High Performance MPX Foil/Self-righting Trimaran-The Test Model

Discussion in 'Multihulls' started by Doug Lord, Dec 28, 2010.

  1. Doug Lord
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    Doug Lord Flight Ready

    You're welcome..... Light air foiling is critical for the new breed of commercial foiler---and for me personally.
     
  2. Doug Lord
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    Doug Lord Flight Ready

    WOLF daughter of fire arrow: some more pictures-these are the first with the two stage ama's/crossarms bonded to the model:

    WOLF  plus foils  11-8-17 001.JPG

    WOLF  plus foils  11-8-17 003.JPG

    WOLF  plus foils  11-8-17 006.JPG
     
  3. Doug Lord
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    Doug Lord Flight Ready

    WOLF daughter of fire arrow: lower seats and "cushions" in place--much detail work left including upper seating, tramps, cockpit, rig and traveler:

    WOLF +foils+ seats    11-9-17 003.JPG


    WOLF +foils+ seats    11-9-17 001.JPG





     
    Last edited: Nov 9, 2017
  4. Doug Lord
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    Doug Lord Flight Ready

    WOLF daughter of fire arrow: foils + seats upside down--- WOLF   foils + seats upside down 11-9-17 002.JPG WOLF   foils + seats upside down 11-9-17 001.JPG
     
  5. Doug Lord
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    Doug Lord Flight Ready

    Heartbreaking Transat Jacques Vabre for Team Gitana-see post 51 in the Gitana thread.
    Course mistake , engine trouble, and damaged ama foils......
     
  6. OzFred
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    OzFred Senior Member

    There is no evidence what so ever of a course mistake. From your referenced link:

    "To put it plainly, our duo was deprived of her major assets for ¾ of the race, which explains the speed deficit everyone observed."

    In other words, the deficit was (almost entirely) due to structural failure of the foils, no mention at all of navigation error.

    PS. The WWW makes it very easy to include URIs for references, it helps greatly to include them when referencing other material (even better to reference the original).
     
  7. Doug Lord
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    Doug Lord Flight Ready

    I don't have the patience to look for it further but there is an article on the Gitana site(I think) where the guys specifically say they made a course mistake and that it cost them well over 60 miles. If you want to discuss this further do it in the Transat thread or the Gitana thread-not this one.

    UPDATE: Found a reference to the article I read and a quote from it by Dolfiman, post 49 in the Transat thread:
    If Gitana speed potential is not technically affected, they still have a chance, they already show at the beginning of the race that they are able to go faster than Sodebo in reaching conditions. Their delay in time is only 30 mn. On the other hand Sodebo is a very sharp machine and currently easier to lead at 100% than new Gitana still in the learning curve as confessed Seb Josse on their site. He also confessed their wrong route option 2 days ago (it was not a tactical move as I presumed optimistically), in french on their site :
    "Thomas and Jean-Luc played a nice weather option that explains today that they are leading the race. After the passage of the Azores we had the choice between jibing several times or going under J0 (big gennaker). Given our position at that time, we opted for gybing and navigation under J1 (genoa) which was to allow us to gain in longitudinal. Sodebo made the opposite choice by shifting in the West to slip. Our choice did not pay, far from it. Not only the state of the sea in the night from Tuesday to Wednesday did not allow us to exploit as expected our choice of sail and our meeting with a grain without wind pushed the nail. In the end, it was Thomas and Jean-Luc who pulled the right edge and in view of the weather conditions that presented themselves in front of our bows we had last night to jibe at 90 ° of the road to get away from the African coast and areas of light winds in our south. On the way out of this resetting, the addition was salty: from a 64-mile credit at 21h, Gitana 17 conceded 60 miles at sunrise. "t's always hard as a decision but the evening files were very clear. Sometimes you have to know how to lose a little to not completely mortgage the next events" .
    =============

    UPDATE #2: From the Gitana site 11/16/17

    Thomas Rouxel: “Ah! It was my first Transat Jacques Vabre and I wouldn't have said no to a little victory! But here we are with this second place and that's no small feat. We made a strategic error at the Azores, which cost dearly and I think it was one of the key points in the race. Added to that, we had foil issues, which no longer enabled us to make a difference in terms of speed. Furthermore, we were up against two mighty candidates.”
     
    Last edited: Nov 16, 2017
  8. OzFred
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    OzFred Senior Member

    A "wrong route option" is not a course error. And neither that nor their engine issues cost them the race. Failed foils did.
     
  9. Doug Lord
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    Doug Lord Flight Ready

    Fire Arrow Foils:

    MPX Fire Arrow.jpg

    Mainfoil:
    MPX main foil modified.JPG

    Port UptiP ama foil:
    MPX i-flap off port foil 003.JPG

    STB. UptiP ama foil and rudder T-foil
    MPX-ama foil.jpg
     
  10. Doug Lord
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    Doug Lord Flight Ready

  11. Doug Lord
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    Doug Lord Flight Ready

    WOLF daughter of fire arrow-- seat /tramp mock up for study: WOLF- 2nd seat-tramp mock up-11-17-17 001.JPG

    WOLF- 2nd seat-tramp mock up-11-17-17 002.JPG
     
  12. Doug Lord
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    Doug Lord Flight Ready

    Righting Moment from foils: older foilers like the Rave and Hobie trifoiler among others used the foils to provide the majority of righting moment and the Trifoiler set speed records using the system. Among the newest catamarans to use dual, independent wands for altitude control are the Whisper and S9 but these boats are relatively narrow
    and use movable crew weight for the majority of righting moment. Fire Arrow and the boats using a similar system have the ability to generate RM from downforce produced by the main foil. Fire Arrow and WOLF use this system to automatically increase RM when required and so use oversquare platforms to increase the separation between the main foil and the lee ama foil.
    A new design has just emerged from Doug Schickler and his partners that shows a very wide cat that uses foils for the major portion of righting moment. They did an executive presentation that is very detailed and you can find it here: and use movable crew weight for the majority of righting moment:

    Volvo Inshore Foiler--Technical Design Information https://www.boatdesign.net/threads/volvo-inshore-foiler-technical-design-information.59460/#post-818265

    ======
    From the pdf:

    "Although the layout is innovative, the elements have been proven in practice. It begins with flapped foils, long proven in the moth to work for automatic ride height control. The big advantages of the flapped foil are reduced control forces, and with that lower costs, as well as good hydrodynamic behavior. The concept of differential lift has been proven in the most recent Americas Cup in the rudder setup. As a primary source of righting moment, it has been long proven by the trifoiler design, as has the central unmoving position of the crew."
     
    Last edited: Nov 18, 2017
  13. TANSL
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    TANSL Senior Member

  14. Doug Lord
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    Doug Lord Flight Ready

    You should sail a foiler if you haven't already....There are many different types of foiler just as there are many different types of "normal" sailboat.
    The "its not sailing " bit doesn't apply to most of them......
     

  15. TANSL
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    TANSL Senior Member

    Sail a foiler must be a marvel, without a doubt. I refer to the "Volvo Inshore Foiler" that appears in the link that you have provided us.
    By the way, in the NZ foiler of the America's Cup I do not think that "cyclists" will enjoy the art of sailing very much.
     
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