Projects: The Vampire: the ultimate foiling experiment

The south east of the UK is home to, arguably, the most innovative hydrofoiling experiment in recent years: the Vampire Project. Through years of hard work and meticulous design, a team comprising of arguably the best in the business, is perfecting a pioneering foiling catamaran that’s really pushing boundaries. We speak to boatbuilder Graham Eeles to find out more.

“The Vampire is just a really great toy,” says Graham Eeles with a grin – and you’ve no doubt he means it. This 20ft long, 10ft wide foiling catamaran is his labour of love and something of a superstar on the foiling circuit; the illustrious product of years of expert tinkering.

The Vampire started life as M20 from Marstrom Composites in Sweden but over the past 15 years she’s undergone a painstaking metamorphosis. Owner William Sunnucks, Exocet Moth designer/fluid dynamicist Kevin Ellway and Graham have been working together to fine tune every element of her design – from the very top of the mast to the end of the bespoke foils – and all in the name of speed.

“It was William who came to us with the idea,” explains Graham. “Knowing that the International Moth is way out of the reach of most foiling fanatics, he asked us how we could make something equally fast and agile, yet more user-friendly.

“Since then, every year, we refine and test elements of the Vampire and every year he pushes us to make her foil faster and for longer.”

Graham Eeles

A ground-breaking design

The Vampire, then, is the ultimate foiling experiment – and consequently, a ground-breaking design. In a catamaran first, she features canted T foils, designed by William and refined by Kevin to emulate the windward heel that drives the international Moth fast upwind. These foils are also connected to a custom gull-wing system that lifts them out of the water from inside the boat – a feature that has the added benefit of making the cat easier to sail on daggerboards in light winds. Plus, it allows the cat to be launched right from the beach.

Impressively, all of these features were designed entirely in-house. “Kevin, William and the team design and refine the key elements and test them using mathematical modelling before they go into production; it’s the most efficient way to make enhancements,” says Graham.

“We’ve striven to perfect the technique we use to refine the Vampire”

However Graham believes that, ultimately, the performance of the boat is down to the construction – and that’s the job of Eeles Boatbuilders. “The theory is important but the theoretical margins of failure are actually bigger than ours; we have finer tolerances. So, over the years, we’ve striven to perfect the technique we use to refine the Vampire – namely, epoxy infusion.”

Impeccable composite construction

Over the course of this project, Graham and co have become epoxy infusion experts. They’ve designed their own infusion tooling to construct exquisitely perfect parts for general sale and for the Vampire – including rudders, hydrofoils, masts, booms and keels. This year, the Vampire team has focused on the hydrofoils and the mast. “We have very high standards; our aim is for our carbon fibre items to be flawless when they come out of the mould,” says Graham. “There’s no performance reason to paint our foils, for instance; how they come out of the mould is how they are designed to perform best.”

Unsurprisingly, then, attention to detail is vital during the epoxy infusion process.

When constructing the foils, for example, Graham’s team painstakingly lays out the carbon fibre design dry, before carefully applying a vacuum bag. “This must be done very delicately, to avoid leaving any imperfections in the foil surface; these could dramatically affect performance,” says Graham. Then they apply vacuum pressure down to -1 bar, leaving everything overnight in order to draw out as much air as possible. The following day, the team pipes in PRO-SET® INF-114 Resin® mixed with INF-211 Hardener®, before the whole piece is put in the oven to cure.

Working on a knife edge

“The foil construction process has taken years to perfect because we’re working on something of a knife edge,” explains Graham. “You want a foil that has optimal strength for its weight. Too light and it’ll break; too heavy and it won’t lift. It’s a very fine line but – thanks to lots of testing on the water and refining in-house – today we can say the epoxy-to-carbon ratio is spot on. The surface finish is also excellent.”

“If I have a question about how to use PRO-SET epoxy, I can just call up West System International”

Importantly, Graham believes that using PRO-SET epoxy products is a key reason why these design elements perform so well. “There’s no way we could deliver composite parts of such a high standard without PRO-SET epoxy products; they’re ultra-strong, light and reliable,” he says. “Plus the product support is great. If I have a question about how to use PRO-SET epoxy, I can just call up West System International. Most other companies are just sales people but not these guys – they know their products inside out.”

Foiling fast and free

So, 15 years and a lot of investment down the line, has the Vampire enjoyed the performance boost that William has been striving for? “Absolutely!” says Graham. “She now foils in all winds and every direction and has a top speed of 34.5 knots.” However, top speed is only part of the story. The team’s aim for this year is to get her foiling consistently fast for as long as possible. “We’re striving for an average speed of about 35 knots. It doesn’t sound like a lot but, believe me, it’s fast,” Graham smiles. “You can travel a long way very quickly at that speed!”

To that end, Graham has been testing the Vampire against herself, putting two crafts on the water to see how they race. He’s also working on a new mast design. “We’ve done the maths for the first one. We’ll tweak it, put it up to see how it performs and then maybe make it a bit lighter, a bit heavier, a bit stiffer – whatever it takes for the optimum speed,” he says.

Of course, the mast is just one part of a complex synergy of design elements, so it’s vital it works with everything else. “The project requires constant thinking,” Graham says. “Do I need to change the angles, the laminate, replace the ropes with wires…how does it all work together for the fastest result? Given the time and effort it takes, you’ve got to have the passion for a project like this.” Something that Graham, without doubt, has in spades.