THE CARBON KITCHEN

How the fastest racing yachts on the planet are built, step by step, at the King Marine boatyard

You watch some of the fastest yachts on the planet cross the start line — the TP52s flying around the 52 Super Series, the maxis sweeping the offshore circuits, the machines racing The Ocean Race — and, before you even notice who is at the helm, a basic question hits you: who builds these boats, and how? A good part of the answer lies in Alginet, half an hour from Valencia, and at the former Team New Zealand base in La Marina de València. That is where King Marine works, a Spanish boatyard that has spent twenty years building boats of the very highest level out of the same carbon fibre used to make rockets and satellites. Matías Bevacqua, one of its project managers, opened the workshop door to walk us through the formula. Let’s start at the beginning — with a boat that does not yet exist.

The boat that does not yet exist

The commission does not arrive as a sealed folder with five hundred drawings. The first contact is handled by CEO Pablo Santarsiero, and the initial brief is deliberately bare: “It’s going to be a 65-footer, an IRC 65, with these characteristics…” — not much more than that. The general shape is there; the structure and the materials are still approximate. And here is the first key point that those of us who aren’t specialists would never imagine: the boat is not fully designed before work begins; it is designed as it is built, in an iterative process. “We don’t just build the boat — we keep modifying it as we move through the process,” Bevacqua explains. A bulkhead or a reinforcement can be added on the fly, along with a thousand other adjustments to what will become a winning boat.

That is why King Marine is in constant dialogue with two distinct figures: the designer, who draws the lines of the hull, and the structural engineer — the “structures specialist” — who calculates how much carbon goes into each zone, which core, and in what form. Each design office has its trusted partner: according to Bevacqua, Botín Partners often works with New Zealand’s Pure Engineering, and Judel/Vrolijk with the US firm SDK; these are the two names behind almost the entire TP52 fleet. And not all boats are alike: a TP52, bound by a “box rule” that fixes its dimensions, evolves very slowly and the yard “already knows how to build it by heart”; a custom maxi, like the Capricorno, is almost a blank page.

The work plan: the countdown begins

With that still-green brief, the project manager assembles the work plan, and this is where King Marine flexes its management muscle: translating a boat that does not yet exist into stages, parts and, above all, hours. Three or four weeks can pass between receiving the project and ordering the mould. The boat has already been through the budgeting stage, so each phase is allotted a number of hours that it is best not to exceed. “In planning you never start from zero,” he sums up; “there is always a solid base to hold on to.” In terms of manpower, a 60- or 70-foot project can mobilise some twenty-five or thirty people: ten on the hull, ten on the deck and eight on the structure, working in parallel.

The mould: a matrix machined to the millimetre

Every King Marine boat is a one-off, a unique piece, and needs its own mould. The hull mould is a female mould — a concave shell on which the boat is built upside down — made off-site on a giant CNC milling machine: a metal structure supports rigid-foam panels that are machined, laminated with carbon fibre and finished with a machinable paste, which is milled again to the final shape.

Here the first obsession that sets the yard apart comes into view. Even though the mould supposedly arrives ready to use, King Marine doesn’t take it on trust: it repeats the vacuum tests, cures it again at 90 degrees and measures its shape to the millimetre on a boat 23 or 25 metres long. The mould has to hold a vacuum without leaks and stay stable at high temperature, because the less it deforms, the better the boat will come out. These are invisible hours that never show on the water, but that separate a good hull from an exceptional one.

The carbon kitchen

Now comes the heart of the process, and it is worth dispelling one false image: nobody “pours” anything here. Carbon fibre is an extremely strong material. Very little of it is needed to withstand the enormous loads these boats are subjected to. A TP52 hull is built from two skins of carbon fibre barely 0.6 millimetres thick, separated by a 30 mm honeycomb core.

The material is pre-preg — carbon fibre pre-impregnated with its resin — which is cooked in an oven under vacuum. Each ply is extremely thin, tenths of a millimetre, so building up a single millimetre of skin means stacking many layers, and not all at once. One ply is laid down, compacted and vacuum-bagged to drive out the air, and the process repeats, so that no air or porosity is left between layers. Once compacted, it is cured under vacuum at 75 to 80 degrees in a cycle lasting anywhere from 8 to 24 hours. And there is not a single bake but three in sequence: the outer skin, the core and the “inner,” or inner skin.

