46 CFR § 171.072 - Calculation of permeability for Type II subdivision.

---
identifier: "/us/cfr/t46/s171.072"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "46 CFR § 171.072 - Calculation of permeability for Type II subdivision."
title_number: 46
title_name: "Shipping"
section_number: "171.072"
section_name: "Calculation of permeability for Type II subdivision."
chapter_name: "COAST GUARD, DEPARTMENT OF HOMELAND SECURITY"
subchapter_number: "S"
subchapter_name: "SUBDIVISION AND STABILITY"
part_number: "171"
part_name: "SPECIAL RULES PERTAINING TO VESSELS CARRYING PASSENGERS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
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."
regulatory_source: "CGD 79-023, 48 FR 51017, Nov. 4, 1983, unless otherwise noted."
cfr_part: "171"
---


# 171.072 Calculation of permeability for Type II subdivision.

When doing calculations to show compliance with § 171.070, 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.

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