Ship Equilibrim Angle, Trim and Heel

Discussion in 'Stability' started by AliKaragisi, Nov 11, 2019.

  1. AliKaragisi
    Joined: Nov 2019
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    Location: Turkey

    AliKaragisi New Member

    hi all,
    Firstly, ı need to calculate ship equlibrim status. My program can calculate all hydrostatics data (Volume, Lcb,Tcb, Vcb, Lcf, Tpc, Mtc, Ix,Iy , Wpa etc..) but ı can not calculate equlibrim condition. For example ı have Weight 750 ton, LCG 30 m from AP, TCG 0.02m stb and VCG 4 m from BL. I need to calculate ship equilibrim for this condition. I can calculate Weight and Displacement equilibrim but cannot trim and heel equilibrim. Which method is use for equilibrim.

    Thanks for your reply.
     
  2. DCockey
    Joined: Oct 2009
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    DCockey Senior Member

    Are you a student?

    If not a student what experience in naval architecture do you have?
     
  3. AliKaragisi
    Joined: Nov 2019
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    AliKaragisi New Member

    i m not student , i m working on my loading software. ı have 3 years experince in ship building but i have been working abouth stability.
     
  4. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    Calculate hydrostatics for various trim values. With this you will obtain, for the displacement you wish to study, how the longitudinal position of the center of buoyancy varies. When that position coincides with that of the CoG - which logically also changes when the boat is trimmed - you will have reached equilibrium floating.
    For the transverse equilibrium position you will have to draw the GZ curves - righting arms - for the desired displacement, define the curve of heeling arms at each angle of heel and calculate the intersection.
     
  5. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    This would be calculated by setting the programme to "free trimming" or uncheck the "fixed trim"...depending on how your software programme is set up.
     
  6. AliKaragisi
    Joined: Nov 2019
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    AliKaragisi New Member

    not fix trim, ı want to calculate real position of ship.
     
  7. AliKaragisi
    Joined: Nov 2019
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    Location: Turkey

    AliKaragisi New Member

    your solution is good but this process is very slow in my software. all hydrostatics (or some trim hydrostatics) calculatingincrease time my equilibrim process..
     

  8. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    I know.

    Please read very carefully what is written above. What does YOUR programme use....???....it is an either or...perhaps you're not very well versed in the programme, hence your statement?!

    This for example..is merely asking to fixed or unfixed...i.e free trimming:
    upload_2019-11-12_15-21-5.png

    or the other way:
    upload_2019-11-12_15-21-59.png

    Thus what does YOUR software programme say. There are many ways to sate this...but you're reply suggests you do not understand the terminology or its implications if checked or unchecked?!
     
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