A Class Catamaran Design Development

Discussion in 'Multihulls' started by Doug Lord, Aug 24, 2015.

  1. Doug Lord
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    Doug Lord Flight Ready

    Great article here: http://www.catsailingnews.com/2015/08/a-cat-dutch-nats-2015-day-2-5-bullets.html
    and here: http://www.catsailingnews.com/
    Mischa Heemskerk got 5 bullets in a row over Glenn Ashby in the 2015 Dutch Nationals. New rig seems to seal part of the foot down to the tramp with half a windsurfer wishbone as a boom coupled with a small squaretop. Center of Effort of the rig appears lower than a "normal" A Cat rig and with the forward third+ of the foot sealed definitely more power:

    [​IMG]

    [​IMG]
     
  2. Doug Lord
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    Doug Lord Flight Ready

    A Class

    Pete Melvin used a similar rig in 2014 at the NZ Worlds at Takapuna. Said it was extremely quick upwind but not so good downwind.
    http://www.sail-world.com/Kaenon-In...-on-A-Class-and-new-America-s-Cup-rule/119332

    From the 2nd link in the first post:
    This event could become a milestone for the Class on rig/sail development, although we reported that Pete Melvin already sailed a similar setup at Takapuna and Mischa also used it before, it is the first time this setup can be assigned 'some' efficiency.

    Mischa's designed sail/solution along his sailing/racing skills was an important asset for his dominance over Ashby. He reported now 7 to 11knots on Saturday, I asked him on the gap with Ashby and he commented on a 4 mins in a 37mins race and +35secs margin obtained only downwind in other race, timed officially.

    Not many top sailors are sailing their own designed foils (Dna Zs) & sail to left the might Ashby wondering what happened. The Worlds will be a good final benchmark for Mischa's rig design, but if Ashby shows up with a windsurfer rig a la Heemskerk, be prepared to modify your boom and quote a cut for your current sail.
    Checking PJ's photo, I think a double windsurf boom might be needed though.

    Mischa reports on his tiny top sail head design helping to stabilize his DNA while foiling, having much concentrated cloth area down the foot, is depowering the top of the sail , which is a logical result of such design. 7-11knots was the range for the 5 consecutive Bullets over Ashby.


    Excellent interview with Pete Melvin where he discusses his rig and the new AC class:

    https://www.youtube.com/watch?t=33&v=3KUJqgTNvW0
     
  3. Doug Lord
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    Doug Lord Flight Ready

    A Class Worlds

    Some comments by Martin at http://www.catsailingnews.com/ about the two leaders at the worlds-both using the rig pioneered by Mischa:

    Rapid sequence as the rib was moving, but I kept pushing the shutter, and glad I did.
    Glenn Asbhy and Mischa Heemskerk are playing another game all together. Mischa I think is even a step above, still much to go, but his foiling speed is off the scale.
    There was not much wind, 8 knots breeze or less for moments, I couldnĀ“t believe their speed, as seen above sequence both start foiling at the mark, while the others go for standard downwind inside tramp and no trap these two push the As as I never seen before for such conditions.
    Manolo Calavia also foiling good, Sacha & Sandro for moments also.
    The swept deck rig beyond Mischa & Glenn's ability I think is playing an important part.
    More on this development later in the week with Pete Melvin's comments. Pete used a similar Glaser sail at Takapuna 2014 Worlds.

     
  4. rcnesneg
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    rcnesneg Senior Member

    How do they adjust the downhaul?
     
  5. Doug Lord
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    Doug Lord Flight Ready

  6. Stumble
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    Stumble Senior Member

    The one issue with these two is they are so much faster than everyone else on any boat its hard to generalize if its the equipment or them. It will be interesting to see what their thoughts on the equipment are after the regatta is over.

    The other issue that comes to mind is if the new rig simply allows earlier foiling, regardless of top end speed it may be a huge breakthrough for light air conditions. Right now it looks like the sooner you can foil the better you are around the course no matter what it takes to get up on the foils. This may change if Rule 8 is repealed and the class can move to more efficient foils in the near future.
     
  7. Doug Lord
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    Doug Lord Flight Ready

    A Class Foilers

    Latest rumor is that Rule 8 stays.......
     
  8. Doug Lord
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    Doug Lord Flight Ready

  9. Doug Lord
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    Doug Lord Flight Ready

    A Class Development?

    From The Foiling Week:

    Official IACA result of the Rule 8 vote.

    From 104 votes cast from National Association allocations the percentages were:

    To remove R8 - 66.34%
    To retain R8 - 33.66%
    The requirement was 66.66% for removal, so Rule 8 will stay

    Incredible!
     
  10. Doug Lord
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    Doug Lord Flight Ready

  11. Doug Lord
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    Doug Lord Flight Ready

  12. wavesails
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    wavesails Junior Member

    simple rope bridle that tights the clew and the deck sweep corner together batten tension is preset beforehand
     
  13. Doug Lord
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    Doug Lord Flight Ready

    A Class Development

    From catailingnews:
    Dario Valenza has been working to launch a new A-Class design with a new mold different from the former Paradox V1 hulls designed by Fischer. The V2 already had a different shape too.

    Now under the 'Carbonix' brand Dario will seek to offer a competitive legal A with the Paradox V3 and in parallel he continues to sell in numbers his 'insert from below' non legal foils.

    Check his new website at www.carbonix.com.au & http://carbonix.com.au/product/paradox-a-class-catamaran/

    [​IMG]
     

  14. Doug Lord
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    Doug Lord Flight Ready

    A Class Development

    Great comments by Pete Melvin on the Mischa rig and sealing the foot to the tramp plus pix of a new tramp and boom: http://www.catsailingnews.com/
     
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