Gitana 17-100' Trimaran Foiler-Launch 7/17/17

Discussion in 'Multihulls' started by Doug Lord, Jul 13, 2017.

  1. Doug Lord
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    Doug Lord Flight Ready

  2. Doug Lord
    Joined: May 2009
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    Location: Melbourne, Florida

    Doug Lord Flight Ready

  3. Doug Lord
    Joined: May 2009
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    Location: Melbourne, Florida

    Doug Lord Flight Ready

  4. Dolfiman
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    Dolfiman Senior Member

    I propose you the translation on the (crucial) anti capsize system :
    " Qustion : What inspires you the capsize of Banque Populaire IX?
    Sébastien Josse: That our Ultim is safer than Armel's! No, just kidding ;) . More seriously, it is a good reminder at few months from this transatlantic race deemed to be boats breaker ! On Gitana, our anti-capsize system is ready. You can see this little box positioned at the top left of the descent, well it's our life insurance. Angles thresholds for heel as for trim are set according to the encountered conditions, which triggers an increasingly ringing alarm when more and more closer to the set values. That gives me time to anticipate if I am either in my life cell or busy on a maneuver ... Anyway, once the threshold reached, a solenoid actuates the cylinder which releases the mainsheet and a piston to release the main carriage. Always about safety, we were inspired by the misfortune of Thomas Coville - a collision with a fisherman a few hours after the departure of the previous Route du Rhum - to think a cabin with a multitude of small portholes to keep maximum visibility on the external environment."
     
  5. Doug Lord
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    Doug Lord Flight Ready

    Thanks!
    Afterthought: interesting that no mention is made of using the mainfoil to develop downforce to slow and/or prevent capsize. That foil can at least 20% to the overall RM and could be an asset-at least until it pops loose....
    The most detailed response about this possibility was made by Vincent Lauriot-Prevost in response to a question I asked about Banque Pop:
    High Performance MPX Foil/Self-righting Trimaran-The Test Model https://www.boatdesign.net/threads/high-performance-mpx-foil-self-righting-trimaran-the-test-model.36058/page-180 scroll down to post 2693
     
    Last edited: Oct 19, 2018
  6. Doug Lord
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    Doug Lord Flight Ready

  7. Dolfiman
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    Dolfiman Senior Member

    Many thanks Doug, yes this second video is really worth it, I have translated the final slide in case of :
    "Flying data :
    The 15,5 t (metric tons) are supported by 4 m2 (4 square meters) instead of 49,5 m2 in Archimedian mode.
    Maximum height of waves : 2,3 m

    Taking off conditions :
    Wind speed > 15 Knots
    Boat speed > 27 Knots
    True wind angle : 90 to 110 deg."
    >>> from this video and some other previous info, at equivalent conditions, the transition from archimedian to full flying results in a speed increase of about 10 Knots, e.g. 22 to 32 Knots in the video with 18 Knots of wind.
     
  8. Doug Lord
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    Doug Lord Flight Ready

    Thanks for doing that! I've been reading so much French lately that I'm actually learning a little-very little. I was sort of stunned by that video-so much tech-just the kind of stuff their competitors might want to know? I sure hope Gitana does well and I guess Banque Pop too-both designers have shared a lot of info with me and I wish both of them well!!
     
  9. Doug Lord
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    Doug Lord Flight Ready

  10. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    New article and video by Team Gitana on Flight: Flight, the great unknown of racing - Gitana : Offshore racing stable created by Baron Benjamin de Rothschild http://www.gitana-team.com/en/a-1287/flight-the-great-unknown-of-racing

    "We're incredibly lucky to be part of a technological revolution like this!" Sebastien Josse

