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Scow Bow's Ingenious Design The Favorite Of Class 40

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  • Scow Bow's Ingenious Design The Favorite Of Class 40

    The biggest category in the race, Class40 stands out too with many new wide-bowed boats. The development of these “scows” confirms that the class is thriving. Out of the 55 forty-foot boats competing, thirty have this feature.

    It was in 2010 that the designer David Raison crossed the Rubicon by adapting the concept of the scow, day boats with rounded bows that sailed on North American lakes at the start of the 20th Century. He came up with the first ocean racing boat like this, a Mini 6.50 aboard which he won the Mini-Transat. The concept was rapidly taken up by other designers and in recent years the scow has become the norm for Class40 boats. And now IMOCA designers have become interested, showing that in terms of development, it is not just a question of foils, but also the shape of the bow.

    Bows like spatulas
    In the 40-foot circuit, Ian Lipinski (Credit Mutuel), moved up from the Mini-Transat which he won twice on a prototype and then on a series boat to take the helm of a David Raison designed scow. He was the first in the class to go down this track. In 2019, he won the Transat Jacques Vabre. _“We could see that things were changing in terms of the design of the boats with some amazing performances in certain points of sail. Since then, the scow has become the obvious choice,” _explained Aurelien Ducroz (Crosscall) who was closely involved in the development of the Lift V2, designed by the team at Lombard.

    Aurelien Ducroz aboard a scow
    The bigger the volume up front, the greater the power. “It’s like the front of a ski with a spatula-shaped tip,” explained Aurelien Ducroz, twice world Free-ride champion, who entered the world of ocean racing about ten years ago. “

    Above Images Courtesy Zan Drejes

    We can see the same sort of development we saw in the mountains with the spatulas becoming longer and wider to allow them to come out faster and stay levitating above the snow. It’s the same principle with a scow. The rounded shape allows the hull to slam less in heavy seas.” But just as with the skis, sailing a scow implies being able to cope with steep slopes. “When Yoann Richomme and Corentin Douguet chose to build the same boat, I knew I hadn’t got it wrong. The Lift V2 is a real success story,” he added.

    For Nicolas Groleau who builds the Raison designed boats and Sam Manuard’s Mach series in La Trinit?-sur-Mer, the scow effect is no longer a mystery. “In terms of design choices, everyone is converging. The boats perform better, sail more comfortably and you get less wet. If you want to win, you need a scow, and that’s why there are so many new boats like this.”
    “_In some points of sail, it means 15% extra speed, which is huge,” _commented Antoine Carpentier (Redman), who is back for a second attempt and aiming higher this time aboard his boat from 2020. Twice winner of the Transat Jacques Vabre in Class40 and Ocean Fifty, he is well aware of the challenge he faces in a line-up which has grown considerably in four years. “Practically half of the fleet is less than two years old. And two-thirds are sailed by top class sailors. That means a lot of people aiming to win or be in the top five.”

    Rounded bows require skilful handling
    “There has been a huge change in the construction of Class40 boats. Our average speeds downwind are closer to previous generations of IMOCA with boats that don’t have carbon, a canting keel or foils. Designers have taken a giant leap forward with the design of the hull,” said Jean Galfione (Serenis Consulting), back for his third attempt in the Rhum with the first of the new Pogo S4 boats designed by Guillaume Verdier. “There are also points of sale where it is much tougher. That’s the reverse side of the coin. The faster you are, the more you slam, and the less comfortable it becomes,” he explained. An opinion shared by Emmanuel Le Roch (Edenred). “In terms of speed, there are points of sail where the difference comes down to 4/5 knots. That is huge. But in terms of how hard it is, it’s black and white. In heavy weather, I would prefer to be aboard a boat with a pointed bow rather than a rounded one. Rounded bows also require more skilful handling. You need to push yourself harder. In races in the circuit, there’s very little in it and the smallest detail counts a lot,” he added.


    New Owen Clarke Class 40 scow in-build
    Posted on 2nd November 2022

    New Owen Clarke Class 40 in-build at Evolution Marine

    Sixteen years ago, Owen Clarke Design (OC) saw the baptism of its second Class40, Bolands Mill. Revolutionary design put that first boat on the podium in the 2006 Route du Rhum, the year where the emerging Class40 ended up dominating the entry list of the iconic ocean classic with 25 boats showing up on the starting line.

    Since those early days, OC has continued to be a leader in the class with eighteen boats delivered, all to private owners and still competing across the globe. In a class with incredibly close racing, reliability and polyvalent design has proven to deliver an edge in race after race.

    Given our history with the class that stretches back to the very beginning, we are proud to announce that construction is well underway on a new, sixth generation design. Commissioned by Michael Hennessy, American skipper of the legendary Dragon, this new OC scow design is intended to take on the best of the Class40 fleet on both sides of the Atlantic.

    Owen Clarke, working with Peter Hobson Design (PHD) and PURE Engineering have come up with the fastest, most versatile Class40 drawn to date. Merf Owen, principal designer, explains: “after a close review of the existing scow bow fleet, we identified key design features that contribute to success and as importantly, those that do not. In 2022 alone we subjected 86 different hulls to CFD analysis and VPP testing against computer models of our competitor’s designs, on the classic ocean racing courses using historical weather data. We are highly confident that the boat can reach the top of the podium across a wide range of courses and conditions”.

    The design team also worked closely with Hennessy to focus on skipper ergonomics, designing a cabin, cockpit and deck that are meant to provide unparalleled protection for its crew and ensuring that they can sail at peak efficiency for transoceanic races. Leaning on his own ocean racing experience, Merf reflected “a fast boat is better able to achieve its potential if the crew can perform at 100%. Hennessy adds: “I strongly believe we’ve been able to ensure this new design supports a better ergonomic outcome than any other boat in the Class40.”

    Evolution Marine in Cape Town has been engaged to build the new boat. Their experienced team, led by Oliver Dawson, has already built the hull and deck tooling and is busy laminating structure. She will be delivered from South Africa to France for final fit out by Marco Lefevre and his Class40 specialists at V1D2 in March of 2023, and will be raced in Europe next season against the best of the Class40 fleet.

    For more information about Owen Clarke’s new scow Class40, please contact

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