News / Green credentials of innovative 'e-sail' cargo ship to be unveiled at SMM

A general cargo vessel fitted with rear-mounted ‘e-sails’ – the 2,850dwt Eems Traveller – may provide an avenue for using wind power on shortsea container services.

Developer bound4blue’s tubular e-sails, sometimes referred to as ‘suction sails’, expel air through a rotor at the top, generating an internal vacuum causing a layer of airflow to adhere to the sail’s outer surface, akin to an aircraft wing. This allows a much smaller sail to generate similar thrust to a conventional sail.

The sail is mounted at the rear of the ship, above and away from the cargo deck, and allows propulsion to be supported by wind power without the cargo blocking the breeze.

Operated by the Netherlands-based Amasus Shipping, the Eems Traveller will be calling at the port of Hamburg for next week’s SMM shipping trade fair.

“Operations to date have delivered a wealth of in-depth data to demonstrate their tangible environmental impact,” said bound4blue CTO David Ferrer. “We look forward to sharing our findings at SMM.

“In addition to our own testing and validation, Lloyd’s Register has now also been tasked with conducting a third-party evaluation to verify achieved performance and savings.

“Given the impact of regulations such as EU ETS, CII and the upcoming FuelEU Maritime move, I can’t think of a better time to push wind power up the shipping agenda,” he added.

Though a number of designs have been proposed for wind-powered containerships, they have generally relied on outboard options such as kite sails, which, while effective, have been deemed too finicky and accident-prone to work. Another idea, a radical Hapag-Lloyd design, features folding sail devices inside fairings located between container stacks.

Meanwhile, a modern tall-sail cargo vessel operated by France’s TOWT Maritime, the Anemos, embarked on its maiden voyage this month. But it came in for criticism after apparently using its engines for more than 30% of the voyage, making it a higher-CO2 emitter than a voyage by a conventional containership.

According to Roar Adland, SSY’s global head of research: “The champagne and cognac producers [TOWT customers] have scored a 40% increase in emissions – but priceless ‘zero-carbon’ marketing.”

And Dr Adland told The Loadstar: “This is very much a ‘back of the envelope’ calculation.”