how to determine sail area

Discussion in 'Boat Design' started by stonedpirate, Feb 13, 2012.

  1. stonedpirate
    Joined: Nov 2009
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    stonedpirate Senior Member

    I appreciate your concern PAR but please, no need to post this on every one of my threads.

    I am no kid. I am a grown man with a degree in computer science. I havent worked with wood since making a birdhouse in highschool.

    I do not have a degree in naval architecture or engineering, like 99.999% of the people on this forum, or the majority of backyard boatbuilders.

    Its a 10' hull, not the titanic, and the answers i get on this forum are invaluable to my goal of designing and building this boat, so please keep your opinions to yourself from this point on as i have heard them 4000 times already.

    Like it or not, this boat will be designed, built and sailed by an amateur. If it kills me, you can rest assured your objection was duly noted.

    Thanks again to the helpful people on this forum :)
     
  2. idkfa
    Joined: Sep 2005
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    Location: Windward islands, Caribbean

    idkfa Senior Member

    Stonepirate,

    Success is about how one deals with failure, everyone has failed, the successful ones learn from it and try again. That takes heart (which you've displayed) and the smarts to listen.

    Par is to be listened too, turn his negativity around and learn from it instead, what is he really trying to tell you.

    It takes time, stick with it, find someone with an eng degree/background who can look over what you (and the forum) come up with.

    It WILL take better help (face to face) than we can give via an internet forum to get it done.

    IMHO idkfa.


    also, you want Par on your side!
     
  3. viking north
    Joined: Dec 2010
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    viking north VINLAND

    Once you have encountered and survived the horror of the first great storm at sea and continue knowing the next one could be worst you will have a greater understanding of PAR's concerns and entered into the crazy world of sailers. Since it seems you are determined to give it a go I recommend the ultimate free standing mast- one whose profile is a circle and constructed from carbon fiber. These have become the choice of Freedom"s and Nonsuch, the great production leaders in freestanding mast systems.
     
  4. Yobarnacle
    Joined: Nov 2011
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    Yobarnacle Senior Member holding true course

    When I was 8 years old, I discovered at the public library a collection of Motorboating Sailing designs annuals. In one was a 3 page article on designing developed surfaces for plywood construction, using a system of radians and perpindiculars. The chine and keel in profile generated the chine in plan. The profile and plan generated the body sections. Simple.
    Then, my interest aflame (not just sparked), I read every book on yacht design I could get my hands on. I made my own equipment. Copenhagen ships curves traced from illustrations. Spline ducks cast from linotype metal in my dads print shop. Though I lusted for a planimeter, I settled for lofting sections on graphed paper, and counting the squares.
    I finally committed a design to wood at age 11. And at age 12, I finished bulding my first 11 foot classic moth. I designed and built 3 more moths before I went to war at age 18.
    My interest in small boat design inspired in me an interest in mathematics.
    Eventually I got a degree in mathematics.
    Computers and internet and design forums didn't exist. My parents, teachers, scout masters, and public library librarians "enabled" this kid!
     

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  5. yipster
    Joined: Oct 2002
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    yipster designer

    I was the one who asumed you were a kid in a previous thread were you memtioned to have learned 3d yachtdesign with 3dmax. so you aint a kid but did not react on my advice to try freeship (no plussign on my smartphone?) To draw a better boat so now we know
    Planty good reply's i'd say, Par's included, do you really want to build a mold first? Really want to sail into your first storm at sea in a peanutshell? Long as you keep subjects like this decently fed fine with me, cheers
     
  6. Stumble
    Joined: Oct 2008
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    Stumble Senior Member

    Since no record keeping organization maintains a record for this category, just head to the south pole and sail around it in a coffee cup. Everything else is just fluff. I am with Par, this poster is desperate to kill himself, and I am done being a part of it.
     
  7. Yobarnacle
    Joined: Nov 2011
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    Yobarnacle Senior Member holding true course

    StonedPirate,
    If you actually construct, equip, provision a 10 foot boat for circumnavigation, is it your intention to sail off alone/ Or do you have plans for one or more larger escort vessels to accompany you?
     
