AC 36 Foiling Monohulls

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

  1. schakel
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    schakel environmental project Msc

    I Agree with you on that. Verdier will do most of these challenges.
    Architecture Navale http://www.guillaumeverdier.com/
    Nice work if you can get it. And you can get it if you try.
    But you have to be at least competent in nautical engineering french.
     
  2. Doug Lord
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    Doug Lord Flight Ready

    I did a thread in the "Sailboats" forum here that was a detailed analysis of a 60' Moth using a bi-foil arrangement, sliding athwartship moving ballast and a 90 degree canting keel*. It seemed like it would work way back then and now-depending on the level of electronics allowed-it would definitely work with startling speed upwind and downwind but the Italians probably wouldn't go for it. I hope TNZ breaks new ground going forward with technology instead of going backwards.

    * 60'+ or - 20' Ocean Racing Monofoiler Design Discussion https://www.boatdesign.net/threads/60-or-20-ocean-racing-monofoiler-design-discussion.15143/page-12#post-428215

    Rough sketch by N Flutter of his take on my concept:



    Monofoiler-60' by NFlutter.jpg
     
  3. Dolfiman
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    Dolfiman Senior Member

    To illustrate what looks like Imoca 60 races in small format/ coastal conditions (inc. runs against chrono, race round Île de Groix and a 24h / 250 NM race with a night) these videos of the 2016 Défi Azimut offshore Lorient, it was the last contest / warm-up before the Vendée Globle itself:
    Défi AzimutDéfi AZIMUT IMOCA 2017 https://www.defi-azimut.net/?mode=archives-videos-2016

    Also the teaser of the next one (23-25 sept. 2017) :
    Défi AzimutDéfi AZIMUT IMOCA 2017 https://www.defi-azimut.net/?mode=medias_videos

    What could be very interesting is the planned conference on "Spolights on innovation" next Friday 22 sept (my translation here below) :
    "As it is the tradition for seven editions, the Azimut Challenge will start on Friday 22 sept. morning (9:30) with a round table organized by the Eurolarge Innovation business cluster. At the Cité de la Voile-Éric Tabarly, naval architects, engineers and experts will detail and explain the new technologies at work and the on-going developments aboard the IMOCA 60. A great way to launch, with main actors of the offshore races, this sporting weekend sporting, convivial and rich of teachings on these high-tech sailing boats, that many teams design, build and prepare in Lorient or its surroundings, in the heart of the Sailing Valley."
    No info yet available on the participants to this conf.
     
  4. Konstanty
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    Konstanty Junior Member

    We need a good transimision of TV at the right time.
    Therefore, I would bet on the seaworthiness of the yacht.
    He should have refitted sails and be resistant to waves.
    High speed would also be expected.
     
  5. schakel
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    schakel environmental project Msc

    Agree with you on that one, A moveable balast but not om a pendulum like Dough lord proposes might work.
    This to have a foiling tack like the now old fashioned AC 50's.
    Waterbalast on a rail that is operated like the reverse working Harken traveller.
    Windward sheeting installation is a perfect enginering solution but needs extra hydraulic energy to work properly,.
    [​IMG]
     
  6. Konstanty
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    Konstanty Junior Member

    Canting keel is OK. Energy should be taken from any windmail. On the rail should be placed acumulator.
     
    Last edited: Sep 16, 2017
  7. michaeljc
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    michaeljc Senior Member

    I am sure that the design will break new ground - at the very least it will upscale what is already being done

    One aspect that will not be compromised (IMO): A physical input from the crew (grinding)

    Another aspect that is inherent in AC: large sail area and heaps of power

    I am going for a 'light' ballast keel and wing foils, and above 12 m (maybe 15 m)
     
  8. Dolfiman
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    Dolfiman Senior Member

  9. Tink proasail
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    Tink proasail New Member

    The whole problem of the foiling cats was that it was just a drag race with the only excitement when something went wrong. To me proper match racing is edge of your seat stuff. My daughter and a whole host of other Optimist sailors did team racing over the weekend it was it was some of the most engaging and skilful sailing I have seen for years. I like the idea of the nip and tuck of upwind displacement sailing with some foiling this off wind. I would just hope it isn't all game over after the first boat reaches the top mark.
     
  10. michaeljc
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    michaeljc Senior Member

    Tink - I agree, but one has to born to the game of test cricket. So many now days are looking for an instant buzz. However, the traditional approach depends so much on sound knowledgeable commentary, backed up with computer graphics, for it to become entertaining on TV.

    In the US the highly technical sport of boxing is taking a big hit of late from short all-out fighting in cages - another sign of the times. Personally, I feel that AC could still do very well without American teams. If they want to come. fine, but AC does not need excessive razzmatazz. My understanding is that AC has a poor following in the US anyway.
     
  11. OzFred
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    OzFred Senior Member

    Above deck sliding ballast has many serious issues that make it impractical, it's been discussed and dismissed a long time ago.

    I think there will be rules like no canting the keel or deploying foils pre-start and no deploying foils until boats are separated by say 2 boat lengths post start or have split tacks away from each other. After that, it's anything goes.

    Don't rule out upwind foiling. The top moths now foil the entire course, I bet within a couple of years the A Class will too, they're already starting to foil gybe. Foil tacks are very much a matter of timing—once someone gets technique right, others will quickly follow. The AC boats only started downwind foiling just before AC 34, yet were foil tacking before AC 35. Who knows what the monos will achieve in 3 years of development and training?

    AC36 boats don't need to survive ocean transits or racing in breeze over maybe 25kn, so they will be lighter and very much faster than the VOR boats they'll (likely) be based on. Wing sails will be mandatory.
     
  12. Konstanty
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    Konstanty Junior Member

    You can use a heavy vertical gyroscope as an energy accumulator. This may be a sliding ballast on the transom.
     
    Last edited: Sep 19, 2017
  13. michaeljc
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    michaeljc Senior Member

  14. Dolfiman
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    Dolfiman Senior Member

    If rapid tacking is the essence of an AC, it needs a quantitative specification to influence the boats design and the human forces involved :
    - how many seconds from full speed to ful speed,
    - peak of energy for, and how this energy is delivered : with or without energy accumulators ?

    All your comments well highlight on this key difficulty to combine modern attractive monohull and that type of racing.

    As we have developed sophisticated VPP tool for the speed issue, we could extend to a Virtual Regatta numerical tool to simulate various combination of races formulas, boat capabilities and human forces requirements.
     

  15. schakel
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    schakel environmental project Msc

    I.M.H.O. a vertical gyroscoop will mechanically tack much harder as without. And that why we needed this energy in the first place for.
    A sliding balast is a contrioversial idea but works according to Dough Lord on unmanned ships.
    In the AC the crew is the moveable ballast.
     
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