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
|
authority: 46 U.S.C. 3306,
3703,
5115; E.O. 12234, 45 FR 58801, 3 CFR, 1980 Comp., p. 277; DHS Delegation 00170.1, Revision No. 01.2
source: CGD 79-023, 48 FR 51040, Nov. 4, 1983, unless otherwise noted.
cite as: 46 CFR 172.240