    Excerpt:
    The stability of the boat when flying, doesn't just come from the shape of the foil, but also the combination of four appendages – the two rudders, the leeward foil and the ‘skate wing'(daggerboard foil), which was initially designed and validated on the Multi70 Edmond de Rothschild(now Maserati). “We created this stability in flight thanks to these four elements”, explains Guillaume Verdier in more depth. “The trimaran is essentially supported on the foil and the skate wing, which stabilises the boat's roll, whilst the T-foil rudders stabilise the trim. The idea is also to have robust, reliable foils, which don't have to be adjusted too much when you're sailing singlehanded, given how much is required of the sailor already on a machine like this.” Sébastien Josse backs up this statement. “Today, we know how to sail under autopilot on flat seas, but in flight mode in the sea and the waves offshore, as the foils aren't operated with a servomotor, (it's currently forbidden by the measurement rule), the pilot doesn't yet know enough about how to handle this type of situation, and admittedly no Ultime is capable of this feat so far… though the time will come for this. When you're singlehanded, in a solid breeze with very ordered seas, you fly under autopilot, the boat is on 80–90% of her foil, but ten centimetres above the water. It's certainly not about gaining in altitude or risking a wipe-out. The foil sustains the hulls and relieves the pressure on the platform. As a result, you fly very low, which doesn't prevent you from going fast! We call that ‘skimming'. We aren't allowed to use servo control, so we're trying to fly like this. When the time comes where we're able to adjust our four appendages in one second, we'll be able to fly higher.”
     
    Last edited: Oct 30, 2018
  11. Doug Lord
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    Doug Lord Flight Ready

  12. Doug Lord
    Joined: May 2009
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    Location: Melbourne, Florida

    Doug Lord Flight Ready

    New article and video as of today, Nov. 3rd: Diving between two worlds - Gitana : Offshore racing stable created by Baron Benjamin de Rothschild http://www.gitana-team.com/en/a-1292/diving-between-two-worlds

    A couple of short, spectacular shots of Gitana flying!
    Excerpt from the article-Seb Josse commenting:

    “Naturally there's some stress before a start like this but it's good stress! You inevitably ask yourself a lot of questions – how you're going to react, how things will play out? – as it's never a trivial matter setting sail alone on a boat across the Atlantic. Competition pushes us further and enables us to push the envelope, but solo sailing itself is physically and psychologically testing and so it goes against nature in a way. We really like it when the race gets off to a ‘gentle' start, and you can find your feet gradually, but whatever happens the switch from the status of landlubber to sailor is a brutal one. In the space of a few hours, you switch from one world to another. The first night at sea is one of the most tense, as you're in a state of high stress. In a few days' time, I'll be in 35 knots of breeze with 5-metre waves and that will my reality at that time, having to face up to my responsibilities, with my seamanship enabling me to cope with it all."
     
  13. Doug Lord
    Joined: May 2009
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    Location: Melbourne, Florida

    Doug Lord Flight Ready

  14. Doug Lord
    Joined: May 2009
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    Location: Melbourne, Florida

    Doug Lord Flight Ready

    Gitana 17 -more on the damage: Pressure Drop - Multi Ultime Gitana Damage Up Close http://www.pressure-drop.us/forums/content.php?8741-Multi-Ultime-Gitana-Damage-Up-Close

    Excerpt-
    The low-down

    The day after his arrival in La Coruña, after several hours struggling to get some sleep, the skipper of the Maxi Edmond de Rothschild gave us the low-down on his race. Airborne from the start to Cap Fréhel, on a reach that will remain etched in ocean racing history for a long while to come, he discusses the passage off Ushant and the mindset he was in before getting into the teeth of the low pressure system. As usual, the sailor tells us exactly how it is in these few hours of racing in the Route du Rhum - Destination Guadeloupe prior to his retirement.

    This retirement has come as a tough blow for the members of the five-arrow stable, who demonstrated unfailing commitment in their preparation for the major meeting that is the Route du Rhum. Every one of them was keen to offer Sébastien Josse a steed that was on a par with his talent. It's a massive disappointment as we had to do a lot of work to be present and relevant at this race. However, offshore racing is and will always be a mechanical sport where breakage is sadly one of the risks. The damage suffered on the starboard float will force us to call ourselves into question, to try to find out and understand what's happened and effect repairs so we can come back stronger. We are in no way seeking to discard the work that has gone before. The quest for innovation we've launched into with the support and enthusiasm of our owners and associates of the Edmond de Rothschild group is no easy task, but the game is worth the candle. Calling into question our pioneering spirit and the vision we have of tomorrow's sailing is not on the agenda,” admits Cyril Dardashti, the director of the team.

    We have a heavy heart for our pontoon neighbours, Team Banque Populaire, who are today trying to recover their boat from offshore of the Azores. These are very hard times, and though the most important thing is that Armel will soon be back amongst his nearest and dearest, my thought have been focused a great deal on Ronan Lucas' team since Tuesday.

    Thank you!

     

  15. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

    Last edited: Nov 14, 2018
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