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.

08.09.2008

The island of Saint Helena in Gitana 13’s line of sight.

par Gitana

Setting out from Hong Kong 25 days ago, Gitana 13 crossed the Greenwich Meridian late morning today and is once again sailing in western longitudes. Positioned 400 miles from the island of Saint Helena and sailing abeam of Angola, the maxi-catamaran in the colours of the LCF Rothschild Group is continuing to make headway, still accompanied by a SE’ly tradewind of between 10 and 15 knots. This air flow should nevertheless fill in over the next few hours. In the meantime, Lionel Lemonchois and his men are making the most of the current conditions to ‘recharge the batteries’ prior to a grand final sprint.

“The seas are flat and there is 10 to 15 knots of breeze. Gitana 13 is making between 15 and 20 knots under gennaker. At the moment we’re heading in a straight line so there are no manœuvres and for once it’s not wet on deck! The boys are making the most of it to chat under the hoods or allow themselves some free time” confided Dominic Vittet during the daily morning call. Though some of the crew are isolating themselves to read or set about their washing, the others are making the most of conditions to check and maintain the mechanical elements of the maxi-catamaran. This is the case for Olivier Wroczynski and David Boileau who spent Sunday in the engine hold. The aim of the operation: to clean the starters and re-tension the belts.

One thing for sure is that the period of calm which Lionel Lemonchois and his men are currently experiencing is being appreciated by one and all. In a few days time, they know only to well that it will be quite a different rhythm aboard the 33 metre maxi-catamaran: “This period of recuperation is important and the crew know how to make the very most of it. The section between the equator and the doldrums may well prove tricky or at least demanding for the crew: lots of manoeuvres, stress and little rest” added the onboard navigator.

As regards ‘environment’, Dominic draws up a rather unusual description of the classic tradewind skies: “The sky has been very overcast since we began our ascent of the Atlantic. The boys aren’t hiding the fact that they are keen to find a little heat again as it’s still cold. At night, salopettes, fleeces and light jackets are still indispensible. Yesterday, we were able to observe an albatross in our wake, which is pretty incredible at these latitudes! However, you mustn’t forget that in the southern hemisphere, we are currently in the winter.”

The weather analysis by Sylvain Mondon (Météo France), router for Gitana Team:
“It was when sailing on port tack in rather sluggish SE’ly tradewinds (just 10 to 15 knots) that Gitana 13 crossed the Greenwich meridian this Monday morning. The long tack which began on Sunday morning, will accelerate a little (average speeds will exceed 20 knots) during the course of the day and the evening in particular as the maxi-catamaran passes to the north of the island of Saint Helena. Lionel Lemonchois and his crew will thus have to continue to make headway on port tack for 12 to 24 hours, prior to performing the gybe which will mark the start of the rapid downwind course on starboard tack towards the equator. The moment and the location of this manœuvre are influenced by the decision of where to cross the doldrums, scheduled for the end of the week and situated between 4°and 8°north in this season.”

At the 1000 UT position report, Gitana 13 was just 4,500 miles from London, with just a third of the course of the Tea Route left to sail. The latest weather forecasts are still showing a passage of the equator on around Thursday 11th September.

The island of Saint Helena
The island of Saint-Helena is a volcanic island spanning 122 km², situated in the middle of the southern Atlantic, 1,930 kilometres from the African coast and 3,500 kilometres from the Brazilian coast. Discovered on 21st May 1502 by the Portuguese sailor João da Nova Castella, the island forms part of the British overseas territories. Since 1657, Saint Helena has belonged to the British East India Company, but the island is essentially famed as the place where Napoleon Bonaparte was imprisoned from 1815 to his death on 5th May 1821.

A few figures
Gitana 13 left Hong Kong on Thursday 14th August at 07h55’32” (UT)
Monday 8th September at 0745 UT, Gitana 13 was sailing at 14°06.67 S / 00°27.42 E

Watch No1: Lionel Lemonchois (Skipper / watch leader / helmsman) / Olivier Wroczynski (trimmer /head of computers and power) / David Boileau (Bowman / head of deck fittings)

Watch No.2: Ludovic Aglaor (watch leader / helmsman) / Laurent Mermod (trimmer) / Ronan Le Goff (Bowman)

Watch No.3: Pascal Blouin (Watch leader / helmsman) / Ronan Guérin (trimmer) / Léopold Lucet (No.1, head of supplies and doctor)

Outside the watch system: Dominic Vittet (navigator)

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