46 CFR 174.090: Permeability of spaces.

When doing the calculations required in § 174.065—

(a) The permeability of a floodable space, other than a machinery space, must be as listed in Table 174.090; and

(b) Calculations in which a machinery space is treated as a floodable space must be based on an assumed machinery space permeability of 85%, unless the use of an assumed permeability of less than 85% is justified in detail.

Table 174.090—Permeability

Spaces and tanks Permeability (percent)

Storeroom spaces 60.

Accommodation spaces 95.

Voids 95.

Consumable liquid tanks 95 or 0. 1

Other liquid tanks 95 or 0. 2

1 Whichever results in the more disabling condition.

2 If tanks are partially filled, the permeability must be determined from the actual density and amount of liquid carried.