3 chine multi-chine sailboats

Discussion in 'Boat Design' started by edik, Jul 15, 2011.

  1. edik
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    edik Junior Member

    Why don't we see more of multi-chine designs, specifically 3 chines? 3 chines are very close to the round bilge and still can be built by an amateur. I just recently saw a very nice design offered by South Pacific Boat Company. The price for the CNC precut plywood kit was insane (about $34K for a 35ft boat) but the boat sure looked good. I think if done right, 3 chine design can be very pretty and can be built by an amateur.
     
  2. waikikin
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    waikikin Senior Member

    VDS 34 is my favourite!:)
     
  3. CutOnce

    CutOnce Previous Member

    I think you don't see more because once you get past simple sharpie type designs the effort/cost required to build rapidly approaches the level of more sophisticated shapes. Costs of building a boat are related to the amount of materials and time, not just the simplicity of the hull shape. Basically, in materials, rigging and needed kit a 35 foot boat costs the same, regardless of whether the hull shape is smoothly curved or boxy. As boats get larger, the money saved by simple hull shapes becomes less and less of a factor.

    That being said, my personal favorite in the type is Paul Beiker's Shilshole 27. If I won the lottery I'd build one in a minute.

    --
    CutOnce
     
  4. PAR
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    PAR Yacht Designer/Builder

    I think the reason you don't see many multi chine hull forms is more about looks. Most can accept a simple hull form of flat or V bottom, considering these "basic" but a viable alternative to the complication of a round bilge build. With the addition of a second chine, a very visually obvious crease is on the topsides, which most find objectionable. In a small boat it looks like they didn't use enough strakes, in a larger craft a bit of a visual short cut. I have several multi chine designs that also happen to have round bilge sisters. I'd say less the 10% select the multi chine version over the strip planked,, molded or lapstrake versions of the same hull form.
     
  5. frank smith
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    frank smith Senior Member

    I think there are a lot of multi chine designs . But most boats are production built , and the
    professionally built one off hull dose not need to be simplified . multi chine is good for aluminum ,or plywood one off amateur construction .
     
  6. edik
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    edik Junior Member

    I started thinking seriously about lapstrake boatbuilding method after looking at Bornriff 33 here, at the forum. If the traditional style is desired and maintained, this is a very interesting method. I also think that lapstrake make welded joint stronger.
     
  7. ancient kayaker
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    ancient kayaker aka Terry Haines

    Unlike some folk I don’t find the “creases” of a multi-chine boat objectionable, in fact a sharp edge is often seen on automobiles where it’s used purely for its esthetic qualities. Placement and fair curves are essential of course.

    I think the multi-chine boat probably peaked with the introduction of decent ply and gradually fall off after the advent of glass fiber. I have been experimenting with ideas for constructing multi-chine boats for a few years, and those who read my posts will know I prefer not to use glass.

    Multi-chine construction isn’t as easy as it sounds. If the planks are precut to their developments and assembled over a mold for the seams to be taped, tiny errors in the stations and developments - along with slight dimensional changes as the planks are bent to shape - usually mean the package does not sit together snugly and adjustments are required. Perhaps it is easier to cut the planks to fit the mold - as for lapstrake - but then the mold gets more complicated as it is now required to define the shape of the hull in every respect. That’s OK for production but an added chore for a one-off.

    S&G simplifies multi-chine construction but it doesn’t work as well when the chine count mounts; there’s an awful lot of drilling and stitching and the hull flops all over the place. Been there, done that.

    For an amateur strip-plank is attractive from a construction point of view: build a mold, apply strips, sand the hull oh-so-smooth and just add glass both sides and the boat becomes tremendously strong with seemingly little effort. Of course the builder soon discovers how much more sanding there is to do but by that time he or she is committed, and it is a very rewarding method.

    Glassing is out for a lapstrake boat, but it doesn’t need it anyway as the laps add a great deal of stiffness and strength. I see very few lapstrake boats these days - I am surprised to read that they are still being built in significant numbers. I am also surprised that molded hulls are constructed by amateurs in appreciable numbers.

    I have used chine log construction for several boats; like the laps of a lapstrake hull it adds stiffness without glassing. However like S&G, it becomes a hassle on a multi-chine hull, and tends to morph into a kind of lapstrake. A couple of years ago I came up with an idea for dry assembling a multi-chine hull, but I ran into the problem of getting the seams strong enough without using glass, and it has gradually evolved back into a lapstrake hull. I suppose it’s Destiny calling . . .
     
  8. pagodaboat
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    pagodaboat Junior Member

    The French made steel, multi-chine, off-shore sailing designs popular in the 1970s. Almost all of these were professionally built, and followed on their love of the Moitessier/steel boat saga. As aluminum became more cost effective after that decade, so did the introduction of better forming techniques. Now we have beautiful aluminum French cruisers like the Ovni range, and multi-chine steel has become limited to the backyard builders in NZ, Australia, and occasionally the USA - all of whom must have a lot of time to devote to their projects.
     
  9. PAR
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    PAR Yacht Designer/Builder

    A lot of assumptions made there Pagodaboat, don't you think . . .
     
  10. edik
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    edik Junior Member

    As long as metal has to be bent only in one direction, multichine remains a viable alternative for an amateur. One can buy CNC cutting files or have the parts professionally precut and many a local metal shops can do the prerolling of the plates. It seems to me that the lapstrake method in particular also allows an amateur to be a little less precise because edges don't have to match completely. Of course, lapstrake method limits the choice of designs to more or less traditional looking boats. BZW, when I say lapstrake I mean 3 maybe 4 chines - not more.
     
  11. edik
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    edik Junior Member

    The front overhang is a little too long for my taste. But generally, I like VdS designs very much because they are no-nonsence.
     
  12. pagodaboat
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    pagodaboat Junior Member

    PAR - No, I'll stand by that post in general - I certainly think the history is correct, and if there is an assumption, it would be in where steel boats are now principally being built. That was a touch narrow. My comment about the backyard builders needing a lot of time would not of course be limited to steel boats - it would apply to all materials, and perhaps even less so to steel which could in fact be the fastest time-to-water of all materials for the home builder. Thanks for noting this assumption.

    BTW, I am really seeking a small, professionally built aluminum hull, but am having some trouble identifying suitable plans. The market is geared to boats larger than what I need - which ideally would be only 30 ft LOA.
     
  13. edik
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    edik Junior Member

    I'm considering Bornrif 33 published here on the forum. It's a beauty and I like the traditional looking lapstrake-method built metal hull. My only criticism of the design is that it looks a little uh...bloated. I talked to the designer to see if a longer, perhaps 36 ft version was in the making and he may do just that - in aluminum. Is Bornrif 33 type boat something you would consider yourself?
     
  14. pagodaboat
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    pagodaboat Junior Member

    edik - Wow! That Bornriff 33 is very interesting indeed. I will look into it further, and post again. Thanks for the tip!
     

  15. edik
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    edik Junior Member

    Check out the construction photos that designer/builder published - they are very informative...
     
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