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.

15.10.2015

Pit Stop in St Malo before Le Havre.

par Gitana

Having set sail from her port of registry in Lorient yesterday to make for Le Havre, the start venue for the Transat Jacques Vabre, the most recent addition to the Gitana fleet was making headway offshore of northern Brittany. At around 12:30am GMT, whilst close-hauled but slightly freed off in around fifteen knots of northerly breeze, the Mono60 Edmond de Rothschild suffered boom damage. This technical incident means that Sébastien Josse and Charles Caudrelier are compelled to make a short stopover in St Malo.

Indeed, the shore crew is already in position in the corsair town to recover the damaged part so it can be repaired at Lorima in Lorient. The monohull fitted out by Baron Benjamin de Rothschild will continue on her way towards Le Havre as soon as possible, so she can join her future rivals in the Bassin Paul Vatine promptly.

Mono60 Edmond de Rothschild, tech spec.

LOA: 20.10m
Waterline length: 18.28m
Beam: 5.70m
Air draught: 29m
Water draught: 4.50m
Displacement (weight): 7.6 tonnes
Keel bulb weight: 3 tonnes
Maximum upwind and downwind sail area: 290m2 / 490m2
Number of sails permitted aboard: 8 (1 mainsail, 7 headsails)
M² of living space: 10m2
Number and type of daggerboards: 2 foils
Source of on-board energy production: generators coupled to the diesel engine + hydrogenerators

Naval architects: Guillaume Verdier / VPLP Yacht Design
Yard: Multiplast (Vannes)
Rudders: C3 Technologies
Daggerboards: Heol Composites
Keel: AMPM (La Mothe-Achard)
Mast: Lorima (Lorient)

Start of construction: September 2014
Launch: 7 August 2015

Retourner aux articles

Heritage