# POSCO and Hanwha Ocean advance high-manganese steel technology for LNG carriers

- **Source:** https://pelavox.com/posco-and-hanwha-ocean-advance-high-manganese-steel-technology-for-lng-carriers/
- **Publisher:** pelavox. (The voice of shipping)
- **Author:** Jason Nicholson
- **Published:** 2026-10-18T05:00:00+00:00
- **Updated:** 2026-10-17T11:03:55+00:00
- **Section:** Shipping / Gas Shipping
- **Type:** News
- **Topics:** Cargo Containment Systems, Hanwha Ocean, High-Manganese Steel, LNG Carriers, POSCO

POSCO and Hanwha Ocean have signed a memorandum of understanding (MOU) to advance the use of high-manganese steel in liquefied natural gas (LNG) carrier cargo tanks, marking a further step towards the commercial application of the material in large-scale maritime LNG transportation.

The agreement was signed on 15 October 2026 at Hanwha Ocean’s Geoje shipyard in South Korea.

The collaboration aims to secure a demonstration vessel equipped with high-manganese steel cargo tanks and evaluate their performance under actual operating conditions.

POSCO International and POSCO Flow will also participate in the initiative, supporting the development and operation of the demonstration project.

## Technology moves beyond LNG fuel tanks

Developed by POSCO, high-manganese steel is designed to maintain strength and impact resistance at temperatures below minus 163°C, making it suitable for cryogenic LNG storage applications.

The material has already been used in LNG fuel tanks installed aboard several types of vessels.

The latest initiative seeks to extend its application to LNG carrier cargo containment systems, which store significantly larger quantities of LNG transported as commercial cargo.

According to POSCO, an LNG-powered vessel’s fuel tank typically requires approximately 1,000 tonnes of material, while a large LNG carrier cargo containment system can require more than 10,000 tonnes.

The company considers high-manganese steel a potential alternative to conventional nickel-alloy materials, including INVAR, which are widely used in LNG cargo containment systems.

## Demonstration vessel to assess operational performance

Under the agreement, the companies intend to pursue the construction of a demonstration vessel fitted with high-manganese steel cargo tanks.

The project will focus on verifying safety, durability and operational efficiency during actual voyages.

POSCO said the technology could accommodate different boil-off rate requirements, while its structural properties are intended to improve resistance to sloshing, the movement of liquid cargo inside tanks.

The proposed independent tank configuration could also allow cargo tanks to be manufactured separately before installation aboard the vessel.

However, these potential advantages will need to be demonstrated in operational conditions before broader commercial adoption.

## Wider applications under consideration

POSCO and Hanwha Ocean have conducted joint research into high-manganese steel applications for more than a decade.

According to POSCO, the material has been installed in LNG fuel tanks and related applications across a cumulative total of 51 vessels as of 2026.

The companies also intend to explore potential applications in LNG bunkering vessels and floating storage and regasification units (FSRUs).

Longer-term development could extend to cryogenic transportation systems for other cargoes, including hydrogen, ethane and ammonia.

The MOU represents an initial step towards commercial deployment in LNG carrier cargo tanks. Neither a confirmed demonstration vessel order nor a construction timetable was disclosed.

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Cite as: "POSCO and Hanwha Ocean advance high-manganese steel technology for LNG carriers", pelavox., 18 October 2026, https://pelavox.com/posco-and-hanwha-ocean-advance-high-manganese-steel-technology-for-lng-carriers/