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.

05.07.2021

The Maxi Edmond de Rothschild goes back to the yard.

par Gitana

After heading offshore for a spot of training on Friday, the crew of the Maxi Edmond de Rothschild returned to its port of registry in Lorient early this Monday morning. Initially enjoying a fast passage towards Fastnet lighthouse, the 32-metre giant set a course to the south in the Bay of Biscay. By Sunday morning, they were still posting high speeds when the maxi-trimaran collided with a UFO. The encounter resulted in damage to the Maxi’s central hull as well as her appendages, forcing Franck Cammas, Charles Caudrelier and their crew to interrupt their passage and return to Lorient. The timing was made all the tighter due to a meaty low pressure system expected to roll across the English Channel and the Atlantic seaboard this Monday evening.

A collision with a UFO, the stress associated with any lift-out

“We were making 30 knots, which is up there for a collision, but it is still our natural ‘cruising speed’ aboard the Maxi Edmond de Rothschild. We felt the initial impact on the daggerboard and then a fairly violent second hit around the rudder on the central hull. It all happened very quickly and it’s always complicated identifying the cause, but the impact sounded hard and it was a firm material,” explained Charles Caudrelier, one of the Maxi Edmond de Rothschild’s two skippers, on his return to the dock.

At speeds like these, collisions with UFOs (unidentified floating objects) are rarely without damage unfortunately… With the impact, the rudder stock on the central hull of the Maxi Edmond de Rothschild’s aft section, was severed. This damage led to the loss of the appendage along with structural damage around the latter. As such, before they could set a course for Lorient, the crew had to make the Maxi secure and deal with the minor water ingress.

Aiming to make the start of the Fastnet Race

In light of these unforeseen events and despite the frustration written all over the faces of the two skippers of the Maxi Edmond de Rothschild and all the members of Gitana Team, the five-arrow team knows that action is the best possible reaction. In this way, as soon as the Maxi Edmond de Rothschild made it back to the dock in the Kéroman base, the team wasted no time in getting down to work. The first job is to get a more accurate assessment of the true extent of the damage before they can work out how to organise the repair operation for the coming days and their upcoming needs on site.

“This kind of mishap is never pleasant but unfortunately we’re all too aware that we run the risk of collision when we’re sailing. It’s something that’s always on your mind whenever you get out on the water. There’s damage to the boat and the stern section of the central hull where the rudder is located in particular. We’ll have to lift the Maxi Edmond de Rothschild out of the water in the coming days. We’d planned to complete our qualifier for the Jacques Vabre and get some more time on the water… but that’s just the way it is! We’re going to have to adapt to the new schedule brought about by this damage. That’s life with offshore racing projects but the good news is that we should be back in action to take the start of the Rolex Fastnet Race in early August.”

First though, Gitana Team will be embroiled in a race against the clock to ensure that the crew is quickly back in training and can put this bad memory behind them.

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