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.

11.07.2006

Back to the Atlantic.

The Grand Prix du Portugal – Portimao will take place from 14 to 16 July. Gitana 11 and Gitana 12 have arrived in the small Algarve port and the crews are due to start training in situ tomorrow to familiarise themselves with the waters. After the 3 Grand Prix in the Mediterranean, this Atlantic event promises to be an exciting new challenge.

par Gitana

A brief history…

In days gone by, Portimao was a favoured port of call for Phoenician, Greek and Carthaginian vessels due to the excellent mooring offered by its spacious bay opening out from the Arade River estuary. Between Sagres, the historic town with its Marine Academy housing the nautical documents created by Henry the Navigator (1390-1460), and Lagos, the port once densely populated with naval shipyards, Portimao is focused firmly on fishing, especially sardines in summer. In this region of the Algarve, a veritable natural amphitheatre towered over by the mountains which bound the Iberian Peninsula, the climate is Oceanic, but in summer it very rarely rains here.

Fairly mild weather conditions…

In fact, during this summer period, a gentle area of low pressure settles in over Spain, while the Azores anticyclone moves up towards Europe. Consequently, a north to north-easterly flow forms along the coast of Portugal from Porto to Cape Saint Vincent, known as the “Portuguese trade winds”. But from the other side of Southern Portugal’s most extreme cape, the breeze is more westerly-orientated and picks up depending on the temperature (between 25° and 30° in July at midday) during the afternoon. The water surface is relatively undisturbed by the relief, as the cliffs are fairly low and the immense beaches lie between rocky outcrops.
As a result, the weather conditions for the Grand Prix de Portimao are likely to be characterised by a westerly breeze of roughly 10-12 knots in the morning, rising to 15-18 knots around 16:00 with the thermal wind, and then dying down by the end of the day while adopting a more northerly direction. In other words, for the start of the Grand Prix de Portimao week, the meteorological situation is fairly standard, since an area of low pressure has stabilised over the Iberian Peninsula and even though the Azores anticyclone is lower than usual over this summer period, it remains wedged over the ocean off Portugal, generating favourable northerly trade winds along the west coast of the peninsula.

So the sailing conditions for this Portuguese meeting are practically perfect.

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