bound4blue receives DNV Type Approval for most powerful installed eSAIL

bound4blue has received Type Approval Design Certification (TADC) from DNV for its Model 3-24 eSAIL®, the company’s largest and most powerful installed suction sail. The approval, formally presented during a handover ceremony at last week’s Posidonia in Athens, confirms the system’s compliance with DNV’s rigorous and well-established classification requirements for safety, structural integrity, and design robustness.

bound4blue’s Model 3 range is designed for larger vessels and projects looking to maximise the possible propulsive contribution from wind power. Units range from 24 metres to 36 metres in height. The Model 3-24 is the first of the new design to be installed, with two units fitted on the DNV classed Klaveness Combination Carriers newbuild MV Baltazar in April. With an expanded sail surface area and optimised aerodynamic profile, the system maximises lift generation, enabling shipowners to achieve greater fuel savings and emissions reductions across a wide range of vessel types.

“Achieving Type Approval from DNV for our most advanced installed eSAIL® is an important step forward, both for us and shipowners looking to harness optimal benefits from wind propulsion,” says José Miguel Bermúdez (pictured, left), CEO and co-founder of bound4blue. “Independent validation from a leading classification society like DNV confirms that the technology meets relevant standards for reliability and performance.”

Commenting on the TADC, Cristina Saenz de Santa Maria (right), CEO of DNV Maritime, says: “At DNV, we are committed to supporting the maritime industry in navigating the energy transition, and we are pleased to award this Type Approval to bound4blue, as it expands the range of technical solutions available to the industry.”

“We’re now beginning to see the next generation of WAPS units. One of the key enablers of these developments is the parallel evolution of technical standards, which have been a vital part of building acceptance in the market. This means working closely with technology providers to assess new solutions against independent technical standards, and we look forward to further collaboration in this area.”

Built on bound4blue’s established Model 2 platform, the new 3-24 eSAIL® features a wider chord and increased sail surface area compared to earlier designs. This enables enhanced aerodynamic efficiency and higher propulsion output, while maintaining the system’s ease of integration, with limited additional system complexity, such as tilting mechanisms.

With fully autonomous operation, eSAILs® utilise boundary layer suction technology, drawing air across an aerodynamically optimised surface to generate propulsive force and reduce main engine fuel consumption and CO2 emissions. This supports both cost reductions and regulatory compliance, including frameworks such as FuelEU Maritime and the EU Emissions Trading System (EU ETS), as well as contributing directly to Carbon Intensity Indicator (CII) ratings and compliance with EEXI requirements.