34th America's Cup: multihulls!

Discussion in 'Multihulls' started by Doug Lord, Sep 13, 2010.

  1. Gary Baigent
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    Gary Baigent Senior Member

    At 40 plus knots boat speed, drag and turbulence from a surrounding paddock fence would be a little higher than .000001 knots.
    Also slip/trip into a fence while running across the wide cat trampolines, (no other boat design has entered into running races while tacking/gybing) and crew would be catapulted skywards, probably with broken legs - before being decapitated by last minute rule changed, wider foils upon hitting water.
    Sometimes conventional thought does not apply.
     
  2. powerabout
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    powerabout Senior Member

  3. Doug Lord
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    Doug Lord Flight Ready

    34th AC

    Big difference-the trifoiler has dual main foils with independent altitude control systems(feelers) that not only provide vertical lift but all of the RM for the boat. On the other hand, the 45's and 72's have a single main foil with manual/surface piercing altitude control and the foils don't generate RM.
    Cool video! By the way Moth's do foiling gybes all the time-and foiling tacks!

    PS- I know the Rave had aluminum foils-I thought the Hobie Trifoilers were foam/glass or carbon?

    Trifoiler foils:
     

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  4. Doug Lord
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    Doug Lord Flight Ready

    34th AC

    From Scuttlebutt tonight:

    "By the way, the Kiwis won their second one-boat race on Tuesday, achieving a top speed of 43.26 knots."
     
  5. P Flados
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    P Flados Senior Member



    Aside from the MOB concerns, this video show what looks like a drastic improvement in team OR gybing.

    If 00:55 to 1:05 was not a full flying gybe (flybe) it was close enough to get the job done,

    23:15 to 23:20 and 23:40 to 23:45 were too far away to get a good look but were also fast, prettly close to flybing.

    08:50 to 09:00 and 11:50 to 12:00 were not a full flybes, but hull time in water was only a few seconds

    03:15 to 03:35 & 18:40 to 18:50 and 22:30 to 22:50 were not so good, but were not near as bad as many we have seen from OR

    If the above is with their big rudder elevator (probably I would guess), and elevator past max beam is thrown out by the IJ, I would expect OR to to do the extra work to come up with a similar performing original rule compliant rudder elevator.

    All of the down under crowd mentally banking on ETNZ dominance due to vastly better flybes, might just start getting nervous given how much time OR has to improve what is now looking pretty decent.
     
  6. EvanStufflebeam
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    EvanStufflebeam Junior Member

    Picture showing a bit of boat 2 from the teams twitter
     

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  7. CT 249
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    CT 249 Senior Member

    18 Foot Skiff and 49er crews have been standing up and running across the boat in tacks for years, and some IC sailors run up and down the plank.

    As long ago as the start of this century, guys on boats like the Beneteau 40.7s Smile and Fruit Machine were running across the boat in roll tacks. The Ultimate/Ultra 30 guys may have been doing it to, and what about the ORMA 60 crews?

    No one seems to have been hurt by lifelines in the boats that have them.
     
  8. powerabout
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    powerabout Senior Member

    The AC 72's are trying to go back to the future and be as cutting edge as a trifoiler and Moth was years ago but the rules are preventing that.
    They are hopping on one leg in a running race
     
  9. Red Dwarf
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    Red Dwarf Senior Member


    If they were monohulls they would have lifelines. And it is impossible for a monohull to do 40 knots or the hard fast manuvers possible with the cats.

    Just saying....
     
  10. powerabout
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    powerabout Senior Member

    maybe in 1970
     
  11. CT 249
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    CT 249 Senior Member

    Volvo 70s are claiming peaks over 42 knots, pretty similar to the cats and almost as fast as the $6,000 bits of kit I sail. It would interesting to see which one turned faster.

    The sailors would still run across the boat about the same speed, with the ease of running across the flatter cat perhaps negated by running across a narrow beam or slightly bouncy tramp. So it still seems hard to see why running across to a lifeline is more dangerous than not having one.
     
  12. Gary Baigent
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    Gary Baigent Senior Member

    Agreed - but there is a slight (that's a joke) difference in distance covered; referring to 18's, crew cover it in three or four steps and they're climbing up hill in latter part ... big difference in running strides covering a tennis court - and also down slope in latter part of an AC72.
    On an ORMA 60 or MOD 70, seems only the helm is running fast (plus their helming cockpit position is halfway across the after aka, well inside the trimarans overall beam).
     
  13. Red Dwarf
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    Red Dwarf Senior Member

    According to this wiki it took 40 knots ofwind for a Volvo 70 to do 24.8 knots. http://en.m.wikipedia.org/wiki/Volvo_Open_70
     
  14. Gary Baigent
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    Gary Baigent Senior Member

    Amusing. Seen any Volvo 70's regularly reaching 40 knots, then going into a gybe. That is an exceptional speed situation for them, hard surfing in hard winds. Wrong analogy, CT.
     

  15. powerabout
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    powerabout Senior Member

    maybe 38kts then wipeout...usually includes a gybe
     
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