Offshore Foiling Revolution-Gitana

Discussion in 'Multihulls' started by Doug Lord, Apr 16, 2015.

  1. P Flados
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    P Flados Senior Member

    Their first outing as a "foiler" was not not near as convincing as the G4. They may be holding back, or just not developed far enough along.

    We are all waiting to see the convincing, passive control, full foiling, open water, big(ish) Tri.

    I have mentally scaled up the open water videos of the G4 as my expectation for high speed foiling in the rough.

    For the short term, I could set a boat with a good chance for stuff like the Jules Verne with a size drop down to ~ 70' if they can stay fast enough in the lighter conditions. The should be able to use foils to stay fast without pounding in the "medium rough".
     
  2. Doug Lord
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    Doug Lord Flight Ready

    So far, it's enough to convince me that a putting a lifting foil-either wand controlled or a surface piercing T-on the daggerboard and ditching the ama rudder T-foils for a single T on the back of the main hull would be a faster configuration with better control. Big advantage could be flying the main hull(and the whole boat) in much lighter air while still being able to push hard in stronger conditions.
     
  3. Corley
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    Corley epoxy coated

    The new press release from the Gitana Team indicate that they are going ahead with building an Ultime type foiling multihull that can also operate in displacement mode build set to commence this year at Multiplast. Design by Guillame Verdier and associates also allowing for operation in crewed and solo configurations:

    http://www.gitana-team.com/en/event.news.aspx?eventid=97&newsid=1118
     
  4. Doug Lord
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    Doug Lord Flight Ready

    Gitana Ultime

    What a great project:
    "This new craft, which will measure between 31 and 35 metres, boasts ambitious specifications. The maxi-multihull will initially be geared up for a round the world via the three capes and she will have to be able to be helmed in crewed as well as solo configuration. However, the singularity of this new Gitana will actually lie in her versatile nature, namely Archimedean as well as flying in certain phases of navigation."
     
  5. brian eiland
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    brian eiland Senior Member

    I haven't been following this foiling subject very closely at all, but boy there sure are lots of VERY INTERESTING things happening, ... and a lot of it all over in France

    I just ran across this posting on another forum, and it prompted me to look up what Doug Lord may have already posted on the subject on this forum. ...thus finding this subject thread. So here is that other posting I saw:

     
  6. brian eiland
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    brian eiland Senior Member

  7. Doug Lord
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    Doug Lord Flight Ready

  8. Corley
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    Corley epoxy coated

    It looks like the new Macif is going to have a lifting foils and T rudder setup as well.

    https://youtu.be/4BEhHgklfs4



    There is also an article on Addonante.com but it doesn't go into much detail on the foiling aspects of the design. There is some interesting info on how the crew quarters are to be configured though.

    http://www.adonnante.com/33549-ulti...-focus-sur-les-innovations-du-trimaran-macif/

    a translated version of the same article on the daily sail linked by QBF on SA:

    http://www.thedailysail.com/offshore/15/68058/0/macif-maxi-trimaran-comes-together
     
  9. Doug Lord
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    Doug Lord Flight Ready

    Wow! This really is a revolution-I can't get over it......Thanks, Corley!
    PS-UptiP foils no less! Now all they need is a lifting foil on the daggerboard and they could get rid of the two ama rudder foils....
     
  10. Corley
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    Corley epoxy coated

    It looks like they have decided to move the mast forward on Macif in the initial renders the mast was sitting on the rear beam or maybe the beams are just further apart now.
     

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  11. coralislander
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    coralislander coralislander

    Can you post the initial renders and url source

    Looks to me the mast is sitting on the rear beam.


    Doug

    by having the lifting foil on the dagger board - would that cause drag during sea states that it is not required? Running with big seas the main hull needs to be in contact with the water 90 % to 96 % ALL THE TIME. iS THAT CORRECT?

    Do a broach surfing on large seas at the bottom of the wave at speed as you would not be using the C foils on the floats or the bow gets knocked to windward with cross swells from either 40 degs or 340 degs whilst entering the bottom to level on to another swell or surfing at the top half - a 50 footer wave or more could cause a tripping capsize if the dagger board with the T foils where not fully retractable.

