Planing Trimarans

Discussion in 'Multihulls' started by Doug Lord, Sep 30, 2006.

  1. Samnz
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    Samnz Senior Member

    My old buccanner 24 would create a huge stern wake untill it hit about 10 knots boat speed, then the main hull would "let go" and it jump to 12 to 14 knots and leave no wake at all.

    I would say the main hull is now "planing" however the Trimaran as a boat is not as the 20 foot long float is not planing but nearly under water, with the fine transom not throwing up much wake.

    At 18 knots boat speed the main hull is not "planing" its flying and the float is now certainly not planing its under water at terminal velocity and just wont go any faster without waves to push it.

    I have also tried it with a really big motor. wont plane just sits at 10 knots digging a big hole... so not a planing boat in my opinion.

    (I Did over 50 races on this boat with a GPS speedo)


    All the tris I have raced on behave like this.
     
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  2. cavalier mk2
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    cavalier mk2 Senior Member

    The complete definition of planing I gave earlier did include wave separation and was a quote from Juan Baader who knew the difference. Go back a page or two. Sounds like your windsurfer was functioning more like a control foil when underwater . The point about calling the whole boat planing was because the displacement as a whole is lessened though I'm not attached to the definition and agree that a lot of amas operate in displacement mode. Where did you have the motor on the Buccaneer and how heavy was it? It might be different if towed and should be interesting to see what other Buccaneer owners say.
     
  3. Capn Mud
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    Capn Mud Junior Member

    Planing amas?

    I respectfully suggest ALL amas will be in displacement mode. Can anyone point to a planing ama?
     
  4. Gary Baigent
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    Gary Baigent Senior Member

    There is the occasional rare planing ama trimarans around like this canard tri here: scroll down to the second section, ptite news,
    http://foils.wordpress.com/
    But these are almost as rare as rocking horse defecation - and don't really apply to the conflict of opinions here regarding more conventional tri platforms - although Doug will surely jump up and start gesticulating.
     
  5. Doug Lord
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    Doug Lord Flight Ready

    Planing Ama

    See below Capn Mud: (from earlier in this thread)

    =============================
     
  6. Chris Ostlind

    Chris Ostlind Previous Member

    Doug,

    While you're trying like heck to catch your breath, you may wish to take a long look at how Jim Antrim's amas are actually shaped before you start to get your toes all curled up in your boot.


    (Edited most of this post because... I simply do not care about the argument anymore)


    After reading all your posts over the last many years on this topic, Doug, I very firmly get the impression that you really, really want this whole thing to be true for some inner desire of yours. The fact that you still haven't been able to back up that desire with anything but hyperbole is telling in its own fashion.

    Certainly, there are much more fruitful pursuits for you to engage than to resurrect a tired, no-can-do argument about planing trimarans...?
     
  7. Capn Mud
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    Capn Mud Junior Member

    Ian's claim is not that prominent on the F-Boat web site. You have to dig down 2 levels through 2 different menus to find this:

    "The hull underwater sections begin with a very fine entry, flowing back to a U-type midsection, followed by a broad flat run aft. Rocker is kept to an absolute minimum for less drag and to encourage early planing. This unique feature was pioneered by the F-27 trimaran and is now standard with all F-SeriesĀ® trimarans, and similar lines are now being used with catamarans.

    The planing ability of the low rocker trimaran center hull also allows a slightly wider hull section to be used, for more room inside, but without any detrimental effect on speed.

    Farrier trimarans have always used a roomier wider center hull since it was discovered with the original Trailertri 18 that a narrow hull was not necessary for high speed sailing. This is made possible by the center hull lifting as the boat heels, rapidly reducing hull width, until the hull is planing on the flat lower sections, avoiding any restricting hull speed. In fact the wider planing hull seems more efficient at higher speeds, while also providing a considerably higher load carrying capacity, and less wetted surface for superior light wind performance."
     
  8. Gary Baigent
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    Gary Baigent Senior Member

    Less wetted surface for superior light conditions - that is complete and utter BS Ian - and you know it. Of course all the really high performance multihulls like A,B,C and D Class cats, the ORMA 60's, Multi 50's, the Swiss lake racers and so on, all carry wide, beer belly shaped after cross section shapes - yes? You can do anything with words, spin away so that clients can mouth on smugly like salesman at barbecues - but those quotes posted by Capn. Mud are in DL's fantasy world - I'm sure he loves them. The real reason for your fat posterior after sections is to carry loads and increase accommodation area, fair enough - just don't rabbit on with that other load of utter toss.
     
  9. Doug Lord
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    Doug Lord Flight Ready

    ==================

    What he said.......
     
  10. cavalier mk2
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    cavalier mk2 Senior Member

    The ballast may have flunked some math as well. For a given area a wide semi circle has less wetted surface than a narrow deeper one.It will also depress less as weight is added. For a design requirement of having usable interior space and load carrying a different approach to achieve speed is needed than that used by the Orma 60s etc... Since Mr. Osland is prosecuting the planing defendants the burden of proof should fall on him. After 4 years he (and others) are unsatisfied with the examples shown so why not try something new and prove the F-boats don't plane ? It might even get him out of the house......
     
