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.

07.11.2010

Hectic night in the storms.

par Gitana

Whilst the leader of the ‘Ultimate’ trimarans is less than 600 miles from the finish, the weather situation is still highly uncertain on the approach to the arc of the West Indies. On either side of the race zone, his three pursuers are trying to tackle the complex weather pattern so as exploit it every which way they can. Aboard Gitana 11, Yann Guichard has opted to skirt to the East of the system in a bid to make up his deficit, but he hasn’t been spared by the ambient instability surrounding the end of this race.

The least that can be said is that the satellite charts for the finish zone aren’t lacking in either colour or spice: To the West, we have the tropical storm “Tomas” and its strong winds and rain squalls. To the East meantime, a North-South storm surge is developing, accompanied by lines of squalls containing considerable storm activity, which is shifting across to the West. In the middle of all that is the island of Guadeloupe, which will as usual play host to the Route du Rhum finish. As such, given the context, strategists and meteorologists are hard at work, 24/7, as are the skippers.

Favouring an E’ly option, Yann Guichard hasn’t found the past few hours at all restful. Beneath leaden skies amidst storms splitting open the horizon with lightning, Gitana 11 is trying to pick her way along, avoiding the most threatening squalls. It’s a game of cat and mouse, in which Idec has paid the price. Indeed, yesterday afternoon, Francis Joyon’s red trimaran traversed a zone of squalls at the edge of the storm surge, in which the wind was virtually inexistent, before stumbling into the centre of the phenomenon. Hence a considerable drop in the speeds we have become familiar with in relation to this round the world recordman over recent days.

Midway through last night, whilst Gitana 11 was making headway in the wind from the zone of squalls we referred to earlier on, Yann Guichard got his first big fright in this ninth Route du Rhum: “Everything happened extremely quickly, in a matter of seconds I’d say! The wind switched from 20 to 45 knots without any prior warning whatsoever. In the strong rush of air, Gitana 11 rose up flying two hulls and I ended up almost vertical. I was trimming in the cockpit with the headsail sheet in my hands. I dumped everything and the boat fell back down the right way up!” explained the skipper of the Gitana Team to his router last night, ensuring him that neither the sailor nor the boat had any injuries to report after this incident. Though the trimaran landed the right way up this time, as a fine helmsman and multihull connoisseur, Yann Guichard knows that it could easily have been very different, especially if Gitana 11 had been carrying more sail area! That’s why, on a dark night, the 36 year old Breton opted to calm things down a bit, throughout the night, and wait for daybreak before powering up the machine once more. In this way the 25 knots of average speed recorded by the trimaran at the end of yesterday dropped off to 14 knots during the night. As planned though, the multihull fitted out by Baron Benjamin de Rothschild had a high output again at the 0700 GMT ranking with Gitana 11 the fastest of the fleet over the past thirty minutes.

Vigilance will be the order of the day this Sunday then as storms and wind are set to accompany Yann Guichard throughout this 8th day of racing.

Ranking for the Ultimate Category on 7th November at 0700 GMT
1- Groupama 3 some 574.9 miles from the finish
2- Sodebo 231.3 miles from the leader
3- Idec 383.8 miles miles astern
4- Gitana 11 some 619.1 miles astern
5- La Boite à Pizza 1,171.5 miles astern
6- Saint-Malo 2015 some 1,489.1 miles astern
7- Défi Cancale 1,500.9 miles astern
Retirement- Côte d’Or II
Retirement – Oman Air Majan

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