AN INNOVATIVE PROJECT

Alain always wanted to design a new 5.5m JI, he also became World champion and Swiss champion in this series. This project has matured many years before moving on to the actual stage and took form in 2009. This is the outcome of 25 years of high-level navigation on all kinds of boats, from dinghies to one design through the multihull racing, but also the whole experience of a sailmaker who was one of the first in Europe to design sails using the computer.

1000 HOURS RESEARCH

This project necessitated extensive work to collect, analyze and synthesize more than 30 existing boats in this class, but also in other series. For a comparison of identical values, several recent or older interesting boats were designed with modern computer tools.

Finally, more than 1000 hours were spent to combine the best of each element on the same single boat.

CNC MILLING MOLDS

To ensure accuracy below the tenth of a millimeter, a 20 m long milling machine, usually served in the automotive and aviation, was used to machine the hull mold. Smaller milling machines were used for the cockpit, the keel, the trim-tab and the rudder.

VACUUM INFUSION & PRECISION

Each element of this yacht is made of vacuum infusion and undergoes a post cure. This ensures maximum rigidity with minimal weight while being in compliance with the class rule. As the the boat is being built, each component or part is checked, their weight and center of gravity is compared to the forecasts prior to being validated. On this project, each shackle is weighed and each element or hardware is calculated to provide the best SAW report (strength / area / weight).

3 HULLS & 73 TESTS

The complexity but also the possibilities of the class rules, gave rise, once the lines defined, to 3 different hulls drawing to analyze the best use of bow/stern girth and waterline. A scale model was built and served for the 73 tests planned to confirm the waves generated by the hull and the extension of its waterlines at target speeds under dynamic situation.

BULB BALLAST CNC MILLED IN THE MASSE

To lower at the maximum the CG (center of gravity) and get the best performance VWAW (volume / wetted area / weight), the bulb was milled in the lead. Compared to casting, this guarantees density and symmetry as well as a perfect finish.

ANTI-TWIST STRUCTURE

Unlike modern 5.5m, with a lead fin and nearly 400 kg of lead in the bottom of the hull,  AM55 has a rigid internal structure connecting the bulb. This one is laser cut as many other parts. Molded lead supplement the fin to reach the desired weight.

BALLAST & RUDDER FINS OPTIMIZED

A global concept means reviewing each element that makes up the boat. For each appendage more than 20 profiles have been tested, according to the Reynolds number given by the speed, to optimize the profile, but also the proportions and trim-tab angles.

CARBON, TITANIUM, PBO & HYDRAULIQUE

Innovation is again present on many aspects.

The mast, boom and spinnaker pole are of course made of carbon, but the innovation comes from the shape of the profile, improving the performance of the sails and lowering the general drag.

Other revolution on board is the Cariboni hydraulic, partly made of titanium, which is lightweight and equipped America's Cup, the Volvo or the Vendée Globe boats.

It comes into action to trim the rig instead of turnbuckles and conventional hoists, but also to swing the mast downwind.

It does not stop there. All shrouds and forestay skip to textile PBO rigging instead of conventional steel, a weight gain of about 65% and handling that have no equal .

The vang changes direction to become a Gnav, pushing the boom down, freeing up more space for maneuver and holding the boom in the air without sails.

ANGLE SENSOR & STRAIN GAUGE

As in aviation, automotive and smartphones, electronic is present on board.

On the keel, a trim-tab (flap) angle sensor displays the adjustment to the degree on the two color LCD screen on the center console.

A traction sensor complements the measures, giving the crew the forestay tension in kg, with a precise and direct setting value. This information is paramount, the forestay hollow having a significant influence on the volume and the trimming of the jib.

Révolution

World innovative sailboat with adjustable shrouds by hydraulic, forward canting mast with swept back spreaders (HCM®)

AlainMarchandYachtDesign

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KNOWLEDGE AND TECHNOLOGIES CONCENTRATED

If you are able as an architect to design an innovative and performing new 5.5 m IC despite the constraints of rules, then you are simply able.

SUI 227 «CinqueCinque» the most advanced 5.5m IC sailboat ever done before, PBO shrouds and no runners