At the Posidonia 2026 exhibition, Lloyd’s Register (LR), K Shipbuilding, bound4blue, and the Liberian Registry signed a milestone MoU to develop a next-generation 50,000 DWT wind-assisted MR tanker. The project will integrate bound4blue’s autonomous eSAIL® suction technology to harness wind energy and deliver direct aerodynamic thrust, substantially lowering fuel burn and emissions. By combining top-tier class, flag, shipyard, and engineering expertise, this joint initiative establishes a validated, safe, and commercially viable blueprint for wind-assisted propulsion across the global liquid bulk market.
Athens | June 4, 2026 – In a major development at the Posidonia 2026 international shipping exhibition, a powerful quadrilateral alliance has formed to reshape the medium-range (MR) tanker market through wind power. Lloyd’s Register (LR), South Korean shipyard K Shipbuilding, Spanish wind-propulsion pioneer bound4blue, and the Liberian International Ship & Corporate Registry (LISCR) have signed a landmark Memorandum of Understanding (MoU). The objective: to jointly develop, optimize, and clear the regulatory pathway for a next-generation 50,000 DWT MR product/chemical tanker featuring Wind-Assisted Propulsion Systems (WAPS).
By uniting a top-tier class society, a leading mid-sized shipbuilder, an innovative technology vendor, and the world’s largest open shipping registry, the joint development project (JDP) aims to strip away the commercial and regulatory uncertainties that have slowed the adoption of wind technology on liquid bulk carriers.
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The Technology: Harnessing bound4blue’s eSAIL® Suction Technology
At the core of the new 50,000 DWT hull design is the integration of bound4blue’s proprietary eSAIL® system. Moving far beyond traditional sails or basic rotor technologies, the eSAIL® utilizes suction sail mechanics (a derivative of the boundary-layer suction aerodynamics pioneered by aircraft designers).
How Suction Sails Generate High Aerodynamic Lift
- Symmetrical Airfoil profile: The eSAIL® is a vertical, thick aerodynamic tower. When wind hits the structure, it naturally generates lift, but traditional airfoils suffer from aerodynamic “stalling” at steep angles, which limits their effectiveness.
- Boundary-Layer Suction: The system utilizes an internal fan to draw in the boundary layer of air through a porous strip on the tail-end of the sail.
- Super-Lift Generation: By sucking in this turbulent air layer, the airflow is forced to remain tightly adhered to the sail’s surface. This re-adhesion eliminates flow separation, generating up to six times more lift than a conventional airplane wing, which translates directly into massive forward thrust for the tanker.
De-Risking the Tanker Segment
Integrating towering vertical structures onto a product tanker deck introduces severe engineering complexities, including blind spots in navigation bridge visibility, interference with cargo manifold crane operations, and explosive-atmosphere ($Ex$-zone) safety regulations.
The JDP will map out an optimal deck layout to ensure the eSAILs® deliver maximum fuel savings without compromising safety during high-stress cargo loading and discharging operations.
Technical Validation and Regulatory Alignment
A primary roadblock for WAPS adoption has been the lack of unified regulatory precedents. Under the signed agreement, each partner will execute a highly specific role to push the design toward a formal Approval in Principle (AiP):
- K Shipbuilding will lead the hull optimization, structural deck reinforcements, and naval architecture modifications required to handle the severe overturning moments (heeling forces) caused by aerodynamic lift.
- bound4blue will provide the complete hardware-software interface, ensuring the autonomous sails automatically rotate to track changing wind angles without requiring extra crew labor.
- Lloyd’s Register will deliver the baseline technical assurance, evaluating the structural integrity, stability criteria, and safety interfaces against the latest LR class rules and International Maritime Organization (IMO) mandates.
- The Liberian Registry (LISCR) will work concurrently to ensure the wind-assisted tanker aligns seamlessly with Flag State statutory regulations, safety of life at sea (SOLAS) conventions, and international load line rules.
Fleet Economics: Navigating EEXI and CII Compliance
The economic incentive for wind assistance has intensified dramatically in 2026 as the maritime sector faces increasingly punitive emissions regulations. For an MR tanker, incorporating a high-efficiency WAPS setup offers an immediate drop in fuel consumption, protecting shipowners from volatile bunker price spreads.
From a regulatory standpoint, the fuel-saving metrics derived from the eSAIL® system will directly optimize two critical regulatory benchmarks:
1. Energy Efficiency Existing Ship Index (EEXI)
The direct aerodynamic thrust reduces the power demand placed on the main two-stroke engine, allowing the vessel to lower its calculated carbon footprint per capacity-mile.
2. Carbon Intensity Indicator (CII)
Because WAPS provides a continuous source of zero-emission propulsion while underway, it offsets daily fuel burn, enabling older or conventionally fueled MR tankers to maintain a compliant CII rating (A, B, or C) and escape the commercial penalties associated with D or E grading.
Executive Perspectives from Posidonia
“This agreement reflects LR’s continued focus on enabling maritime decarbonisation through practical, scalable solutions. By supporting the development of next-generation tanker designs, we are helping shipowners and operators navigate the transition to lower-carbon operations while maintaining commercial viability.” said, Alberto Pérez, Head of Maritime Commercial Markets, Lloyd’s Register
“As demand for sustainable shipping solutions continues to grow, this MoU will further strengthen our capabilities in eco-friendly ship technology development and enhance our competitiveness in the global MR tanker market.” said, Tae-Hyun Koh, Chief Technology Officer, K Shipbuilding
“For shipyards, wind propulsion is becoming an important part of future-ready vessel design, especially in segments such as MR tankers. By bringing our experience and know-how to this Joint Development Project, we can help define how the eSAIL® system can be integrated into MR tanker newbuild designs in a safe, practical and commercially competitive way.” said, Daniel Mann, Chief Commercial Officer, bound4blue
“This project marks an important step in advancing practical decarbonisation for the tanker segment. Integrating wind-assisted propulsion on MR tankers can reduce emissions while strengthening the sustainability and competitiveness of global shipping, and thereby we are helping to unlock immediate fuel savings and emissions reductions while strengthening long-term regulatory compliance.” said, Thomas Klenum, Executive Vice President, Liberian Registry
About the Partners
About Lloyd’s Register (LR)
With a legacy spanning over 260 years as the world’s first marine classification society, Lloyd’s Register is a premier global professional services group specializing in marine engineering, technology, and compliance solutions. Owned entirely by the politically and financially independent Lloyd’s Register Foundation, LR supports fleet performance across 30,000 vessels globally through its advisory arms and advanced digital platforms like OneOcean.
About K Shipbuilding
Headquartered in Changwon, South Korea, K Shipbuilding is a premier mid-sized shipbuilder established in 1967. Having delivered more than 700 vessels worldwide, the shipyard possesses elite expertise in constructing high-performance chemical/product tankers, gas carriers, and container ships. The company is actively focusing on modernizing its portfolio with next-generation, eco-friendly hull architectures.
About the Liberian Registry (LISCR)
Managing over 17% of the world’s ocean-going commercial fleet, the Liberian Registry encompasses more than 6,000 vessels aggregating 300 million gross tons. LISCR is internationally recognized as the world’s largest open registry, maintaining an elite track record of safety compliance while proactively supporting green maritime legislation.
About bound4blue
Founded in 2014 and headquartered in Cantabria, Spain, bound4blue is a leading developer of automated, low-maintenance wind propulsion systems. The company boasts an expansive operational fleet, with its eSAIL® system chosen by tier-one global owners including Eastern Pacific Shipping, Maersk Tankers, and Odfjell.
Source: bound4blue