Banque Populaire IX - Ultim 32m Trimaran foiler

Discussion in 'Multihulls' started by Dolfiman, Oct 16, 2017.

  1. Doug Lord
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    Doug Lord Flight Ready

    Banque Populaire: I just discovered that the boat uses a small flap on the daggerboard lifting foil. I had thought that the only way they could change the angle of incidence of the mainfoil was to rake the board. Interesting that the knobs shown above refer to adjusting the rake of the daggerboard and there does not appear to be a control for changing the flap angle? Am I missing something, Dolfiman?
     
  2. Dolfiman
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    Dolfiman Senior Member

    Dear Doug, I have no better news on that point, just remind that project Director Renaud Camus mentioned this small flap on the central daggerboard (in quote #6). One can presume that they also have let open the possibility to adjust the rake of the whole daggerboard for this first year of tests. How work the numerous knobs (8 starboard and 8 port) ? Are they acting directly on foils and how ? Or are just the repetition of the foil settings ?
     
  3. Doug Lord
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    Doug Lord Flight Ready

    On the previous page there is a knob on the upper right that says "SAF FL BD" --could that possibly refer to a flap(FL) on the board(BD)?
    They wouldn't have a flap if they couldn't adjust it? I'm sure that they can also adjust the daggerboard rake for the predictable "median" of flap settings for different conditions.
    Then there is always the possibility that the flap adjustment is manual/mechanical.
    We know from what Verdier said about Gitana that flap adjust under load is possible and that the whole mainfoil concept was designed as part of Gitana from the beginning but that may not be true of Banque Pop-they could have added the main foil after they found out what Gitana was doing so maybe the structural reinforcing is not as robust?
    I sure wish these guys would shed some light on this stuff and I'm extremely grateful for Guillaume's openness about Gitana . Cool stuff!
     
  4. Dolfiman
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    Dolfiman Senior Member

    Quite sure that "SAF FL BD" means "Foil of the port rudder", as SAF is probably a reduction of "Safran" (= rudder , exactly the immerged part of a rudder), Fl for Foil and Bd is "Babord" (= port). This knob is associated with "montée" et "descente", which means "up" and "down", whether the rudder is up when not in use (ie winward) and down when used (ie (leeward).
    When there are "+" and "-", that refers to more or less rakes, like for the "Rake Dérive" knob, "dérive" meaning daggerboard.
     
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  5. Doug Lord
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    Doug Lord Flight Ready

    Thanks!
     
  6. Doug Lord
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    Doug Lord Flight Ready

  7. Doug Lord
    Joined: May 2009
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    Location: Cocoa Beach, Florida

    Doug Lord Flight Ready

    From Seahorse/Scuttlebutt Europe:

    A very personal relationship
    [​IMG]
    Solo ocean racers trust their lives as well as their results to their autopilots, none more so than the skippers of the new generation of foiling Ultim - where the pilots themselves also face unprecedented new demands

    After Vendee Globe winners Team Banque Populaire elected to go with B&G for the pilot systems on their own first fully foiling Ultim we spoke to B&G’s R&D team about their rather enormous new brief...

    ‘Sailing upwind everything feels relaxed and calm, and you’re unaware that you’re doing 23kt,’ says Matt Eeles, B&G’s R&D lead on the Banque Populaire project, ‘but as you bear away onto a reach you really feel the power and acceleration. Your senses are heightened as the full power from the canted wing mast and the sails rapidly accelerates the boat from 20 to 40kt.

    ‘With the foils raked back and emitting a resonating scream there is no sign of the bows burying. Looking outside the helm position without goggles is nearly impossible as the apparent wind beats you in the face and your eyes hurt as you try to stare at the foils to see all three hulls flying in the air.

    ‘We frequently saw SOG go into the 40s, peaking at well over 40kt under pilot when fast reaching in 25kt TWS,’ he adds. ‘High averages will be crucial for this project and I can easily see them being able to achieve averages into the high 30s sailing downwind while maintaining a safe and stable platform. After reaching at over 40kt, downwind at 35kt was quite a pleasant ride!’

    Full article in the June issue of Seahorse: www.seahorsemagazine.com
     
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  8. Dolfiman
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    Dolfiman Senior Member

    Most interesting article on a crucial development : an autopilot able to cope with all sailing conditions of an Ultim and its accelerations, inc. full flying and transition phases, really challenging !

    F. Gabart also stimulate the research on that field, with two experts of his team, Benoit Piquemal and Émilien Lavigne (who is preparing a thesis on that). And FG adds another futuristic challenge : how can we able to measure the real wind ahead , that will hit the boat 10 s later :
    "And for Gabart himself, he feels there is still much more to improve. His first port of call is the autopilot, the vital, key component in single-handed racing.

    “At the moment, the autopilot is just following… it’s just measuring what happens and acting on it,” he says. “When a sailor is steering, he’s also anticipating what he sees in front of him or what he could imagine – because this is on his feelings; he can anticipate things.

    “Will an autopilot in the future be able to just look in front of the boat, to measure the wind ahead? Maybe in a few years we can measure the wind that will arrive. We could just look a mile in front and say, ‘Okay, in ten seconds, I will have this type of wind’.”

    And that’s enough time for a skilled skipper to make a judgement on how best to steer his craft. “We just need a few seconds,” asserts Gabart. “At least you know what the wind will be in ten seconds. It’s wonderful information.”
    Ref : Smart sailing: François Gabart's trimaran MACIF is a floating tech lab - iQ UK https://iq.intel.co.uk/smart-sailing-trimaran-macif-francois-gabart/
     
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