What is the origin of projet??
This is a project of the Bénéteau Group. We have been following the technological developments of foils in motorboats for a few years now. In order to hope to see this technology arrive in yachting, we have developed a hydrofoil concept boat which will be used at the start of races. Racing yachts are getting faster and faster, an America's Cup with racing monohulls is announced at 40 n?uds?!
The aim is to follow the racing boats (bring VIPs or journalists) in greater comfort. At the moment, motorboats are far too unpleasant at high speed in the chop.
How was projet? set up?
We worked in a closed cell with 3 partners. Sarrazin Design - Groupe DEMS, a style and design agency, SEAir for the design and manufacture of the flight systems and Noval, for the design and manufacture of the electric lifting and locking systems for the foils and the hydraulic motor chair.
Internally, Olivier Fougère and I are managing this project together. In total, there are about 20 people, who have worked for 9 months with the utmost discretion.
This boat still has a design particulier??
Indeed the study project is a race accompanying boat. Therefore, the cockpit is at the stern so that the passengers are installed at the bow, without visual obstruction while sailing comfortably at 25 to 30 knots. And for the surveillance of the water, it is largely elevated.
It's an experimental phase. Like all flying boats, safety is the primary objective. We navigate in bucket seats, with seat belts, shock vests and helmets.
Can you tell us about the behaviour of foils??
The design office decided to put 4 foils, two at the front and two at the back. The range of use in flight is from 15 to 40 knots. To enter the world of the yachtsmen, we are trying to eliminate the electronic adjustments of the foils (rake...) and we are working on their versatility and simplicity. The idea is to make a comfortable and flexible boat to take people along safely.
The objective is to be able to foil in the chop. Today, the tests validate comfortable high-speed sailing under foil up to a sea of 1 m to 1.50 m.
For the democratization and the reduction of costs, we have worked on the accessibility of piloting, by simplifying as much as possible the adjustments of electronic foils and by automating the adjustments during navigation.
Is this hull particulière??
This boat is an opportunity to develop new concepts: new hull, new materials and new manufacturing processes. For the occasion, the boat has been made of fiberglass infused around a core of high density PVC foam. We obtained a weight saving of 30% compared to a standard production.
Contrary to appearances, it's not a semi-rigid. The foam padding that surrounds the rigid hull is a protection that allows you to approach racing boats.
It's a whole new generation of 2V hull. It integrates new parameters such as the position of the foils or the rise and fall of the engines. The first V has a fairly high step up. We played on 2 decks to gain buoyancy and to lower the engines.
What are the constraints of homologation??
There is no provision for foils in terms of certification. So we have designed a hull equipped with the "accessories" that are the foils. Moreover, the boat will sail as well with or without them. For the current application for approval, we are aiming at category B with 8 or 10 people.
While the ship is flying, why such a strong one motorisation??
The objective is to go at 40 knots, with or without foils. 400 horses are needed for the 5 tons of this boat. At an average speed of 25 to 28 knots, a reduction in consumption of at least 20% is already visible.
How is foils? used?
First of all, this concept to be viable must be simple and easy. In the harbour, the foils are fully raised above the boat. So there are no problems of dirt, size or risk of breakage. We wanted to play it safe, all the mechanisms are also out of the water.
We have automated as many systems around the foils as possible, such as a locking system when they are ready to be used. To switch to "flight" mode, we don't have to stop, as they are operable in slow motion.
As far as driving is concerned, how is it passe??
Climbing on foils is smooth. Navigation just becomes much more comfortable. After trying it, you don't want to go back to Archimedean mode. As far as the turns are concerned, the foiler behaves like a normal boat, it takes an angle when cornering. Thanks to the 4 foils, you can sail at 25 knots in complete safety. However, we won't try to turn at 40 knots.
Although there are still studies to be carried out, we are already very satisfied with the results obtained. With this conceptboat, we are validating the flight up to 40 knots.
At low speed, you sail without the foils and when you want to follow fast boats, you switch to flying mode. Boats that are going 30 knots, you can follow them without any problem. All the more so as the races we want to follow take place in a bay relatively sheltered from the swell. It's an ideal playground.
What about suite??
After a first phase of 3 weeks of sea trials and technical validations, the boat returned to the shipyard for a general inspection, before optimization and new test phases.
