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.

10.11.2003

On her way back up….

par Gitana

After having set out once again yesterday at 13h00 French time from Porto Santo following a 3 hour long pit stop in the Madeira archipelago, Gitana set out in pursuit of the race leaders. Although those in the lead are currently galloping along in a steady very southerly trade fort he season, (under the Canary Isles), Gitana had to make sure she steered clear of the Canaries and wind holes caused by her volcanic relief. She also had to try and catch up with Bonduelle, Banque Populaire and Foncia as soon as possible, all of which had left the Portuguese port a little earlier.

Lionel Lemonchois and Marc Guessard are going to do one better than catch them up. At today’s midday check-in, they were ahead of the three tris in question who had all opted to head straight through the Canaries. A choice which they are paying a heavy price for and which enables Gitana to leap forward from 11th place at 4h00 (French time) this morning into 8th place by midday today, behind Sopra Group, just 32 miles (59 km) ahead of Gitana’s dark blue and white bows. The race is far from over yet! Gitana remains slightly westward. Over time, on the approach to the Doldrums 1300 miles (2400 km) ahead, this difference could turn out to be a clear advantage.

An understanding trade wind…

This north-east 20-knot wind (27 km/h), as regular as clockwork is having a tough time settling over the canaries this year. What is the reason for this ? A fickle zone of high pressure is pinning the trade wind down along the coast of Africa, preventing it from coming over the Canaries, breathing its warm wind and enabling the big staysails (gennakers) to be hoisted. So, the answer is to go in search of the slightest puff of wind to wriggle free from this zone of high pressure, increasing the number of manoeuvres and risks. As luck would have it, the point at which the trade starts, should be moving north tomorrow, which should help the second group of boats, led by Gitana. This trade wind will enable the crew to hoist the famous gennaker, so that those on board can concentrate on sailing the boat fast and getting the maximum performance from her. Lionel and Marc will have to manage gybes, concentrating on helming extremely well, and make the speedometer climb to speeds which landlubbers can only dream of. Next aim, the Doldrums, if all goes according to plan, for Friday…

Retourner aux articles

Heritage