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.

04.11.2016

The foiler revolution.

When the IMOCA measurement switched to a more one-design format in 2013, notably with regards to the masts and keels, one might be forgiven for thinking that the creativity of the naval architects would be kept in check. Instead, Guillaume Verdier and the VPLP design office in Vannes, south-west Brittany, have given rise to some amazing new, let’s…

par Gitana

Taking inspiration from what the multihulls are undergoing in other domains, particularly in the America’s Cup, with its foiling catamarans that y above the water thanks to ‘L’ shaped foils, the designers have adapted the concept for the Vendée Globe monohulls. e boats don’t really y but the foils they carry on each side enable the hull to be supported by the water, which limits the drag and opens up an unsuspected universe of power.

Within the racing stable tted out by Ariane and Benjamin de Rothschild, this major innovation has swiftly been allowed free expression. Indeed, ying is a skill already familiar to the Gitana Team. First off, for several years Sébastien has been sailing the foiling Moth, which is a fascinating and especially unstable carbon creation. Familiar with this aerial method of sailing, the skipper quickly began foiling on the GC32 catamaran Edmond de Rothschild and has competed with the five-arrow team in the famous Bol d’Or on Lake Geneva. Next, more surprising still, in the spring of 2016, in a new departure at the controls of the Multi70 Edmond de Rothschild, the team became the first oceanic trimaran in history to take off from the surface of the sea where they reached no less than 43 knots of speed, pushed along by just twenty or so knots of breeze.

Given such a track record, it was only natural for the Gitana Team to envisage the use of foils in the Vendée Globe. This bold wager has since been taken up by the teams of five other new boats (Banque Populaire, Hugo Boss, No Way Back, Safran and St Michel Virbac) as well as by Jérémie Beyou, whose Maître CoQ is a former generation hull, albeit one equipped with ‘moustaches’.

Since that time, each of them has been able to showcase the benefits in lots of conditions with the foils enhancing performance. However, this innovation remains very recent, which logically raises questions about such things as reliability over a ‘long distance’ course like the Vendée Globe. In the round the world race, besides solidity, one of the main challenges will involve use of these foils in the numerous phases of weather transition, as well as in the extreme situations that the sailors might have to negotiate in the seas of the Deep South.

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