---
kind: "section"
citation: "46 C.F.R. § 42.20-7"
title: "46"
number: "42.20-7"
heading: "Flooding standard: Type “B” vessel, 60 percent reduction."
url: "https://uscodex.org/cfr/46/42.20-7"
---

# §42.20-7. Flooding standard: Type “B” vessel, 60 percent reduction.

- (a) Design calculations must be submitted that demonstrate that the vessel will remain afloat in the conditions of equilibrium specified in [§ 42.20-12](/cfr/46/42.20-12.md) assuming the damage specified in [§ 42.20-11](/cfr/46/42.20-11.md) as applied to the following flooding standards:
  - (1) If the vessel is 225 meters (738 feet) or less in length, it must be able to withstand the flooding of any one compartment, except the machinery space.
  - (2) If the vessel is over 225 meters (738 feet) in length, it must be able to withstand the flooding of any one compartment, treating the machinery space as a floodable compartment.
- (b) When doing the calculations required in [paragraph (a)](#a) of this section, the following permeabilities must be assumed:
  - (1) 0.95 in all locations except the machinery space.
  - (2) 0.85 in the machinery space.

## Notes

### Amendments

[CGD 79-153, 48 FR 38648, Aug. 25, 1983]

### Authority

Authority: 46 U.S.C. 5101-5116; Department of Homeland Security Delegation No. 00170.1, Revision No. 01.4; section 42.01-5 also issued under the authority of 44 U.S.C. 3507.

### Amendments

[CGD 79-153, 48 FR 38648, Aug. 25, 1983]