AC 36 Foiling Monohulls

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

  1. bhnautika
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    bhnautika Senior Member

    :)CT luv the double cultural reference
  2. OzFred
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    OzFred Senior Member

    I get the feeling that double luff mainsails are in the same boat (so to speak…). There's a Lewis Francis Herreshoff* patent from 1925 that seems to cover it, showing it goes back nearly 100 years. But so far it's not been successful. In practice, pocket luffs and wing masts seem to do the job well enough when paired with a single skin sail.

    Perhaps a case of "I like your old remix better than your new remix". ;-)

    * Son of the famous Captain Nathanael Greene Herreshoff, but seems to have worked independently of Herreshoff Designs, Inc.
    Last edited: Mar 8, 2018
  3. Dolfiman
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    Dolfiman Senior Member

    I wonder about double surface mainsail internal air pressure : is an overpressure necessary, wishable ? If no air feeding at the leading edge, is there a risk of low pressure (at high apparent wind speed) between the two sails, and therefore a striction of the sails just after the mast, loosing the beneficial streamline ? Are canvas with either battens or non zero flexure caracteristic necessary at the leading edge ?

    An academic paper on « Conceptual ideas on double surface sail inflated by dynamic pressure » was presented by Germans at the Innovsail 2013 conference, being the core part of first author Soren Bruns Diploma Thesis within TU Berlin and FutureShip Gmbh.ören-brüns-48a91a72/

    Second author Heikki Hansen is NZ and worked on sail development within the America'cup.

    Excerpt from their introduction : « The concept is a double surface sail, which is to be inflated by the dynamic pressure at the leading edge of the profile. The fundamental principle is the same as used by paragliders and kites, where openings at the leading edge of the wing allow the air to “fill” the profile to give it a beneficial aerodynamic shape. »

    But since then, I have not seen further development from FutureShip or academic.

    The paper :
    Doug Lord likes this.
  4. Doug Lord
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    Doug Lord Flight Ready

    Heads Up: The end of March may bring answers to the degree to which the new AC boat will be one-design. I hope The Rule has lots of latitude but I think it will be closer to one design, unfortunately.
  5. Konstanty
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    Konstanty Junior Member

    According to my opinion, the pressure in the middle is needy in the front part of the sail. When the chamber is tight, it can come from a single point of hypertension of wind at the top.

  6. Doug Lord
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    Doug Lord Flight Ready

    Jimmy back with Luna Rosa: America's Cup: Spithill changes teams >> Scuttlebutt Sailing News
    Excerpt from story and interview:
    The 38-year-old, a multiple world champion in fleet and match racing, is now hungrier than ever to win back the Auld Mug after losing out to Emirates Team New Zealand in 2017. Read Spithill’s first interview since the news broke:

    - How does it feel to reunite with Luna Rossa Challenge after you helmed them to the Louis Vuitton Cup Finals at the America’s Cup in 2007?
    It’s great to be back with Luna Rossa Challenge – I have a lot of great memories from the four years we spent in Valencia during AC 32, and this time I have been impressed with the tools, technology and people they have in place. It’s a great mix of experience, new energy and enthusiasm in an open environment – the makings of a great team.

    You have a vast amount of experience and, presumably, a lot of learnings that you bring to the table?
    Of course as a competitor you’re always learning, and since the last race of AC 35, I’ve been thinking every day about the America’s Cup. Naturally, you go over the previous campaign piece by piece, focusing on all the key moments and decisions during the four years. Lately I’ve been able to understand how a lot of the other teams operated, and that in itself is very educational.

    Any conclusions?
    Ultimately, two things stood out for me: trusting my instincts is key, and the hunger has only gotten stronger.

    And speaking of your past experiences, your collaboration with Oracle Team USA resulted in some iconic sailing moments. When you look back at it, what comes to mind?
    What an amazing ride, with some amazing people. Without Larry Ellison and Russell Coutts, there is no way I could have gotten to this point in my career. I’m fortunate to have been able to work alongside some of the most successful people in sport and business, and lucky to be able to call them good mates. I look forward to catching up with them in the future.

    It’s been announced that the boat for America’s Cup 36 is an AC75 monohull. First thoughts?
    The boat is going to be a beast. It reminds me of America’s Cup 34 and the AC72 foiling catamarans. Nothing like this had been done before, and this boat is on the cutting edge of technology. There are a lot of unknowns with the AC75, which will push people to the limit and really challenge all the teams involved. However, this challenge and difficulty is really appealing, and I’m really excited to be back in the game.

    And what are your thoughts about moving to Italy?
    Last time with Luna Rossa challenge it was the Valencia campaign and we moved straight to Spain – this time I’m looking forward to living in Italy. Personally, I’ve had a lot of success racing and competing in Italy, and lifestyle and especially the food are awesome! I love the Italian culture, the landscape and the people. I have to admit, though, that I will need to work on my Italian.

    Speaking of the culture, time for some quick-fire questions . . .

    Your favourite Italian dish? Margherita bufala.
    Pasta or pizza? Both.
    Your favourite gelato flavour? Stracciatella.
    Can you swear in Italian? Exceptionally well!
    Your favourite Italian phrase from what you can speak of the language so far? Va bene.
    Your favourite Italian football team? Juventus.
    Public transport or Ferrari? Ducati.
    Last edited: Mar 14, 2018 at 2:20 PM
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