  11. Chris Ostlind

    Chris Ostlind Previous Member

    Cav,

    Are you a person with one iota of original thought, or are you merely a Doug Lord apologist who types whatever sentiment Doug spews, just because it suits your masked Internet persona?

    Come on, man, get some functional originality going for yourself and use whatever grey matter resides within. I do not have to prove that any tri does not plane. Simple visible logic will tell you that... if you are paying attention long enough.

    You prove that they can. Use your own boat, if you actually have one, that is. Remove the amas, get some of your friends as movable ballast to get out on it like a fast dinghy and let 'er rip with a good camera rolling from a chase boat. Put that bad boy up on a plane and share the evidence with us as your denouement.

    Personally, I don't think you have the needed cheeky parts to go out and do it, so it shall remain an arguing point in which you simply spew and never do. In an ironic way, this inability to perform puts you in the same company as our boy DL, the king of never getting anything done after wasting years on this and a dozen other forums.

    Want to have some fun as Doug's favorite, attack dog, buddy? Ask him to show you the boats he has produced in the last 8 years, photos/videos of them working as designed and how they are now in the hands of others as intact and functional fulfillments of his original vision. My boats are conceived, built and being used by the kind folks who share the energy that takes them out on the water in all sorts of great adventures. Perhaps you and Doug can get together and show us all what real boats the two of you have created, built and currently sail successfully?
     
  12. cavalier mk2
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    cavalier mk2 Senior Member

    If you look in my gallery Ballast you can see my boat is not demountable. The real issue here is you know you can't disprove Mr. Farrier's planing claims and are too chicken to use the helpful budget testing methods offered to you. In fact your only idea (which is surely reflecting your design skills) is to take off amas , put on racks and add a huge amount of weight in live ballast, and of course weight isn't helpful to planing. Use the load line method and start filming. Maybe you can get a cable show like Myth Busters interested in the idea and let them arrange things but to be safe tell them you are only acting the Devil's Advocate roll so you don't look the complete fool when they figure out Mr. Farrier is right. He might even send you a commission for the help in advertising.
     
  13. Chris Ostlind

    Chris Ostlind Previous Member


    So, with all this blindlingly fast technology flying out of the F-boat idiom, why is that all the best designers of the world's fastest boats (Irens, VPLP and the rest) have never seen the light and flipped-over, wholesale, to get a leg up on their competition through this, so-called, planing hull form? With tenths of knots being the crucible for victory in that world, what would stand in the way of the best skippers insisting that they have F-boat fatties to vanquish their dumb-cluck, tardy thinking opponents?

    Perhaps the bone simple answer is that Irens and VPLP can recognize BS when they see it and instead rely on their own vast experience, fluid dynamics studies and all the tools at their disposal when it comes to the design of the fastest boats on the planet. Here's a big clue for Doug and any of his dream-scheme minions... Hydroptere does not use a fatty hull for in-the-water, low speed efficiency as proclaimed by Mr. Farrier. Who better to teach you about performance than the folks in that camp?

    Cav, please do some homework and let yourself become less of a reactionary based on what sounds cool and what emanates from marketing hype.



    It funny that you mention this about F-boats and planing. Apparently, this elusive condition is dearly sought after by the folks who sail them and equally apparent are the regular comments in which F-boat owners tell of one guy in the fleet being able to lift his boat enough through heel that he can easily outpace the rest of the clan.

    If planing were such a feature, then why is that so many of the guys sailing them just can't seem to get them into that condition? It would seem to me that if a boat is going to be designed specifically to generate the benefit, that it would be easily reachable by any simple guy who tosses down the money. When you go into the car dealers and buy a Honda Accord with an ABS, do you also have to go to the Bondurant School of Racing to learn how to use it, or does it just sit there, patiently waiting for the most inexperienced driver's input before it does its thing? Yeah, I thought so.
     
  14. Chris Ostlind

    Chris Ostlind Previous Member


    And you think that amas don't weigh anything? Please tell me that this isn't another helium is the answer rant. All trimarans are demountable, Cav... if you have the sack to demount them, that is. Ever see the photos of Groupama 3, upside down off the coast of NZ... with the ama clearly free from the rest of the boat? No guts, no glory, Cav.

    And please, Cav... don't show us more of your ignorance in areas in which you certainly have no expertise... "filming" is an antiquated term that implies that physical film is actually moving through a camera. If you knew how many folks were still using film in this day and age of digital recording you might want to quietly rephrase your comments. It is this sort of uninformed use of terminology that sits at the heart of your poorly thought-through arguments on this greater topic.

    How ironic that you frame my argument so successfully. Thanks

    I will wager that you will have more to say in your sputtering fashion. I just can't find the time to kick your butt any longer. I will send a free set of canoe plans to the first one to write me offlist after Cavalier proves that he can't keep his mouth shut on the topic.
     

  15. cavalier mk2
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    cavalier mk2 Senior Member

    Ladies and gentlemen and ballast, will you really feel safe in this man's canoe ? Just for fun I'll put a picture of my utility canoe in my gallery. Feel free to borrow design elements and whether your boat planes or not wear your float coat and sail safe !
     
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