46 CFR § 45.61 - Correction for superstructures and trunks.
---
identifier: "/us/cfr/t46/s45.61"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "46 CFR § 45.61 - Correction for superstructures and trunks."
title_number: 46
title_name: "Shipping"
section_number: "45.61"
section_name: "Correction for superstructures and trunks."
chapter_name: "COAST GUARD, DEPARTMENT OF HOMELAND SECURITY"
subchapter_number: "E"
subchapter_name: "LOAD LINES"
part_number: "45"
part_name: "GREAT LAKES LOAD LINES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "46 U.S.C. 5104, 5108; Department of Homeland Security Delegation No. 0170.1."
regulatory_source: "CGD 73-49R, 38 FR 12290, May 10, 1973, unless otherwise noted."
cfr_part: "45"
---
# 45.61 Correction for superstructures and trunks.
(a) Where the effective length *E* of superstructures and trunks that meet the requirements of subpart D of this part is 1.0*L,* the minimum summer freeboard may be corrected by subtracting
1/2H<sub>s</sub>.
(b) Where the effective length of superstructures and trunks is less than 1.0*L* the minimum summer freeboard may be corrected by subtracting a percentage of one-half of the standard superstructure height (*H*<sub>s</sub>) determined by the formula:
Percentage = (*E*/2*L*) (1 + *E*/*L*) × 100
(c) To be eligible for the correction a trunk must—
(1) Be at least as strong and as stiff as a superstructure;
(2) Have no opening in the freeboard deck in way of the trunk, except small access openings;
(3) Have hatchway coamings and covers that meet §§ 45.143 through 45.147;
(4) Provide a permanent working platform fore and aft with guardrails;
(5) Provide fore and aft access between detached trunks and superstructures by permanent gangways;
(6) Be at least 60 percent of the breadth of the ship in way of the trunk; and
(7) Be at least 0.6 *L* in length, if no superstructure, is provided.