Construction of the AC45 catamaran at Core Builders composite - First hull coming out of its mould
This week marked a significant milestone in the building of the new AC45 catamarans, when the first hull was released from its moulds at the Core Boatbuilding facility in Warkworth, north of Auckland, New Zealand.
'This is an exciting time for us,' said Tim Smyth, who along with Mark Turner directs the boatbuilding operation. 'This is where we get to see the quality we have achieved.'
Built in carbon epoxy with honeycomb cores, the hulls are extremely stiff and light structures, engineered to tight margins and demanding very high accuracy from the boatbuilders. The sandwich construction involves two carbon skins less than 1mm thick laminated over an ultra-light honeycomb core, with the laminates baked under vacuum pressure in a giant oven for eight hours at 80°C.
The hulls are built in two halves in female moulds. Then internal bulkheads and structures are added, before the two halves are bonded together to create a single hull.
There was an air of anticipation as the two half-hulls were released from their moulds, lifted by hand and placed in cradles. The finish quality and details were closely inspected, before Smyth gave a satisfied smile. 'They are good,' he said, as the rest of the boatbuilding team returned to their tasks.
The workload at Core Boatbuilders has been intense as they meet the challenge of setting up a semi-production run of high-tech wing-sail catamarans, which will usher in the new era of America’s Cup racing.
While the first boat begins to take shape, the larger task remains to produce a number of these high-tech boats in time for teams to prepare for the America’s Cup World Series starting in Europe in mid-2011.
Also under construction at the Warkworth site are the wing sails that take these yachts to a new level of performance and sophistication. 'These boats are special because of the wing sails,' said Smyth. 'That is what makes them distinct.'
Overall, the articulating wings represent a similar surface area to the hulls, but are much more complex. 'More than 350 parts go into the wing. That is a lot of components to build and put together.'
Smyth and Turner led the construction of BMW ORACLE Racing’s victorious hard-wing trimaran and have drawn on that experience in building the AC45s. However, in one sense the smaller catamarans and their wings present an additional challenge. Instead of building a single custom design, a still-undetermined number of absolutely identical catamarans have to be built, requiring tooling for a semi-production run.
'It all has to be repeatable and efficient to keep the costs down. It is one thing to do that with hulls, but I don’t think anybody has done a production run of wings before.'
With any new design, there is usually a period of testing and refinement before committing to final production. With the AC45s, the pressure has been on the designers and builders to get it right first time, because the tooling is already committed.
Smyth is confident that if any issues arise from sea trialing, they will be able to address them. But he is hopeful that most refinements will be confined to areas like deck layouts and handling systems rather than major structural pieces.
Because of the tight time constraints, Core Boatbuilders has sub-contracted some of the work to companies in and around the Auckland region.
'We are building the first boat here,' said Smyth, 'but after that we probably will not build any more hulls.' Cookson Boats are already working on a second set and they will continue to produce hulls, while the Core site concentrates on the wings.
'Logistically, this has been a big undertaking for us because of the very tight timeframe,' said Smyth. 'It is all happening so quickly that it is hard to take a breath and assess what we have achieved. We are not congratulating ourselves just yet. If you think of the construction process like a funnel, we are still at the wide entry point. There is a long way to go.'