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.

20.01.2008

“Little by little, the bird builds its nest”….

par Gitana

…this popular saying fits our crew like a glove as we adapt to Gitana 13’s non-stop pace, mile after mile. This relentlessness has meant that the stand-by watch has been kept busy. For three-hour shifts, the stand-by watch can be called on to lend a hand to the crewmember on deck for any maneuvers.
Let me explain: Gitana 13 loves to fly a hull, which is perfectly appropriate in the flat expanse of Quiberon Bay but strongly discouraged when we’re roller-coastering over rough seas. This means we constantly need people on deck to man the sheets and “tame” the beast. But there are three sheets to trim—four when the genoa staysail is up. It’s easy to see that the three-man watch on deck, helmsman included, cannot do it all themselves. So in addition to standard maneuvers, the stand-by watch is also enlisted to trim sails. Since the stand-by period is also when we eat, we need to down our meals fast.
The Doldrums—a zone synonymous with multiple maneuvers—are not far off (we should reach them overnight Monday), which means that things won’t calm down for us for awhile yet. No one is complaining, of course, and we’re ready to give all we have to maintain our lightning speed on the big blue. Skipper Lionel Lemonchois, in his wisdom, decided to have Dominic Vittet—normally off-watch—get a little more involved. Twice a day, Dominic replaces one of us on stand-by. Today, Léo Lucet and Olivier Wroczynski were the lucky ones who were able to log six uninterrupted hours in their bunks.
We covered 575 miles over the past 24 hours, and our goal for the day is of course to top this number. Saturday was punctuated by sail changes: gennaker, then solent, then staysail, then solent again, gennaker again, and finally solent again and staysail again. The wind is as unstable as before in terms of strength and direction, but at least we haven’t been slowed by slack winds like yesterday. So maybe 600 miles today…in any case, our motto hasn’t changed: we still have a long way to go. In the meantime, we’ll keep hurtling forward at 25-30 knots, with some long, lovely stretches above 30 knots. We’re getting wet, but the water is warm. Cold would be okay too, but warm is definitely better!

Good night

Nicolas Raynaud

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