    I thought running with the sea state the dagger board would be fully raised remembering the main hull shape is usually rounded where they have the dagger board on the main hull. Remember also as Corley has mentioned they have increased the size substantially re the T foils on the rudders so assuming the T Foils on the dagger board would have to be substantial also as per your suggestion.
     
  12. Corley
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    Corley epoxy coated

  13. Doug Lord
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    Doug Lord Flight Ready

    foil configuration

    ==================
    I think the daggerboard mainfoil with wand,electronic or manual control of the flap, would allow the boat to safely fly the main hull in conditions where it otherwise would not be safe. With the daggerboard able to develop downforce as well as vertical lift, heave control of the boat would be outstanding in most conditions. It would cause excess drag in very light air but in around 5-8 knots of wind would fly the main hull-before it would due to wind pressure alone. It's important to understand that with a wand or electronic means of controlling the mainfoil flap the main foil begins to unload as soon as the main hull flies, allowing a tremendous reserve of power that would be applied directly and automatically to pitch/heave control. More pitch control authority than any system I've seen yet. And the angle of heel of the boat would be automatically controlled via a combination of vertical lift and downforce as needed.
    The daggerboard, working with the rudder T-foil, would allow the elimination of the two ama T-foils. I think the daggerboard mainfoil would be beneficial in winds from 5 knots on up and would allow superior pitch control because the main and rudder foil would control the ride angle of the ama uptip foil preventing it from pitch excursions that otherwise might occur. This is another reason why the daggerboard foil, with controllable lift, would allow the boat to be pushed harder than a boat without it.
    I don't see the daggerboard foil causing a "tripping capsize" but I do see it preventing that in the majority of conditions.
     
  14. coralislander
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    coralislander coralislander

    Thanks for that contribution!

    Some seas that are not safe. These boats are supposed to be designed for these conditions, around the world to break the existing record.

    http://www.sail-world.com/photo/Pho...in the Southern Ocean by Gordon Frickers1.jpg

    [​IMG]

    [​IMG]

    https://scripps.ucsd.edu/projects/ttide/wp-content/uploads/sites/56/2015/03/Moore_5-03-2015_FUJIFILM_0620.jpg

    Imagine those conditions during darkness hours. Maximum precaution would have to prevail. Accordingly I think the record will be broken by the boat transiting the doldrums during the circumnavigation , which is twice. Also before the doldrums there is considerable areas - the tropics- where the winds are the speeds where the main hull dagger board elevation capability uptip foils as you state would slow the vessel significantly.

    I assume by your term the rudder T foil would have a dual electronic controllable flap for elevation, either side - the main hull rudder.

    Are electronic controlled T rudder foils and main hull electronic dagger board uptip foils allowable by the WSSC for non assisted power records. If so how would that electronic power be stored and delivered to the system?

    Have main hull dagger / centre board uptip foils with electronic controllable flaps been designed as yet. If so is a detailed pic re same available that could be posted here within this thread.

    The tripping capsize as per your interpretation,do you mean pitch polling, because I meant sideway capsize, like extreme broaching as I thought whilst running the main dagger board would be raised as much as possible as it would be dangerous to have it fully lowered or significally lowered.

    Re the "The dagger board, working with the rudder T-foil, would allow the elimination of the two ama T-foils."

    How do you see the operation for ocean races or other races in accordance with the ISAF RACING RULES which state the vessel must have emergency rudders as strong as the main hull rudder. At present to comply Tris have retractable or hinged ama T foil rudders. Does your terminology "elimination" include retractable and hinged T foil ama Rudders?
     

  15. Doug Lord
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    Doug Lord Flight Ready

    I have tried to answer your questions as best I can:
    PS-I found the ISAF "Offshore Special Regulations" ( http://www.sailing.org/specialregs ) but didn't find any mention of what you said about rudders. Do you have a link-maybe I missed it?

    ===================
    Pictures below show a scaled down Test Model of a 19.5' version of the Fire Arrow utilizing the foil concept I have been describing. A larger version would have different proportions. The main foil and rudder foil are T-foils and mounted on the main hull. The ama foils are UptiP foils based on the breakthru invention by TNZ in the 34th Americas Cup. These UptiP foils are refined versions that require no adjustment while foiling.Last picture shows the port UptiP foil:
     

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