Where magic happens

The America’s Cup has evolved a great deal since its inception. But one boatbuilder is perhaps responsible for bringing about the most groundbreaking changes – and it’s right here in New Zealand.

The high-tech facility in Warkworth that’s become one of the world’s hottest carbon fibre specialists.

There’s an old adage about ‘books-and-their-covers’ T that applies perfectly to Warkworth’s Core Builders Composites (CBC) – a company that’s been a fundamental part of Team USA’S Oracle boats over the last few America’s Cup events. It’s not until you’re actually inside the building that you realise it’s something special. The modest exterior and simple 90s décor belies the fact that this place is responsible for some of sailing’s most advanced technology.

Turning off Warkworth’s main drag, I began looking for a big, flashy place with large signs and Oracle logos. Were it not for Google Maps pinging that I’d arrived, I’d have driven past it. But once inside, it hits you. This building helped transform the sport of yachting, and certainly the America’s Cup, into what it is today. After a short wait, I’m greeted by director Mark Turner. Turner, a boatbuilder by trade, has been working with Larry Ellison since the days of his maxi monohull Sayonara and helped set up CBC

in 2001. I start off with “OK, I want to tell people what’s special about this company – about the technology and special capabilities you have here – and how it helps make something amazing, like an America’s Cup campaign and this new Sail GP series happen.”

Turner, very direct, is off. “To start with, one of the bits of machinery we have here, which I guess you could call special, is a very large five-axis CNC machine. It dictated us choosing this building – the old Rodney Times print facility – in the first place. It has a six-metre-high stud, which is what we needed for the machine’s three-metre Z axis. The machine itself has an operational envelope of eighteen metres by six metres by three metres. And it is accurate to 0.02mm.”

Sounds impressive, right? But the machine’s stats are just the tip of its operational iceberg. Throughout its various production stages, a component might come into contact with the CNC facility many times. From the initial creation of a component’s mould, right through to post-production machining and polishing.

“It has a variety of applications. It lets us do very large, single-piece moulds, so we can build plugs [models of a part, from which a mould is created] for yacht hulls or, indeed, other structures which are non-marine related. Right now, though, it’s spending a lot of time doing post-machining as part of the Appendage Programme (the hydrofoils) for the Sail GP boats.”

At CBC, repeatable accuracy is key, particularly for the Appendage Programme – responsible for the 36 hydrofoils used by all the six boats in the Sail GP event. The CBC team begins by digitally creating the ideal shape for the hydrofoil on the computer before using the CNC machine to carve the shape from a tooling compound. The resulting part is called a plug and it’s a replica of what the final part will look like.

A carbon fibre layer is placed around the outside of the plug and cooked in an oven, creating a mould. Carbon fibre is used for the mould because it behaves the same way as the finished component will during later ‘cooking phases’, thereby removing thermal expansion as a potential source of error.

Once the mould’s cooked and cured, more than 250 individual layers of carbon fibre are applied – each about 0.3mm thick – into the mould to slowly build up the shape and internal structure of the hydrofoil.

Foils are cooked in four separate stages to ensure each section cures properly. Finally, the hydrofoil is returned to the CNC machine for post-production machining. It is this final stage, where the foil is given its final shape and a mirrorsmooth finish, that makes it a piece of hydrodynamic wizardry, providing maximum lift with minimum drag.