bound4blue installs eSAIL® wind propulsion systems on Maersk Trieste under Maersk Tankers agreement

Spanish wind propulsion technology provider bound4blue has completed the first installation phase of its agreement with Maersk Tankers, with four eSAIL® suction sails installed on board the medium-range tanker Maersk Trieste.

The installation marks the initial delivery under a December 2024 contract covering a total of 20 eSAIL® units to be fitted across five advanced MR tankers. The deal represents bound4blue’s largest commercial order to date.

Each of the installed units measures 24 metres in height and uses bound4blue’s autonomous suction sail technology. The eSAIL® system generates aerodynamic lift by drawing air across an optimised surface, enabling higher lift performance compared with conventional rigid sails of similar dimensions.

The Maersk Trieste retrofit followed a two-stage installation process designed to reduce vessel downtime. Preparatory “wind-ready” work, including deck pedestal installation and electrical modifications, was carried out at Yiu Lian Shipyard in Shenzhen, China. Final installation was completed at EDR Shipyard, where the sails were lifted into place, secured to pre-installed foundations and connected to onboard power and data systems using a plug-and-play approach.

System integration was supported by marine system integrator Njord.

According to bound4blue, the eSAIL® systems are configured for individual vessel profiles and are designed to deliver double-digit reductions in fuel consumption and CO₂ emissions, while improving a vessel’s Carbon Intensity Indicator (CII) rating. The systems can also generate regulatory and cost benefits under frameworks such as FuelEU Maritime, through the Wind Reward Factor, and under EEDI and EEXI requirements.

bound4blue’s technology has received type approval from DNV and is designed for installation on both newbuilds and retrofit projects across multiple vessel types, including tankers, bulk carriers, Ro-Ros, cruise vessels, ferries and gas carriers.

José Miguel Bermúdez, CEO and co-founder of bound4blue, said the installation represents an important step in scaling wind propulsion within the tanker segment.

“Our system was designed from day one to deliver maximum performance with minimum complexity,” Bermúdez said. “That’s especially important for scaling up installations within segments that present specific integration challenges, such as tankers.”

He added that the design allows tankers to benefit from wind-assisted propulsion without altering operational profiles, including avoiding tilting systems and retaining a normal operational air draft.

Commenting on the project, Claus Grønborg, Chief Investment Officer at Maersk Tankers, said:
“For the tanker industry, progress on emissions reduction requires concrete investments and implementation. At Maersk Tankers, we focus on deploying advanced energy-efficient technologies to reduce fuel consumption and CO₂ emissions. Implementing Wind-Assisted Propulsion Systems at scale enables more energy-efficient voyages for our customers, while supporting compliance with FuelEU Maritime and the EU Emissions Trading System.”