U.S. Code of Federal Regulations
Regulations most recently checked for updates: May 29, 2020
When doing the calculations required in § 172.225,
(a) The permeability of a floodable space, other than a machinery or cargo space, must be assumed as listed in Table 172.240;
(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; and
(c) Calculations in which a cargo space that is completely filled is considered flooded must be based on an assumed cargo space permeability of 60% unless the use of an assumed permeability of less than 60% is justified in detail. If the cargo space is not completely filled, a cargo space permeability of 95% must be assumed unless the use of an assumed permeability of less than 95% is justified in detail.
Table 172.240 - Permeability
Spaces and tanks | Permeability (percent) |
---|---|
Storeroom spaces | 60 |
Accommodations spaces | 95 |
Voids | 95 |
Consumable liquid tanks | ^{1} 95 or 0 |
Other liquid tanks | ^{2} 95 or 0 |
Cargo (completely filled) | 60 |
Cargo (empty) | 95 |
Machinery | 85 |
^{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.