Hanwha Ocean’s design solution allowing LNG carrier’s switch to ammonia gets ABS’ thumbs-up

September 18, 2026, by Melisa Cavcic

The American Bureau of Shipping (ABS), a classification society, has handed out approval in principle (AIP) for a multi-purpose fuel tank and fuel gas supply system design that enables a liquefied natural gas (LNG) carrier (LNGC) to shift from LNG to ammonia fuel without replacing the fuel tank or fuel gas supply system (FGSS).

Photo caption (L to R): Matthew Tremblay, ABS Senior Vice President, Global Offshore Markets; Rostom Merzouki, ABS Vice President, Global Sustainability; John Ki Lim, Hanwha Ocean General Manager and Team Leader of Commercial Vessel Development team; and Dong Kwon (Duke) Lee, Hanwha Ocean Senior Vice President and Head of Basic Performance R&D Center. Courtesy of ABS

Hanwha Ocean has received ABS’ approval in principle that covers the fuel tank and integrated fuel gas supply system for an electrically propelled LNG carrier powered by a gas turbine.

According to the classification society, which reviewed the design against relevant class and international requirements, the system is designed to supply either LNG or ammonia to the gas turbine, enabling transition from LNG to ammonia fuel.

Gareth Burton, ABS Senior Vice President of Global Engineering, commented: “Fuel flexibility is a practical requirement for owners navigating an evolving regulatory environment, and the engineering challenge of achieving it without tank replacement is significant.

“This design addresses that challenge directly, and ABS is pleased to support Hanwha Ocean in verifying the concept’s feasibility against applicable requirements.”

ABS describes this approval as the latest development in a series of related projects with Hanwha Ocean, including AiP for an ammonia gas turbine propulsion system in 2023 and gas dispersion study of a 174,000 cbm LNG carrier with an ammonia gas turbine in 2024.

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Young Chang (James) Shon, CTO of Hanwha Ocean, emphasized: “Although uncertainties remain regarding implementation of environmental regulations, the maritime industry’s path toward net zero remains clear.

“Hanwha Ocean’s multi-purpose fuel design offers shipowners a practical and flexible pathway from LNG to ammonia while safeguarding long-term competitiveness. Hanwha Ocean will continue developing future-ready technologies that support sustainable shipping.”

This AiP comes months after ABS inked a memorandum of understanding (MOU) with Seatrium to advance innovation, regulatory alignment, and sustainable technologies across the maritime and offshore energy sectors.