---
kind: "section"
citation: "46 C.F.R. § 171.072"
title: "46"
number: "171.072"
heading: "Calculation of permeability for Type II subdivision."
url: "https://uscodex.org/cfr/46/171.072"
---

# §171.072. Calculation of permeability for Type II subdivision.


When doing calculations to show compliance with [§ 171.070](/cfr/46/171.070.md), the following uniform average permeabilities must be assumed:

- (a) 85 percent in the machinery space.
- (b) 60 percent in the following spaces:
  - (1) **Tanks that are normally filled when the vessel is in the full load condition.**
  - (2) **Chain lockers.**
  - (3) **Cargo spaces.**
  - (4) **Stores spaces.**
  - (5) **Mail or baggage spaces.**
- (c) 95 percent in all other spaces.

## Notes

### Amendments

[CGD 79-023, 48 FR 51017, Nov. 4, 1983, as amended by USCG-2014-0688, 79 FR 58287, Sept. 29, 2014]

### Authority

Authority: 46 U.S.C. 2103, 3306; E.O. 12234, 45 FR 58801, 3 CFR, 1980 Comp., p. 277; Department of Homeland Security Delegation No. 0170.1.

### Source

Source: CGD 79-023, 48 FR 51017, Nov. 4, 1983, unless otherwise noted.

### Amendments

[CGD 79-023, 48 FR 51017, Nov. 4, 1983, as amended by USCG-2014-0688, 79 FR 58287, Sept. 29, 2014]