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.

09.11.2003

Express call into Porto Santo.

Gitana arrived in Porto Santo (Madeira) at 10h00 French time on Sunday morning. A pitstop of just three hours. The shore team changed the broken runner and checked over the on board electronics which had been adversely effected by the humid conditions.

par Gitana

Boat master, Olivier Wroczynski was in Madeira to greet the trimaran : “Gitana moored onto a big military nun buoy outside the harbour onto which we had fitted a long line. Once that was done, François Denis and I boarded the boat. Francois climbed straight up the mast to fit the new runner which we had brought with us. That took just an hour. As he was working away 20 metres above deck, I dried the connexions of the electronics and computers. Apparently, in rough seas, through capillary action, water comes up the cable raceways linking the repeaters at the helm station to the central hull.
Once that had been checked out, everything was in working order once again. We also cleaned and dried the whole boat”.
Meanwhile, Lionel and Marc disembarked to take a quick shower and chat with other crews who were also making a quick stop-over there. Foncia (torn staysail and problems with the mainsail halyard), Bonduelle (central rudder damage) and Banque Populaire (problems with one of the float’s rudder) got underway once again after having sorted out the various problems (2 hours before Gitana). As for Bayer, she will be grounded until Sunday night at least as part of the fairing on the aft crossbeam is seriously damaged.

Bound for the tradewinds

In spite of this set back, the Gitana Team was perfectly relaxed. Olivier Wroczynski : “Lionel and Marc were very calm about this short stopover. I thought they were very relaxed about the whole thing”. Madeira was right on Gitana’s course anyway. And the stop only lasted for three hours. Gitana got underway at 12h00 GMT in a 10 knot (18 km/h) south-westerly wind, whereas Foncia, Bonduelle and Banque Populaire had hardly any wind at all when they left harbour.
Gitana now aims to optimise her weather route to pick up on the warm, steady trades, bound for the Equator.

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