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Thread: "Caledonia Yawl 2" - 7 planks vs. 4

  1. #1
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    Default "Caledonia Yawl 2" - 7 planks vs. 4

    I am about to buy plans for the Caledonia Yawl and noticed there are now 2 - one for a 7 plank version the "Caledonia Yawl 2".

    Does anybody besides me just kinda like the prior look of 4 planks? Just curious.

    If you were going to build one or have built one, which would you do, and would you go plywood or solid planks? Looks like solid planks are option for the 7 plank version. Perhaps that is one reason there is now a 7 plank version. Thoughts?
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  2. #2
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    Default Re: "Caledonia Yawl 2" - 7 planks vs. 4

    The 4 plank is obviously ideal for plywood, getting planking stock that wide is not easy and more likely to split anyway, hence the 7 planker. I actually prefer the lines of Welsfords 6M Whaler.....once you have seen too many farings, they start to look normal, even if good looking.

  3. #3
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    Default Re: "Caledonia Yawl 2" - 7 planks vs. 4

    It's very much personal preference ..... I prefer the 7 plank. Here's a photo of my Selway Fisher canoe yawl JIM, about the same size as a Caledonian yawl. 7 planks.

    Hoisted up.jpg
    '' You ain't gonna learn what you don't want to know. ''
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  4. #4
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    Default Re: "Caledonia Yawl 2" - 7 planks vs. 4

    The CY you posted a picture of is not a standard CY. It’s sheer was modified by the builder.

    The 7 strake looks better to me but the four strake looks fine, too.

  5. #5
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    Default Re: "Caledonia Yawl 2" - 7 planks vs. 4

    Please don’t use Xena as an example of anything related to Caledonia Yawls other than perhaps as a warning.

    I think the more strakes version is quite possibly easier to plank and build, as it requires far less twist in a huge garboard. I also think it’s quite a bit prettier.

    The Sooty Tern is very nearly just a six-plank version of the four-plank Ness Yawl, and having built one of each of those myself, I most definitely prefer the 6-straker there both in building and in action.

  6. #6
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    Default Re: "Caledonia Yawl 2" - 7 planks vs. 4

    Ah - thanks for the posts. I'm about half way through watching offshoreharbor.com 's 40 part video series on making one. The 7 planks is actually growing on me quite a bit. Interesting - I thought there were differences between that sheer shape on the Xena and the stock Caledonia - very worth noting.

  7. #7
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    Default Re: "Caledonia Yawl 2" - 7 planks vs. 4

    Last edited by Matt young; 02-10-2018 at 11:07 AM.
    "Yeah, well, that's just, like your opinion man"
    -The Dude-

  8. #8
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    Default Re: "Caledonia Yawl 2" - 7 planks vs. 4

    They do both look GREAT!

  9. #9
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    Default Re: "Caledonia Yawl 2" - 7 planks vs. 4

    Matt,

    I think Iain may have redrawn the 4 planker as well as the new 7 planker. Best to ask him.

    I noticed the 4 planker has an aft keel piece, the 7 planker doesn't. That might mean the 7 planker turns slightly quicker and the 4 planker goes staight better under oar/ motor.

    The 4 planker will be a bit quicker to build. Fewer planks...fewer joins. More significant when building a bigger boat, especially if you were building it outside, but I depends how you go at it and whether you buy a kit.

    The 4 planker has a wide garboard. On the good side that means no joggling floors which makes them much quicker to cut and fit. Also the parts around the motor well will be a bit easier to fit.

    Because of the garboard width the 4 planker is sometimes built with a thicker plank, 12mm instead of 9. That makes it stiffer, but can give you a task bending it forward onto the inner stem. The 7 straker strake being narrower and thinner 9mm, is supposed to bend more easily at this part.

    The 4 straker is harder chined obviously. On the good side this reduces roll speeds for cruising, but racers like fast rolls speeds. It also usually makes the boat slightly drier as the water is pushed outwards more horizontally from lower down. This also helps reduce dynamic wetted area. Also on the good side the stronger V bottom is a softer ride in chop and waves (less heave motion) than a rounder multistrake section. On the down side any crossflow over a chine angle of 15 or so degrees is more prone to developing turbulence, so the 4 straker might be slightly slower at higher froude speeds. On the bad side though the 7 straker has more laps which add wetted area below the waterline at lower speeds, though a rounder shape in theory has slightly less area, but it's only marginal. The chines of the 4 straker might make it a bit stiffer, but if the 7 straker has a bit more bilge volume that is also a stiffening factor so might be another wash.

    Historically Nordic boatbuilders went to alot of trouble to hew their boats out of fewer planks, because the trees were available and to reduce leak points and fastening numbers before good adhesives etc. Cutting up 4ft wide boards into narrow strips again is a bit of a nonsense and originally was a bit of a sign of inferior narrow board timber availability, but the waterline shape will be resolved with more resolution though, which should improve hydrodynamics.

    They are both lookers. I bought 7 strake planks, and Iain probably has incorporated many ideas and thoughts from feedback into that one after a decade or two. People will perceive it as newer, and perhaps more desirable second hand maybe. I've come to enjoy the simplicity of the Mk1 4 straker though and think it probably takes more skill for a designer to use fewer laps to still get a good shape. I find something very attractive in a simple (shaker?) way about the 4 strake fully open boat with a uniform colour making the lines stand out. He nailed that one early.
    Last edited by Edward Pearson; 02-15-2018 at 05:11 AM.

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