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.

29.11.2002

Multihulls must not be associated with the notion of frafility.

Member of the Gitana Design Team, Gilles Ollier is also one of the greatest international specialist when it comes to ocean-going multihulls. Gitana X was built in his Vannes-based (Brittany) Multiplast shipyard, where many mythical giants were also born*. The architect / builder takes an insightful look at the Route du Rhum which just came to an e…

par Gitana

“First of all, underlines Gilles Ollier, we must avoid the association of multihulls and the notion of fragility. Exceptional weather conditions were encountered this year, conditions which were so horrendous that they caused a tanker to sink, generating a major oil pollution ! Sure, the trimarans had to face more damage than usual, due to the weather, but anyway the common proportion of race retirements on a Route du Rhum is 50%. This race involves solo sailors on multihulls, in November : that’s too many factors at the same time, in my opinion… Personally, I have not wished to get involved in that field of 60 ft trimarans designed to race single-handedly – we’ve been asked 5 times, and I turned down the offers. On the other hand, I was glad to participate in the Gitana project, because the goal was to come up with an unusual boat, not to “clone” the existing solutions”.

Learn and start over

“With the Gitana Design Team, we decided to start from scratch. The result is visibly original ! And everyone agrees to think she has a big potential”. Gitana X is now wintered, and the technical staff will start to work to prepare the forthcoming season. One of the major jobs will of course be the mast : for the new spar, the team has decided to start from the same design as the first one. Gilles Ollier : “the experts are working things out right now, and their conclusions have not been revealed yet – I nevertheless think that the race for lightness has had a price, paid during the last season by everyone… The previous season, there had been no damage and everyone was feeling confident : they all went further in their quest for weight reduction, and a limit has been reached… We have to bear in mind that we’re not in the rigid field of pure sciences, and we’re working on prototypes. But in 2003, the boats will be reliable !”

* among other sailing myths, Multiplast has built Orange, the current Jules Verne Trophy holder, and Geronimo, the world’s biggest trimaran, skippered by Olivier de Kersauson.

About the Route du Rhum

www.routedurhum.org
www.france2.fr

Retourner aux articles

Heritage