Top left to right: Van Den Heede’s Harlé-designed cigar which finished third in the 1989/90 race a little under three days behind winner Titouan Lamazou; the first Finot saucer – 1992 victor Bagages Superior; Geodis won in 1996 with the first canting keel; after the capsize disasters of the stormy 1996 race and the introduction of new rules on vanishing stability Finot moved on from dramatic saucer shapes to create double-winner PRB which went on to have a longer competitive life than her more extreme predecessors; 2008 winner Foncia moves further away from the skimmers with a boxy flat-bottomed hull which was also shallower (ie lighter) than previous Imocas; Macif 2016 – evolution not revolution with more topsides and deck sliced off to save weight and lower CoG plus daggerboards canted in for lift rather than out to increase sideforce with heel; Banque Pop 2016 – hulls start to be influenced by the first use of curved foils to deliver lift, from here hull stability will play less and less a part in Imoca design; Hugo Boss 2020… narrow waterlines, small flat aft sections for easy ‘release’, decks slashed away wherever possible and symmetric reversible C-foils rather than the multi-faceted wing designs featuring some significantly longer wing spans chosen by Alex Thomson’s Vendée Globe rivals. Above: design progression from PRB 1996 to Macif 2012 to 2016 winner Banque Populaire and the slightly narrower Hugo Boss 2016
being nearly parallel to the water at rest but producing tremendous lift (and right- ing moment) as soon as she heels. In flight Apivia leans entirely on her great wing but Hugo Boss will sometimes lean a little more on the edges of her hull. And the other two recently launched
Imocas, Corum and L’Occitane, are even more different! Juan Kouyoumdjian has got us used to his original solutions, and Corum is no exception. Although the hull is taken from the same mould as that of Arkea Paprec, Nicolas Troussel’s Corum looks like a UFO compared to its hull sister. We are now very far from the image of a shoebox, or even a stealth aircraft, which were the new trends in 2019 Imocas. In my opinion there is also the strong the ‘Professor’, Michel
influence of
Desjoyeaux, who manages Nicolas’s campaign. Plus of course the well-known desire of Corum’s skipper himself to depart from the established paths. By creating an immense lateral bulge
JK has revolutionised the way to design that type of boat, anchoring his thinking around Imoca rules which mandate rigid
stability criteria when it comes to self- righting. His analysis leads him to create sufficient lateral volume to save weight from the bulb, which on its own needs to allow the boat to right itself from a cap- size. The extra volume will also come in handy when moving gear from side to side. Really, all Imocas are still a bit heavy to
fly, and any weight gained in the ballast allows them to fly a little earlier. And who- ever flies the most has every chance… of winning the Vendée Globe! Note also the profile of the mainsail, carefully tailored to deliver the right amount of power in the best possible place. The most original of all the new Imocas,
L’Occitane, comes from an architect new to the class, Sam Manuard, who won first in the Class Mini, then in the Class40. The idea was to design a narrow scow to the limits of the Imoca rule’s attempts to exclude the scow philosophy. For several years the Imoca rule has
imposed a maximum width measurement of 1.12m taken 1m aft of the bow. So impossible to make a bow like those on the winning Mini Transat designs. However,
Manuard has still delivered a very full spoon bow and a hull narrow enough to meet all of his objectives: 4.9m. With the scooped-out bow quickly
raising the nose at speed, combined with full curved sections below the water, the waterline length is the shortest in the fleet at 16.45m. As intended, L’Occitane sails noticeably pitched upwards, despite her centre of gravity being quite well forward. So soaring when not able to fly! Despite the frustration of architects this
class, still the most liberal of all, continues to grow and has a secure future if it adapts to new challenges. On the early evidence of L’Occitane scow shapes will probably drive the next generation, but the rule preventing hollows in the hull continues to irritate naval architects, many of whom also regret that for the next cycle at least rudder elevators will not be permitted. But Vendée Globe 2020 shows us that
progress comes in many ways. Ways that even a few years ago we had not even thought about. There will be plenty more! With thanks to Jean-Baptiste Epron for his superb illustrations
SEAHORSE 47
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