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.

05.09.2008

Slowed pace along the Africa coast.

par Gitana

Setting out from Hong Kong on 14th August 2008, Gitana 13 is tackling the climb up the Atlantic having rounded the legendary Cape of Good Hope in the early hours of yesterday. At a reduced pace over the past few hours, the maxi-catamaran in the colours of the LCF Rothschild Group is having trouble getting free of the clutches of a zone of light winds this morning. This isn’t of great concern though as Lionel Lemonchois and his men know that they’re soon to hit the SE’ly tradewinds and thus the expressway to the gates of the equator.

We generally talk about the calm before the storm but the opposite is true for Gitana 13! The raging elements at the tip of South Africa have given way to evanescent winds and a calmed sea, as the 33 metre maxi-catamaran sails along the African coast bound for the equator. The situation is the result of the remains of the ridge of high pressure from the Saint Helena High: “we were caught by a zone of calms at around 0200 hours this morning. It wasn’t really part of our programme but we’re making do with the situation. Outside there are smooth seas despite some residual swell, and the anemometer is rarely exceeding 5 knots! We didn’t really make much headway last night, encircled by the tentacles of this calm spell (zone of very light winds)” conceded the onboard navigator this morning.

However, this calm weather is in no way synonymous with a drop in pace aboard Gitana 13. Indeed, these light airs have called for permanent attention on the part of the ten sailors. Trimming the boat as best they can in order to exploit the slightest gusts and thus stand a chance of getting free and finding the way out, such has been the motivation of Lionel Lemonchois’ men: “On deck, activity has been fairly intense throughout the night. You might think that no wind relates to no effort… but it’s quite the opposite. The little amount of wind certainly enables a relaxed atmosphere but requires an enormous amount of physical effort: shifting sails to balance out the weight, fine trimming, manœuvres (gennaker hoisting); those on watch are frequently accompanied by the standby watch on deck” explains Dominique ‘Mino’ Vittet.

For the time being the skipper of Gitana 13 hasn’t been able to begin repairs to the area of the boat which was damaged last Tuesday: an 80 cm crack on the starboard beam: “Despite the calms, Lionel hasn’t yet begun repairs as our ship’s wound requires tranquillity, as well as a few extra degrees. Heat is essential for the resin to set. As we wait to make sufficient northing and ensure that we have all the right conditions, Lionel is drawing up plans and preparing all the details of the intervention” the onboard navigator tells us.

The first signs of an ESE’ly air flow are this morning beginning to fill the sails of the maxi-catamaran equipped by Baron Benjamin de Rothschild, and the way out can’t be far now. From then on, Lionel Lemonchois and his nine crew will endeavour to make as much northing as possible in order to find the established SE’ly tradewinds, synonymous with the expressway to the equator.

A few figures
Gitana 13 left Hong Kong on Thursday 14th August at 07h55’32” (UT)
Friday 5th September at 0845 hours UT, Gitana 13 was sailing at 29°30.30 S / 15°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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