HD Hyundai Heavy Industries, GTT and LR have launched a joint project to develop a 150,000 cbm ultra-large ethane carrier, exploring the next step in large-scale ethane transportation.

Lloyd’s Register, HD Hyundai Heavy Industries and GTT have signed a joint development project agreement to develop and technically assess a 150,000 cbm ultra-large ethane carrier , incorporating GTT’s Mark III Slim design.

Announced at Gastech 2026 in Bangkok, the project will bring together HHI’s shipbuilding expertise, GTT’s cargo containment technology and LR’s classification and technical assurance capabilities to develop and review the vessel design in accordance with LR Rules.

The 150,000 cbm ULEC concept is the largest vessel design for the ethane carrier segment. As ethane trade volumes continue to grow and voyage economics become an increasingly important consideration for operators, the industry is exploring larger vessel concepts capable of transporting greater cargo volumes while maintaining high standards of safety, operability and efficiency.

Through the JDP, the partners will evaluate the technical challenges and opportunities associated with scaling ethane carrier capacity to 150,000 cbm. The project will focus on vessel design development, cargo containment integration, safety considerations and compliance with applicable classification and regulatory requirements.

The collaboration aims to establish a robust technical foundation for future ultra-large ethane carrier projects while providing greater understanding of the design, operational and safety considerations associated with vessels of this scale.

Constantinos Chaelis, Global Gas Segment Director, LR, said: “As the ethane trade expands, owners are looking for larger and more efficient vessel concepts that can deliver operational and commercial advantages without compromising safety or reliability.

“This collaboration provides an opportunity to apply our advanced gas carrier expertise to the development of a credible and technically robust 150,000 cbm ULEC concept that helps establish a clear technical pathway for future projects in this segment.”

Hongryeul Ryu, Chief Technology Officer, HHI, said : “HHI has continuously pursued technological innovation, with optimized ship designs tailored to operating conditions and customer requirements serving as one of its core design values.

“This JDP is founded on the same design philosophy and aims to introduce a new solution that enhances both vessel performance and economic efficiency.

“HHI’s 150,000 cbm ULEC, incorporating the MARK III SLIM design, is expected to become a next-generation vessel that achieves both weight reduction and improved performance. Furthermore, this project is anticipated to represent an important milestone in establishing a new paradigm for ship design through the application of the latest cargo containment system (CCS).”

François Michel, Chief Executive Officer, GTT, said: “Thanks to the versatility of our technologies, we can deliver greater efficiency across ethane transportation. With Mark III Slim, this translates into increased cargo capacity and shorter vessel construction times. GTT, HD Hyundai Heavy Industries and Lloyd’s Register share the ambition and responsibility to advance a new generation of increasingly efficient vessels that maintain the same rigorous standards of safety, reliability and industrial compliance.”