2025
Marine
Wind Propulsion is Making a Comeback
From rigid sails to kites and rotor systems, innovative technologies are enabling ships to harness wind power to reduce fuel consumption and cut emissions. Sika, the global adhesives and sealant specialists, is playing a vital supporting role – collaborating with partners and sharing materials expertise to drive this emerging industry forward. One standout examples is the Solid Sail and Aeoldrive system, developed by renowned shipbuilders Chantiers de l’Atlantique’s in Saint Nazaire, France.
Eight Orders Secured
Originally launched to advance maritime sustainability, the project has already secured orders for eight Solid Sail rigs. Each rig will enable fuel savings of around 1,000 tonnes annually, equivalent to approximately $750,0001 and CO2 emissions of 3,200 tonnes.2 In this massive construction project, Sika is contributing with its bonding and molding expertise from prototype to regular production.
Reshaping the Soul of Maritime Travel
One glance at the 66-meter (216.5 foot) carbon fiber mast and its massive 1,500 (16,146 m2 feet) -square-meter sail rig reveals the monumental scale and ambition of this project. The mast alone consists of five separate sections. But that’s not all. As Laurent Castaing, CEO of Chantiers de L’Atlantique SA puts it: ”With Solid Sail, we’re not just building ships – we’re reshaping the soul of maritime travel, steering ittoward a cleaner, more respectful relationship with the sea.”
150-year Shipbuilding Legacy
With over 150 years of shipbuilding heritage, Chantiers de l’Atlantique SA continues to thrive under the leadership of Laurent Castaing, solidifying its position as a world-leading shipyard known for innovation and a commitment to circular thinking. Based in Saint-Nazaire on France’s Atlantic coast, the company has a history of crafting iconic ocean liners andcruise ships.
90% Fuel Cost Reduction
As of 2025, the French shipbuilder has received orders for eight Solid Sail rigs, with some vessels featuring up to three roating masts operated from the bridge. The first delivery – comprising two masts – is for Neoline, a relatively new roll-on/roll-off (Ro-Ro) cargo shipping line that will offer a greener alternative to conventional freight, aiming to cut fuel consumption by 80–90%. Built in Turkey and operated from France, the ship will soon provide regular monthly service between Europe and North America.
Like Driving a Hybrid at Sea
“The sea is our future,” says Jean-Pierre Jugé, Key Account Manager at Sika. “There’s a growing push to decarbonize the maritime sector—not just for environmental reasons, but also for the significant fuel savings. While mechanical propulsion is obviously still necessary, Solid Sail offers a hybrid approach, much like driving a hybrid car.”
Early on, Chantiers de l’Atlantique’s recognized it needed specialized expertise to build carbon fiber masts–something not available in-house. “This was more like designing a high-performance sailing yacht or even a spacecraft,” says Cyril Hoebler, a Head of Marine and Composites at Sika.
Embracing the Sail-Racing Spirit
In true sail racing spirit – where creativity and teamwork are everything – a group of experts from a regional industrial consortium teamed up to launch the Solid Mast Factory. The project brought together some of South Brittany’s most innovative companies and veteran sailors.
“Our goal was to achieve large-scale production of carbonfiber masts with foldable composite sails for commercial and cruise ships – available to any interested shipbuilder,” explains Hoebler.
Impressive Collaboration
The lineup of contributors was impressive: Avel Robotics, pioneers in robot built thermoplastic hydrofoils; CDK Technologies and Multiplast, known for their high-performance sailing yachts and composite parts; SMM Composites, specialists in large-scale mould production; and Lorima, one of the world’s largest manufacturer of carbon masts and booms.
“The first step was to create a production mould,” says Hoebler, who collaborated closely with SMM Composites. Building the mould for the 66-meter carbon fiber mast required a resin capable of handling the complex infusion process while delivering high strength and reliability.
Best in Test
“After rigorous testing, the team choose SikaBiresin® CR131,” he explains. “It’s low viscosity and high glass transition T° (TG) were ideal for the process, offering excellent cold infusion properties, an extended pot life and favorable curing conditions – for mold stability.”
With the mold completed, the next challenge was
constructing the mast itself. Given its massive scale, the
team decided on a wet lay-up with a pre-preg carbon fiber
– a material pre-impregnated with resin in a partially cured, frozen state.
Bonding the Mast
For final lamination and bonding, the team specified SikaPower® 751, a non-filled injected liquid adhesive formulated for larger surface applications. “751 was the best-in-class adhesive selected by the design team due to its properties (low viscosity to avoid bubbles, and a combination of high elongation and mechanical resistance). In total, 100 liters were cast into the trailing edge, and 2 x 70 liters into the internal sleeves, seamlessly bonding the three 22-meter segments into a single mast,” explains Hoebler.
Simply Breathtaking
“The resulting mast was breathtaking,” says Jean-Pierre Jugé, recalling how he was able to stand inside the hollow structure before it was mounted. “The industry is moving quickly now.”
Growing Market Potential
By 2023, the wind-assisted propulsion market was valued at $71.7 million — and it’s projected to soar to $40.48 billion by 2034. 3 This rapid growth reflects the maritime industry’s drive to cut emissions and boost fuel efficiency. With 29 systems installed by mid-2024 and 72 more on order, confidence in wind-powered solutions is clearly gaining momentum.4
1. Calculated on an average marine diesel price (MGO or VLSFO) of $750 per tonne.
2. Burning 1 tonne of marine diesel emits, c. 3.2 tonnes of CO2, or 3,200 tonnes annually.
3. Research and Markets 2025: ”Wind-Assisted Propulsion Market - A Global and Regional Analysis: Focus on Application, Technology, Installation Type, Vessel Type, and Region - Analysis and Forecast, 2023-2032”
4. Den Norske Veritas (DNV), as reported in Seatrade Maritime News, Paul Bartlett, Feb 4, 2025 https://www.seatrade-maritime.com/wind
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Key facts
Main project owner: Chantiers de l’Atlantique
Location: Saint-Nazaire on France’s Atlantic coast at the mouth of the Loir River, a hub for seafaring innovation and racing.
First commercial delivery: Neoline, a French shipping company established in 2015
Solid Sail Mast Factory Consortium: Avel Robotics, CDK Technologies, Lorima, Multiplast and SMM
Sika product details and benefits:
- SikaPower®-751 is a non-filled, two-component epoxy adhesive designed for bonding large surfaces and used as an infusion resin. Its primary benefits are:
- Optimal viscosity and a wide range of working times for bigger surfaces
- High mechanical strength: Provides robust and durable bonds capable of withstanding significant mechanical stresses (superior strength-to-weight ratio)
- Excellent aging resistance: Maintains adhesive properties overtime, ensuring long-term performance even under challenging environmental conditions.
- SikaBiresin® CR131, an epoxy resin system suitable for the production of high-performance fiber reinforcement parts and molds
- >100 years is how long Sika has supported the maritime industry
- >20,000 boats per year build with Sikaflex®
- Most cruise ships built since 1990 use Sika Marine’s technologies
- > Sika’s dedicated global Marine Team consists of naval architects, engineers and chemists with over 150 years of combined experience