# How is Intact Stability claculation Done??

Discussion in 'Software' started by bhabanism, Apr 5, 2006.

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### bhabanismJunior Member

Can any one advice me on how can the Instact Stabiliity calculation be done and what are cross curves of stability??

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### ABoatGuyMember

Suggest you get a copy of "Principles of Naval Architecture" at www.sname.org

It is all in there.

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### jehardimanSenior Member

Depending of where you are bhabanism, Basic Ship Theory by Rawson & Tupper may be easier to find. Both will provide the basics.

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### MikeJohnsSenior Member

Intact stab. is just ther righting moment of the vessel plotted against the rotation of free to trim hull. (free to trim means the fore and aft floatation line is adjusted as the vessel rotates )

Cross curves are for vessels of variable displacement such as cargo ships, the stab. curves are calculated for different displacements.

{edited to add clarity} Each of a number of curves curve represent a certain heel angle the horizontal axes is displacement and the vertical axis is righting arm gz, alternatively it can be the righting moment.

What sort of vessel are you analyzing?

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### MikeJohnsSenior Member

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### GuillermoIngeniero Naval

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### Greenseas2Senior Member

Stability calculations.

For starters, let's not make this more cmplicated than it is. Start with the Displacement to length formula, or D/L This formula is;

D/L= D/LWL/100 x cubed

D/L= Displacement divided by Watreline length divided by 100, the result is cubed

Also Calculated the Aove water/below water area ratio

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### BassoomJunior Member

I have all what u want

This site will give a full Marine engineering lectures, which will give u a very good idea of almost every thing

http://www.usna.edu/NAOE/courses/en200/

download the pdf chapters & enjoy yourself

also i have attached a small word file of my own work to give u a quick idea about stability.

Have a nice time

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• ###### 1-Introduction.doc
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