HD Hyundai, GTT and LR Develop 150,000 cbm Ultra-Large Ethane Carrier

HD Hyundai Heavy Industries (HHI), GTT and Lloyd’s Register (LR) have launched a joint development project (JDP) to develop and technically assess a 150,000 cbm ultra-large ethane carrier (ULEC), incorporating GTT’s Mark III Slim cargo containment system.

The agreement was announced at Gastech 2026 in Bangkok and brings together HHI’s shipbuilding capabilities, GTT’s cargo containment technology and LR’s classification and technical assurance expertise.

The project will assess the vessel design against LR Rules and examine the technical requirements associated with scaling ethane carrier capacity to 150,000 cbm.

Project targets larger-scale ethane transportation

The proposed 150,000 cbm ULEC represents the largest vessel concept currently designed for the ethane carrier segment. Growing ethane trade volumes and increasing focus on voyage economics are prompting the industry to examine larger vessels capable of transporting higher cargo volumes while maintaining safety, operability and efficiency.

Under the JDP, HHI, GTT and LR will assess the technical challenges and opportunities associated with developing the larger-capacity vessel.

The work will cover vessel design, integration of the cargo containment system, safety considerations and compliance with applicable classification and regulatory requirements.

The partners aim to establish a technical basis for future ultra-large ethane carrier projects and build greater understanding of the operational and safety considerations involved in vessels of this scale.

Mark III Slim cargo containment system

The ULEC concept will incorporate GTT’s Mark III Slim design. The partners will assess how the latest cargo containment technology can be integrated into the larger vessel concept.

Constantinos Chaelis, Global Gas Segment Director at 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 at 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 at 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.”

Technical assessment to support future ULECs

The JDP will provide a framework for evaluating the design, cargo containment integration and regulatory requirements of a 150,000 cbm ethane carrier.

The project comes as the ethane shipping market considers larger vessel configurations to support growing cargo volumes and improve transport economics. Its findings are expected to provide technical insights into the feasibility and requirements of scaling up ethane carrier designs.