bound4blue has received Type Approval Design Certification (TADC) from DNV for its Model 3-24 eSAIL, with the certification formally presented during a handover ceremony at Posidonia 2026 in Athens.
The Model 3-24 sits in bound4blue’s Model 3 range for larger vessels, and the company says the new design is intended to maximize wind power’s propulsive contribution.
What DNV’s TADC certifies for the Model 3-24 eSAIL
DNV’s approval confirms the Model 3-24 eSAIL’s compliance with DNV classification requirements covering safety, structural integrity, and design robustness.
Where the Model 3-24 is installed first
bound4blue says the Model 3-24 is the first of the new Model 3 design to be installed. Two units have been fitted on the DNV classed Klaveness Combination Carriers newbuild MV Baltazar, with those units installed in April.
Design features: expanded sail area and boundary layer suction
The Model 3-24 system has an expanded sail surface area and an optimized aerodynamic profile, built on bound4blue’s Model 2 platform. Compared with earlier designs, the company says the Model 3-24 features a wider chord and increased sail surface area.
bound4blue describes the eSAILs as fully autonomous systems that use boundary layer suction technology to draw air across an aerodynamically optimized surface to generate propulsive force. The company also describes the boundary layer suction technology as intended to reduce main engine fuel consumption and CO2 emissions, and as designed for limited additional system complexity such as tilting mechanisms.
Commercial and compliance positioning for shipowners
bound4blue says its Model 3 range units span from 24 meters to 36 meters in height, and frames the design change as enabling enhanced aerodynamic efficiency and higher propulsion output while maintaining ease of integration.
The company links the system’s emissions reductions to regulatory compliance, including FuelEU Maritime and the EU Emissions Trading System (EU ETS), and says it contributes directly to Carbon Intensity Indicator (CII) ratings and compliance with EEXI requirements. It also describes wind propulsion as increasingly used for retrofit and newbuild decarbonization strategies, with the fully autonomous systems positioned as plug-and-play alongside conventional propulsion and supporting future fuels such as methanol and ammonia.