So theoretically the wind can’t heel you all the way over anyway. This heeling moment then is reduced to zero. As an example, lets say the boat leaned all the way over. Includes definitions and indexes in French, German, Italian and Spanish to make the material as accessible as possible for international readers.

As the displacement is constant it is sufficient to consider the variation of the lever arm of the moment. I guess MR=AS*128 is simplistic, but what would be a more precise formula, if you know what conditions the boat should perform well in? I'd imagine it would take the sail area into account, the beam, the draft, the maximum wave height and possibly other things. As the boat heels over the distance aloft to the center of pressure of the wind is lowered and thus the heeling moment is reduced. The moment that opposes the heel is called righting moment. On the other hand it's true that a boat wouldn't necessarily sail well at the heel angle it has its maximum righting moment and it's something that I would like to take into account. I looked at your post and well It definitely underline that it's not a simple matter. if you know the conditions in which the boat should perform well, how do you go about finding a 'sufficient' value for the righting moment. which is dependent on the sail area which makes a lot of sense, although not as precise as I'd imagine something like that to be since it doesn't take into account the length of the mast(s), and maybe a couple other things that I think should matter.įor the design I'm looking for it would be about 10*128, and since its a really small boat that is in the ballpark of the righting moment it would already Hoc Hi! What I meant by sufficient is what a naval engineer would consider sufficient. What I find more interesting is 'required righting moment' = sail area ( in m^2 ?) * 128. I still find it a big weird to use that formula instead of taking the maximum righting moment you get by calculating the righting moment for different heel angle, as I'm trying to calculate this for a keeled sailboat where the form stability is half the story. Thanks a lot! I was confused about what Mr and As stood for in your first post.Īs I understand it, the first formula is the righting moment that come from the hull shape the displacement + the number of people who can use their weight to try to right the ship.

Righting moment definition