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.

23.09.2012

Leg 4 Cascais – Marseille: the final sprint is on!.

par Gitana

After setting out from Portugal last Thursday, the MOD 70 fleet is beginning its fourth day at sea in the leg between Cascais and Marseille. This new day of sailing promises to be similar to the last one as the leading trimarans are forecast to make Marseille tomorrow morning. Though Oman Sail’s victory is becoming an increasing certainty as each hour passes, the order of arrival of its pursuers is still in some doubt. Two duos have formed in the chasing pack and Edmond de Rothschild Group and Spindrift Racing look set to continue jockeying for position right the way to the finish line.

“The wind variations you can have within 100 metres of another boat are quite incredible. Since this morning, the wind has rotated 180° and every time we round a headland there are more surprises. You have to constantly adapt to it and you need a bit of luck on your side too. Over the coming hours, the wind will be clearer and it will gradually build. The end of the race will be the opposite of what we have in our wake though, which is very good news!” admitted the skipper of Edmond de Rothschild Group at noon.

The zones of calm which have marked the latest few days of racing for the MOD 70s, and the Alboran Sea crossing in particular, are but a bitter memory this afternoon. Indeed, as they make their way along the South coast of Spain this Sunday, the pace has gradually changed on the deck of Edmond de Rothschild Group and its adversaries. The forecast breeze has finally kicked in and the trimarans’ speeds have at last picked up. This is sure to boost spirits aboard after the many wearing hours of uncertainty in the calm conditions: “We’re neck and neck with Spindrift, which we hooked up with again this morning. It’s good for morale. The wind has picked up, so that’s a boost too. We’re sailing downwind in 10/15 knots. Conditions aren’t very violent as yet, but we’re really powering along now. We’re disappointed with our current position obviously. However, we’re going to battle all the way to the finish so as we’re not the last crew to make Marseille!” said a determined Thomas Rouxel, one of the six crew aboard Edmond de Rothschild Group.

At the tail of the fleet, Sébastien Josse and his men have put their disappointment to one side in order to attack the home straight, which will carry them to Marseille. They are all too aware that these last 500 miles will be boisterous as the wind could well reach 30 knots tonight: “We’ve recharged the batteries so we can be ready for action on deck until the finish. There are still a few moves we could pull, with the passage of the Balearic Islands in particular, where we’ll have to make a decision about which trajectory to adopt” explained Sébastien Josse.

Before they complete this fourth offshore leg, the European Tour crews will have to leave “La Cassidaigne” mark to port, which is an isolated hazard some 3 miles to the South-West of Cassis. If things pan out the way things are shaping up right now, Musandam – Oman Sail will take victory in this race between Cascais and Marseille tomorrow morning, Monday, given how favourable the weather situation is for the frontrunners. Meantime, the trimaran fitted out by Baron Benjamin de Rothschild is likely to cross the finish line early in the afternoon.

The crew of the MOD Edmond de Rothschild Group in Leg 4

Sébastien Josse (Skipper), Olivier Douillard, Florent Chastel, David Boileau, Antoine Koch, Thomas Rouxel

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