Carbon Fibre

What do BRITANNIA’s hull, mast, sails, foil arms, foil wings and rudder all have in common? They are made primarily from carbon fibre. Over the past decades, from America’s Cup boats to Formula 1 cars to road bikes, carbon fibre has become arguably the most important material in high-performance sport.

At INEOS TEAM UK, one of the team in charge of sourcing the materials to build BRITANNIA, and the manufacturing processes behind her, is Manufacturing Manager Michel Marie. The 36^th America’s Cup is Michel’s ninth, having started in AC28 in ’92, so he knows more than most just how important carbon fibre is in the modern-day Cup.

“Simply put”, Michel explained, “carbon fibre is the strongest per-weight ratio material available to mankind. That is why we use carbon fibre in the manufacturing of our yachts, from the top of the mast right through to the bottom of the foil arms”.

“The main benefit of carbon fibre is its weight-to-strength and weigh-to-stiffness ratio. Whilst there may be metals of a similar strength, carbon fibre is a very fine fibre, which enables you to orient it towards the strength you require within a component.

“For example, carbon fibre is three times stronger and 40% lighter than aluminium but just as important is that unlike with metals, you are also able to tailor the orientation of the fibre towards the load you want it to withstand.”

One example of that benefit in BRITANNIA is in the sails, which are made up of many layers of carbon fibre. When the AC75 boats are flying at speeds of over 50 knots, the sails come under extreme loads, and the orientation of those carbon fibre layers is designed to minimise the distortion in the membrane.

To ensure the team has access to the best materials possible, a key contributor to BRITANNIA’s carbon fibre has been INEOS and INEOS’ carbon fibre supplier, Toray, the world-leading manufacturer of PAN-based carbon fibres. The entire hull of BRITANNIA is made from Toray carbon fibre, as are the one-design foil arms manufactured by Persico in Italy.

As one can imagine with a 6.5 tonne boat and well over 1500 sq ft of sail area, all the teams challenging for the 36^th America’s Cup use a lot of carbon fibre. That is why, more than ever, recycling and sustainability is vital. At the end of the 35^th America’s Cup, therefore, all the teams wrote several sustainability goals into the rules for the next edition of the Cup.

INEOS TEAM UK was involved in the writing of that rule and within that committed to two key goals linked to carbon fibre. The team had previously developed a life-cycle assessment system for AC35, a valuable material selection tool used to establish the environmental burdens of a composite material over its lifetime ahead of procurement. The first commitment, consequently, was to continue using that tool through this campaign throughout all the manufacturing processes, from the making of the first mould right through to the racecourse in Auckland.

The second commitment was then to use recycled carbon fibre in the team’s manufacturing processes, for which INEOS TEAM UK partnered with West Midlands based ELG Carbon Fibre who operate the world’s first and largest carbon fibre recovery plant.

ELG has recycled all the team’s carbon fibre waste from the 35^th America’s Cup which comprised of pre-impregnated and cured parts and reprocessed those into thermoset and thermoplastic compounds and non-woven mats. Those were subsequently used in various areas of the team’s manufacturing processes, including in the manufacturing of the boat’s cradles, deck moulds and more. It is one small but important step towards a circular economy in the America’s Cup.

The AC75 boats in this Cup are the most complex and extreme boats seen to date. The boats are, as Michel recalls, perhaps most similar to the huge 90-foot trimarans seen in the 2010 Deed of Gift Match in the way they are pushing the boundaries in terms of material sciences. That means, more than ever, that carbon fibre, and a strong understanding of how to make the best use of the material, is absolutely key to building a light, reliable and safe boat.