the final geometry of the foil must of course be fully accurate.’ For the America’s Cup, Persico Marine in fact are the official supplier for all foil arms for all teams, to one-design standard at 300kg each – with a tolerance of less than one kg. At their facility in Nembro, Persico made arm tests of these foils with all of the teams. ‘Only we can provide these services as we have the necessary machines – we use the best of man and the best of machine’ explains Somerville. ‘We take each new foil to the test bench, test it to 100 per cent and a bit more. Some we also stress to full failure and we then supply the data gained to the teams, which is a unique service.’ A Volvo 65 foil made by Persico that had sailed around the world twice was tested to failure in their facilities. They expected it to break at a load of 11 tons, but it only failed at 18 tons. Another big issue now is the time frame. Mark Somerville describes this challenge: ‘Big regattas start at a certain date and teams need to meet these dates and have enough time to try and test before. As a consequence, we need to deliver early enough or not at all. And the foils are often the most expensive part of the whole boat. So we also need to come up with ideas how to build faster. We try very hard to improve and automate. In the next 12 months we shall install new machines that will set new standards in both quality and timing.’ Foils and their manufacturing have developed dramatically and continue to do so as foiling itself and the understanding of this technique by the sailors evolves. The two foils for the new Hugo Boss and others for the next generation of Imoca have a very different design from previous profiles, and the technical experts at Persico have worked
Top: Thomas Ruyant winds up his new Persico-built Advensin September – the sixth foiling Imoca to be
launched in just seven weeks. The science of sailing yacht foils is in a phase of rapid
development and each new raceboat out of the shed sports a
different, and differently engineered, set of foils. Top right: An AC foil arm under extreme loads at Persico’s in-house foil testing facility. As well as building foils, Persico
applies both the know-how and the same equipment to effectively test new foil designs,
ensuring their strength is sufficient for the planned programme of use
extremely hard to match the building process to the constraints that have come up with the new designs. As the Chief Executive of Alex Thomson Racing recently said, grand prix yacht racing at this level is no longer just about qualified naval architecture and competent ocean racing, but also an engineering challenge at the very highest level.
The engineering community now understands this a lot more, so failures have become rare and solutions more commonly available. Still, at Persico Marine they are confident and comfortable that the company can do more than others and stay a step ahead. Most foils are now moveable, one example of which is the “wing” for the ClubSwan 36, which is somewhat easier to make than Imoca or AC foils, due to its size. Size matters - and smaller is easier to build as the effects described above are less of an issue. This is still America’s Cup-level technology, but on a smaller scale. The Swan only has one foil, which moves through the boat to stick out on either side. Also, on well-designed and balanced boats, the foils are now increasingly replacing canards or daggerboards, making these superfluous by also providing all of the lateral resistance the yacht needs.
At Persico Marine, designers, engineers and directors are very proud to have supplied all new America’s Cup foil arms. The new AC75 monohulls will be more
airborne than ever in the 2021 Cup races, without keels but sporting ballasted foils.
It’s a nice way to celebrate the 100th anniversary of the dream of the American brothers, Malcolm and Thomas McIntyre, who were the first to imagine a flying monohull. It was only in the 1950s that another American, Gordon Baker, achieved the unthinkable by flying a monohull for the very first time with the boat Monitor, which achieved speeds of 30kts and more on its hollow steel hydrofoils.
From those times it has been a long way via canting keels to the cutting-edge, high-tech composite foils used today. As Marcello Persico puts it: ‘It has been, and still is, a remarkable journey through time and evolution and, in recent decades, we have been a core part of this.’ Indeed, the experience gained at Persico is valuable to engineers and designers and boat classes. Just remember that Persico Marine built all the hulls for the Volvo Ocean 65, plus 24 daggerboards. Now it is the America’s Cup, the new generation of Imoca Open 60s, of which the new foiling boat for Thomas Ruyant is a prime example, but also large and very large high- performance cruising yachts such as the latest and largest Wally to date. Tango, the fourth Wallycento box rule 100ft superyacht, was recently launched at Persico Marine.
www.persicomarine.com
q SEAHORSE 77
PIERRE BOURAS
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122
