SUBCHAPTER M for Inland Waterways

A towing vessel is required to be in full compliance with Subchapter M in order to operate, with a valid COI issued by the Coast Guard onboard. Once a towing vessel has a COI, the vessel can operate in accordance with any limitations on the COI for a period of five years, subject to periodic inspections to maintain the COI.


Several accidents sparked the change from uninspected towing vessel into inspected towing vessel. In September 2001, a towing vessel struck a bridge at South Padre Island, TX. The bridge collapsed, and 5 people died when their cars or trucks went into the water. On May 26, 2002, a towing vessel struck the I–40 highway bridge over the Arkansas River at Webber Falls, OK. The bridge collapsed, and 14 people died when their cars or trucks went into the Arkansas River.


On July 20, 2016, the U.S. Coast Guard (USCG) published Subchapter M, which established inspection standards for towing vessels. Most towing vessel operators were required to obtain certificates of compliance under Subchapter M’s new mandates by July 20, 2018.


Subchapter M is a part of the Code of Federal Regulations (CFR), Title 46 (Shipping), Chapter I, Parts 136 to 144. The intent of Subchapter M is to provide a unified basis to inspect U.S. Flagged towing vessels that pull, push, or haul alongside, which had previously not been required to be regularly inspected by the United States Coast Guard (USCG).

A towing vessel is required to be in full compliance with Subchapter M in order to operate, with a valid COI issued by the Coast Guard onboard. Once a towing vessel has a COI, the vessel can operate in accordance with any limitations on the COI for a period of five years, subject to periodic inspections to maintain the COI.


There is a phase-in period for obtaining a COI for a towing vessel, dependent on the size of the operator’s fleet. Yearly, starting on July 20, 2018 through July 19, 2022, one quarter (25%) of each towing vessel operator’s fleet subject to Subchapter M will need to have a COI at the end of the next year. Operators with a single existing towing vessel will need to have a COI not later than July 20, 2020.

Subchapter M, Sections 136.130 and 137.202, describe the options available to a towing vessel operator for obtaining and retaining a COI. In summary, there are three means to obtain and retain a COI:


§ Have the local USCG Office(r) in Charge of Marine Inspections send a USCG inspection party (USCG Option), or


§ Have an approved Towing Safety Management System (TSMS) or equivalent, referred to as the TSMS Option and:


o Have a survey by a Third-Party Organization (TPO) or equivalent documenting the vessel condition, or


o Have a survey by internal surveyors documenting the vessel condition, audited by a TPO.


There are nine parts within Subchapter M – four deal with administrative requirements for inspection and five address specific requirements for manning, operating, equipping, and constructing towing vessels. Each Part addresses a specific set of requirements:


Part 136 – Certification This Part addresses the applicability of Subchapter M to towing vessels, how to get a certificate of inspection, and other administrative duties of the USCG.


Part 137 – Vessel Compliance This Part defines the responsibilities for compliance, inspection and surveys for certification, drydocking and internal structural surveys the type of inspections.


Part 138 – Towing Safety Management System This Part describes the elements of TSMS, certification, audits and Coast Guard oversight and review.


Part 139 – Third Party Organization The requirements for a TPO for approval to carry out surveys and audits on behalf of the USCG.


Part 140 – Operations Requirements for crew safety, vessel operational safety, navigation and communication equipment, towing safety, and vessel records.


Part 141 – Lifesaving Minimum requirements for survival crafts, lifesaving appliances, and crew training.


Part 142 – Fire Protection Minimum requirements for firefighting and fire detection and prevention onboard.


Part 143 – Machinery and Electrical Systems and Equipment Minimum requirements for mechanical or electrical equipment and systems onboard a towing vessel for propulsion, machinery spaces, towing machinery, pumps, piping, electrical control, and steering.


Part 144 – Construction and Arrangement Minimum requirements for the design, construction, and arrangement of towing vessels to comply with stability and watertight integrity requirements, fire protection, emergency escapes, ventilation, crew spaces, , and crew protection.

Consult Maritime partners with Ocean Time Marine (Australia) to assist you with compliance for ISM and mini ISM with their Safety Management System (SMS) Software / Template.


Consult Maritime partners with Ocean Time Marine (Australia) to provide vessel owners and operators with safety management system (SMS) resources and services to improve safety culture and stay safer at sea.

Consult Maritime helps you identify improvements that can be made and quantify the benefits to your operation. We work with you to implement the agreed safety solutions.