Stoned Pirates first hull

Discussion in 'Boat Design' started by stonedpirate, Apr 8, 2010.

  1. dskira

    dskira Previous Member

    Yes, built the ****** and go sailing. :D
    Cheers
    Daniel
     
  2. stonedpirate
    Joined: Nov 2009
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    stonedpirate Senior Member

    hear hear :)
     
  3. BertKu
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    Location: South Africa Little Brak River

    BertKu Senior Member

    No Daniel,

    StonedPirate should first see what needs to be done to get out of the seaharbor and the tone and supports he gets from the harborcaptain. He should make a few phonecalls first. The restrictions going to be put on him might be such, that he may wants to abolosh this small boat and build himself a decent one and go sailing around the world in anyway, but then in style.

    Bert
     
  4. stonedpirate
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    stonedpirate Senior Member

    Are you trying to say my mini yacht has no style :p
     
  5. BertKu
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    BertKu Senior Member

    Yes, the boat has style, but I bet that a nice lazy leather TV chair with a 102 cm Flat screen TV + a large king size double bed will be more comfortable, but will not fit in your mini yacht. How are you going to entertain a nice friend? Hang him or her from the mast upside down?
    Bert
     
  6. ancient kayaker
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    ancient kayaker aka Terry Haines

    With a draft of 1.2 m, a length of 3 m, and a beam of 1.2 m, I estimate the displacement at around 2.5 T. The target was 500-600 kg.

    Bolger was a skilled boat designer. He knew a thing or two and could get away with the unconventional approach. There was a good reason for everything he did.

    SP, I'm not saying that you are not a skilled boat designer, but if you miss the displacement target by a factor of x4 there's a chance you are not - and you did say this was your first boat.

    Now I am the last guy to criticise anyone for being unconventional, maybe a little nuts, or designing and building a boat without the least idea how. After all, that's precisely what I did. If I was to be that hypocritical there are people around here that would laugh their underwear off.

    I am neither an adequate boat designer nor even a half-decent sailor, although I am working on both of those. However, Please don't make the maiden voyage a round-the-world attempt. So far as I know we do not have any Darwin prize winners in our forum and we don't want to start now.

    As for advice, I suggest you download Free!Ship so you can get the basic hydrostatic data for your design, so you can at least ensure the CoG is well below the metacentric height, the first step towards stability. It will also give you a rough idea of how much of a push it will take to propel the boat through the water. If I had done that maybe my first 2 boats would not have ended up as garbage.
     
  7. alan white
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    alan white Senior Member

    For calculating displacement, find out the area of the proposed below-water midsection. Multiply that midsection area by the waterline length (10 ft).

    Multiply that times the prismatic coifficient (just use .55 if you don't know it).
    This gives you the cubic volume of water displaced by the boat in cubic feet.

    Multiply the cubic volume in feet by 64 lbs (that's how many lbs are in one cubic foot of seawater). The result is your displacement in lbs.

    As you pick up design, you should get used to doing this simple formula backwards so that you can start with the target displacement and end up with submerged midsection area.
     
  8. portacruise
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    portacruise Senior Member

    Why reinvent the wheel? Seems much easier and safer to take some form of proven existing sea survival capsule as a start. Then add whatever bells and whistles according to your priorities.

    Porta

     
  9. bhnautika
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    bhnautika Senior Member

    SP I did a quick mock up of the boat and put the waterline near the chine and as you can see the displacement is at about a tonne. You would have to get the centre of gravity at or around this waterline as anything above 150mm higher and the boat would fall over.
     

    Attached Files:

  10. stonedpirate
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    stonedpirate Senior Member

    He can sit on the deck :p

    Its a record attempt. Not a pleasure cruise :)

    Yes, i figured it would be the chine if the V had a volume of 600kg and i wanted to load 600kg :p

    Thanks all for the tips. Makes designing a lot easier with the basics under my belt :)

    Will research center of gravity :)

    Cheers
     
  11. rwatson
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    rwatson Senior Member

    Hey - how come no-one mentined the most obvious design flaw of all ... the square stern behind the added V in the hull?

    This sucker will not be able to travel more than 1 or 2 knots under sail or power due to the major drag going on.
     
  12. stonedpirate
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    stonedpirate Senior Member

    Funny you should say that.

    I have tried to make the exact hull in carlene for the chine shapes and it wouldnt let me make a square v to the transom.

    I said screw it and kept the shape carlene gave me because it looked nice.

    Turns out the software knew more than me :p
     
  13. stonedpirate
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    stonedpirate Senior Member

    [​IMG]

    [​IMG]

    Displaces one ton to the first chine.

    Too much freeboard? :p
     
  14. rwatson
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    rwatson Senior Member

    When I did my welding course, the instructor said he hated teaching sculptors how to weld. They were having so much fun joining shapes together, they didnt want to bother with learning how to do quality welding.

    Seems to apply to hull design. People get such a buzz out of drawing shapes in computers, they cant be bothered actually producing designs that work as boats.

    This stuff may "look nice" - but you've got a lot of learning to do to make a hull that will actually be a boat, not a decoration.
     

  15. masalai
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    masalai masalai

    Get really stoned and enjoy life on the land - in that hull... and you may live to see another day, - At sea, NOT I, said the fly, and masalai agrees.... Manie has done the research and knows stuff in the micro sail challenges...

    We had one bidding for a Darwin Award but it broke up within 40 miles just after passing under the Golden Gate Bridge... He built of Alloy... Good entertainment for a while...
     
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