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.

20.05.2003

Gitana in Marseille.

After spending 72 hours at sea without any problem and having covered 750 miles (1389 km), sailing with the remaining 2/3 of the dagger board, Gitana arrived in Marseille / La Ciotat, just before a strong Mistral (35-40 nœuds / 65-74 km/h) kicked in.

par Gitana

At 18h00 French time (GMT + 2) yesterday, Monday 19th May, Gitana moored up at the quayside in La Ciotat (next to Marseille), coming from Cadix (Spain), after having retired from the Challenge Mondial Assistance.

Lionel Lemonchois : “No problem underway. We left Cadix (Spain) in westerly winds, passing Gibraltar downwind. But afterwards, the wind dropped. We crossed the Alboran Sea under engine power (as far as Cap de Gato / Almeria). Then the southerly wind picked up and we almost always sailed at 20 knots (37 km/h) wuith the big gennaker (foc ballon) up. The piece of the dagger board which had remained stuck in the casing and was down as far as it could go. We were sailing with 1.50 m less. But that’s perfect downwind. We still have no explanation as to why the dagger board broke…“

Back into the shed

Whilst the Multiplast yard and the Gitana Team build a new dagger board so that Gitana can take part in the Cagliari Grand Prix in Sardinia from 12th to 15th June, the trimaran will be hauled out in La Ciotat.

The main work will consist of checking that the dagger board casing was not damaged when the dagger board broke. The foil wedges have to be changed to modify their angle of attack and make them more efficient. Lastly, apart from the usual maintenance work for a competition prototype, a complete check-up of the new past stepped for the Grand Prix de Lorient at the end of last April.

The Gitana Team has therefore set up its Mediterranean base, with the aim of getting her back in the water as soon as possible to get down to some intensive training with a view to the Cagliari meeting.

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