aluminum poles should get me around 1000nm resistance to bending per pole. Final length from main hull to ama center will propaby end up at 1-1,2m. This should safely support my 100l amas.

    I's is indeed quite beautiful and a great place to live.
    But Sailingwise when i read Cape Town, South Africa I'm quite envious. ;)
    Lake Constance on my doorstep does provide us landlocked austrians with some decent sailing. mostly light winds and a little crowded.
     
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