  8. Lister

    Lister Previous Member

    In 2009 you posted this picture. Interesting boat. I must say you are persevering, but hurry up, the clock is ticking.


    [​IMG]
     
  9. stonedpirate
    Joined: Nov 2009
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    stonedpirate Senior Member

    I have freeship, carene, strip planking kayak software and just about every other free program out there. Whats your point?

    Our species have been building boats for thousands of years without freeship.

    Whether i use freeship, max, clay, paper mache, pencil sketches or balsa models is up to me. So now you know what exactly? :rolleyes:

    My intentions for this boat is stated in the other thread.
     
  10. stonedpirate
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    stonedpirate Senior Member

    Slow and steady wins the race :)

    That russian guy did it in his 70's

    I've still got 40 years of sailing in me. Thats if the peanut in a storm doesnt kill me.
     
  11. water addict
    Joined: Jun 2004
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    water addict Naval Architect

    Stoned Pirate-
    Have you sailed the ocean before during rough weather? If not, you might gain some insight into your design and passge attempt by doing some ocean passages on more normal boats before going the the extreme you are considering.
     
  12. Yobarnacle
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    Yobarnacle Senior Member holding true course

    the most seaworthy vessel in the world is a tightly stoppered bottle.
    the problem is crew injury bouncing about inside, and control issues. How do you make the boat go where you want. And more important, how do you prevent it going where you don't want, like on the rocks on a lee shore.
     
  13. sharpii2
    Joined: May 2004
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    sharpii2 Senior Member

    There are four problems with this rig:

    1.) The tall, un stayed mast will either be too flimsy or too heavy,
    2.)There will not be enough head stay tension to keep the luff of the jib straight, allowing the boat to even reach reasonably well,
    3.) when the jib is shortened. its Center of Area (CA) moves too far forward for anything but downwind sailing, and
    4.) it's difficult to add more sail to the working rig.

    For a boat that may well end up being tumbled end for end, you need a rig that can take a tremendous amount of punishment and still stay standing.

    The mast head sloop or cutter (a sloop with two jibs) fits this bill best, followed by a gaff sloop or cutter.

    Adding stays to a rig strengthens it incredibly over just a cantilever pole.

    As for boat length, I think only length over deck is counted. Spars that extend past the deck aren't.

    A mast aft rig could be made to work by moving the mast forward or by putting a very sturdy boomkin on the transom, to make room for a lower and upper back stay. The upper back stay will need a spreader facing aft. You will also need a pair of spreaders for your shrouds, as you will need at least a pair of upper and lower shrouds.

    As I hope you can see, getting rid of the boom is probably far more trouble than its worth, if you want to end up with a real sailboat, rather than something that can just sail down wind.

    The gaff rig can dispense with the spreaders only by having a shorter mast (which can have a thicker section per given capsize moment), and by having a gaff, to extend the upper sail outward, so it doesn't need to be so tall per given area.

    A sprit sail sloop could also work with a very short mast, which could be bolstered with a pair of lower shrouds on each side, with the mainsail looking almost square in profile. In stronger winds, the sprit could be removed and a smaller jib headed main sail could be raised in its place.
     
  14. Stumble
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    Stumble Senior Member

    again, since no record keeping organization tracks this record, you can define leingth any way you want. Build a 10' boat with a 10' sprint, and a gin pole in the stern to keep the rig up, and just decide to define it how you want.
     

  15. Yobarnacle
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    Yobarnacle Senior Member holding true course

    Since you are planning a current borne voyage rather than sailing, except token control, how about a 10 foot diameter rigid life raft capsule. LOA is only 10 ft. :) Give it 10 foot draft also. Lotsa carrying capacity. :) Copy the portugese man-o-war from nature. A corruscated inflatable sail crest.
    If you could devise a mass of stinging tentacles beneath to catch fish for you?
     
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