RobG

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Everything posted by RobG

  1. Sure, but I think the basic premise is correct: the older you get, the harder it is to learn new skills. Both those guys were very, very good sailors before they started foiling. They do show that if you already have the skills, they can be applied to a new environment where a same–aged competitor without those skills may never be able to acquire them, or at least really struggle.
  2. "…Imperia has tried to condition its registration to a delay in payment of the fees" So they were hoping to delay, probably to give them more time to raise the capital (or whatever). Given that their conditions have been rejected, their entry is now effectively unconditional. Are they now in limbo? Or has their entry been accepted (assuming vetting has occurred) and the countdown has started on the 10 days to pay USD1 million or withdraw.
  3. I think you're over thinking it. According to the protocol, any challenge that meets the requirements must be accepted so ETNZ don't get to pick and choose, though they offer inducements to get teams to enter (such as help with a design package, periodic payment of entry fees vs one off, etc.). A last minute conditional challenge is a way to extend the date that money has to be paid. By having conditions and delaying acceptance until 21 December, they give themselves the maximum time before the final payment deadline of 31 December (allowing for 10 days after acceptance before any payments are due).
  4. The late comers don't pay anything until 10 days after their challenge is accepted, the other $3mil is due on 31 December. Putting conditions on their entry is a way of delaying acceptance and keeping their options open a little longer. Delaying acceptance until 21 December means they keep them open for as long as possible (without change to the protocol, which seems unlikely at this stage). The secrecy of the challengers is a sign that they're most likely serious, even if uncertain.
  5. RobG

    New Olympic Dinghy Selection

    FFS, when you have just 40 people in a room with an open ballot, why are they using such a shitty electronic system at all?
  6. RobG

    Teams?

    There is no "[off] the shelf" AC75.
  7. RobG

    Teams?

    If you're trying to say there's a difference between "spirit and intent of this Protocol" and "this Protocol", good luck with that. In the background section B there is: "RNZYS and CVS now record in this Protocol ("Protocol") the arrangements … [that] will apply to the Thirty Sixth America's Cup Match". There is no reference to "specific articles", the whole thing is the Protocol. It's implausible to argue that, say, acquiring a surrogate in June 2018 then entering in November 2018 was not a breach of the intent of section 11.1.d. of the Protocol, regardless of what was done with the surrogate after being acquired.
  8. RobG

    Teams?

    Not so. Section 6.1 b of the protocol requires that any team that enters must provide a statement in writing that it has complied with the spirit and intent of the protocol since the final race in 2017. So if they've gone outside the bounds of the protocol at any time after the last race of 2017, they're in breach of the protocol the moment they lodge their entry. Delaying entry doesn't change that.
  9. RobG

    Teams?

    Assuming they're using this version of the protocol, entries are closed. In summary: The period for entries opened on 1 Jan 2018 (6.1) The period closed on 30 June 2018 (6.1 a) Late entries closed on 30 Nov 2018 (6.1 b) Entry fees must be paid: First payment: USD1m Within 10 days of the acceptance of a challenge (7.1 a) Second payment: USD1m on 30 Nov 2018 (7.1 b) Late payment: within 3 months of acceptance of the entry or no later than 31 Dec 2018 provided the entry was made before 30 Nov 2018 (the reference to 6.1 b) Performance bond: 31 Jul 2018 (with conditions as for 3 above for late entries) A team entering on 30 Nov can wait until their challenge is accepted before paying anything. From being notified of acceptance, they have 10 days to pay USD1m. Then until 30 Dec to pay another USD3m (noting that payments can be deferred and may be at lest partially refundable). There can be no further entries without a change to the protocol.
  10. RobG

    Foils fail.

    Though the forces in displacement mode, say less than 15kn, should be way less than when foiling at 50kn, when the manoeuvres will also be very much faster. It will be interesting to find out why the arms are failing. It may be a consequence of design, construction, materials or testing. Or some combination.
  11. RobG

    Foils fail.

    Yes, but that doesn't preclude them also doing destructive mechanical testing. Test of Mechanical Characterisation Through the close collaboration of specialised laboratories, we carry out mechanical characterisation tests. These tests are destructive, carried out on specially produced specimens and aim to define the characteristics of mechanical resistance and the behaviour of the material subjected to almost static loads. The applicable loads can be: traction, compression, flexion (3 or 4 points), cutting. The investigatable materials and structures can be monolithic composites or sandwiches and metals International certification bodies have created regulations specifically designed to obtain precise characteristics from each type of test. That infers that through destructive testing, they should be able to recommend changes to make the structure pass the tests. So it may be that they have been failing earlier than expected, so upgrades get them through one phase of testing, but then they fail at the next. 1.5 tonnes at the end of a 3.3m arm, dropping into the water at 50kn must place enormous stress on the arm, with huge torque as one side immerses first. Also crashing off foils while one is raised, the boat will decelerate quickly, but the raise arm will not want to.
  12. RobG

    Teams?

    It's strange that 8 teams have paid $2m (I guess refundable if they fail vetting or don't agree on conditions) and none of them want to have their name in lights. To me, any conditions should have been sorted before the late entry deadline. Making a conditional bid at the close of late entries is not a good look. How long can the potential challengers drag out the negotiations? Anyway, it seems at least 1 will likely go ahead. The performance bond is due on 31 December, so perhaps that will be the cut-off date for conditional entries.
  13. RobG

    Teams?

