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.

12.11.2016

Cape Verde points.

par Gitana

After setting sail from Les Sables d’Olonne on Sunday 6 November, the twenty-nine competitors in the Vendée Globe are experiencing their first weekend at sea. The leading group, nicknamed the seven musketeers by observers, is still being led by Armel Le Cléac’h. Aboard Edmond de Rothschild, Sébastien Josse is right in the game, holding onto his westerly separation; a mature position with a view to the upcoming passage through the doldrums. The solo sailors are currently approaching Cape Verde and the negotiation of the archipelago highlights the problems with the wind shadow from these islands offshore of the African coast.

Seven boats – five of which are foilers – are in the leading pack and currently benefiting from a NE’ly trade wind of around twenty knots in order to drop down towards the southern hemisphere at speed. Led by Armel Le Cléac’h, the head of the fleet is setting a blistering pace. However, because you rarely get out of it what you put in, particularly in offshore racing, the toll for this quick sprint down towards the equator is the noisy discomfort from the monohulls and an all-pervading fatigue in all the voices from the sea this Saturday.

This is particularly true given that this bunched start to the race, somewhat reminiscent of the “Solitaire du Figaro”, is forcing the men to pull out all the stops at the helm in order to stay in contact with the leaders prior to what is always a very tricky crossing of the doldrums.

The right measure
The final string of islands to negotiate in their descent of the North Atlantic, Cape Verde is set to be abeam of the first competitors from late afternoon this Saturday. At 14:00 GMT, Armel Le Cléac’h was positioned some twenty miles or so from Santo Antao, the most northerly island. Looking at the trajectories, the majority of the leading group seems to have opted for a route to the West of the Portuguese archipelago, with the exception of Briton Alex Thomson, who may still choose to pass between the islands as he has done before on occasion. The sailors know the dangers of getting too close to these coasts, because to leeward the trade winds are inevitably ruffled by the land mass.

The wind shadow of the islands to the South will also be worth keeping an eye on, particularly in terms of Pico do Fogo, the highest point of the volcanic island of Fogo, which culminates at an altitude of some 2,829 metres!

Edmond de Rothschild, hunting down Hugo Boss
At 14:00 GMT, Sébastien Josse had clawed back another place in the ranking, moving up into 5^th place some 62 miles shy of the leader. Having covered 462.5 miles in the last 24 hours at an average speed of 19.3 knots, Edmond de Rothschild is one of the fastest boats at the head of the fleet. Solely Hugo Boss outclasses her in these conditions having devoured 476.9 miles. However, it’s worth noting that the two men have opted for different strategies, on opposing sides of the race zone, Sébastien Josse favouring an angle of attack and the gateway into the doldrums whilst Alex Thomson was letting the speed and power of his 60-footer do the talking.

Ranking on 12 November at 14:00 GMT

Armel Le Cleac’h (Banque Populaire VIII) 22,404.8 miles from the finish
Alex Thomson (Hugo Boss) 24.7 miles astern of the leader
Vincent Riou (PRB) 37 miles astern
Morgan Lagravière (Safran) 53.6 miles astern
Sébastien Josse (Edmond de Rothschild) 62.2 miles astern
Jérémie Beyou (Maître CoQ) 63.4 miles astern
Paul Meilhat (SMA) 67.9 miles astern
Yann Eliès (Groupe Gueguiner – Leucémie Espoir) 143.2 miles astern
…

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