Diab, Brødrene AA celebrate 50 years of composite ferry innovation, sustainability

Diab (Laholm, Sweden), a global company offering foam solutions and composites, is celebrating its 50-year collaboration with Brødrene AA (Hyen, Norway), constructor of fast, energy-efficient ferries. Diab reports that the partnership has been instrumental in the development of sustainable high-performance foam cored structures for the maritime, rail, subsea and industrial sectors.

Founded in 1947 by brothers Olav Aa and Bertel Aa, Brødrene AA began as a shipyard crafting leisure boats from mahogany and other timbers. The shift to composite materials began in the mid-1970s inspired by the launch of the glass fiber-reinforced polymer (GFRP) Minesweeper HSwMS Viksten by Saab Kockums. Partnering with Diab, Brødrene AA then ventured into foam cored production, marking a pivotal moment with the launch of the Haaen, claimed to be the world’s first foam sandwich passenger vessel in 1975. The launch of the 85-foot catamaran Hyen in 1979 marked another significant milestone, combining Norwegian Maritime certification with DNV class approval. The Hyen remains operational in Iceland today.

Throughout the 1980s and 1990s, Brødrene AA continued to push the boundaries of GFRP construction. The 1992 launch of Moonraker, a 36-meter superyacht with a top speed of 66.7 knots, highlighted the performance capabilities of lightweight Diab-cored structures.

“Together, we’ve sailed through challenges, harnessed new composite technologies and navigated the seas of change.”

The late 1990s also saw Brødrene AA build superyachts and rail components, as well as infused carbon fiber and foam sandwich structures for ferries, resulting in vessels that are 30-40% lighter than their aluminum counterparts. This weight reduction translated into up to 40% fuel savings, further enhancing the efficiency and sustainability of its ferries. The shipyard has since launched approximately 80 carbon fiber vessels, with 10 more electric and hybrid craft currently under construction.

Diab’s lightweight DNV type-approved Divinycell H foam features a PVC formulation that delivers optimized mechanical performance for Brødrene AA. Highly resistant to the fatigue, slamming and impact loads seen in high-speed ferries, Diab says that Divinycell H also matches the processing requirements at Brødrene AA — being easy to machine, thermoformable and offering low resin uptake during the infusion process.

“Our engineers have worked consistently to improve the performance of the foam cores throughout our partnership,” explains Viggo Karlsen, managing director of Diab Norway. “We have reduced component weight at Brødrene AA by supplying tightly toleranced thicknesses that create the smoothest laminates and by evolving our flow- and form-based finishes to reduce infusion times.” 

Another key focus of the Brødrene AA and Diab partnership is a combined commitment to sustainability. Diab has reported making significant strides in reducing the carbon footprint of its materials, achieving a 50% reduction between 2016 and 2023. Brødrene AA’s use of durable carbon fiber and foam composites extends the lifespan of its vessels, minimizing the need for replacements and reducing overall life cycle costs.

The Vision of the Fjords, a 100% electric, zero-emission hybrid-electric tour vessel received multiple awards including a JEC Innovation Award for its design and environmental impact, while the shipyard’s latest projects — include the refit of two ferries, MS Baronessen and MS Baronen, — aim to extend their hulls and switch to battery power. This initiative, using Diab cores, will incorporate Norled’s SHIFTR battery replacement technology, enabling quick battery swaps and enhanced operational efficiency, further exemplifying Brødrene AA’s commitment to circular design and sustainable solutions.

“As we commemorate 50 years of collaboration with Diab, we reflect not only on our shared history but also on what lies ahead,” says Tor Øyvin Aa, CEO, Brødrene AA. “Together, we’ve sailed through challenges, harnessed new composite technologies and navigated the seas of change. As we take on the next half-century, our partnership with Diab remains steadfast and it drives us forward as we pioneer the development of the lightest, cleanest, high-performance ships of the future.”