    That's a pity. To what extent are Luna Rossa leveraging ETNZ's design? Will there really be 4 teams in 3 different designs? It would be great to see these boats survive to the next cup, at least so we can see another round of development and make it more viable for teams to enter. USD200,000,000 for a chance of winning is a big barrier to entry, surely the cost will come down over time.
  14. RobG

    AC75 vs F50 and Maxis

    Steering, sail trim and foil controls need to be coordinated to keep the boat level. If anyone is out of sync, the boat doesn't stay level. I think the fact that such high quality sailors take a bit of practice to get it right shows just how difficult it is.
  15. RobG

    Team NYYC

    I think Loose Cannon is suggesting something like like this, al la Moth spreaders.They just swivel to wherever suits. The stays attach to the mast per your diagram.
  16. RobG

    AC75 vs F50 and Maxis

    Perhaps you missed: "I've been learning to how to steer again after a long time as a tactician…". You're allowing your passive–aggressive side to take over.
  17. RobG

    Team NYYC

    Sure, but in a competition tightly controlled by rules, it really doesn't matter unless there's a significant performance boost (such as the novel foil system). Dual skin sails have been tried many times over the years, maybe there are some gains but no one has found them to be worth the effort. Yet. It seems to me that they will closely model a pocket luff, which is certainly better than a mast + soft sail where high performance matters, so it might be a practical version of a large pocket luff. But to say they're better than a wing mast + soft sail infers the offshore multi guys either haven't thought it has enough promise to bother with, or they've looked at it seriously and think it's inferior. It may well be the former, but I'm not writing off the latter. ;-) It must also be said that the large offshore multis have a relatively conservative approach and go for incremental gains rather than giant leaps (as evidenced by their approach foil development). So maybe dual skin sails are on their to–do list, but they're focused on foil development at the moment.
  18. RobG

    Team UK

    It's not a simple equation though, anhedral may have benefits but so does a straight wing. The optimal amount, from say zero to say 30° max, will depend on a number of variables. The maximum anhedral is about 30° below horizontal (to fit within the rule geometry limits), so where the outer wing is horizontal, the inner wing will be depressed about 60°. That requires the arm to be raised about 30°, so the boat will be lower to the water. It can't be lengthened or reshaped to compensate (supplied equipment, geometry limits). But raising the arm also moves the outer wing further out, so more RM. Any additional lift from the inner wing for leeway control is anti–RM. At the maximum (say 60° below Hz), about 15% goes to vertical lift that takes away from the outer wing's lift. It also creates a torsion to leeward, so stress on the joint and more anti–RM. For a straight wing, (no anhedral), the arm can be lower and the boat higher for the same foil depth at the joint. Canting the foil to windward lowers the boat, creates lift to windward and moves the foil further out, so it too gains RM. There are lots of pros and cons to consider. I don't think the tip of a straight wing angled say 20° to windward piercing the surface is much of an issue (provided it's allowed for in the design) until the boats are near the limit. It will most likely happen going to windward where maximum windward lift is used, so a flat foil may be less prone to ventilation drops.
  19. RobG

    AC75 vs F50 and Maxis

    So now you get the point. I doubt that it's slower than a non–foiling version in conditions where it can foil. Can you point to evidence of any existing boat where that is the case? There are number of other multis with similar systems. The drag of the control system (i.e. the wands) is insignificant, the dual-T foil setup is not inherently slower than any other system (consider the same configuration where the windward foil can produce downforce).
  20. RobG

    Team NYYC

    Probably the first. Hardly novel, e.g. Gitana, whose mast not only rotates but cants as well (as do lots of others), though it doesn't have spreaders. I think the whole dual–skin thing is bullshit, a wing mast and soft sail is likely just as good. Gitana's sail has almost no shape at all, the camber comes from mast rotation and wind pressure.
  21. RobG

    AC75 vs F50 and Maxis

    Any faster than what, a non–foiling Whisper? As A Class said:
  22. RobG

    Team NYYC

    Yes, but they may be small with the hinge in the darker part toward the trailing edge. Perhaps this is the light wind setup, with bigger flaps and anhedral for heavier stuff. There are benefits to a straight foil when it's light and leeway isn't an issue. I'd guess it has a better lift/drag ratio than the heavily angled INEOS foils.
  23. RobG

    The Winning Foils AC36

    It's very easy to get false 3d effects in 2d images that appear to reverse curvatures (effectively reverse stereo vision or stereopsis). If the foil has a concave or hollow trailing edge, the light strip along the edge is explained as reflected light coming from ahead. It's your brain trying to make a 3d image from 2d data that makes it a convex chord-wise curve when if fact it's concave. Try this: look at the image, close your eyes, rotate it 180° and look again. You may well now see a hollow along the trailing edge. Or not.
  24. RobG

    Team NYYC

    Every image taken by a digital camera is "shopped" before being stored. Look at the intersection of the jib luff and the bridge, it has exactly the same artefacts as the arm and foil, likely the result of a sharpening filter. It's also on the crew silhouette on the sail. The foil may indeed have been altered, but the halo over the bridge isn't conclusive evidence.
  25. RobG

    AC75 vs F50 and Maxis

    Overlaying a mirror image of the starboard arm over the port arm shows either they're different shapes or there are some cinematic effects to account for (possibly the latter, modern digital cameras do an awful lot of processing for the sake of aesthetics, forsaking geometric accuracy). But either way, the orientation of the wings is roughly as you suspect, and the anhedral allows more or less independent control of horizontal and vertical lift by the flaps.