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.

23.11.2016

Rudder damage resolved aboard Edmond de Rothschild.

par Gitana

Yesterday evening, at 21:00 GMT, the final ranking of the day reinforced Sébastien Josse’s second place. At that time, the solo sailor was 96 miles behind leader Alex Thomson and had a few miles on third placed Armel Le Cléac’h. The pace was still high and the top trio had no intention of easing up, instead doing their utmost to make full use of the weather situation on offer. However, thirty minutes later, the skipper of the Mono60 Edmond de Rothschild contacted his shore crew. Whilst sailing in a NNW’ly breeze of between 25 and 30 knots and making headway at an equivalent speed, Gitana 16 hit a UFO (Unidentified Floating Object). The impact involved the starboard rudder of the 60-footer and the incident, which was inevitably violent at such speeds, damaged the appendage’s lifting system.

The breakage of the starboard foil on Hugo Boss at the weekend and, more recently, the retirement of Vincent Riou earlier in the day, serve as a timely reminder that collisions with UFOs, though they colour a sailor’s everyday life, are no less formidable for the gear and the machines, particularly when these happen at such high speeds.

Sébastien Josse had a bitter experience of this last night. Under the impression that the toughest part of his work was behind him in the afternoon, having managed to stay ahead of the low despite some very unstable wind conditions, the skipper of the Mono60 Edmond de Rothschild had to face up to a series of technical issues after colliding with a UFO with the boat’s starboard rudder. In the impact, the rudder’s lifting system was damaged, preventing the appendage from slotting back into its housing in the lower position.

Back on shore, a team made up of Pierre Tissier, Gitana Team’s technical director, David Boileau, boat captain for Gitana 16 and Armand de Jacquelot, a member of Gitana’s design office, got in contact with Sébastien Josse to offer him remote solutions to effect repairs and help him as best they could with putting these into practice. After over four hours of forced stoppage the problem was resolved and with the Mono60 Edmond de Rothschild’s starboard rudder back in position and in operation, Sébastien Josse was finally able to continue on his way.

During this incident, the skipper of the five-arrow racing stable lost some hard-earned, precious miles. Indeed, it’s worth remembering that yesterday the top three competitors had managed to stay ahead of a front, which was accompanying the head of the fleet towards the Cape of Good Hope. This very smooth operation had enabled Sébastien Josse and his two fellow escapees – Hugo Boss and Banque Populaire VIII, to secure a good lead over their pursuers, the first of them, Safran having been relegated to nearly 300 miles behind the leader, whilst SMA, 5^th, lamented a 462-mile deficit.

At the 04:00 GMT ranking, Edmond de Rothschild had logically yielded his 2^nd place and is now some 169.4 miles astern of the British monohull. For all that, Sébastien Josse is back on the racetrack, which is a great satisfaction in itself.

Ranking on 23 November at 04 :00 GMT

1. Alex Thomson (Hugo Boss) 18,143 miles from the finish
2. Armel Le Cleac’h (Banque Populaire VIII) 102.2 miles behind the leader
3. Sébastien Josse (Edmond de Rothschild) 169.4 miles behind the leader
4. Morgan Lagravière (Safran) 348.8 miles behind the leader
5. Paul Meilhat (SMA) 405.6 miles behind the leader
6. Jérémie Beyou (Maître CoQ) 553.7 miles behind the leader
7. Yann Eliès (Quéguiner Leucémie Espoir) 1,004.3 miles behind the leader

…

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