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.

01.04.2008

From one system to another.

Since setting out from San Francisco on Saturday night (UT), Lionel Lemonchois and his ten crew have been experiencing a diversity of weather, characteristic of this east to west crossing of the North Pacific. With 952 miles actually made good over the ground in the past 48 hours, the maxi-catamaran in the colours of the LCF Rothschild Group is mai…

par Gitana

Lionel Lemonchois and his men have racked up two days on the water since they passed under the Golden Gate Bridge on Gitana 13. Already they have observed a wide range of conditions served up by the North Pacific: the powerful NW’ly wind of the first few hours quickly gave way to less steady winds as they rounded a ridge of high pressure. This slight drop in speed was short-lived however as a few hours later the wind picked up again with the approach of a cold front…

“Yesterday we had to put in a tack to the NW to enable the wind to head sufficiently. These few hours sailing close to the wind weren’t the most pleasant… we really struggled to make headway!” said Lionel Lemonchois.

In these conditions, it’s not easy to discuss things on deck and even less so to get off to sleep when the rest watch comes around: “It was impossible to sleep this afternoon as once you were in the bunk, the movements of the boat left us ping-ponging between the bulkheads. Fortunately, since the passage of the front and a gradually more organised sea, it’s already slamming less aboard Gitana 13. We are still being sparing with our steed as the Pacific has not settled down enough to enable us to lengthen our stride. We’re approaching things the right way though!” said the skipper of Gitana 13 positively, as the maxi-catamaran gradually picked up speed last night.

Now on starboard tack, Gitana 13 is on a heading of 241 as she prepares to encounter her next system: there is good cloud cover dropping down from the NW with 30 knots of wind forecast. As a result, the wet atmosphere is still par for the course for Gitana Team for the next 24 hours.

Far from the direct course
In this North Pacific crossing, the men on the maxi-catamaran equipped by Baron Benjamin de Rothschild, are engaged in a virtual race against the giant trimaran skippered by Olivier de Kersauson, the current record holder.

At the 0730 ranking this morning, Lionel Lemonchois and his crew had a 371 mile lead over the reference time; a figure which is partly explained by the lateral separation of Gitana 13 in relation to Geronimo’s 2006 attempt. Indeed the conditions encountered by the “Admiral” at the time, led him to pass a long way south of the great circle route. A direct course, which as we can see on the cartography, would force the sailors tackling this record, to adopt a very N’ly trajectory to make Yokohama. This is pure theory however as in reality the weather conditions dictate a much more S’ly course compared to that of the ideal track.

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