The core is what sits in the middle of the sandwich, between the two carbon skins, and it is what turns a thin laminate into a rigid, ultra-light structure. It is usually Nomex — an aramid-paper honeycomb, hollow and light — or PVC foam of the Divinycell type. The choice matters: the stiffest material does not bend, and boats are full of curves, so in areas of tight curvature a foam that can be thermoformed to copy the hull’s exact shape is used. And there is a workshop secret in the inner skin: when a 30-millimetre Nomex honeycomb is closed, a great deal of air is trapped inside, and King Marine has developed its own methods to let that air escape so the sandwich is perfectly consolidated. Total thickness is around 30 millimetres on a TP52 and reaches 35 or 37 on an 85-footer, always thinner and lighter wherever the loads are lower.

The skeleton: a carbon jigsaw

On a classic yacht, the internal skeleton — the frames — forms a grid. On these boats there is none of that: the bulkheads and structural elements are separate pieces, each with its own laminate, built on a structures table. Bevacqua sums it up with a perfect image: it is like assembling the skeleton of a toy dinosaur. What comes off the table is a rough part, which is then fitted to its exact position by laser scanning and cut on a CNC milling machine so that it slots in to the millimetre.

Execution is checked obsessively: every part, at every step, undergoes an ultrasonic inspection — a non-destructive test — to confirm that the plies are properly bonded, with no air and no defects. “We’re not assessing how strong the part is,” he clarifies; “we’re assessing that it is properly made.”

The assembly

Once the hull is cured, the mould is removed and assembly begins: first the structure to the hull and, finally, the deck to the hull. The precision demanded of every measurement is extreme, and it is here that King Marine’s craftsmanship becomes visible — in the control of the “taping,” the carbon tapes that stitch the bulkheads and the rest of the structural elements to the hull.

And here is a counter-intuitive, highly revealing idea: a carbon racing boat has no teak, no fine woods, no luxury of any kind, so the only thing the eye can settle on is how it is made. King Marine has developed procedures to make that bonding both extremely high in quality and pleasing to the eye: shifting a tape by five millimetres shows. Each tape laid to the millimetre is, at once, engineering and craft — while the paintwork advances in parallel.

The position of every winch, traveller or grinder is no improvisation either: it is a continuous conversation between the sailing team, the designer and the yard. Some elements go exactly where the structures specialist dictates and do not move even two millimetres; others are negotiated and call for a local reinforcement of an area. Then come the secondary structures and the interiors — “small” jobs that in fact consume an enormous amount of time. It is worth clarifying what is not made in-house: the mast, the boom, the keel and the rig are made elsewhere and assembled at the yard, which only builds the structure to receive the mast (chainplates, mast step, fittings). The rudders — and the composite foils — are made at King Marine, under the responsibility of its specialist, Juan Auge.

The formula

The final stretch links the keel installation, the commissioning — bringing all the systems online — and the sea trial. How much time does all this take? The last boat Bevacqua ran from scratch was the Capricorno, an 83-foot Judel/Vrolijk: sixty weeks of construction, more than a year of work. For the TP52s, the in-house man is Tono Llorens, who has the class’s planning timed down to the last detail.

So what, then, is the formula? There is no single spectacular trick. There are twenty years of craft, a team that has sailed together for more than twenty years, and an almost artisanal flexibility — if a project needs a bigger oven, the oven is made bigger. And there is, above all, a sum of invisible obsessions: the millimetre on the mould, the ultrasound on every part, the air driven out of the sandwich, the tape laid to the millimetre because someone is going to look at it. “We know where projects begin and what road we have to travel, and that is what keeps us awake,” sums up project manager Matías Bevacqua. That is the formula. The next time you watch one of the fastest yachts on the planet go by, you now know what hides beneath that sub-millimetre skin: two decades of craft, baked layer by layer, in a Valencian oven.

(Photo: María Muiña - SailingShots )

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