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.

05.11.2010

Approaching the front.

par Gitana

As they approach the front associated with a depression, a system already dealt with by Franck Cammas and Thomas Coville yesterday, Yann Guichard and Francis Joyon have been on differing courses since Thursday; a fact which has been sufficiently rare since the start of this ninth Route du Rhum that it is worth a mention. Positioned nearly 110 miles to the South of her closest rival, the maxi-trimaran fitted out by Baron Benjamin de Rothschild is not only displaying the highest VMG of the morning position report, but is also likely to be experiencing smoother conditions over the coming hours.

Despite the latitudes, the SE’ly tradewind glide has temporarily been replaced as they pass through a front which is blocking the path to Guadeloupe and Pointe-à-Pitre for the solo sailors in the Ultimate class. However, rest assured that this phenomenon, stemming from a stormy low, will soon be in the wake of the maxi-trimarans, who will see the gradual re-establishing of the tradewind air flow from this afternoon.

After over 1,500 miles of velocity made good, Gitana 11 and Idec have been marking each other since yesterday afternoon, which we can testify to given the very different trajectories. Indeed the two sailors haven’t opted for the same logic in approaching the front, which is taking shape ahead of them.

Whilst Francis Joyon is favouring speed on a reach at 34° North, Yann Guichard is on an upwind tack at 32° North, a choice which is certainly forcing him to sail closer on the wind, but is also enabling him to display a better heading than his adversaries this morning. In such route options, you have to look at the intelligence of the sailors and their respective onshore routing teams: “each of them chose the route which is best suited to the characteristics of their boat. We are each very different from the others, so it’s not surprising that we’re not hunting down the same weather conditions” indicated Sylvain Mondon, Gitana Team’s meteorologist, before going on to explain the short term strategy set up with Yann Guichard to best negotiate this tricky zone: “We’ve opted to pass through the front further to the South so as to have less breeze than Idec, both on the way in and the way out of the phenomenon.”

In practice, on the race zone, this passage through the front translates into a freshening wind. In this way, the wind has been progressively clocking round to the right since yesterday, switching from SE to S then the SW this morning. Throughout this rotation, it has been rising in a crescendo: reaching around ten knots yesterday and then, shortly after 0400 hours this morning, pumping out close to 20 knots… and it’s not over yet. Indeed for Yann Guichard and Gitana 11, the strongest wind is expected during the actual passage through the front, which it is reckoned will take place at around 0900 hours GMT this Friday morning. The anemometer should then record an average speed of between 23 and 25 knots, gusting to as much as 30 knots potentially. Aboard the 23.50 metre maxi-trimaran, Yann Guichard is preparing to encounter rough to heavy seas. As such the ride over the next few hours won’t be the most comfortable of sensations and the speeds are likely to drop off considerably. However, the skipper of Gitana Team is on the attack and he’s racked up a good stock of sleep in preparation for the future headsail changes and reef taking!

Ranking for the Ultimate Category on 5th November at 0400 hours
1- Groupama 3 some 1,574.5 miles from the finish
2- Sodebo 297.5 miles from the leader
3- Idec 341.2 miles astern
4- Gitana 11 some 347.6 miles astern
5- La Boite à Pizza 792.7 miles astern
6- Défi Cancale 1016.1 miles astern
7- Saint-Malo 2015 some 1073.6 miles astern
Retirement- Côte d’Or II
Retirement- Oman Air Majan

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