Lloyd’s Register (LR), HD Hyundai Heavy Industries (HHI) and GTT have launched a joint project to develop a 150,000-cbm ultra-large ethane carrier (ULEC). The new concept will incorporate GTT’s Mark III Slim cargo containment system. According to the partners, it will be the largest vessel design in the ethane carrier segment. The joint development project (JDP) was announced at Gastech 2026 in Bangkok. Larger vessel for growing ethane trade The project responds to growing ethane trade volumes and increasing demand for more efficient transportation. A larger vessel could carry greater cargo volumes and improve voyage economics. At the same time, the partners aim to maintain high safety, operational and efficiency standards. HHI will contribute its shipbuilding and vessel design expertise. GTT will provide its cargo containment technology, while LR will provide classification and technical assurance. LR will also review the vessel design against its rules. Project to assess 150,000-cbm design The partners will examine the technical challenges of increasing ethane carrier capacity to 150,000 cbm. The work will focus on vessel design and cargo containment integration. Safety and compliance with classification and regulatory requirements will also form part of the assessment. “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,” said Constantinos Chaelis, Global Gas Segment Director, LR. Mark III Slim incorporated into vessel HHI said the 150,000-cbm design incorporating Mark III Slim is expected to reduce vessel weight and improve performance. “This JDP is founded on the same design philosophy and aims to introduce a new solution that enhances both vessel performance and economic efficiency,” said Hongryeul Ryu, Chief Technology Officer, HHI. GTT also highlighted the potential benefits of its cargo containment technology. “With Ma