her , behind (wouter) my replies.
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<br>-Believe if we look ahead and specify lighterweight boats being allowed to race equally, in several years time we will similarly have a number of excellent higherspeed lightweight designs in the 20 class
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<br>(wouter) Wrong, It is far easily to optimize an existing platform with respect to handling and sailshape than it is to redesign the whole platform to a ligther one. The costs involved are very different and everybody can easily upgrade to the optimized setup but not as easily to a foundamentally redesigned platform. Cat builders will not put out several different designs for the same class. They will put out alterations to the existing platform.
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<br>>>>-Eventually the 18s will have to also update to the lighterweight design technology and building techniques.
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<br>(wouter) I doubt it. F18 works in its current configuration, just as the H16 does. As long as the class has active fleets it will not feel the need for lightweight.
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<br>>>The parameter that will bring this discussion on crew weight to focus is "overturning moment to righting moment ratio".
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<br>(wouter) Wrong sentence should be "overturning moment to righting moment ratio when wind is stronger than start of double trapping". The last is probably somewhere around 10 15 knots.
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<br>>>>Designers have gradually increased this ratio in an effort to build faster boats at low cost than the competition via higher sail area to weight ratio. This doesn't work if you can't hold the boat down, does it?
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<br>(wouter) Indeed, anybody wants a US I-20 ? This width, forced by trailorbility is the achilles heel of every cat. And the main reason why F18's beat iF20's on elapsed time in the stronger winds. Having said this, it does work in conditions with windstrengths below double trapezing.
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<br>>>Remember the recent Olympic catamaran selection trials? The old boat 10ft wide with 237sqft of sail area beat all the new designs with more sail area including spinnakers but only 8.5ft wide.
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<br>(wouter) yeah well not really unexpected considering this boat is also 13 kg's ligther and the other boat only had 15 sq.ft. moresail area. Look about just right to cancel eachother out. Now I'm not sure who sailed the boat but I consider Tornado crews to be the best in the catamaran world. I doubt if this all can be put down to width.
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<br>>If you don't go up in righting moment as you go up in sail area, then you can't drive the sails to their capability and the boat moves out of the competitive weight range for normal weight people and it won't perform well in strong winds.
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<br>(wouter) Indeed, STRONG winds. An important sidenote.
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<br>>>>> The only other way to increase sail area to weight ratio is to reduce weight. With this approach manufacturing cost takes off like a rocket and the light weight boat is very fragile. What I'm talking about here is building two hulls for the weight of one.
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<br>(Wouter) Stealth, BIM, Taipan, Spitfire, A-cats all boats very much cheaper than this designers boats and also F18 and iF20's. many times it was predicted that these boats would break the second you sat on them. That is if you had not looked at them before that time because that would break them too. Obviously the wrong in this point has been extensively proven.
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<br>>>>The only way to equalize this described advantage if a total boat weight and crew weight rule were to be implimented as Steve would advocate would be to add adjustable or telescoping racks or wings to the hulls
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<br>(wouter) Wrong and VERY misleading. Racks eqaulization would only work AT ALL in STRONGER winds, and NOT AT ALL at below double trap winds. This system is therefor one of the worse equalisation systems that you can think up. Furthermore because the righting ratio advantage isn't a fixed ratio but proportional to windstrengh. What are going to do rule different wingwidth with respect to windstrength AND crewweight AND crew height ?. I've looked at this for the F16 HP class but have dropped it completely.
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<br>>>The other option used of carrying weights and various jib and spin sizes for crew weight that particular race weekend seems overly complex , inflexable and adds burden to sailors and measurers , also never liked the idea of carrying added weights though have in years past , and really does not equal the playing field as accurately as racks would achieve .
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<br>(wouter) The last claim is very blunt and ambitios to say the least sorry carl.
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<br>Wouter
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