Tripon remains reserved about his choices though clearly he is very satisfied with the build of the boat and its clear potential. There are clear constraints within the IMOCA rule regarding the shaping and width of the bow and Tripon, Manuard and the Nantes yard have developed their choice very close to the limits allowed, echoing the shapes of the latest generation of Class 40s and Minis. Their choices are a collaboration between the sailor, the builders and Manuard and his design team.
Vendée Globe: Armel this seems like a bold choice in terms of the hull shape of your new boat?
Armel Tripon: To my mind it is not that much. In fact what surprised us was that no one has gone down this route, which, in my view, has many advantages. We started from a common belief, but we really worked hard on the VPPs and the computer modelling and simulations to endorse our gut feeling.
VG: What was your initial finding?
AT: With foils now we can see that all who have them manage to fly, but we are still affected very strong accelerations and decelerations (particularly as the boat rises and touches down or goes into the wave). This makes for very demanding, uncomfortable sailing for both the boat and the skipper. Our question we sought to answer was how to maintain a high average speed throughout a course of several months like the Vendée Globe. The scow is our best answer to that question.
VG: What are the advantages of this choice of hull?
AT: I see two obvious advantages. With this type of hull we find that in strong winds and in seas instead of sailing into the backs of waves it tends to surf on the back of the it. As a result, we have significantly less bumps and we can expect a steady, more consistent higher speed. The second advantage that has already been proven on our and other smaller craft is that they are much drier than conventional hulls. That’s a significant improvement in terms of comfort when you're in the Southern Ocean.
VG: Is this the only innovation?
AT: No there are more. On an IMOCA there are so many parameters and such as the position of the ballasts or the role of the foils. We have very offset foils (very outside the hull, ed note) to be able to add leverage. We also have a system that allows them to be fully retracted to avoid additional drag. We saw on the last Transat Jacques Vabre that competitors without foils were quite successful downwind. Beyond that it is about moding and optimising, how to learn how to use the boat.
VG: Was there also any desire to stand out, to be seen to be doing something different?
AT: Absolutely not. We mainly just tried to our own beliefs. It turned out that we were very much in line already with Sam Manuard’s thoughts and those of the builders. From there on, from first principles, we did not then ask too many questions. That's how we're playing it. We hope to be among the leading pack and prove we have got it right.
The Designer’s View.
For his first IMOCA, Sam Manuard has chosen not to follow the current type form, such as it is.
Sam Manuard: "This is an idea I've had in mind for quite some time. But I didn't want to impose it without being sure. We started modelling two hulls: one typical one and the other more radical. We passed them to CFD (computational fluid dynamics modelling) and it soon became apparent to us that the scow hull proved to be more efficient reaching in a seaway.
Going down this new path is obviously a source of some stress. We may be convinced that the option is interesting, but in the end it is what happens on the water that determine if we made the right choice.
But remember hull shape will not be the only factor, the use of ballasts and the position of the foils are determining factors. And if we look at others, Guillaume Verdier's designs while not so radical, are close to what we have done. The handling and performance of APIVIA and Advens for Cybersecurity on the Transat Jacques Vabre help reassure us.