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.

09.11.2006

Dogged determination.

The bad luck keeps on coming aboard Gitana 12 but Thierry Duprey du Vorsent keeps on keeping on. As if having his bow ripped by a whale wasn't bad enough, his mainsail sustained a serious tear above the third reef during Wednesday night …

par Gitana

The bad luck keeps on coming aboard Gitana 12 but Thierry Duprey du Vorsent keeps on keeping on. As if having his bow ripped by a whale wasn’t bad enough, his mainsail sustained a serious tear above the third reef during Wednesday night …

Despite the tribulations raining down on Thierry Duprey du Vorsent, the skipper has recovered his morale after the repair of his mainsail that took ten hours. This Thursday morning, Gitana 12 was again able to travel at reasonable speeds towards Guadeloupe. Seriously handicapped by these successive incidents, the trimaran should reach the “Butterfly” island on Friday afternoon (local time). Determined to bring this first solo experience to a successful conclusion, Thierry Duprey du Vorsent can be proud of his numerous acts of DIY improvisation. Gitana 12 may have had her wings clipped, but her skipper is not entertaining the thought of throwing in the towel, to the point of considering diving to install a new bobstay in order to try to hoist his gennaker!

Thierry Duprey du Vorsent (Gitana 12) 13:30 UT:

“The mainsail has torn (I’ve got absolutely no idea why) above the third reef… It happened at 22:00 on Wednesday and I finished my repairs at 08:00 Thursday. I’m quite proud of what I’ve done, actually: I’ve bodged it up “junk” –style by binding the mainsail battens together and reducing the surface area. This is allowing me to hoist roughly two reefs for the moment, but if the breeze dies down, I could have roughly the surface area of one reef. I can’t pull too hard on it because it’s not quite up to the standard of a master sailmaker! What’s more, I can’t use the hook (which blocks the halyard) and so the sail is not that tight when sailing.
For the moment, I’ve got 14-18 knots of south-easterly wind and I’m advancing at between twelve and twenty knots ten degrees beneath the direct route to the finish. The wind should ease off below 20° North on Friday while turning north-eastwards. The end of the course, and especially the rounding of Guadeloupe, is going to be very difficult. If the wind well and truly dies down and the sea flattens out, I’m already planning to dive in to install a new bobstay to hold the whisker pole: at least I’ll then be able to hoist the gennaker… and proceed more or less normally. In any case, my spirits are high again, but it’s continually a case of fine one day, disaster the next! Yesterday, when I saw the tear right along the length, I had to fight back the tears… But I’m over that now: after all, I don’t want it to end up like The Raft of the Medusa!”

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