---
kind: "section"
citation: "46 C.F.R. § 154.440"
title: "46"
number: "154.440"
heading: "Allowable stress."
url: "https://uscodex.org/cfr/46/154.440"
---

# §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 σB/2.66 or σY/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)](#a-1) of this section may be specially approved by the Commandant (CG-ENG) if the equivalent stress (σc) 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)](/cfr/46/154.439.md?p=a), published in “Rules for Building and Classing Steel Vessels”, 1981.

## Notes

### Amendments

[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]

### Authority

Authority: 46 U.S.C. 3703, 9101; Department of Homeland Security Delegation No. 0170.1.

### Source

Source: CGD 74-289, 44 FR 26009, May 3, 1979, unless otherwise noted.

### Amendments

[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]