# calculating heal

Discussion in 'Stability' started by burley1, Jan 28, 2010.

1. Joined: Jan 2010
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### burley1Junior Member

can any one help. I'm trying to calculate what wait is needed for a 14 ft sailing dingy, and weather I need a trapeze. the formula that I'm using is, the force in the sails x the hight of the CE x the depth of the CLR x the force against the dagerboard. but is there any set wind force used in this equation. and is the force on the dagerboard = the force of the wind?
cheers

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### gonzoSenior Member

You need to substact the force created by the stability of the hull

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### burley1Junior Member

I am currently working to get a place at a university to study marine architecture, and this is sort of a project to show them.
as I have no training in this field I am very sketchy on the theory behind all of the analysis work.
one problem that I'm having is that this is a sailing dingy and will no doubt be top heavy, relying on the crews wait to keep her upright. does the stability of the hull + rig still play a roll in the equation when there is no self righting factor ( waited keel or ballast).
this design is very similar in shape to the Merlin rocket. if that helps at all.
cheers

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### gonzoSenior Member

There will be some initial stability. That is why the boat can float upright without a crew. It isn't much though. The easiest way to know if you are on the right track, is to look at dinghies that have or not trapeze. See what your calculations show for each.

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### burley1Junior Member

is this something that is used allot in dingy design? or is it more common to guesstimate for smaller boat such as this. as there as lots of variables that can play a part on a boat this size.

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