46 CFR § 154.440 - Allowable stress.

---
identifier: "/us/cfr/t46/s154.440"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "46 CFR § 154.440 - Allowable stress."
title_number: 46
title_name: "Shipping"
section_number: "154.440"
section_name: "Allowable stress."
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"
---


# 154.440 Allowable stress.

(a) The allowable stresses for an independent tank type A must:

(1) For tank web frames, stringers, or girders of carbon manganese steel or aluminum alloys, meet σ<sub>B</sub>/2.66 or σ<sub>Y</sub>/1.33, whichever is less; and

(2) For other materials, be specially approved by the Commandant (CG-ENG).

(b) A greater allowable stress than required in paragraph (a)(1) of this section may be specially approved by the Commandant (CG-ENG) if the equivalent stress (σ<sub>c</sub>) is calculated from the formula in appendix A of this part.

(c) Tank plating must meet the American Bureau of Shipping's deep tank standards, for an internal pressure head that meets § 154.439(a), published in “Rules for Building and Classing Steel Vessels”, 1981.

[CGD 74-289, 44 FR 26009, May 3, 1979, as amended by CGD 82-063b, 48 FR 4782, Feb. 3, 1983; CGD 77-069, 52 FR 31630, Aug. 21, 1987]