There’s been a new foiling catamaran flying about Southampton Water for the last few weeks and visitors to this year’s PSP Southampton Boat Show (September 12-21) will have a chance to get a close-up look at Stand C43a (right next to the Boat Show Eye).
What started as a research project at Southampton Solent University has become a full-blown new boat launch. "This was never meant to happen so fast," says her designer, senior lecturer in ship design and veteran 49er sailor, Ron Price. "She flew the first time we took her on the water right around Easter time and she just keeps getting better and better."
At first glance Solent Whisper resembles a scaled down AC72 (see AC34 video highlights: the ultimate comeback). The narrow, square-headed main is deliberately styled to look like a wing sail and the miniature jib almost looks ornamental on the bow. The wave-piercing hulls are reminiscent of San Francisco 2013 and the enormous bowsprit will get used only when the breeze is below 10 knots.
But the difference lies in the fact that this super-lightweight 5.2m (6.2m LOA) multihull has retractable vertical T-foils – twin rudders and centreboards – in place of the J boards or C boards seen on the AC72, the A-class catamaran and various other foiling cats either in production or still at the prototype stage. T-foils, according to Ron Price are not only more efficient than curved foils (just ask the US Navy), but they are also the key to the Whisper’s stability.
Launching is simplicity itself – even singlehanded shouldn’t be too much of a challenge, then hop aboard and head for deeper water. The angle of attack for each foil is adjustable in flight, as is the flap on each of the wings. The flap creates lift and the angle is adjusted by using a wand connected to a gear system on the trailing edge of the main foils. With the hulls in the water, the wand trails behind setting the flap at full lift angle. As the hulls rise, the wand drags closer to the vertical until at the determined ride height (set by a dial on the hull), the flap is set to neutral.
Smooth stable flight
But the four foils all remain in the water at all times. No grinding one up while riding precariously on the other three. In fact, according to her designer, keeping both the wings submerged is the key to her stability and performance. On take-off both foils provide lift but as soon as one foil is more heavily loaded than the other, the lazy one acts as a counter force, keeping the angle of heel in check.
There’s actually no need to trapeze when foiling – even though two are fitted for getting up to top speed. There’s hardly any need to lean the rig and hull to windward, although go much more than 5 or 10 degrees to leeward and things would get messy fast.
Ron hopes to sign a production agreement soon and is tweaking the design to make the Whisper as economic as possible to produce. ‘Ideally I’d like production to stay in the UK, so I’m aiming to get the man hours required to build each hull down to about two days maximum. I’d also like to keep costs low, so I’m aiming for something around £15,000 for a complete boat.’
It is hoped that a retail production version will be available for the London Boat Show in January 2015.
“I’m hoping that my design ideas will make inshore and small boat racing more accessible and affordable for the average club racer, those who sail for pleasure and people with disabilities,” adds Ron. "The boat is easy to sail in its stable mode, but at the top level expert sailors will be able to tweak the foil set-up to sail the boat more effectively." For more foiling boats see, 10 Fantastic Foiling Boats.
Solent Whisper specifications
LOA: (incl bowsprit) 6.2m
Foil length: 1.0m
Max ride height: 800mm
Crew weight: 150kg
Mainsail: 12.9sq m
Jib: 3.2sq m
Spi: 13.5sq m
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