Permeability (nautical): Difference between revisions
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==Usage== |
==Usage== |
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Permeability is used in ship survivability and damaged stability calculations in ship design. In this case, the permeability of a space is a percentage from 0 to 100. Alternately, the permeability may be a coefficient from 0 to 1. The permeability of a space is the percentage of volume of the space which may be occupied by seawater if the space is |
Permeability is used in ship survivability and damaged stability calculations in ship design. In this case, the permeability of a space is a percentage from 0 to 100. Alternately, the permeability may be a coefficient from 0 to 1. The permeability of a space is the percentage of volume of the space which may be occupied by seawater if the space is flooded. The remaining volume [not filled with seawater] being occupied by machinery, cargo, accommodation spaces, etc. |
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==Example== |
==Example== |
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Typical values from the U.S. Code of Federal Regulations are: |
Typical values from the U.S. Code of Federal Regulations are: |
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* 0.95 for voids (empty spaces) and living spaces |
* 0.95 for voids (empty spaces), tanks, and living spaces |
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* 0.85 for machinery spaces |
* 0.85 for machinery spaces |
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* 0.60 for spaces allocated to stores. |
* 0.60 for spaces allocated to stores. |
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Revision as of 21:52, 15 August 2007
Permeability of a space in a ship is the percentage of empty volume in that space.
Usage
Permeability is used in ship survivability and damaged stability calculations in ship design. In this case, the permeability of a space is a percentage from 0 to 100. Alternately, the permeability may be a coefficient from 0 to 1. The permeability of a space is the percentage of volume of the space which may be occupied by seawater if the space is flooded. The remaining volume [not filled with seawater] being occupied by machinery, cargo, accommodation spaces, etc.
Example
Typical values from the U.S. Code of Federal Regulations are:
- 0.95 for voids (empty spaces), tanks, and living spaces
- 0.85 for machinery spaces
- 0.60 for spaces allocated to stores.
This implies that for damaged stability calculation purposes, machinery spaces are only 15% full with machinery by volume (100% - 85% = 15%).
References
- Title 46 U.S. Code of Federal Regulations