USCG: Updated guideline for towing vessel stability compliance

The United States Coast Guard Marine Safety Center updated its Design Verification Guideline DVG H1-18 regarding the general arrangement plans for towing vessels.

This document was published on 4 June 2024.

Purpose: The Design Verification Guideline (DVG) serves to provide comprehensive guidance and information to the marine industry regarding the verification of stability compliance for towing vessels certified under 46 Subchapter M of the U.S. Coast Guard regulations. Its primary aim is to ensure that these vessels meet specific safety and operational standards related to their structural integrity and stability.

Applicability: The guideline applies to general arrangement plans of towing vessels that either had their keel laid on or after July 20, 2017, or underwent a major conversion after that date. It clarifies that while the Marine Safety Center (MSC) can review these plans, owners have the option to pursue plan verification through three specified sources:

• A registered professional engineer (P.E.) licensed by a U.S. state or the District of Columbia.
• An authorized classification society delegated with issuing the SOLAS Cargo Ship Safety Construction Certificate under 46 CFR 8.320.
• Directly with the U.S. Coast Guard.

References: The guideline cites specific regulatory references that must be adhered to during the verification process. These include:

• 46 CFR 144 for Construction and Arrangement.
• Marine Safety Manual (MSM) Volumes II & IV.
• ABS Rules for Building and Classing Steel Vessels for Service on Rivers and Intracoastal Waterways.
• ABS Rules for Building and Classing Steel Vessels Under 90 Meters (295 feet) in Length.

Submittal Checklist: A detailed checklist is provided to ensure that the submittal package for general arrangement plans includes essential documents such as a letter of intent, application for inspection, outboard and inboard profiles, and deck arrangements. These plans must sufficiently detail compliance with the requirements of 46 CFR Subchapter M for independent verification.

General Review Guidance: The guideline outlines specific compliance requirements under Subchapter M, focusing on:

• General and Structural Fire Protection.
• Escape Requirements including means of escape for crew and passengers.
• Crew Spaces and accommodations.
• Rails and Guards for crew safety.
• Window Construction and Visibility ensuring safe operation and navigation.
• Watertight or weathertight integrity of the vessel.
• Collision Bulkhead specifications for structural safety.

Special Consideration: It acknowledges that in certain circumstances where unusual arrangements or conditions warrant, the Officer in Charge, Marine Inspection (OCMI) may authorize departures from specific Subchapter M requirements. This is contingent upon maintaining an equivalent level of safety.

Disclaimer: The guideline clarifies that it does not substitute applicable legal requirements nor does it impose legally-binding obligations. It represents the Coast Guard's current guidance and assists various stakeholders—industry, mariners, the public, and regulators—in applying statutory and regulatory requirements effectively.

For more information, please see the document below (available only to subscribers):

General Arrangement Plans for Towing Vessels