FRENCH SAIL SYSTEM MOVES UP A GEAR

Prototypes of the Solid Sail/AeolDrive solution developed by Chantiers de l’Atlantique are to be installed and tested at the Saint-Nazaire shipyard, as the precursor to marketing in the cruiseship sector and other fields.

Originating in the Ecorizon R&D programme implemented 13 years ago, and encapsulating the company’s strategic move to production of ‘low-emission’ and ultimately ‘zero-emission’ newbuilds, the system is based on huge sails made of rectangular, long-life composite panels.

The schedule for the on-site installation is split into two phases. The initial step will be the emplacement of a 38m-tall mast with a 550m² sail area during the autumn of 2021, to be followed a year later by a full-scale model standing 95m and bearing 1,200m² of foldable, Solid Sail. The centrepiece of the whole is the AeolDrive rigging and 70 degree-tiltable mast, combined with a balestron allowing rotation through 360 degrees.

A system of force and position sensors will enable the aerodynamic and kinematic performance of the assembly to be evaluated while monitoring the stress levels in the mechanical elements.

The new test sails follow work carried out until the end of 2019 with a 1/5 scale prototype demonstrator equipped with a 50m² Solid Sail mounted on a scaled-down 15m mast and balestron, fitted on a pier in the harbour of Pornichet, just west of Saint-Nazaire. Previous phases in the development and testing process entailed seagoing trials on, firstly, an 18m racing yacht and, subsequently, on a 90m sail-equipped, luxury cruiseship of the Ponant fleet making transatlantic crossings.

The shipbuilder indicated that the Solid Sail/AeolDrive could have its first commercial application on a 200m cruise vessel newbuild, where it would supplement a dual-fuel engine propulsion system. The arrangements would reduce greenhouse gas emissions by more than 50% relative to more conventional powering arrangements. In 2018, Chantiers de l’Atlantique proposed such a design series, dubbed the Silenseas sailing cruise vessels, initially in 190m and 210m versions each accommodating 300 passengers, with 4,350m² of sail on three masts. Future use on merchant ships as well as large pleasure boats is under consideration.

It is claimed that the composite Solid Sail has a lifespan five times longer than fabric sails, and can be manufactured without the size constraints inherent to the latter. The rectangular panel configuration facilitates the automatic raising and lowering of the sails.

The solution is the outcome of cooperation between Chantiers de l’Atlantique and industrial partners from the Brittany and Pays de la Loire regions. A high degree of regional, national and EU public funding has been ploughed into the programme, including support from the European Regional Development Fund (ERDF), the 2020 European Research and Innovation Programme, and the French Energy Management Agency (ADEME).

“A collective dynamic has been established around the Solid Sail/AeolDrive project, thanks to the mobilisation of many regional players… which now want to explore a new and promising market,” stated Laurent Castaing, general manager of Chantiers de l’Atlantique. “We are going to maintain this momentum so that we can move up a gear when, after the final phase of testing, we can move on to the marketing of a solution adapted to the current and future challenges of an even more environmentally-friendly navigation system.”