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Thread: Bulb

  1. #1
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    Default Bulb

    Jarndyce and Jarndyce

    The Mighty Pippin
    Mirror 30141
    Looe
    Dragon KA93

  2. #2
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    Default Re: Bulb

    Real pr0n! Yay!

    Fabulous photo. Weirdly airship erotic, too, LOL.
    Gerard>
    ​Freeland, WA

    Resistance is NOT futile.

  3. #3
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    Default Re: Bulb

    Illuminating.

  4. #4
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    Default Re: Bulb

    Try to imagine the complexities in trying to make 3/8" (or thicker) steel plate take that shape...
    Hope for the best, but plan for the worst.

  5. #5
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    Default Re: Bulb

    Fun with explosive hydroforming.
    Simpler is better, except when complicated looks really cool.

  6. #6
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    Default Re: Bulb

    Schwing

    Simpler is better, except when complicated looks really cool.

  7. #7
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    Default Re: Bulb

    "Fun with explosive hydroforming." Paul

    Probably so, but not a process that many shipyards I know about can do.

    I read a paper a few years ago that described a process that Hyundai Heavy Industry uses, where they put an electric arc tool (basically a TIG welder with no shield nor wire feed) in a 3D CNC tool and 'draw' loops and designs on a steel plate in a very precise pattern. As the metal cools it shrinks at the arc path and draws the plate into the proscribed shape. Pretty interesting...
    Hope for the best, but plan for the worst.

  8. #8
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    Default Re: Bulb

    Donn's hat
    http://englishplus.com/grammar/00000294.htm

    I've seen some film of Koreans using gas torch and cold water to form those curves.
    Creationists aren't mad - they're possessed of demons.

  9. #9
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    Default Re: Bulb

    The bulb in the OP makes visual sense to me, but the one in post#6, on the Zaandam, has me stumped. Is it supposed to reduce drag or make the ship's motion more comfortable or what?

  10. #10
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    Default Re: Bulb

    Reduce drag, Bob. It is actually more efficient than the one in the OP, but more difficult (read, expensive) to build.
    Hope for the best, but plan for the worst.

  11. #11
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    Default Re: Bulb

    I see by the waterline that the bulb breaks the surface at rest. Then it slopes downward before the stem rises. Is this a shape that is more efficient over a wide range of speeds, or is it aimed at a specific cruising speed and wave length?

  12. #12
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    Default Re: Bulb

    It is most likely optimized for the 'standard' loading and cruise speed of the ship. Most merchant ships are terribly underpowered for their mass, when compared to other ship types, so they can operate as efficiently as possible. Dollars-per-nautical-mile is a merchant ships' nemesis, and everything possible is done to reduce the dollar consumption. Optimizing route, propeller, hull condition, speed, and yes, the shape of the bulb are all items closely considered to enable a ship to make a profit for her owners in a very, very competitive trade.
    Hope for the best, but plan for the worst.

  13. #13
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    Default Re: Bulb


  14. #14
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    Default Re: Bulb

    I think that is a bulb with a slightly different purpose, Canoeyawl...
    Hope for the best, but plan for the worst.

  15. #15
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    Default Re: Bulb

    Quote Originally Posted by mmd View Post
    I think that is a bulb with a slightly different purpose, Canoeyawl...
    It is pertinent though. Admiral Taylor noticed that warship ram bows were less resistfull than the conventional fore foot, and so developed the original onion bulb bow.
    It really is quite difficult to build an ugly wooden boat.

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