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.

23.02.2008

Climbing upwind.

Aboard the maxi-catamaran equipped by Baron Benjamin de Rothschild the speed has picked up again. Finally free of the zone of calms yesterday morning, Lionel Lemonchois and his nine crew have got back together with weather conditions, which are more favourable to their progress towards San Francisco. These miles nevertheless involve a beat against…

par Gitana

The passage of the Atlantic Inter-Tropical Convergence Zone – which was virtually non-existent – left some of the crew of Gitana 13 unsatisfied. However the ‘double’ helping of the Pacific Doldrums, which Lionel Lemonchois and his men have had to negotiate has reset the counter… Thinking they were free of the pitfalls of the equatorial front on Thursday, the ten sailors of Gitana Team have had to quickly review their judgement: “On Thursday morning we thought we’d got clear of it but the Doldrums filled in via the East and enveloped us in its calm conditions! We finally extracted ourselves from this second Doldrums yesterday morning and rapidly hit NE’ly breezes. However, instead of 12 hours of reaching (beam wind), which were alluded to in the grib files a few days ago, we were only allowed three hours of sailing in excess of 19 knots with slightly eased sheets… a bit short!” observed Dominic Vittet.

Gitana 13 is now sailing upwind on starboard tack, in a NE’ly air flow oscillating between 10 and 15 knots. In this type of breeze, combined yesterday evening with choppy seas on the nose, Lionel Lemonchois and his nine crew opted to reduce the sail area in order to spare their steed: “We have one reef in the mainsail and the staysail is in position up forward. More than the wind though, it’s the sea state which is influencing our progress. Added to that, the chop we’re encountering at the moment is compromising our desire for speed. It’s already slamming a great deal aboard Gitana 13” the onboard navigator confided with us early on yesterday evening.

This morning the maxi-catamaran is sailing off the coast of Salvador and lies 1,570 miles from the finish. Less than 6 days of close-hauled sailing in perspective then for the crew of Gitana 13 to complete this Route de l’Or.

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