achieving such exact precision in the build is where the skill lies, says CEO Marcello Persico: ‘It’s a challenge for us and that’s why we have developed our many tricks to be able to manage this! Even so it’s not easy. It’s not like putting a block of aluminium in a machine and then switching it on…’ If the design of foils is all about packing maximum structure into the smallest available area the challenge of constructing AC50 wings is very different, more of an aerospace problem, concentrating mainly on building a large structure in the lightest possible manner. In some instances the carbon ply weights on the AC50 wings are coming out at under 20g/m2, in other words so thin and fragile that they can no longer be laminated by hand.
‘You’re using lighter materials than you’ve ever used before,’ says Persico. ‘Even the glue films and the resins are a lot thinner and lighter.
‘Of course there’s been a lot of material testing to make sure that you’re not driving it too light, because you don’t want the thing to fall apart. Bottom line, these are the most complicated parts you could probably build…’
Volvo Ocean Race
Persico built the VO65 hulls, primary keel structure, bowsprits, daggerboards and their cases, plus all the daggerboard tooling and associated parts. During the last
Above: VO65 boat no8
comes out of the female mould at Persico for the new Akzo Nobel Volvo team. This is effectively the 9th VO65 hull from Persico – during their remarkable rebuild of the wrecked Vestas in the last race virtually a whole new hull shell was moulded. At their facility in Bergamo Persico now boast clean rooms (above right) that would not disgrace a race car or even a small aerospace manufacturer. But even this level of resources has been tested by some of the AC50 parts, in particular the foils with
their complex variable deflection profiles…
race the company rebuilt Team Vestas Windfrom its wreckage, in a remarkably short time. Now Persico have taken on the entire construc- tion awarded by Volvo Ocean Racing, save for the deck, of the one new VO65 being built for this year’s round-the-world race. Vital to building the VO65 is its one-design integrity. To achieve this Persico received all the moulds and jigs from Volvo, so the parts are identical whether they were built in 2014 or this year. The result is amazing: on an all-up displacement of just over 11 tonnes, variation between boats is <20kg. As Somerville points out: ‘That’s a smaller tolerance than the piston of your car. There hasn’t been a one-design boat built to those percentage tolerances ever before… at any scale.’
Such is their confidence in their processes that the all-up weight of the VO65 does not need checking as along the way everything is measured, weighed and approved by class manager James Dadd. ‘Every single part is built out of a mould that has already been approved by Volvo,’ says Somerville. ‘Then when the part comes out it’s trimmed and detailed and it’s weighed and checked for the correct geometry, and every part then has an “approved part” label number put on it. When the boat’s finally assembled, there is no doubt that every single part is correct. ‘We’re not building boats like a
typical boatyard and we’re not building boats like we were doing even 10 years ago,’ says Somerville. ‘The process
engineering and design have moved on so much. It starts in the technical office with designing of the processes, making sure that you design them to fully take advantage of your infrastructure, your CNC machines, ovens, hot presses, plotter cutting tool [all materials are plotter-cut to the right size and geometry], and so on.’ For sailors it would be
understandable to feel that the new VO65 will be faster or better somehow than the existing boats from the last race. However, this is just the legacy of the days when boats were built much less accurately and using ‘floppy’ Kevlar rather than rigid carbon/Nomex. Resin systems have also improved greatly, with a wider variation in curing temperatures, with lower-temperature curing resins being used to minimise distortion while retaining the best mechanical properties. ‘We don’t perceive the new boat to be any different from the first seven – they’ll all be identical. The last boats all went around the world and there was very little to be done on them and very little degradation.’
www.persicomarine.com
q Brought to you in association with
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