With development made in technologies and the important growth of US liquefied gas export markets, US Coast Guard examiners are seeing a new trend on ships carrying liquefied petroleum gas (LPG) and ethane. Namely, these vessels are using their cargoes as fuel during ocean transits.

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The use of cargoes other than methane as fuel is allowed in international waters under the International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk, 2016 Edition (2016 IGC Code), Chapter 16. However, US regulations in 46 CFR 154 have not established appropriate standards for use while the ship is in the navigable waters of the US.

The use of methane as a fuel is addressed in 46 CFR 154.703 and was first intended to a means to control cargo pressure within the cargo tanks. Now, various liquefied gas cargoes are being used as marine fuel, in order to comply with the established ECA standards.

Due to the fact that US regulations are silent on the use of alternate gases as marine fuel on liquefied gas carriers, USCG encourages operators of gas carriers aiming to use cargoes other than methane as fuel in US navigable waters, as defined in 33 CFR 2.36, to seek approval of Commandant. Specifically, each individual vessel must request approval, according to 46 CFR 154.32.

In addition, the US Coast Guard's Hazardous Materials Division (CG-ENG-5) will consider requests to use cargoes other than methane as fuel on a case-by-case basis. To request approval to burn alternate cargoes as fuel in US waters, the owner/operator must send the following information to CG‑ENG-5:

  • International Certificate of Fitness for the IGC Code;
  • Certification by the vessel’s Flag State accepting the use of an alternate cargo as fuel in accordance with the 2016 IGC Code;
  • An attestation from the vessel’s Classification Society confirming the vessel has been built according to the applicable 46 CFR 154 requirements;
  • An attestation from the vessel’s Classification Society confirming the vessel complies with the 2016 IGC Code for use of an alternate cargo as fuel.

When the documents are received, CG-ENG-5 will evaluate the submission and, upon satisfaction that equivalent levels of safety have been achieved, it will issue a letter allowing the ship to use the alternate cargo as fuel in US waters.

Vessels should keep a copy of the letter on board.