Flying the leeward hull
Tuesday January 8th 2002, Author: James Boyd, Location: United Kingdom

Cat sailor Paul Larsen (right) with designer Malcolm Barnsley and his new creation
As speed freaks go, Australian cat sailor Paul Larsen ranks in the top league. A former Team Philips crewman, Larsen ended up sailing round the world with Tony Bullimore on Team Legato in The Race and since then has been one of the regular crew on Cam Lewis' Team Adventure, which many view as the fastest of the Ollier twin-hulled giants. Most recently Larson discovered short handed offshore sailing, winning the 50ft class in the Transat Jacques Vabre with former Team Philips crewmate Alex Bennett.
So what could possibly be a greater adrenalin rush for such a velocity junkie than a giant cat? The answer: a radical craft designed to demolish the outright World Speed Sailing record. At London Boat Show, Paul Larsen has been touting his latest project, designed by British naval architect Malcolm Barnsley.
It would be hard to find someone better qualified than Larsen to be test pilot of this craft, but this is not just to his recent career sailing big cats.
Larsen comes from Healesville in Victoria, Australia and grew up with Simon McKeon, now driver for Lindsay Cunningham's C-class catamarans and his outright record breaker, Yellow Pages Endeavour, which today holds the world speed sailing record of 46.58 knots, averaged over a measured half kilometre. He and McKeon used to create boats and blast them around a lake at the nearby dam. "We'd try a monohull and try to make it go faster and make it longer. Then we'd try a multihull and then go to proas. We made canting rigs - all that from some kids with a few lumps of balsa."
Later he was exposed to Cunningham's incredible C-Class catamarans as they trialled off Melbourne's Sandy Point. "They have the same grace you get watching a big maxi or an America's Cup boat. It is pure efficency going upwind," he says of this fascinating but, at present, largely dead class. It therefore comes as no surprise to see his attraction to the many pioneering aspects of Team Philips' design. " Team Philips was just fantastic. Even knowing how it turned out, I don't think I would have swopped that programme for five Club Meds. It was such an inspirational programme. It was like something we tried out on the dam," he recalls.
Sailrocket, as Larsen's latest project is codenamed until such time as Pepsi or Microsoft step in as sponsors, comprises one 11m long hull (hollowed away below the waterline in the middle) with a foil and rudder, one crossbeam (giving an overall beam of 8.5m), joining the main hull to a small float (again fitted with a foil) on which the canting mast carrying 21.8sqm of sail is attached.
The design uses what Barnsley describes as "counterfoil - completely bypassing the stability limits encountered in monohulls, multihulls and indeed most speed record attempt craft to date." By inclining and separating the keel and sail components the overturning effect of the sail is almost completely eliminated. This will be aided by the flap on the aft side of the aerofoil crossbeam, so much so in fact that Sailrocket is expected to fly her LEEWARD hull at high speed.
Larsen says that an equally important element of the design is that due to the foil configuration the weight carried on the water remains constant regardless of the sail loading - in other worlds Sailrocket shouldn't become airborne. "The biggest problem with Yellow Pages - is that after a while you either reach the limit of your righting moment. or you don't have any boat in the water, " comments Larsen.
At present Larsen and Barnsley are looking for a sponsor and this will dictate whether the boat is built professionally in carbon fibre and the latest materials or whether they put it together themselves in cedar. "The boat could be sailed in six months - it depends who you get on board as sponsors. £250,000 would do it properly," comments Larsen. "At the moment we just want to showcase the idea - this has only come about in the last month." He adds however that Barnsley has been developing speed sailing craft for more than a decade and the concept and construction of scales models for Sailrocket has been under development for two years now.
Compared to Yellow Pages its weight is 70% (250kg) and is sailed with only one pilot. It has variable geometry for coarse and fine tuning of the rig position/angle. The result, Larsen feels, should be much faster than Yellow Pages and that was a boat capable of bursts of speed exceeding 50 knots from standstill in less than five seconds (sailing the 500m course at the world record speed takes just 19.44 seconds it should be remembered).
Larsen proposes to develop the boat slowly and so will start off with a softsail rig and work up towards a solid wing rig. But all this depends upon them getting a sponsor...
See page two for some design drawings...
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