46 CFR § 154.459 - General.

---
identifier: "/us/cfr/t46/s154.459"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "46 CFR § 154.459 - General."
title_number: 46
title_name: "Shipping"
section_number: "154.459"
section_name: "General."
chapter_name: "COAST GUARD, DEPARTMENT OF HOMELAND SECURITY"
subchapter_number: "O"
subchapter_name: "CERTAIN BULK DANGEROUS CARGOES"
part_number: "154"
part_name: "SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "46 U.S.C. 3703, 9101; Department of Homeland Security Delegation No. 0170.1."
regulatory_source: "CGD 74-289, 44 FR 26009, May 3, 1979, unless otherwise noted."
cfr_part: "154"
---


# 154.459 General.

(a) Each cargo tank must have a secondary barrier that meets Table 3 and except as allowed in Table 3, the hull must not be the secondary barrier.

(b) If the Commandant (CG-ENG) specially approves an integral tank for a design temperature at atmospheric pressure lower than −10 °C (14 °F), the integral tank must have a complete secondary barrier that meets § 154.460.

(c) If the Commandant (CG-ENG) specially approves a semi-membrane tank under the requirements of an independent tank type B, the semi-membrane tank may have a partial secondary barrier specially approved by the Commandant (CG-ENG).

(d) If Table 3 allows the hull to be a secondary barrier, the vessel's hull must:

(1) Meet §§ 154.605 through 154.630; and

(2) Be designed for the stresses resulting from the design temperature.

Table 3—Secondary Barriers for Tanks

|  |  |  |  |
| --- | --- | --- | --- |
| Integral | No secondary barrier required | Tank type not usually allowed | Tank type not allowed. |
| Membrane | ......do | Complete secondary barrier | Complete secondary barrier. |
| Semi-membrane | ......do | ......do | Do. |
| Independent: |  |  |  |
| Type A | ......do | ......do | Do. |
| Type B | ......do | Partial secondary barrier | Partial secondary barrier. |
| Type C | ......do | No secondary barrier required | No secondary barrier required. |
| The hull may be a secondary barrier. |  |  |  |

(14 U.S.C. 632; 46 U.S.C. 369, 375, and 416; 49 U.S.C. 1655(b); 49 CFR 1.46(b))

[CGD 74-289, 44 FR 26009, May 3, 1979, as amended by CGD 82-063b, 48 FR 4782, Feb. 3, 1983]