Thank you Robert, I'm aware of both, though didn't know Brown book included info on Constant Camber--thanks! Happily, I just downloaded the book on Kindle Unlimited, so the author gets his royalty and I still get to read for free. I love the internet. I have spoken with John Marples a time or two, and I understand there are now 3 similar methods; Constant Camber by Brown and Marples, Cylindrical molding by Hughes and this "toroid sectioned" shape as well.
This one allows more refined shapes than cylinder molding does (as does C-C), and likely it allows more refining than C-C as well (Marples and Brown either have or are contemplating suing this patenter--too similar) The thing I really want is how to design to the technique. More "recipe" and less "high concept"! C-C is brilliantly simple--for lots of small boat shapes, not just multihulls, but it apparently did not prove viable as a commercial venture, and the inventors/designers are understandably reluctant to teach me what they do for a living. Perhaps I should have asked John, not "how" but rather encourage him to write a book on designing to the concept then sell that book.
There is a 12 page manual for the cylinder mold construction method: file:///C:/temp/Cylinder%20Mold%20Construction%20Manual.pdf It mentions a manual on video or DVD.
I think I have this--it's included as an appendix to his catalogue/portfolio--ar at least it did in 1998 which is the date on my copty! Designing for cylinder molding is a bit more intuitive than CC or Toroid molding
I have wondered whether it would make sense to combine cylinder molding with Rob Denney's intelligent infusion by using curved, female mold laminating surfaces.
It almost certainly would, but Rob's designs require a high degree of precision so they'll "fold" into the completed shape with minimal joins and re-working. C-C hulls have quite a lot of tolerance and both halves (or both or all three hulls) are not very near spec or even each other. My level of OCD is OK with that, but many aren't.