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Re: Other: "Stabilty Factor' conquered (finally) *Pic*
By:Kudzu
Date: 5/26/2009, 10:45 pm

: Care to share ?

No problem. Just make a donation to my fund. :)

First, use the cross curve function in Freeship with a 250 lb displacement at 15 degrees. You will get a number something like .247. That is the short leg of a triangle and you have to calculate the different legs of the triangle. I use this site.

http://www.carbidedepot.com/formulas-trigright.asp

You know Angle A (15 degerees) and side A from Freeship. What you need to know is side B. In my case it is .9504. That is the height of the Metacenter above the waterline.

Determine your waterline at 250 lbs. In my case it is .370

The subtract the water line height from the Metacenter height.
.950 - .370 =.580 That is the metacenter above the waterline in decimal feet.

So convert that to inches. .580 x 12 = 6.966" That is Metacenter above the waterline in inches. That was the hard part to figure out. Getting to that number. Took me two days to figure out what everything was. Now that you have that the formula is simple.

(Metacenter/7.5) x 100 = stabilty factor.

(6.966/7.5)*100_92.88 stability factor.

The definition was found on the Bear Boat web site.
There is thread over on BoatDesign.net where I finally grasped this.

http://www.boatdesign.net/forums/stability/freship-stability-again-27396.html

Yea, I know this is confusing. Email me if you get lost and we work through one.

Messages In This Thread

Other: "Stabilty Factor' conquered (finally)
Kudzu -- 5/23/2009, 12:32 pm
Re: Other: "Stabilty Factor' conquered (finally)
Phil Nelson -- 5/26/2009, 8:21 pm
Re: Other: "Stabilty Factor' conquered (finally) *Pic*
Kudzu -- 5/26/2009, 10:45 pm
Re: Other: "Stabilty Factor' conquered (finally)
Phil Nelson -- 5/28/2009, 7:13 am