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.

10.11.2013

Oceanic beat.

Last night the two 70’ trimarans competing in the Transat Jacques Vabre hit the launching pad along the edge of the Azores High so as to pick up the pace this morning in a solid north-easterly tradewind at the latitude of Rabat. Still topping the leaderboard, Edmond de Rothschild is gradually extending away from Oman Air-Musandam with a lead of 80…

par Gitana

The race enters phase two

After three testing days in a feisty weather system, the sailors have left the European continent in their wake. Now they’re switching to an oceanic beat where the periods on watch at the helm will run more regularly and their bodies will have time to recuperate. And though the morale of Sébastien Josse and Charles Caudrelier is in tune with the average speeds racked up over the past few hours, the duo is continuing to remain fully focused.

“We’re sailing downwind, gliding along nicely and we’re making fast headway,” Charles admitted at noon. “We tried to get some rest last night, but we got disturbed by a series of squalls, which caused us to do a fair amount of manoeuvring. We can’t complain though, we’re heading towards the sun. Life is rather good, but it’s full-on! We need to remain focused as we’re going very fast. You also have to keep your position on the leaderboard in perspective with multihulls, because though it’s good to have a slight edge over Oman, all that can change in the blink of an eye.”

Indeed, when your making 30 knots downwind under gennaker on a multihull, you have to keep a constant eye on your machine, as you would milk on the hob. Due to stick with the tradewind system for three to four days, the duo will have to really show what it’s made of in terms of piloting before the next lull, which is forecast for their approach of the Doldrums. In the meantime, the crew will have to smoothly negotiate their passage past Madeira and then the Canaries, where the wind shadow from these very high altitude islands will have to be considered with the utmost care. They will also have to constantly watch their backs to keep a look-out for any attacks from their rival because it too is now sailing to the oceanic beat, which is a familiar exercise for the round the world sailors that are Sidney Gavignet and Damian Foxall. Looking at the trajectories this afternoon, Oman Air-Musandam appears to be attempting to get some westerly separation.

Helming, eating, sleeping

Even though the speed is accompanied by permanent stress aboard, now is also the time when it is important to stock up on energy for the next stage of the race. “Up until last night, it wasn’t easy to get any rest or even to eat, but things are better now,” explained the skipper of the trimaran fitted out by Baron Benjamin de Rothschild this morning. “Last night we each managed to get three hours sleep in fragments and it’s done us good! With regard food, we’ve done more snacking than really eating; we haven’t yet opened our day bags with the freeze-dried meals, but we should get a chance to treat ourselves to some of that today.”

Ranking on Sunday 10 November at 1530 GMT:

Edmond de Rothschild (Josse-Caudrelier) 4,129 miles from the goal / 27.10kt average over 2 hours
Oman Air-Musandam (Gavignet-Foxall) 80.39 miles behind the leader / 26.90kt average over 2 hours

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