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.

19.05.2008

Rounding the high pressure.

Setting out from Qingdao late yesterday morning, the maxi-catamaran in the colours of the LCF Rothschild Group have set a good pace over the first part of the course. By economising on the number of manoeuvres, and aided by a stronger breeze than originally banked on, Lionel Lemonchois and his crew have managed to rack up the miles. At 1500 hours U…

par Gitana

Sailing at the edge of a zone of high pressure, the 33 metre catamaran had to gybe at the start of the afternoon so as to distance itself from the mass of high pressure shifting slowly eastwards.

Now clear of the incessant ‘ballet’ of cargo ships and fishing boats crossing their route, the sailors of Gitana Team are no less vigilant. The reason for this is that in addition to the craft themselves, it’s the drifting nets of the fishermen which are creating hurdles for Gitana 13.

Weather flash from Sylvain Mondon (Météo France)
By arriving in the East China Sea in a moderate 12 to 16 knot NW’ly, Gitana 13 will have to negotiate the approach of a small zone of high pressure. Indeed this pressure, currently situated over the region of Shanghai, is shifting slightly eastwards and will disrupt the N to NW’ly air flow, which has been established on zone since Sunday. At the same time, the wind will clock round to the N once the zone of high pressure approaches. The light winds are arriving via the west and Lionel Lemonchois and his crew will have to make easting for several hours in order to limit the influence of the easing wind.
Over the course of tonight, the N’ly wind will continue to clock round to the NE and then the E, filling to around twenty knots. It is this well organised air flow which will enable Gitana 13 to round to the E of the high pressure and adopt a more direct course towards their goal midway through the night. On Tuesday, once Gitana 13 reaches the SE edge of the zone of high pressure, the E to SE’ly winds will be a lot lighter (10 knots or less), which will temporarily slow the maxi-catamaran’s progress.

Once they get past this obstacle, the SE’ly wind will freshen again to between 15 and 20 knots, which will enable Gitana 13 to quickly make the island of Taïwan in downwind conditions, via the Japanese island of Ishigaki.

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