Sailboat large angle of stability appendages

Discussion in 'Stability' started by xdeeperbluex, Jun 19, 2017.

  1. xdeeperbluex
    Joined: Jun 2017
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    xdeeperbluex Junior Member

    Hi guys , regarding the calculation of large angle of stability for example using Maxsurf the appendages volume of a keel bulb needs to take into account ? Thanks for the clarification
     
  2. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    My opinion is that you have to consider it. Not only for the calculation of stability at large angles, but also for calculations of hydrostatic values.
    In general, it is assumed that errors in calculations of up to 2 or 3% are acceptable, but if the keel volume is greater than that percentage, with respect to the submerged volume, failure to take it into account would introduce too large errors.
     
  3. xdeeperbluex
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    xdeeperbluex Junior Member

    Thanks, it is 40ft boat with a bulb keel and the difference is 100mm on Gz and 8 deg on angles if the complete keel bulb and relative ballast is considered or not.Anyway i am agree with you but checking online o have seen report without keel displacement
     
  4. TANSL
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    TANSL Senior Member

    They are two different things, but closely related. You can take into account or not the volume of the keel and the bulb but you must always take into account its weight to determine the c. of g.
     
  5. xdeeperbluex
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    xdeeperbluex Junior Member

    Yes sure the weight of the ballast and keel structures needs to be always into account of full displacement
     

  6. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    Yes, completely sure.
    Not only full load displacement, it is an important component of the light ship weight.
     
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