Rectangular Tubing for Yacht Design?

Discussion in 'Multihulls' started by member 76956, May 21, 2022.

  1. member 76956

    member 76956 Previous Member


    I've been thinking a lot about rc-modeling multihull sailcraft lately and have been tinkering with the idea of starting with rectangular tubing, in pvc or metal, representing the interior compartments, bilges, etc, then adding greatly abbreviated bulkhead shapes, to the outside of these, on which the outer hull sides will ultimately be hung. The crossbeams connecting the hulls could also be made of rectangular tubing.

    *Then it occurred to me, it might be possible to do this for a full-size yacht?!

    If lightweight prefab or easily constructed units could be obtained or made, then I'm thinking that this might speed vessel construction for a homebuilder or even a commercial yacht builder, greatly reducing the complexity and man hours involved. It may even add reserve strength and rigidity to the underlying structure.

    Perhaps, even some of the hull shaping could be done with what would amount to oversized mitre cuts?

    Most of the building process would be "subtractive" instead of additive as in typical yacht construction. All the bits that weren't needed would be cut away, then reused, recycled or disposed of.

    This works for many other types of projects, why not yachtbuilding?

    I'm guessing the trade-offs would be extra weight, materials and cost; but I'll bet, with a clever design, this can be well mitigated or even reversed to some extent.
    Last edited: May 22, 2022
  2. AlanX
    Joined: Mar 2022
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    Location: Perth, Western Australia

    AlanX Senior Member

    Boat building is in the end a cost problem. Buying more aluminium then you need is ... expensive.
    Custom made super-sized sections would also be very very expensive and awkward to handle.
    Having said this, I am aware that some boats cut large aluminium/steel tubes to make rounded chines.

    Arthur Edmonds discusses in his book "Designing Power and Sail", designing a boat with three different framing types and selection the one with the lowest weight.
    Cost and weight is that important.

    Regards AlanX
    fallguy likes this.
  3. member 76956

    member 76956 Previous Member

    I really tend to agree with you; but, I kind of want to figure out a way to do it, for some reason.

    Don't worry, it's probably just a phase :)

    *I will get a copy of that book.
  4. AlanX
    Joined: Mar 2022
    Posts: 113
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    Location: Perth, Western Australia

    AlanX Senior Member

    If you want to design and build a boat yourself, you should pick the "Stitch and Glue" construction method to start (you can progress to other methods later).
    Next get familiar with some boat design software that allows the development of "unfolded" panels (from your design).
    FreeShip and Carlson Design Hull Designer are two that I used. There are others.

    You can use Arthur Edmonds' "Designing Power and Sail" to determine the scantlings for your design.
    Other than ISO 12215-5 (surprise!) and AS 4132 (withdrawn), most of the free standards on the Internet are not really suitable for DIY.

    Start with a canoe for your first design (you can give it away if you don't really like it).
    There are thousands of design ideas you can use for inspiration.
    It takes me about three weeks to convert an idea (or a picture) into a buildable design, but my boats are small (<7m) sailboats and canoes.
    Sometimes I just build a model, sometimes I just lose interest.

    Here is an example of a pontoon that I designed from scratch:

    Regards AlanX
  5. member 76956

    member 76956 Previous Member

    Very helpful

    Cheers mate
  6. redreuben
    Joined: Jan 2009
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    Location: South Lake Western Australia

    redreuben redreuben

  7. member 76956

    member 76956 Previous Member

    Yes, aluminium "tube-frame" construction. I like it :)

    It's also a great resource.

    That 44' sailing cat is just gorgeous.
    Lots of interior space.
    It's got a Saloon you could dance in!

    Last edited: May 23, 2022
  8. member 76956

    member 76956 Previous Member

    Icon .ico file for Carlson Hull Designer. (WINDOWS USERS)

    Just download the file and remove the .jpg bit, leaving "Hull Designer.ico" which you can then paste in the "hulls-designer" folder.

    Then simply change the icon on the desktop shortcut, from "properties," if you made one.

    It'll look 100% better than the one made by the system.


    Attached Files:

  9. willy13
    Joined: Jan 2022
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    Location: Canandaigua NY

    willy13 Junior Member

    Has anyone successfully found aluminum tubing or pipe in a marine grade 5000 series? I say successfully because there are internet sites that claim to manufacture it, but I can never find it from a supplier.
  10. bajansailor
    Joined: Oct 2007
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    Location: Barbados

    bajansailor Marine Surveyor

  11. Eric Lundy
    Joined: May 2017
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    Location: Vermont

    Eric Lundy Junior Member

    I am using broken hockey sticks....
  12. willy13
    Joined: Jan 2022
    Posts: 57
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    Location: Canandaigua NY

    willy13 Junior Member

    Improved corrosion resistance and weldability. While 6061 and 6063 obviously can be welded with no problems, its done all the time, 5052, 5083, and 5086 all are less likely to have cracking problems at the welds. When TIG welding 6000 series you need to make sure you use enough filler rod or you can get cracking. With 5086 you can TIG with no filler rod. Thats how good 5086 is for welding. Plate is just as popular in the 6000 series, you just don't hear about it in the marine industry since the 5000 series generally has better corrosion resistance.
    bajansailor likes this.

  13. rberrey
    Joined: Oct 2010
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    Location: AL gulf coast

    rberrey Senior Member

    O'Neal Steel has both sheet and plate in 5052 but no tube . There are plenty of ship yards in the Al Gulf coast area building Navy ships out of Aluminium . If 5052 tube can be had I would think O'Neal Steel could put you on it .
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