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.

03.09.2008

Deliverance approaches.

par Gitana

This Wednesday morning, whilst the crew of the maxi-catamaran in the colours of the LCF Rothschild Group is attacking its twentieth day at sea, the Agulhas Cape is still 90 miles ahead of their bows. Despite yesterday’s forecasts, Gitana 13 is slightly behind schedule which is the result of a difficult day as much for the men as the gear. Grappling with a new front associated with a low, Gitana 13 has suffered, and Lionel Lemonchois and his men are lamenting some damage to the starboard beam up forward. Their entrance into the Southern Atlantic will certainly be well deserved!

Contacted by his shore crew, Lionel Lemonchois went over the circumstances of the damage which was incurred by Gitana 13 yesterday afternoon: “As we were heading towards the front, which we knew was set to be rather venomous, the wind was gradually picking up. The crew, who had fully anticipated this strengthening wind, had perfectly adapted the sail area so that Gitana 13 would suffer as little as possible. We had up to 55 knots at the strongest part of the system. However, it was the seas more than the strength of the wind which caused us problems. They continued to build until the waves reached 6 to 7 metres. As we were sailing against the current, the seas were abrupt and fairly breaking. One of the waves was stronger than the others and Gitana 13 dropped down heavily. It was one impact too much!” conceded the skipper of Gitana 13, before going on to say: “It was a dark night, the seas were still very big and there was nothing more we could do. As a result we’d decided to heave to for the night, in order to be able to inspect the damage at daybreak. It consists of a crack spanning over 60 cm on the forward section of the starboard beam. However, to the best of our knowledge it isn’t detrimental to the boat’s structure. However, we’re continuing investigations together with the help of Gitana Team’s shore crew.”

Since 0400 hours UT, the maxi-catamaran equipped by Baron Benjamin de Rothschild has got back on course towards the Cape, whilst remaining vigilant and adopting a reduced sail area. Given the numerous members of the crew aboard Gitana 13 who are skilled in composite, together with the material we have on the boat, the crew should be able to repair the damage themselves. However, such an operation will have to wait until they get into some milder conditions.

The positive point at the start of today is that the sailing conditions and life aboard for the crew have greatly improved over the past few hours. The wind is now blowing at between 15 and 22 knots and the seas have eased on the whole and are thus becoming more practicable.

A few figures
Gitana 13 left Hong Kong on Thursday 14th August at 07h55’32” (UT)
On Wednesday 3rd September at 0845 (UT), Gitana 13 was sailing at 34°49.13 S /21 °38.77 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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