Permeability of a space in a ship

Ship

Since the end of the age of sail a ship has been any large buoyant marine vessel. Ships are generally distinguished from boats based on size and cargo or passenger capacity. Ships are used on lakes, seas, and rivers for a variety of activities, such as the transport of people or goods, fishing,...

 is the percentage of empty volume in that space.

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

Coefficient

In mathematics, a coefficient is a multiplicative factor in some term of an expression ; it is usually a number, but in any case does not involve any variables of the expression...

 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 International Bulk Chemical Code 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%).