---
kind: "section"
citation: "46 C.F.R. § 28.575"
title: "46"
number: "28.575"
heading: "Severe wind and roll."
url: "https://uscodex.org/cfr/46/28.575"
---

# §28.575. Severe wind and roll.

- (a) Each vessel must meet paragraphs [(f)](#f) and [(g)](#g) of this section when subjected to the gust wind heeling arm and the angle of roll to windward as specified in this section.
- (b) The gust wind heeling arm, Lw in figure 28.575 of this chapter, must be calculated by the following formula:
- (c) The angle of roll to windward, A1, is measured from the equilibrium angle, Ael, and is calculated by the following formula:
- (d) The angle of equilibrium, Ael in figure 28.575, is calculated by determining the lowest angle at which the gust wind heeling arm, Lw, is equal to the righting arm.
- (e) The area “b” in figure 28.575 must be measured to the least of the following:
  - (1) The angle of downflooding, (Af);
  - (2) The angle of the second intercept, Ae2 in figure 28.575, of the wind heeling arm curve, Lw in figure 28.575, and the righting arm curve; or
  - (3) A heel angle of 50° (0.87 radians).
- (f) The angle of equilibrium, Ael in figure 28.575, must not exceed 14° (0.24 radians).
- (g) Area “b” in figure 28.575 must not be less than area “a” in figure 28.575.

## Notes

### Amendments

[56 FR 40393, Aug. 14, 1991, CGD 88-079; 56 FR 47679, Sept. 20, 1991, CGD 88-079, as amended by CGD 95-072, 60 FR 50461, Sept. 29, 1995; USCG-2004-18884, 69 FR 58344, Sept. 30, 2004; USCG-2008-0906, 73 FR 56509, Sept. 29, 2008]

### Authority

Authority: 46 U.S.C. 3316, 4502, 4505, 4506, 6104, 8103, 10603; DHS Delegation 00170.1, Revision No. 01.4.

### Source

Source: CGD 88-079, 56 FR 40393, Aug. 14, 1991, unless otherwise noted.

### Amendments

[56 FR 40393, Aug. 14, 1991, CGD 88-079; 56 FR 47679, Sept. 20, 1991, CGD 88-079, as amended by CGD 95-072, 60 FR 50461, Sept. 29, 1995; USCG-2004-18884, 69 FR 58344, Sept. 30, 2004; USCG-2008-0906, 73 FR 56509, Sept. 29, 2008]