Technical
Unstoppable forces
While Class40 design moves forward apace parallel improvements in materials and build techniques are adding a further layer to the relentless improvements in sailing performance and reliability that we are seeing
When Aurélien Ducroz won the Class40 World Championships last summer, his victory against stiff competition in this intensely competitive fleet was a strong endorsement of his own skills and talent, but also a validation of Crosscall, his radical and remarkable new boat. Kudos is due to the Marc Lombard design office, whose new Lift V2 design exploits the class’s 2020 rule change to the full. Crosscall’s builder, Grand Largue Composites (GLC), also deserves credit for delivering a boat that didn’t just meet its design weight target but surpassed it, coming out of the moulds lighter than even the design team had expected. And that’s another feather in the cap for Sicomin, which supplied nearly all the materials. The boat turned out to be faster
than Lombard’s VPP had calculated, as GLC’s managing director Xavier Gosselin explains, and since Crosscall’s launch at the end of 2021 it has become clear that the CFD modelling for the Lift V2 design was run at less than its actual top speed. It has also proved to be an excellent performer in light airs, with Ducroz overtaking most of his rivals after poor starts in two of the World Championship races, staged on an often almost windless Bay of Biscay. But while the boat is showing itself to be a good all-rounder it is conceived and optimised for a specific purpose: winning the Route du Rhum. The Lift V2 is a
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development of Lombard’s Lift 40 design which Yoann Richomme sailed to victory in the last edition of the race in 2018, crossing the Atlantic from St-Malo to Guadeloupe in 16 days and three hours – eight hours ahead of his closest rival – and establishing a new class record. Crosscall is reckoned to be capable of shaving another day off that record, given similar weather. For context, that’s faster than most of the older generation of Imoca 60s. Whilst the new Richomme boat
was built by Lalou Multi, Ducroz’s was built by GLC in Caen, Normandy and Gosselin was involved in the composite manufacturing design loop for the Lift V2, working closely with Lombard’s team, before he started building it. A small, independent custom boatbuilder and manufacturer of high-end composite parts, GLC has built Ocean Fifty multihulls and a seaplane as well as five Class40s, high-performance dinghies and the XO range of small cruising and racing keelboats, plus a range of non-marine projects. Over the last 15 years GLC has earned an enviable reputation for the quality of its vacuum-infused epoxy composite hulls, parts and structures. Since the establishment of the company, Sicomin has been its sole supplier of epoxy resins for infusion, hand lamination and adhesion and has also supplied fibres, core materials and more. ‘We have been using their products since the beginning, we
Above: the current world champion Class40 Crosscall is lighter than its design weight and faster than predicted by Marc Lombard’s VPP. Credit is due to the builder Grand Largue Composites and Sicomin who supplied nearly all the materials
have never had a problem and I would not want to risk trying a different supplier,’ Gosselin says. Crosscall is also notable for being
the first Class40 partially built with natural flax fibre. Ducroz was very keen to use the maximum of flax in the build, Gosselin says, but Lombard – who had to certify and warranty the structure of the boat in ocean racing use – was more cautious. A compromise was reached; the cockpit was designed to be effectively non-structural with the mainsheet loads supported separately. This allowed the cockpit to be built with a hybrid biaxial fibre that has 50 per cent flax content, which Sicomin had produced specifically for this project. Other elements that incorporate flax fibre include the tunnel, the engine cover, the ballast tanks and the cap. The rest of the boat is reinforced with 100 per cent glassfibre. Given the enormous stress loads
that a Class40 hull must withstand, the extreme danger of any structural failure in mid-ocean and the need to make these boats as lightweight as possible, using even that amount of a relatively unproven material like flax is quite a bold move. That said, the use of flax is an easier choice to make in Class40, where carbon fibre is banned in hull construction to stop costs from spiralling out of control, than in the full-carbon Imoca 60 class where even the most eco-conscious teams have found that using flax for anything
POLARYSE
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