---
kind: "section"
citation: "46 C.F.R. § 171.067"
title: "46"
number: "171.067"
heading: "Treatment of stepped and recessed bulkheads in Type I subdivision."
url: "https://uscodex.org/cfr/46/171.067"
---

# §171.067. Treatment of stepped and recessed bulkheads in Type I subdivision.

- (a) **For the purpose of this section—**
  - (1) The main transverse watertight bulkhead immediately forward of a stepped bulkhead is referred to as bulkhead 1; and
  - (2) The main transverse watertight bulkhead immediately aft of the stepped bulkhead is referred to as bulkhead 3.
- (b) If a main transverse watertight bulkhead is stepped, it and bulkheads 1 and 3 must meet one of the following conditions:
  - (1) The separation between bulkheads 1 and 3 must not exceed the following:
    - (i) If the factor of subdivision (FS) determined from § [171.065 (a)](/cfr/46/171.065.md?p=a) or [(b)](/cfr/46/171.065.md?p=b) is greater than 0.9, the distance between bulkheads 1 and 3 must not exceed the maximum separation calculated to demonstrate compliance with [§ 171.065](/cfr/46/171.065.md).
    - (ii) If the factor of subdivision is 0.9 or less, the distance between bulkheads 1 and 3 must not exceed 90% of the floodable length or twice the maximum bulkhead separation calculated to demonstrate compliance with [§ 171.065](/cfr/46/171.065.md), whichever is smaller.
  - (2) Additional watertight bulkheads must be located as shown in Figure 171.067(a) so that distances A, B, C, and D, illustrated in Figure 171.067(a), satisfy the following:
    - (i) Distances A and B must not exceed the maximum spacing allowed by [§ 171.065](/cfr/46/171.065.md).
    - (ii) Distances C and D must not be less than the minimum separation prescribed by [§ 171.065(e)](/cfr/46/171.065.md?p=e).
  - (3) The distance A, illustrated in Figure 171.067(b), must not exceed the maximum length determined in [§ 171.065](/cfr/46/171.065.md) corresponding to a margin line taken 3 inches (7.6 cm) below the step.
- (c) A main transverse bulkhead may not be recessed unless all parts of the recess are inboard from the shell of the vessel a distance A as illustrated in Figure 171.067(c).
- (d) Any part of a recess that lies outside the limits defined in [paragraph (c)](#c) of this section must be treated as a step in accordance with [paragraph (b)](#b) of this section.
- (e) The distance between a main transverse watertight bulkhead and the transverse plane passing through the nearest portion of a recessed bulkhead must be greater than the minimum separation specified by [§ 171.065(e)](/cfr/46/171.065.md?p=e).
- (f) If a main transverse bulkhead is stepped or recessed, equivalent plane bulkheads must be used in the calculations required to demonstrate compliance with [§ 171.065](/cfr/46/171.065.md).

## Notes

### Authority

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.

### Source

Source: CGD 79-023, 48 FR 51017, Nov. 4, 1983, unless otherwise noted.