---
kind: "range"
citation: "46 C.F.R. §§ 45.143–45.147"
title: "46"
from: "45.143"
to: "45.147"
count: 3
url: "https://uscodex.org/cfr/46/45.143..45.147"
---

# §45.143. Hull openings above freeboard deck.


Closures for openings above the freeboard deck must be as strong as the structure to which they are attached and must be weathertight.


# §45.145. Hatchway covers.

- (a) Hatchways in position 1 and 2 must have weathertight hatch covers with gaskets and clamping devices.
- (b) The maximum ultimate strength of the hatchway cover material must be at least 4.25 times the maximum stress in the structure calculated with the following assumed loads:
  - (1) **For ships 350 ft or more in length, at least 250 lb/ft 2 in position 1 and 200 lb/ft 2 in position 2.**
  - (2) **For ships less than 350 ft in length, at least <I>AL</I> in the following formula—**
    - (i) **Position 1—**
    - (ii) **Position 2—**
- (c) Hatchway covers must be so designed as to limit the deflection to not more than 0.0028 times the span under the loads described in [paragraph (b)](#b) of this section and the thickness of mild steel plating forming the tops of covers must be at least 1 percent of the spacing of stiffeners or 0.24 in, whichever is greater.

# §45.147. Hatchway coamings.

- (a) Except where the Commandant determines that the safety of the vessel will not be impaired in any sea condition, each hatchway must have a coaming that is at least—
  - (1) 18 inches in position 1; and
  - (2) 12 inches in position 2.
- (b) Each hatchway coaming required by this section must be made of steel or equivalent material.
- (c) The height of these coamings may be reduced or omitted if the Commandant is satisfied that safety of the ship is not thereby impaired in any sea conditions.