SolidSail
SolidSail, sometimes referred to as Solid Sail or SolidSail Mast Factory in reference to the eponymous subsidiary, is a wind propulsion technology designed for large vessels, developed by Chantiers de l'Atlantique in Saint-Nazaire, France. This innovative system is based on rigid sails made of composite materials and a tilting gaff rigging, enabling hybrid or primary wind propulsion for commercial and cruise ships. It is also the name of the subsidiary created by Chantiers de l'Atlantique in 2023.
Three SolidSail units are currently used for the propulsion systems of the longest sailing ship ever constructed, the Orient Express Corinthian, which is able to rely exclusively on its wind-powered propulsion in optimal conditions.
History
Project genesis
The development of SolidSail is part of the Ecorizon program, launched in 2007 by Chantiers de l'Atlantique and dedicated to energy and environmental efficiency for ships. After preliminary studies, a first sailing concept ship named Eoseas was presented in 2009. It was a pentamaran passenger ship 305 meters long equipped with five masts supporting of sails, capable of sailing under wind power alone in strong winds.The technology was the subject of two patents filed in 2009 and 2017. The project accelerated in 2014 with research and development funding from ADEME as part of the Future Investment Program. The project was led by engineer and former sailor Nicolas Abiven.
Technological development
Between 2016 and 2019, a series of tests conducted in various conditions confirmed the viability of the concept. Chantiers de l'Atlantique then embarked on the development of an adapted rigging system, resulting in 2019 in a solution known as Solid Sail/AeolDrive.The SOLID SAIL 2.0 research program, conducted between 2018 and 2020 by ENSTA Bretagne in collaboration with Chantiers de l'Atlantique, G-Sea Design, and Multiplast, created a fluid-structure calculation chain to precisely dimension the composites and optimize the sail geometry. This Breton consortium, certified by the Pôle Mer Bretagne Atlantique and the EMC2 cluster, brought together four main partners and five subcontractors for a total budget of €994,000. The program was co-financed by the European Union and the Brittany Region. The work, coordinated by Alain Nême, resulted in the creation of a predictive numerical model validated by tests on a 1/5th scale prototype, both on ENSTA's MASMECA platform and in Pornichet.
The results of this work were published in January 2022 in the international journal Ocean Engineering under the title "Efficient jib-mainsail fluid-structure interaction modelling – Validations with semi-rigid sails experiments" by Antoine Morvan, Matthieu Sacher, Alain Nême, Jean-Baptiste Leroux, and Christian Jochum from the Institut de Recherche Dupuy de Lôme, as well as Nicolas Abiven from Chantiers de l'Atlantique.
A second research program, called JIB SEA, succeeded SOLID SAIL 2.0 and ran for 18 months until December 2021. It aimed to finalize the full-scale design model by taking into account additional parameters such as the influence of the jib on forces transmitted through the mainsail and UV aging. ENSTA Bretagne contributed experimental expertise and extensive knowledge on fluid-structure interactions, enabling modeling of stresses experienced by rigid panels forming the sail to predict deformations and propulsion forces.
Testing program
Validation of SolidSail technology took place in several successive phases. A first 1/10th scale prototype with a surface area of was tested in 2016 on a small J/80 sailboat in Pornichet Bay. The following year, in 2017, the upper half of the sail at 1/2 scale was tested on Jean Le Cam's 60-foot IMOCA monohull. These tests achieved 85% of the boat's speed capacity, a result considered positive given the sail's weight.Between 2018 and 2019, the 88-meter three-masted vessel Le Ponant operated by Ponant was equipped with a 1/2 scale prototype with a surface area of on its foremast during its technical stop in Marseille on 25 October 2018. The ship tested this sail for one year during transatlantic crossings to the Caribbean and Cuba, under various operating conditions. Jean Emmanuel Sauvée, president of Ponant, stated: "When Chantiers de l'Atlantique proposed collaborating with us on this rigid sail technology, we were immediately interested. Le Ponant, our historic sailing ship and the company's origin, remains more than ever a flagship of our fleet, and wind propulsion is undoubtedly an energy of the future."
Simultaneously, a 1/5th scale prototype was installed and tested for two years on a jetty in Pornichet port. These tests validated the numerical models developed by ENSTA Bretagne.
