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.

18.11.2002

Automatic pilots. The solo sailor’s.

Crucial for who is sailing single-handed, the automatic pilot takes the helm when it's time for a sail change, time to plot the route, to cook a meal and of course to sleep. Nevertheless, this precious help is not at ease in all sea conditions, and its reliability can sometimes be criticised. In charge of these matters for the Gitana Team, Richard…

par Gitana

Crucial for who is sailing single-handed, the automatic pilot takes the helm when it’s time for a sail change, time to plot the route, to cook a meal and of course to sleep. Nevertheless, this precious help is not at ease in all sea conditions, and its reliability can sometimes be criticised. In charge of these matters for the Gitana Team, Richard Bastide tells us more about this helpful yet imperfect device.

“I’m a little tired’, said Ellen MacArthur today during the daily Route du Rhum audio session. “I steered Kingfisher all night, it was the only solution”, in order to maintain or even widen the gap between herself and rival Mike Golding. Why is that ? Because an automatic pilot is only a crutch, and does not replace the sailor’s know-how when it comes to playing with the wind. Worse, on a multihull, it can even be dangerous in certain conditions, for example downwind under gennaker (large jib, between the genoa and the spinnaker). Effectively, a major steering mistake while sailing fast can result in a capsized boat. The pilot does not anticipate the waves, does not see nor feels the wind gusts : its only task is to keep the boat on the proper course (direction). And when the solo sailor is ready to leave the helm, he reduces the power of his racer. All the solo sailors say so, pilots cannot be trusted too much !

Towards more safety

“The main problem we encounter, explains Richard Bastide, concerns the fact that the pilot does not react to the differences of sea states… Furthermore, the trimarans sail quite fast in heavy seas, conditions in which they are tough to handle. In our domain, the problem is really critical, because when the boat gets up on a float, the skipper has to be able to straighten the situation in no time – put it back flat on the water – or else it capsizes. What would solve this would be a pilot capable of measuring the distance between the float and the water surface, a pilot which would bring the boat closer to the wind when a certain limit has been reached. Research will be oriented in that direction, because that’s what the skippers ask the pilot manufacturers. For the time being, what’s important is to have a proper pilot installation, so the jacks can work in the best conditions possible (the jacks are the pilot’s arms) : we have seen to many jack breakages due to a bad installation, and in this case, the skipper has to give up the race… A pilot’s installation can be decisive as far as race results are concerned. For reliability reasons, these devices have their own electrical circuit. Aboard Gitana X, Lionel Lemonchois had taken 2 automatic pilots for the Route du Rhum’.

About the Route du Rhum

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