On Sunday 27th July the Foiling Vampire had its first outing. Ben Clegg + William Sunnucks sailing accompanied by Graham Eeles, Ollie Newman and Chris Mathews on the rib. Finbar Anderson pacing us in his new Mach 2 Moth.
The Vampire flew immediately despite the light wind. First a long beam reach out of the Colne estuary, up to 22 knots. Then upwind, not foiling properly yet but I'm sure it will. Then downwind, easy foiling, no need for a spinnaker. Then a problem - the wand flipped behind the bias rod and the foil stalled. Whilst sorting it out we drifted backwards and the port wand broke. Proper limiting strings needed.
Plenty of problems to solve. The worst was the "Bambi" problem - the foil flips up when you heel to windward, something that is difficult to avoid unless you get your crew weight right under the boom.
But also much was right - the mainsail looked good, the boat felt stable in flight, the rudders felt light and easy to control, the boat flew in low wind strengths.
No real photos or GPS data yet. Just a video taken by Dan King who was on a rescue boat supporting the Solo Nationals. More sailing this coming weekend, then probably back to the works to fit latches to hold the foils down properly.
The idea: the Foiling Vampire draws more from the 11 foot International Moth than other foiling catamarans. It is an adapted M20 (see below) currently being fitted with inverted T foils - not the L shaped foils used by the AC72s and C Class catamarans.
Our objective is to build something faster than a Moth and more versatile: if it works it may also be faster than the existing generation of L foil catamarans. We are aiming for something that is easier to launch and sail than the moth, with better performance in light winds.
At the time of writing nothing is proven. In the next few weeks we will know if it works.
The Vampire with C foils in 2013
Competing projects: like everything this has all been tried before. We studied the Off Yer Rocker project, a C class with T foils that lifted well, but was never fast. Another T foil project is Whisper, a very light 18 footer developed by Ron Price and Southampton Solent University. The wands are fitted directly to the foils, and flight is early and stable. It is already sailing successfully on Southampton Water.
Meanwhile orders are being taken for dozens of L foilers from France (Sail Innovation - Flying Phantom) and Holland (Nacra FCS or “Flight control system”). In Texel 2014 the Nacra 20 FCS took line honours, one minute faster than the standard Nacra 20 footer. The Flying Phantom was also fast, but it ran aground hard whilst in the lead.
Why T foils? I am increasingly convinced that the L foils will prove to be a development cul de sac. They are a clever response to AC72 and C class rules that put limits on beam and control mechanisms. The L can be angled to make the height self regulating as in a V foil - see the picture of the Nacra above. The angle of attack can be changed with a control system, and different angles of cant achieved through the curve of the vertical part of the foil. But they also have some disadvantages. There can be a lot of leeway, and foiling upwind has been difficult to achieve. In some conditions it may be quicker to stay in displacement mode.
The Vampire is being developed in a rules free environment. We trust that if the concept works, the rules will adapt.
The moths have been sailing successfully on T foils upwind and downwind for about 10 years. They use a wand to control height and once foiling they achieve impressive speeds. We have calculated that in this year’s Texel conditions a well sailed Moth would have rounded nearly 30 minutes faster than the Nacra 20 FCS - assuming they didn’t meet the same fate as the Flying Phantom.
Who has been involved? I started work on a design brief in September 2013 following the Falmouth International C Class Championship, the "Little America's cup". But I needed an experienced designer to do it properly - dimensions, angles, control systems, theoretical testing and so on . After some persuasion Kevin Ellway, designer of the Exocet Moth came on board.
Kevin shook up the concept from beginning to end. In particular he introduced leeboards instead of daggerboards, which would have a number of benefits: wider effective beam, easier to assemble, easier to launch from a beach, windward foil completely removed from the water, no need to disengage the wand mechanism on each tack. There were also some disadvantages, principally the need to fix the angle of cant.
Kevin’s analysis was converted into CAD drawings by Rich Taylor and into moulds by Lee Morgan. Then it was over to Graham Eeles as builder. The wands have been built by Philippe Oligario, wand manufacturer to the Moth class. Grant Piggott has done the sail modifications, and numerous others have contributed through debate: Simon Farren, Ollie Egan, Finbar Anderson, Simon Northrop, Simon Reynolds, Russ and Penny Clark, Dave Chivers, Graham Bridle, Ollie King, Kyle Stoneham, Neal Pawson and many others - I've probably forgotten someone important. Many thanks to all those involved - even if the project falters I've enjoyed the journey.
The total raised for the Brain Tumour Charity has now reached £12,016, plus of course the tax credits. Many thanks to all donors, Laser sailors and helpers who have participated. See https://www.justgiving.com/michael-hare/
16th July: The new foils are nearly ready for the Vampire, a much adapted Marstrom 20. We will rig the boat this weekend at the factory, and snagging problems should be dealt with next week ready for a launch before the end of July.
The design has little in common with the L foils appearing on the Flying Phantom, the Nacra FCS or the America's cup boats. Some basic details:
Beam with one foil down: 4.7metres
Weight: 180kgs - up from 162kgs last year
Upwind sail area: 22.5 sqm - down from 27.8 sqm last year
Spinnaker: 27sqm. Light winds only
Lift out speed: 12 knots
Theoretical max speed upwind in 12 knots of wind: 19 knots at 50 degrees to true wind angle
Theoretical max speed downwind in 12 knots of wind: 25 knots at 140 degrees to true wind angle
Foil designer: Kevin Ellway (designer of the Exocet Moth)
Builder: Graham Eeles
Originator and owner: William Sunnucks
We want to create a catamaran which sails faster than a Moth. This is a demanding target which may take a while to achieve with consistency: the moths have 10 years of foiling development and once up they are now faster than almost anything else on the water. VPP calculations suggest a Moth could have rounded Texel in under two hours in this year's conditions - the leading boat, a Nacra FCS took 2 hours 30 minutes.
We also want a boat that remains fast in light winds and can be launched from the beach.
On Saturday 21st June we set off in our Formula 18 catamaran from Stokes Bay to "watch" the JP Morgan Round the Island Race. There is no formal entry for small catamarans but two elected to round the island that day and compare their times with the official results:
* Will Sunnucks and Phil Sharp on an Edge
* Nathaniel Ward and Mark Greenaway in an Alado
The Edge rounded from start to finish in 9 hours 36 minutes, the fourth fastest time of the day.
The day started with a long paddle from Stokes Bay to the start line. After 3 miles we accepted a tow from a kindly yacht and eventually started outside the North end of the official start line at 7.39am.
The beat to the Needles was long and slow, with a strong tide pushing us along as much as the wind. The F18 was slow in these conditions and we had great difficulty overtaking the quarter tonners. We would get through, but with one bad tack they would be through us again.
It wasn't until St. Catherine's point that we started to pull away. Once the spinnaker went up we were fast even though the wind was light.
After Bembridge ledge we caught up with the bigger yachts, easily overtaking them as they struggled with their kites on a close reach. It was a particular pleasure to overtake Rebel, a Farr 45 skippered by Ben Ainslie.
Nathaniel Ward and Mark Greenaway also got round in good shape, but elected to come straight back to Stokes Bay rather than head for the finish line.
This was a great day's sailing, and the results are very similar to those achieved in Tornados in the past, and of course Simon Northrop's efforts in the Round Goodwins race. Small cats can be faster and more seaworthy than many yachtsmen believe, and its good fun seeing all the technology on show out there.