Full-scale demonstrator
In February 2022, a full-scale prototype was installed at the Chantiers de l'Atlantique site in Saint-Nazaire. This demonstrator, costing €18 million with 50% public funding, comprised a 66-meter composite mast and a rigid sail composed of ten panels that fold onto each other. The assembly weighed approximately 20 tonnes and constituted one of the world's tallest self-supporting composite masts. The mast was assembled in less than six months, showcasing French expertise in composites.The demonstrator was tested for over two years before being dismantled during the night of 24–25 April 2024. It was then installed on the first sailing cargo ship of the Nantes-based shipowner Neoline, the Neoliner Origin, a 136-meter vessel under construction at the RMK Marine shipyard in Turkey.
In March 2022, the SolidSail/AeolDrive system received an Approval in Principle from Bureau Veritas, a French classification society. This validation was issued in accordance with Bureau Veritas technical rule NR 206 relating to Wind Propulsion Systems, published in 2021. Frédéric Grizaud, Senior Vice President of Chantiers de l'Atlantique, emphasized that "the Solid Sail concept is the first of its kind, and constitutes the most advanced and innovative wind propulsion solution on the large ship market."
Industrialization
In May 2023, Chantiers de l'Atlantique announced the creation of SolidSail Mast Factory , a dedicated company bringing together six industrial partners with equal shares: Chantiers de l'Atlantique, Avel Robotics, CDK Technologies, Lorima, Multiplast, and SMM Technologies. This factory, located in the Rohu zone in Lanester, required an investment of approximately €20 million financed by the shareholder companies.The factory gradually entered operation starting in spring 2024, with a machining robot delivered by Savoyard company CRENO in March, followed by a second robotic draping machine designed by Fives Machining at the end of July 2024. The latter uses customized Atlas head technology to enable series production of 65-meter carbon masts with a diameter of approximately 3 meters.
The manufacturing process is considerably simplified compared to the initial artisanal method. Only two half-shells each the length of the mast are now produced, compared to six half-shells forming three sections previously. Draping, which was 98% manual for the first masts, is now 95% automated by robot at SMAF. At cruising speed, the factory should produce ten to twelve masts per year, with a 40% reduction in production costs compared to the prototype.
Technical description
General concept
SolidSail technology is based on a semi-rigid sail consisting of rectangular panels made of composite materials assembled together. Unlike traditional textile sails, this design enables very large sail areas to be achieved, up to per rigging units, while maintaining the structural strength necessary for navigation on large vessels. This option pushes the limits for deployed sail area, as conventional sails are much more fragile beyond a certain threshold.Sail structure
SolidSail sails consist of composite panels framed by carbon battens forming a rigid structure. The inner membrane is made of thin fiberglass and epoxy. This panel construction allows accordion-style folding, facilitating sail storage and deployment. The panels fold onto each other without requiring external action and without flapping, which is essential for safety on very large surfaces.This design gives SolidSail ten times the resistance of conventional sails, with an estimated lifespan of 20 to 25 years, approximately five times that of a fabric sail of equivalent dimensions.
AeolDrive rigging
The SolidSail system relies on a specific rigging called AeolDrive, also developed by Chantiers de l'Atlantique. This system includes carbon composite masts that can reach 85 to 100 meters in height depending on the version. The mast is mounted on a 360° rotating steel gaff allowing navigation optimization regardless of wind direction. It also has a 70° tilt capability to reduce air draft and allow passage under bridges, particularly in New York where bridges reach 54 meters.File:Le navire Orient Express Corinthian avec ses trois mâts SolidSail à quai aux Chantiers de Saint-Nazaire.jpg|thumb|The Orient Express Corinthian with its three SolidSail masts at the Chantiers de l'Atlantique
File:Neoliner Origin with the Pont de Saint-Nazaire.jpg|thumb|On the right of the image, the two SolidSail masts of Neoliner Origin in tilted-down position with the Saint-Nazaire Bridge
The rigging is fully automated and secured up to 40-knot winds. Sail deployment takes seven minutes, while lowering requires only five minutes. With the EolSide system, it is possible to dissociate wind direction from vessel trajectory, offering great navigation flexibility.