Jump to content


  • Content Count

  • Joined

  • Last visited

Community Reputation

5 Neutral

About STYacht.com

  • Rank
    Super Anarchist

Contact Methods

  • Website URL
  • ICQ
  • Skype

Profile Information

  • Location
  • Interests
    design, analysis, performance of sailing (and foiling) yachts

Recent Profile Visitors

7,453 profile views
  1. I also think the smartest would be for woxi to retire. It would always leave an asterisk on the win* of Comanche. Woxi is a legend already. To add to this they sailed, without any doubt, the best elapsed time on this course. I think it was a foul. I don't think any interpretation of the film evidence can say it wasn't, barring heavy 'financial' blindness. I think it can only be answered with dsq now after the fact. Time penalties are half measures at this point. If the time is exactly the difference what is the point? Just little enough to allow the win or just long enough to
  2. maybe so, but it also a classy move to not impede the starboard tack yacht holding its course with an aggressively close tack. I think it will come down to the skipper. What will he want to be remembered for? And what past do the skippers have with each other?
  3. I would be surprised if this did not go to the room. Which is a pity.
  4. Sorry, not buying into the carbon = brittle argument. That is ancient, and has no bearing on properly conceived laminates. If you mean that unidirectional fibres have less strain to failure than ... fill in blank ... well that is true. But brittle depends on many choices. Kind of agree about absorption of energy but more in the skins than in the core. Something small and pointy will always get through if position is bad - it is a skin designed around the concept of normal pressure over an area. As for weight saving, I think the point of the design is to save weight, yes, but
  5. GBH, in the flat aft end of the VDS you see no such ribs. There is surely core there, whether more impact resistant high elongation 100+ kg/m2 foam or kevlar honeycomb, I cannot be sure. What I said about the usefulness of the stiffeners really does apply to the rounded areas below the chine and to the bow. I am not sold on the fault tolerance of this arrangement, but there is a fundamental logic there. I reckon they will bond the ribs back down and reduce their span by 1/2 (additional deep longitudinals over the top) and it will not be an issue again, unless NDT or samples removed s
  6. GBH this is really a different structure layout compare to what we have seen of Gitana in photos. Gitana seems to be cored aft of the keel everywhere. Mental exercise - take a piece of plastic sheet, like a binder cover or something. Hold it so it has a radius of curvature in one direction. You do not need stiffeners in the the direction the is parallel, it has inherent stiffness IN THAT DIRECTION because of curvature. But you do in the direction that is in fact curved. Because in a thin sheet it is easy to make more or less radius, provided it is only in the one plane. The stiffe
  7. These foil boxes/casings are anything but substantial. At least in the pictures I have seen. One end is attached to the hull and the other end to is supported by an end-plate that is connected to the floor and to nearby bulkhead. The hull connection should stand much more than the weight of the boat because of the force arm created by foil. The casing is quite short compared to the boat width or to the foil length. But anyway, uplift can be easily calculated. Foils are lifted out from the water by uplift and this makes the upper limit predictable. But in case of negative angle it increases pr
  8. I believe the single-skinned hull solution would be good without mustaches and vice versa. Together these are recipe for catastrophe. The single-skinned hull concept is actually brilliant. It should work well under tension that rigging creates. Sandwich composite is heavier because the inner layer is useless ballast until it has to work against the deformation. Until that it is rather compressed and has to stretch a lot until it starts do work against the deformation. This allows more movement than pre-stretched single-skinned material. But because carbon does not stretch a lot the trick is ho
  9. Yep. So which boat will be the first to sport L rudders, and fast!
  10. Possible reasons - aid in re-righting moment required, in combination with other box rule requirements aerodynamic drag stiffer topsides panels without added weight
  11. I also don't think the Welbourne patent covers much. To be infringing, a foil has to fall within all the angles mentioned in the claims and fully retract. I don't think any of the IMOCA foils fully retract. Angle of attack between 2-6 degrees AND foil is "5 and 20 degrees to a horizontal plane when the vessel is in a non-heeled state" AND "having a stowed position in which the lifting hydrofoil is disposed inward of the hull" http://www.google.com/patents/US7644672 The following is cut and paste, plus highlighting. No commentary included ... The above described lifting hyd
  12. Now that's a really interesting image. Any chance of a link? Too lazy to search today. https://www.google.com/patents/US4635577
  13. LeoV, there is a patent, here link to EU version. I am told the US is the same, and perhaps there is something like this south of the equator. The patent was awarded. Neither you nor I are patent lawyers nor judges, so saying that you cannot patent a foil used in a different way is ... I guess up to somebody else. Doug, please point out what you see or read in the patent that is embodied by the VPLP/Verdier foils. I don't see it. that said, I am told Hugh is getting a royalty from VPLP, so maybe it was just easier, or maybe my info is wrong. I never said the pate
  14. LeoV, there is a patent, here link to EU version. I am told the US is the same, and perhaps there is something like this south of the equator. The patent was awarded. Neither you nor I are patent lawyers nor judges, so saying that you cannot patent a foil used in a different way is ... I guess up to somebody else.
  15. Clean, What is your source to make that statement, or is it simply your opinion? [rest assured I have read the patent]
  • Create New...