Shipquestions for schooltask

Discussion in 'Education' started by black_sheep, Sep 18, 2009.

  1. black_sheep
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    black_sheep Junior Member

    Hi!

    I got some questions that i can't give answers to, so I hope someone here can?

    -What determines the value of the minimal freeboard?
    -What is the number of bulkheads related to?
    -What is the bilge radius?

    Thanks :)
     
  2. Itchy&Scratchy
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    Itchy&Scratchy Senior Member

    You cant determine any of the above without more information, size of boat?
    What is its main purpose -what is the vessel to be used for?
    Building method -steel? fibreglass? wood? etc
    Sail powered? Motor powered?

    etc etc etc
    J
     
  3. black_sheep
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    black_sheep Junior Member

    All right.
    You see, the questions are repeatquestions from the chapter in the book, and they are not related to any vessel. So that's why I wonder.
    link to q's (number 124): http://dokmar.com/vragen.asp?BoekID=9&TaalKeuze=_US&Hoofdstuknummer=19
     
  4. Raggi_Thor
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    Raggi_Thor Nav.arch/Designer/Builder

    Have you read the book? :)
     
  5. black_sheep
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    black_sheep Junior Member

    Sure. But it is nothing about it..Or, what can you get out of this:
    "The plimsoll mark or freeboard mark consist of a circle with diameter of one foot, which through a horizontal line is drawn with as upper edge the centre of the circle. This level indicates the minimum freeboard insalt water summer conditions. Beside the circle is a number of horizontal lines indicating the minimum freeboard as above."

    I guess that's the answer for "determines the minimal freeboard" But if you could explane it to me, so i would understand it?

    But there's nothing about the other two.
     
  6. jehardiman
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    jehardiman Senior Member

    Either there has to be more information in context or the questons are just poorly worded.

    Once at school we were given the question. "The majority of marine boiler tubes are produced by ______?" The obvoius answers were (at the time ) Babcock-Willcox or Foster Wheeler. The answer that was wanted was "Cold drawing".

    But in reference to the first two questions, go review your damaged stability notes and the answers should jump right out at you. And no, the Plimsoll Mark does not "determine" the minimum freeboard, it marks it (though if you are a Deck Cadet it is sort of a GOD SAYS answer). As for the other, go review an dimensioned structural midships drawing...again the answer will be obvious.
     
    Last edited: Sep 18, 2009
  7. Raggi_Thor
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    Raggi_Thor Nav.arch/Designer/Builder

    OK, you can read about plimsoll amrks and the North Atlantic in the Winter etc.
    A typical homework asnwer would be "Minimum freebord for a given vessel, as shown by the plimsoll mark, is determined by the season (winter/summer) and the region's climate (North/South Atlantic for example).

    Wikipedia tells you:

     
  8. hoytedow
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    hoytedow Wood Butcher

    So, he would have to answer for each condition, then...?
     
  9. Raggi_Thor
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    Raggi_Thor Nav.arch/Designer/Builder

    Well, I don't think so but it's better to ask the teacher if the answer should be detailed or more general. Maybe they just want to know that you have read about the plimsoll mark and know how to us it in practice?
     
  10. hoytedow
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    hoytedow Wood Butcher

    Thanks.
     
  11. Raggi_Thor
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    Raggi_Thor Nav.arch/Designer/Builder

    Maybe in the book they forgot to tell that the plimsol marks are on the hull of the ship?
     
  12. black_sheep
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    black_sheep Junior Member

    So, thanks for the answers guys. It was helpful :)
    Now, i have a new one. And it goes like this:

    "Why are there sometimes big local differences in local upward pressure and the weight acting on a section of a ship?"

    Is it because of the waves, and where the ship is in the waves? If the aft are at the top of the wave, and fore are in the trough?
    ...no wait, can it depend on the cargo? Where the cargo is placed? .. I don't know

    Thanks again!
     
  13. gonzo
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    gonzo Senior Member

    Both. However, if this is to answer a test, it doesn't matter whether it makes sense or not. Read the book or ask the professor.
     
  14. black_sheep
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    black_sheep Junior Member

    It's a hand-in task..
     

  15. Raggi_Thor
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    Raggi_Thor Nav.arch/Designer/Builder

    I have seen some graphics showing distribtion of weight and flotation for a ship.
    While the sum of the two are equal, maybe you have seen this too, the wight is not evenly distributed while the pressure from the water is (quite).
     
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