AC 36 Foiling Monohulls

Discussion in 'Sailboats' started by OzFred, Sep 13, 2017.

  1. Doug Lord
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  2. OzFred
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    OzFred Senior Member

    There is talk of video of a big crash in fairly benign conditions. The online version has been taken down, did anyone manage to grab it before it left? Or some screen captures?
     
  3. Doug Lord
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  4. OzFred
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  5. AlexanderSahlin
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    AlexanderSahlin Junior Member

    Yes, rudder ventilation is very likely on this configuration. With the large lateral separation between main- and rudderfoil, the rudder foil will have less submergence as soon as you have any heeling angle. The rotation-axis for heeling is also inclined, so you get a coupling between heeling-rotation and vertical movement. This provides for a machine, that is very challenging to sail as soon as you have any gusts or waves.
    Very good move by the INEOS team to put together this test-boat so early in their project. Should have been done by the AC-organizers before deciding the AC-75 class-rule.
     
  6. Doug Lord
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    Hard to tell but it looks to me like the lee foil popped loose causing an instant and quite violent capsize?
     
  7. Doug Lord
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    INEOS T5-best footage yet: ( from catsailingnews/INEOS) The crash at 44 secs in shows the lee main foil mostly out of the water(stop and start the video until you see it). There is a lot of spray around the rudder which may be ventilating as well. As far as I know the "altitude control" on this boat is manual which could be the explanation.......
    UPDATE- it appears that the dihedral*of the two main foils may be different?
    * should have been anhedral as pointed out by OzFred below

     
    Last edited: Sep 1, 2018
  8. Doug Lord
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    Doug Lord Flight Ready

    T5 being towed: Giles Scott and Ben Ainslie onboard-
    pix from INEOS/ Pressure Drop

    AC 75 proto Ineos T5 being towed.jpg
     
  9. OzFred
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    OzFred Senior Member

    Anhedral. Yes, it seems different. They may well have a number of foils for testing.

    I think it's a different event though. The boat seems to be on the wrong tack and I can't see how it can capsize to port. That would mean capsizing to windward, I can't see how that could happen. It doesn't look like it's going to capsize at all.
     
    Last edited: Sep 1, 2018
  10. Doug Lord
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    It's definitely not the same incident as in the little fuzzy video....... I think in the "T5" (last)video they flew it right out of the water. I think it heeled to windward because they eased the sheets as they realized what was about to happen and since the two crew were sitting to windward the boat leaned in that direction because they still had some rudder lift? It was more a pitchpole initiated by a lack of mainfoil lift-not really a capsize.
     
  11. Doug Lord
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  12. Doug Lord
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    Doug Lord Flight Ready

    UKAC T5 under tow:

     
  13. Doug Lord
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    Doug Lord Flight Ready

    NZAC Cant System:
    A first glimpse at the AC75 the foil control system, one of the supplied parts which will be used to raise and lower the foil arms through sailing manoeuvres.
    After a 6-month design process by Emirates Team New Zealand the system has been undergoing testing this week in Auckland lead by project Manager Peter ‘Brush’ Thomas.


     
  14. OzFred
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    OzFred Senior Member

    America's Cup: Raft of Protocol changes as more Challengers emerge

    An interesting article from Sail-World. The headline is a little misleading, most of the changes are irrelevant to the masses. The interesting change is that teams can now modify 12.5% of the first and second hulls, rather than 25% of just one (either one, not just the first as stated in the article).

    There are also claims of up to 5 more challengers, but that seems to be mostly bluster in response to attempts to reduce the size allocated for team bases. No names were named. At present there are 3 challengers, I think there's an allowance for 6 bases:
    1. Luna Rossa Challenge
    2. INEOS Team UK
    3. American Magic (New York Yacht Club)
    There have been rumours of another challenge from Italy, firstly from Sardinia and now Yacht Club Imperia. We'll have to wait until 30 November to find out, or later if the rules are changed to allow it (which is possible if a potential challenger wants).
     

  15. Dolfiman
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    Dolfiman Senior Member

    About Yacht Club of Imperia surprising challenge, here is a translation of the Vela y Motore web site :
    "The new consortium is called Columbus 2021 and can count on an availability of 50 million euros with the financial involvement of companies specializing in high technology, research centers, universities. Roberto Sicari is the president of the new union while the legal partner was chosen by the K & L Gates studio, founded by Bill Gates' father, with 2,200 lawyers spread across 50 countries. The design of the hull has been assigned to Bertone Design which will also make use of the collaboration of university institutes while the construction of the two hulls will be the task of Adria Sail, the Fano di Maurizio Testuzza company. It is not yet known, however, the crew that, as communicated during the press conference held in the context of the Gathering of Vele d'Epoca, will be international and with female grafts but it is already expected that the training will take place in the waters of Imperia. Not only that, of the five regattas of approach to the Cup to be carried out in the Mediterranean by regulation, Imperia is a candidate to be the seat of at least one. The surprising initiative, which has fallen on the "sleepy" reality of the imperial capital, obviously has a prologue. And the mayor Claudio Scajola has explained it, elected to the last administrative of the last month of June. "After a week of my establishment - he said - I was contacted by Roberto Spingardi, vice president of Bertone Design, explaining the project that was born and that the new consortium had chosen Imperia and the Yacht Club as a reference for the challenge to the America's Cup : convinced me that, for Imperia, the operation will be at no cost ». Scajola has kept that operation secret until the penultimate day of the Vele d'Epoca rally. Tommasino Gazo"
    Ref : Imperia lancia la sfida all'America's Cup http://www.velaemotore.it/imperia-lancia-la-sfida-allamericas-cup-17437

    Imperia is a mid-size town on the Ligurian coast, not far from Genoa :
    REGATE | YCIM http://www.ycim.it/index.php/regate/
     
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