# Heeling and Righting moments calculation

Discussion in 'Hydrodynamics and Aerodynamics' started by ClaudioD, Sep 3, 2021.

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### TANSLSenior Member

That is obvious, if the final water line were known, but it is almost certain that this calculation will not give the value of the total ballast, nor the position of its CoG, which balance the heeling moment at 30ยบ.
If what you want is an approximate calculation, the "Bernouilli formula" could be used with a coefficient C = 2 (the worst case) but taking into account that the wind not only acts on the sails but also on the part of the hull that is above the waterline.
If what you want is a much more exact calculation, in my opinion, you should use the procedure that I am indicating, although it is an iterative process, that is, it will not give the figure on the first attempt.

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### ClaudioDJunior Member

This is not a real size boat, is just a model of 127cm LOA
Side hull height is about 7cm and probably masked by the waves....and wind will heat the Center of Effort at 60cm above water !!

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### TANSLSenior Member

Sorry, but a 127 cm LOA boat is a real size boat with the problems (as far as we are talking) of a 127 m LOA boat. The calculations are the same.

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### ClaudioDJunior Member

You just simply forget the Scale Factors !!!

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### ClaudioDJunior Member

No progress, I will stop here !!!!

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### TANSLSenior Member

I think you are not understanding anything I am saying. Probably because I express myself very badly. I do not forget the scale factors when they have to be taken into account but that has nothing to do with what we are talking about. I am talking about calculating a 127 cm LOA boat, at 1/1 scale and, therefore, without scale factors that intervene in any calculation.
I don't know what you expected someone to answer you but my opinion is that if no one gives you an exact figure or formula, it is not because of the badness of the members of this forum, but because such an answer does not exist.
"No progress", only because with the answers obtained you do not know how to progress. Others may think that you already have more than enough information to calculate what you are looking for.

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