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.

16.07.2004

Major damage to Gitana 11.

Half an hour after midnight, Fred Le Peutrec called his HQ ashore to notify them that his trimaran had just been damaged in major way and that the crew was heading towards La Trinité-sur-Mer (Southern Brittany – France).

par Gitana

« We are making way towards our home base in La Trinité sur Mer after a violent collision with something or other. The daggerboard was partly raised and the rudder of the central hull was snapped off and here is an ingress of water up front. Boat speed at the time was 25 knots and the transom is partly destroyed. It’s not serious as there is a watertight bulkhead aft. But there’s a fair bit of water in the middle hull. The crew is okay and no-one was injured. We have to save our batteries as we are no longer able to charge them. We’re 1,300 miles from our base in La Trinité sur Mer. Eveyrthing’s fine on board. We are able to handle this on our own and do not require any assistance. »

It was still daylight when the collision happened as Gitana 11 is mid-Atlantic with a three hour time difference. The trimaran is not in any danger as both floats are intact, although an ingress of water has no doubt drowned the engine which is why the crew has dismounted the batteries so they don’t drown in seawater in the bilges.

Two hours later, the President of the Race Committee, René Boullaire, stated that Gitana 11 was lying 49°57.2 North by 37°01.7 West at 13 knots, heading about 50° (North East). At 3h00 Friday morning, Gitana 11 was still making ten knots on the same heading. The fleet is sailing on the northern face of a high pressure system in relatively easy conditions with a 20-knot westerly breeze and a long north-westerly swell.

At 8h00 this morning, Gitana 11 explained that the leak on a level with the dagger board casing had been repaired but that the engine alternator was not working any more. As a result, the batteries have lost their charge and the trimaran can no longer communicate by Inmarsat (telephone and e-mail). Her position is now being monitored by the Argos safety beacon. Gitana 11 will take three to four days to reach the Breton coast, as she has been sailing at an average speed of just 10 knots over the past few hours.

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