# Freeing Port Calculation

Discussion in 'Boat Design' started by Whaler4me, Jan 23, 2004.

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### Whaler4meJunior Member

Is there a calculation for the size (area) required for freeing ports on a boat??

What information do I need in order to calculate this ??

Thanks in advance for any help.

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### danielroJunior Member

Hello, taken from the article 24 of the 66'Load Line Convention the total area of freeing ports shall be greater that the obtained by the following calculations:
A = 0.7 + 0.035 * L when L = or < 20 meters or A=0.07*L if L > 20 m. being L the length of the well (deck) but if the bulwark height is more than 1.2 meters you must increase 0.004 m2 for each meter of well's length and 0.1 m of height difference (it refers to the difference in bulwark height compared with 1.2 meters).
The same if the bulwark height is less than 0.9 m. You must decrease 0.004 m2 for each meter of well's length and 0.1 m of height difference (now compared with 0.9 m)
I hope this information will be useful to you
regards

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3. ### danielro+Guest

Freeing ports

Hello
following my last post, for fishing vessels of 24 m or over, the total area will be A=0.07*l and for fishing vessels of 12 m in length the total area will be A=0.035*l, being l the length of the bulwark, for vessels with a length between 12 and 24 m you can interpolate. (imo resolution a.749(18))
Regards

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### ilgazcanJunior Member

hi danielro.thanks for your information.Does this formula empirical or any class society's formula.can you declare this.Thanks again

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### GuillermoIngeniero Naval

As Daniel said, that is stated in a IMO resolution, also known as "Code on Intact Stability for all Types of Ships covered by IMO Instruments (IS Code)".

Cheers.

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