Coast Guard issues design criteria guidance for LNG fuel systems

The following is the text of a blog on Coast Guard Maritime Commons:

(WASHINGTON) — On July 12, the Office of Design and Engineering Standards (CG-ENG) issued Change 1 to Policy Letter 01-12, Equivalency Determination – Design Criteria for Natural Gas Fuel Systems, which uses the International Code of Safety for Ships Using Gases or Other Low-Flashpoint Fuels (IGF Code) as a basis for allowing the installation of liquefied natural gas (LNG) fuel systems on U.S.-flag vessels.

The use of natural gas as a shipboard propulsion fuel is a leading alternative to traditional oil fuels for meeting domestic and international air emission requirements. However, since LNG is relatively new as a marine fuel in the U.S., there are no federal regulations to address the safe design of shipboard LNG-fueled systems.

Policy Letter 01-12 was first issued in April 2012 to provide a streamlined approach for establishing equivalency under the Code of Federal Regulations, using interim guidelines published by International Maritime Organization (IMO) during development of the IGF Code as a baseline standard.

The IGF Code became effective Jan. 1, 2017, and provides substantive improvements over the earlier interim guidelines, including: revised terminology for clarity in fuel containment system design; a well-defined approach for considering alternatives; clarification on risk assessment requirements; new options for protective tank locations; and an expanded section on LNG fuel bunkering.

The improvements adopted by the IGF Code reflect a better understanding of the rapidly evolving nature of new fuel technologies, and continued reliance on what is now an outdated standard is no longer warranted. Therefore, this policy letter update uses the IGF Code as a baseline standard for vessels using LNG fuel as an alternative to those fuel systems covered by current domestic regulations.

To view the policy letter, click here.

By Professional Mariner Staff