Remember, we presented you the strange AmerX40 prototype at the beginning of the summer when it was launched. A 40-foot dinghy monohull, very wide, which can deploy two lateral foils to increase its speed and stability.
Curious, we phoned her designer/tester during her trip from Normandy to La Rochelle. When he arrived in Aber-Wrac'h, Eric Prang told us that the boat lacked power due to problems with the sail cut and the absence of a spinnaker. But above all, the development of numerous appendages (foils, retractable electric motors, pneumatic ruddersâ?¦) had not allowed him to seek performance under sail. So everything remains to be discoveredâeuros¦
We found our passionate inventor at the opening of the Grand Pavois, eager to share with the public the sailboat, fruit of his invention. The boat presented is an empty shell. If the deck and the hull are finished and painted, the interior is raw aluminum with just a rough floor. Eric Prang voluntarily left the fittings aside to leave the equipment very accessible during the development phase.
We asked him a few questions to get his impressions after this first trip:
Do the foils work as expected?
" Currently the boat is not in its lines. Without the fitting, the front is too light and the boat leans back by about 2°. As a result, when deployed, the foils don't have a good impact. But I noticed that as soon as you put the foils on the water, the boat straightens up and moves much less. It becomes comfortable and safe. On the other hand, lowering the foils means losing between 0.5 and 1 N. But it's too early to draw any conclusions, because too many parameters - such as the sail trim, which makes us lose too much power - have to be solved first. "
To get an idea of how the foils work, you will find 2 videos shot during the delivery.
Doesn't the lack of ballast penalize stability?
" I am not afraid that my boat will turn over. Very wide, it already has a nice stability of form. Moreover, on board all the weights are concentrated under the floor, at less than 50 cm from the bottom of the hull, so at less than 50 under the water level: batteries, tanks, generatorâ?¦ Even with a lot of wind, as we encountered in the delivery, the boat never took an excessive heel. It never puts the liston in the water. "
Are the electric pods satisfactory?
" I had a problem at first with my propellers coming out of the water when we were motoring. I purposely didn't want to lower the pods too much so as not to expose them to floating objects. But I had to modify the system so that they would go lower. The system of pneumatic cart that goes up and down the engine (one on each side) works very well. I think the propellers will have to be adapted as well. But the maneuverability with 2 engines spread out like this is perfect. "
Why use a pneumatic system?
" I use a pneumatic system rather than a hydraulic one, because I find it easier to manage on a boat. On each side, a tube that runs from the bow to the rear skirt - a tube that also serves as a clamp and contributes to the rigidity of the boat - acts as an air tank. A compressor maintains the pressure inside. And hoses feed each point. Thus the anchoring is controlled with this system, as well as the raising and lowering of the rudders and engines. The advantage is that if a leak occurs, you don't have a lot of oil everywhere as it is the case with hydraulics! All the boat is thought in double, a little like a catamaran with the advantage of the redundancy in case of breakdown. For example, there are 2 air tanks and 2 compressors ".
What is the next step in the project?
" Now that I have solved the first technical problems and that I have the key points well in hand, I will be able to start the interior design. Probably this winter in La Rochelle. But all this will be decided according to the feedback I get on the Grand Pavois exhibition . "
