I'm seeking truth, and real workable solutions........ within my parameters, not arguing for the same of arguing, or to support my position or choices. I have no problem at all with being wrong...... I've been wrong enough that I'm used to it, and see it as a just step on the path. The foam core construction fell right in with my objectives. It would be beyond stupid to resist changing materials when that change plays into my objectives so well........... sheer stupid stubbornness. Likewise the offset mast......a design feature which I have not yet become entirely comfortable with. I do want the main portion of my junk rig to be able to fly over the boat on those points of sail where it is oriented mostly laterally. Basically anything "south" of a beam reach, or even a close reach, which means on one tack the flow over the sail would be reverse of the other tack. Not really a problem except that the camber will be at the wrong end on one tack, unless it's centered. I'm toying with ways to shift camber, ideally passively, and outrageous concept ;-) However it may not be relevant. How much difference in performance is there is real world sailing with the camber 30% aft of the luff, or at the 50% point? Theory says it should be significant, but theory is not always borne out in real life sailing. An example is the "good tack / bad tack" belief regarding the cambered junk rig. Arne Kverneland, who basically pioneered the cambered junk rig, and is the guiding light if anybody can be called that, for those who have adopted the modern junk rig, discovered through extensive testing that the performance of the camber panel junk rig on the tack where the sail hangs free of the mast is indistinguishable in real life from the tack where it lays against the mast..... known by many as "the bad tack". This is relevant only in pointing out that our expectations are often not borne out in the real world. I rather like the idea of having the option of hanging the main sail well over the side, or hanging it over the boat. The boom will be quite long, as the aspect ratio will be low. The mast will not be tall, standing only about 9M above the top of the bridge deck cabin.... about 36' or actual "air draft" (height above cwl). The shorter the mast has both advantages and disadvantages. I will be sacrificing ultimate performance, but the low aspect sail will have a great deal of footage for light winds. The junk rig does not flog due to the battens, so when faced with light and variable winds, I can have all sail up..... no flogging, no huge spinnaker inflating and collapsing and being a general nuisance.
The solutions you propose to your problem are interesting. As I said, I too looked at those cat designs. I find my self replying to your questions with, 'you would not have to do that if this criteria was different'.. If that bugs you I will desist. But I think we are learning a lot about boats fast. I was impressed how you quickly agreed about stern fineness. Facts guided you, not ego. I must respect that. But also, move the mast, change the construction material! Much wisdom. Mad respect!
Agreed. But I think It is better to say, as early as possible, what can I do with 10,000$?. Or what can I do with 50,000$? Etc. It is anti intuitive to me to commit to a platform first, then see what fits.
Also you have made the point of ongoing costs. That also is an important criteria people do not think enough on. In aviation there is a TBO. Which is an accounting idea that tells you the cost to budget for every hour you operate the plane. Afaik, there is not a similar idea in boats. Nobody has a $ per sailing hours for sails, or hulls. Or they do, and I have not found it yet.
I've long ago examined what I can do with the funds I have available to build, and what ongoing income I have, and this is a major driver, if not the major driver. I'm a poor man, I don't have deep pockets. Weight is proportional to cost until we start striving for extreme weight reduction, and then it describes a parabolic curve in the opposite direction. Within a given weight range / cost range, the objective is to build the boat that provides the best living and sailing environment / most usable space. The cat fulfills that very well. Cats increase rapidly in weight / cost with length. The Woods Tamar for example, at 31 feet is almost double the weight of the KD 860 (stock) at 28 feet. I don't expect the KD 9. The Kohler Pelican at 11.5M has an empty weight of only 2200 KG, against the KD 860 at 1800 KG. The weight per meter of length in this case is going down from 209 - 191 for the longer boat. This is definitely the exception, NOT the rule. Most boats go the other way. I expect the KD9 to increase in weight per meter as the 860 because of where the length will be added, as well as the knuckle. Underwater dimensions could be changed, increasing displacement out of proportion to length increase to compensate.......... a cascade effect in the wrong direction. The foam sandwich construction alleviates this...... It's a balancing act. Increasing length just for ride and speed is simply not on the table here. Those are NOT priorities. Note the way Bernd created a "wing" as on a trimaran main hull or on a Harry Proa in the attached photos, in contrast to what Pete Hill did. Pete's knuckle is an added complication to an intelligent infusion mold. The "wing" on Pellican is simply an extension of the bridge deck cabin over the hull. This is less elegant in appearance, but would seem to offer a simpler construction of hull sides, where hull sides would be identical pairs, mirror images of each other. The full length hull molds would be far simpler with only two surfaces, the bottom and the side. The wing can be an add on separately infused piece. Note the temporary bulkhead used during bridge deck cabin top construction. The cabin top is a compound curve on both boats, and will have to be built "the hard way".... hand finished both top and bottom. There is no way to produce this compound curve with a simple mold. It's a case where it's easier to do the job the "hard way" than the "easy way". The only compound curve on the entire boat.
H.W.
But things like Rob's built in tender makes me think he puts thought into it. Embracing trailering too!
It is probably a simpler task to lengthen, as opposed to swapping hulls. Afaik, most lengthen by adding a chunk in one spot in the middle. But I can no more assist with these than the change out of your hulls. I think you may want to get a professional to check your work.
Posted by: StoneTool <owly@ttc-cmc.net>
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