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.

14.11.2002

The work goes on.

Gitana is back at her pontoon in La Trinité sur Mer (Atlantic coast, France), and it's now time for analysis. Architects, builders, structure engineers and experts and busy examining the trimaran, trying to understand why the mast broke in its upper portion.

par Gitana

Gitana is back at her pontoon in La Trinité sur Mer (Atlantic coast, France), and it’s now time for analysis. Architects, builders, structure engineers and experts and busy examining the trimaran, trying to understand why the mast broke in its upper portion.

Gilles Ollier, member of the Gitana Design Team and builder of Gitana X : “At the end of the mast construction, we carried on ultrasound tests and it turned out to be perfectly homogenous. The option of a monolithic and narrow mast had the advantage of being lighter than the traditional wing masts. Alain Gautier has the same mast, and he is still racing ! For the moment, we cannot say anything. We are waiting for the first expertise results before being able to examine the two mast portions ashore“.

Next step, back to the yard

Next Saturday, November 17, the fair weather should allow to un-step Gitana X’s mast (depending on the expertise results) and to take her out of the water. The trimaran will then go back to her yard, Multipole 56 in La Trinité sur Mer. Olivier Besse, project manager : “This premature retirement from the Route du Rhum was obviously not planned. This will allow us to lengthen our winter working session and set-up period. The whole Gitana Team is already at work. We know there’s a lot to be done on sails, appendages, and of course we have to build a new mast. Our objective is to re-launch the boat before a mid-March 2003 deadline. We have long training sessions planned before the opening race of the Orma Championship, which will begin in the spring of 2003“.

About the Route du Rhum (Classification, map, news)

www.routedurhum.org
www.france2.fr

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