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.

18.08.2008

Bad and good.

par Gitana

No, decidedly Gitana 13 doesn’t like it! She detests these long days beating against 20 – 27 knot winds and in particular this short, little chop, which the two floats never quite manage to position themselves on at the same time. Unrestrainedly twisting the platform, the waves restrict the carbon. The fibre rebels as it seldom enjoys these ‘elastic games’, and responds by springing back violently, which makes life on board pretty unbearable: sleeping becomes an impossibility and consists of hanging onto the bunk with both hands. Eating is an extremely perilous exercise too and despite the numerous precautions, only part of the water from the kettle ends up in each cup. Each crew member on watch is given a real dowsing and the hood becomes a highly sought after refuge.
At the keyboard, it’s like being a child of two who is learning to eat… In short these headwinds are transforming our descent towards the equator into a long, laborious exercise and it has already added a few extra days to our record. We knew this would be the case when we set off, but we’re just hoping that this will be the difficult part of the course and that the Indian and Atlantic Oceans will dish up their customary big surfs.

As regards food, the crew has got back into their ‘good’ habits. No fried food: it’ll be Chinese noodles and freeze-dried food all the way to the finish now. Fortunately, together with Ronan Le Goff, we got a good supply of fruit prior to our departure: bananas, apples, watermelons, mangos, oranges, lemons and grapefruit will be our only fresh food during this long spell of ‘stomach punishment’. We’ll have to make sure that everything’s consumed in a certain order and at a certain time…

Tomorrow we’re going to reach the waters of the island of Natuna, midway between Borneo and Singapore.

Dominic Vittet

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