Retractable Y-shaped foils, adjustable in three dimensions

Inspired by the appendages of the America's Cup foiling monohulls, these Y-shaped foils have a wingspan of over 5 metres. They are designed to generate powerful lift, increase power and offer a wide range of adjustments to optimise flight at every point of sail and in all conditions. Beyond their impressive size, these foils feature many unique innovations.

Revolutionary U-shaped rudders

These are probably the most visually striking innovations on the new Maxi Edmond de Rothschild. To fly high above rough seas while maintaining control, the team wanted very long rudders that would remain in contact with the water. The challenge is that longer rudders tend to flex under load, severely affecting steering and the efficiency of their lifting surfaces. A new geometry was needed to give these appendages maximum stiffness, resist cavitation and ultimately improve control of the boat and make better use of its power. The result is a set of U-shaped rudders over 4 metres long, a metre longer than those on Gitana 17. Their shape, reminiscent of a tripod or an inverted π, is only the visible part of what makes them so distinctive.

A daggerboard optimised to stabilise the boat and limit cavitation

With its wide span, the daggerboard resembles an aircraft tail assembly, with two adjustable flaps: one on the vertical section and the other on the horizontal section, the distinctive “manta-ray wing”. On Gitana 18, the innovation is to position this wing behind the vertical part of the appendage, rather than directly beneath it, to minimise flow disturbance and cavitation.

Rig: adjustable spreaders to control mainsail power while sailing

Gitana 18’s mast is 1.50 metres taller than its predecessor’s. The boom is also shorter, creating a more slender sail plan. The major innovation is a set of spreaders that can be adjusted while sailing to bend the mast fore and aft. Actuated by hydraulic rams, these spreaders can pivot through 35 degrees to adjust the bend in the middle of the mast. This unprecedented system allows the sailor to control mainsail power: adding depth in light winds to take off sooner, or flattening the sail to reduce power at high speed or in strong winds. Adjusting the depth, and therefore the power, of the mainsail can also save a solo sailor time and energy by reducing the need for risky manoeuvres or headsail changes.

Central hull:
an integrated, structural coachroof

The naval architects and Gitana design team wanted an exceptionally stiff, structurally robust platform. This applies both to the floats, which must withstand heavy loads from the foils and rudders, and to the central hull, which is subject to torsion. The enclosed coachroof is integrated into the hull and contributes to its structural strength. Inside, the cockpit brings all sail-handling controls together, with ergonomics shaped by many hours of design and development. The coachroof also stands out for the number and size of its windows. This configuration meets the visibility requirements of the Ultim class rules and gives sailors the best possible view to keep a visual watch.

04.02.2008

On ice.

par Gitana

Average winds of 50 knots, gusts up to 65. During this black night, illuminated only by the white caps, Gitana 13 is heaved-to, no sails up, the wheel tied off, with the men on watch keeping an eye on things. Surrounded by the sensation of major storms, those that leave their mark. A few big swells roll in and shake things up, but we are pretty well protected by Tierra del Fuego. Farther out, where we would be if we hadn’t decided to wait things out, it must be hell. The mere thought of it, when we see how the seas batter the boat here, sends shivers down our spine, and the mast alone is enough. Any more would simply be too much. And then the thought of sailors from bygone days who had to face the same storms…but they didn’t have any way to avoid them like we do today. How did they do it? Respect!

Tonight, Sunday night, we are at about the same place as we were Saturday morning—north of the mouth of Lemaire Channel—thanks to the weather forecast. It alone prevented us from taking a real beating. Yesterday, Saturday, we could have rounded Cape Horn, but it was afterward that things would have gotten dicey. Cape Horn is one thing, but getting around the whole southern tip of the Americas and climbing upwind along the coast of Chile—one of the most inhospitable coasts in the world—is another. That’s where we would be now, starting our turn northward, if we hadn’t put things on ice. We wouldn’t be dealing with little swells, but big breaking rollers six to ten meters high, if not more. With no way out if there was a problem. The southwesterly to westerly wind relentlessly batters the coast. No need to say more, since we, like the boat, are sitting it out for now. The rest is just conjecture. We hope to leave our pseudo pit stop on Wednesday. By then, a new low-pressure system, similar to the one that we’re experiencing now, will have passed through. We’ll be able to get back on the road, even though the going won’t get any easier.

Goodnight

Nicolas Raynaud

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