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.

21.03.2007

Gitana 13 suffers rudder blade damage.

par Gitana

Yesterday, Tuesday 20 March at around 22:30 (French time), the crew of the maxi-catamaran Gitana 13 informed its HQ ashore that the boat had just hit an UFO (unidentified floating object). The starboard rudder has apparently been broken at stock level but remains attached to the float, which is impeding the boat’s correct functioning. This minor damage is however sufficiently prohibitive to cause the boat to turn around. All is well on board, but Gitana 13 has had to abandon its attempt at the record for the Discovery Route between Cadiz and San Salvador – Gitana 13 left Cadix sunday 18 March at 9:08.07 UT.

Lionel Lemonchois and his crew are currently heading for the nearest dry land, in this case the island of Gran Canaria in the Canaries. But before stopping off on the holiday island, the crew are planning a dive in order to free the section of the rudder that risks damaging the rear underside of the starboard float and is the reason for the boat’s very slow speed. This essential work must be carried out swiftly, but it’s going to be tricky on account of current weather conditions.

Depending on the final diagnosis made on Gran Canaria, a temporary repair may be made in order to allow the boat to return to Trinité-sur-Mer.

Lionel Lemonchois, skipper of Gitana 13: “It was night time when we became aware that the starboard rudder was malfunctioning. It seems that an impact broke the stock clean through and the rudder is now hanging beneath the float. We have to try to remove it as soon as possible. It’s vital as otherwise, we won’t be able to continue due to the risk of holing the boat and taking on water. Léopold Lucet will go down and we’re in the process of preparing for the operation. It’s going to be difficult at open sea and in the current weather conditions, but we have no choice, we have to try. Otherwise, it’s 4 knots max. as far as Gran Canaria so as not to damage the boat. The problem is that we’ve now got ideal conditions for cracking on towards San Salvador rather than going back!”

More infos in the middle of this afternoon…

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