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.

11.02.2008

Expected slow-up.

Onboard Gitana 13, the thrill of rounding Cape Horn is fading as the crew gets back to business in blustery conditions. Lionel Lemonchois and his crew of nine had a busy weekend, as they had to deal with unstable winds along the coast of Chile.

par Gitana

The men onboard the maxi-catamaran equipped by Baron Benjamin de Rothschild were again knocked around by restive seas with winds gusting at 50 knots: and of course they were sailing close-hauled.

The waters along the Chilean coast lived up to their unforgiving reputation, as Gitana 13 had to weather another low-pressure system: “We got pretty battered about for the past few hours. We’ve had rain, wind and high seas…but that’s par for the course in this area. The winds here are always relatively strong and unstable, which whips up difficult and uneven seas. We call these seas ‘boat-breaking’,” said Lemonchois yesterday evening.

After the tumult, Gitana 13’s ten sailors face totally different conditions today: a light breeze. Lemonchois and his crew are currently skirting around the Easter Island high-pressure systems lying to the west. After this transition, they will reach the southern-hemisphere trade winds. This transition area is tricky, with weak and shifty winds. They have to make it through as fast as possible.
They will then reach southeasterly winds, which translate into long reaches in sustained winds. “We’re really looking forward to getting back into some milder weather. Not only for the improved sailing, but for the sake of the crew. We’ve been wrapped up in our oilskins for nearly 15 days, and we simply can’t wait to strip off our layers of polar fleece,” said the skipper of Gitana 13.

As soon as it taps into the trade winds, the 33-meter catamaran will open up its stride and pick up the pace. There’s only one concern, according to Lemonchois: “In the latest forecast, we see that the trades sometimes lose strength. We just need to hope that they come through for us.”

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