AC 36 Foiling Monohulls

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

  1. OzFred
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    OzFred Senior Member

  2. Doug Lord
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    Doug Lord Flight Ready

    American Magic proto:
    AC- American magic lrge.jpg
     
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  3. Tiny Turnip
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  4. Dolfiman
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  5. OzFred
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    OzFred Senior Member

    It's not a prototype, it's NYYC's boat 1.

    A very different hull shape compared to ETNZ. The bow is ugly, but I guess it will start to look beautiful if it wins.
     
  6. Doug Lord
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    Doug Lord Flight Ready

    -------------------
    Wrong: From Merriam Websters Deluxe Dictionary,p1473- "Definition of prototype- " a first full-scale and usually functional form of a new type or design of a construction(like an airplane)" If you're going to nit pik, knowing what your're talking about might help...... I like the bow.
     
  7. OzFred
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    OzFred Senior Member

    You're the only one calling it a prototype.

    A prototype is a precursor to a full production version, they aren't built to be used as a production version might. Their purpose is to test aspects of design and construction. This boat could well be the one the NYYC uses in the qualifying events and America's Cup itself, it's a full production version, not a prototype. All boats used in AC events undergo ongoing development and testing until the last race is run. To that extent you might as well call all AC boats (or more broadly all racing boats) prototypes.
     
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  8. CT249
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    CT249 Senior Member

    Actually according to Merriam-Webster* (note the hyphen and correct spelling or punctuation), it's "nitpick".Definition of NITPICK https://www.merriam-webster.com/dictionary/nitpick

    If you're going to nitpick, knowing what you're (note the correct spelling) talking about might help. :)
     
    Last edited: Sep 20, 2019
  9. Doug Lord
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    Doug Lord Flight Ready

    American Magic and TNZ prototypes. Interesting to see the Magics nose down attitude compared with TNZ on foils before her dive:

    American Magic proto 9-25-19.jpg

    American magic foiling 9-25-19.jpg


    TNZ proto foiling.jpg

    TNZ: Dive, Dive, Dive:
    TNZ Dive Dive Dive 9-25-19.jpg
     
  10. OzFred
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    And the missing credits for those images are where?

    I think you're misinterpreting ETNZ's "nose dive". The bow is designed to ship water when it digs in a bit, just like the IMOCAs.

    Charal Voile - #Vivonsfort
     

    Attached Files:

  11. OzFred
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    Not much has been seen of Luna Rossa's boat, there have only been some images of it wrapped in plastic like these posted a few days ago:

    Road To Cagliari: the journey of the new Luna Rossa
    [​IMG]
    [​IMG]

    However, things will be clearer when boat 1 is launched on 2 October:
     
  12. Konstanty
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    Konstanty Junior Member

    Small difference[​IMG]
     
  13. OzFred
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    OzFred Senior Member

    Indeed: one has progressed to reality with multiple versions sailing more–or–less as designed from version 1. The other? ;-)

    Is the diagram supposed t be to scale? I think the centre of gravity of the AC schematic should be much further to windward with the boat flat (or maybe slightly heeled to windward), so the righting arm (RA) is longer. The Speed Dream RA is put in the centre of the keel strut, likely it is further to leeward given the weight of the boat vs the bulb.

    There is also no indication of weight, RM is not solely dependent on RA. It may well be the that (actually sailing) AC75s have much more RM than the diagram indicates, and the Speed Dream concept much less.
     
  14. OzFred
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    François Chevalier et Jacques Taglang have published a book on America's Cup boat designs that includes the following image that puts the AC75 in perspective with the AC50 and 72.

    [​IMG]
     

  15. Doug Lord
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    Doug Lord Flight Ready

    Interesting thing I just realized from the TNZ photo: when a foil supporting 80% of the boat or so is displaced sideways to leeward and the boat has a centerline rudder, it seems to me that the roll axis of the boat would be a diagonal between the main and rudder foils and that that would cause the AOI of the foils to increase as the boat heels?
     
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