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.

10.11.2016

Under the zone of high pressure, bound for the Doldrums.

par Gitana

Yesterday evening, the weather forecasts had us believe that the head of the Vendée Globe fleet would experience a good boost in speed overnight as they finally shook off the effects of a ridge of high pressure that had been slowing the progress of the solo sailors for over 48 hours. However, the precious NE’ly breeze, synonymous with slipping along nicely southwards in the tradewinds, kept them waiting… Positioned the furthest over to the West of the leading pack, Sébastien Josse is currently lying in 6th place some 33.9 miles astern of the leader, Armel Le Cléac’h, and is bunched together with Jérémie Beyou and Morgan Lagravière, 4th and 5th at the 14:00 GMT position report.

Besides the technical appeal of the Imoca monohulls and the fascination of an adventure like a solo, non-stop, unassisted round the world yacht race, the sailors’ ability to decipher and analyse the grib files is one of the key ingredients of offshore racing. This is heightened by the fact that the weather is far from an exact science.

Second yesterday at the 21:00 GMT ranking, Sébastien Josse lost ground overnight. Sailing further over to the West and hence the closest to the centre of the zone of high pressure, the skipper of Edmond de Rothschild had to contend with lighter winds than forecast: “Last night, the grib files were announcing more pressure, but it didn’t kick in as forecast. We had to make do with what we were given and just accept the fact that rivals like PRB were coming off better than us… Nevertheless, this boat is a reference downwind in light airs,” Sébastien pointed out. “The weather pattern for the start of the race has evolved a great deal between the forecasts we had prior to the start and what we’ve found on the water, but that’s the name of the game! Right now, we’re no longer in the squally system that has coloured our progress for several days, but there’s still a fair amount of instability. The skies are dotted with large bands of cloud and under some of those you have breeze, whilst under others it’s very light. Despite all that, the good news today is that the ridge of high pressure is well behind us now. Our biggest concern at the moment is the wind shadow from the islands, with Madeira this morning and the Canaries further down the track. We’ll have to correctly deal with that before we focus on our entry into the Doldrums.”

In terms of life aboard, the skipper of Edmond de Rothschild is fully into offshore mode now and the negotiation of the ridge of high pressure will have at least given him the benefit of some good chunks of rest after the initial taxing days of this race. Indeed, we cannot say it enough, the Vendée Globe is a long-distance race, an IronMan, where the most important thing is to make sure you last.

Ranking on 10 November at 14:00 GMT

Armel Le Cleac’h (Banque Populaire VIII) 23,243.4 from the finish
Vincent Riou (PRB) 16.6 miles astern
Paul Meilhat (SMA) 27.9 miles astern
Jérémie Beyou (Maître CoQ) 32.6 miles astern
Morgan Lagravière (Safran) 32.8 miles astern
Sébastien Josse (Edmond de Rothschild) 33.9 miles astern
Tanguy de Lamotte (Initiatives Coeur) 62.9 miles astern of the leader
Alex Thomson (Hugo Boss) 65.5 miles astern
…

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