canoe tramson

Discussion in 'Boat Design' started by aprophet, Oct 31, 2010.

  1. aprophet
    Joined: Jul 2009
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    Location: portsmouth va

    aprophet Junior Member

    I hope this is the right place for this is it possible to add a transom to a canoe and is there a formulae to get the measurements right size of transom versus length of canoe etc TIA guys
     
  2. pistnbroke
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    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    real question is what do you want to put on the transom ..what sort/style of canoe and can we have a picture
     
  3. alan white
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    alan white Senior Member

    There is no particular formula for determining transom position since chopping off the tail of a canoe is not going to result in a hydrodynamically ideal hull.
    Your canoe was designed to be pointed at both ends. Purpose built transom-ended canoes would be designed somewhat differently with the bottom sweeping up to the transom waterline.
    Try to stay light with either an electric troller or a very small gas outboard. Remember you have to reach it without capsizing. Realize the weight hung out there will affect trim and safety unless it is inboard enough. This could be as much of a reduction of a e.g. 16 ft boat to a 13 ft boat. Or, if the canoe is pretty wide, say 38" beam, you could cut off less.
     
  4. Mr Efficiency
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    Mr Efficiency Senior Member

    Why chop into the hull ? just adapt a lightweight outboard bracket with the odd strut here and there to connect it to the hull. A tiny outboard out there shouldn't cause too many dramas.
     
  5. aprophet
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    aprophet Junior Member

    my outboard is a johnson 2 hp it seems like it is 22-23 lbs I have a outboard brcket now and there is not much steering going on under power it is a polyester copy of a coleman it may be a little more round then a coleman. I will try to get a picture up this evening. thanks
     
  6. gonzo
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    gonzo Senior Member

    You can cut the stern above the waterline. That will give you enough to clamp the outboard without changing the lines of the hull.
     
  7. pistnbroke
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    Location: Noosa.Australia where god kissed the earth.

    pistnbroke I try

    most seem to put the outboard on one side without any problems...how can it not steer with the outboard thrusting at up to 40 degrees to the line of travel ???? ( ie when you try to turn)
     
  8. alan white
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    alan white Senior Member

    An electric motor works well offset to the side. It's light to begin with, and the battery, which can be located closer to the midway point along the length, can be mounted off-center to balance the motor perfectly.
    There's not much available to balance an offset gas outboard side to side (the gas tank is never consistent in weight). Therefore a gas outboard would probably do better on a transom.
    Probably two foot would be about the right amount to cut off the boat to mount the gas outboard. Others may chime in but it's all guesswork without a lot of analysis, and anyway, it ain't rocket science. Whatever you do, you could buy a couple of spare canoes for the cost of a proper analysis so I say go for it and report back.
     
  9. gonzo
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    gonzo Senior Member

    We run a canoe with a side mounted outboard without any problems.
     
  10. Easy Rider
    Joined: Oct 2009
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    Location: NW Washington State USA

    Easy Rider Senior Member

    aprophet,
    I know what you're going through. The side bracket engine works ok w some engines. I had a 3 hp Evinrude that turned fine and was a smooth and quiet OB. Put a 2 hp Suzuki on it and turn more than 10 degrees and it would suck air or cavitate badly ..was almost useless. Then I unloaded a canoe on the beach w a side mounted OB, left for a few minutes and she rolled over in the water. Ages ago I had a "Y" sterned canoe that worked well and basically came to the conclusion that a center line mounted engine was'nt necessary but almost. About 14 years ago I bought a Clipper flat sterned canoe and that was the end of all my problems. I usually go about 7 knots w my 8 hp or 6 hp 2 stroke 2 cyl OBs running at about half throttle ...nice and quiet. Then when I'm frisky I can go about 12 to 14 knots but need to make steering changes VERY carefully.Can do graceful figure 8s if I'm slow and smooth w the tiller when running solo. However I usually have ballast tanks of wife fwd and trim is good. My 18' canoe was created by putting a "dam" in the mould of a 20' freight canoe. That's why my stern is so narrow. A proper freight square sterned canoe, with a much wider transom is often called a "Grand Lakes" canoe will carry bigger loads and handle more power w much better trim attitude. There is a photo of a real nice "Laker" canoe in a canoe building article in Wooden Boat Magazine this month. A fellow named Timothy was on "design" a while back presenting, making and selling (more or less) kits for his Laker style canoes. Check it out or Google Clipper Canoes or talk to me some more.
     

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  11. ancient kayaker
    Joined: Aug 2006
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    ancient kayaker aka Terry Haines

    I’ve been there, done that, not a happy memory. I extended the transom below the transom and it was slow and noisy.

    A lightweight outboard hung off to one side won’t cause a problem until you leave the boat: even if you arrange to swing it back to center while you are still aboard the higher CoG may still cause a capsize if it’s heavy enough or the canoe is light enough. Test it first with something cheaper of the same weight.

    As Gonzo said, if you want it on the centerline you can cut the stern above the waterline to form a small transom. It only has to wide enough to accommodate the motor clamp. You can slope it forward if necessary to get greater width on the top edge provided the motor will still deploy at the correct angle. Alternatively, or additionally you can force the sheers further apart to gain additional width at the stern.

    Another solution might be to extend a shelf off the stern shaped to accept the clamp, if the motor shaft is long enough - might need some ballast forward.
     
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