Gyroscopic Multi-Hull Design

Discussion in 'Multihulls' started by venomousbird, Aug 23, 2011.

  1. venomousbird
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    venomousbird Junior Member

    The only other idea I can come up with would be putting the mast on a swivel that is attached to the exterior hull assembly, and having it mechanically controlled to remain at the right angle. It would only have to move in the event that the exterior hull reached a certain critical angle. It gets away from the simplicity I was hoping for unless I can come up with some sort of mechanism, but it would be possible. I'll see what I can come up with.

    This is about as good as I can do at the moment. Not entirely accurate, but again, illustrates an idea:

    http://www.youtube.com/watch?v=FoOjQSuWUPw
     
    Last edited: Aug 24, 2011
  2. oldsailor7
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    oldsailor7 Senior Member

    The only other idea I can come up with would be putting the mast on a swivel that is attached to the exterior hull assembly, and having it mechanically controlled to remain at the right angle.

    You are talking about a windsurfer arn't you. :eek:
     
  3. Rick Tyler
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    Rick Tyler Defenstrator in chief

    I think by this point that you've given up form stability and have created a complex heavy structure that will have to rely on ballast to keep the living space upright. Also, I don't see what keeps your masts upright in the absence of widely spaced hulls.

    It's a noble thought exercise, but I think there are good reasons that this has not been tried before.

    Would your goal be more easily met by a traditional catamaran with hulls that are bilaterally symmetrical around the water line (where the upper and lower halves are identical), and have internal fixtures that can be mounted either on the deck or overhead, and moved using a screwdriver and a wrench when inverted? Duplicate all the deck-mounted sailing bits and provide a way to move and mount the mast on what used to be the underside of the boat and you've gotten what you want without having to reinvent naval architecture.

    Personally I wouldn't want to buy and would NEVER want to own a boat which compromised its living arrangements in anticipation of a very rare event, but it seems a lesser evil than the drawings above.
     
  4. oldsailor7
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    oldsailor7 Senior Member

    Apart from all of the already suggested problems, having all the foils(sails) at the back of the boat would make it hard to balance without a big forward dagger/centreboard and a forward rudder. Forward rudders are very inefficient and would result in cranky steering boat. The vortice disturbance from the forward rudder would interfere with the board and the resulting induced drag would badly affect the performance of the boat, making it a real dog. :eek:
     
  5. upchurchmr
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    upchurchmr Senior Member

    Please go help someone put up the mast on a Hobie cat or any other daysailing boat. Once you figure out the effort it takes just to push the mast up in no wind, you might have an idea about what it takes to hold up a mast with sail in the wind.

    You need some practical experience before you talk about putting the mast on a swivel with some unimagined piece of hardware to hold it in place. The methods of putting up masts have been developed over centuries, and they won't be changed without practical knowledge.

    Go buy a Hobie, they're cheap and easy to use. You won't die in spite of what you imagine. Eventually you need to sail it until it flips over, the show yourself what it takes to right it. Tens of thousands of people have done this and survived.
     
  6. Wavewacker
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    Wavewacker Senior Member

    Typical posts.

    You know, a motor cat has basically the same problem inverted. Go back to your first idea, when I saw the second I thought it was something to walk on water with (lol)

    Your first idea, with an outboard hanging of the stern will give you the balast to keep your cabin upright. It also depends on the infill of the cabin, so all that crap about lead keels looks to me, as a novice and non-engineer, as a justification to crap on your idea. Common sence tells you there would be some seats in your cabin where you plant your tail end, just use seat belts, that tube cabin will eventually right itself.....think of an airplane! I don't see any more weight in your cabin as in any other cabin, in fact, it could be built with aluminum framing and fitted as a racing mono, web seats and such, and still have more weight on the sole of the cabin than the ceiling. If you bearing-race contraption around the cabin allowed for a very easy movement, you would certainly rotate upright. The race device will be a problem in mtetal, that would be heavy. Think of a monorail train tarck and roller system......maybe just pivot points at the stern and bow would be better, that would be easier to fabricate.

    Another way to accomplish that balance would be with water balast in several ways within the cabin. Maybe just the holding tank would be sufficient.

    With a toy like that I can see that the object of each outing would be to see if you could roll the craft just to show off. You'll need retractable boards depending on which side is down.

    And since this is so unconventional, why not forget sails and foils and use a kite pivoted off the bow? If you need some of the glory and glee of sailing.

    Keep thinking outside the box.....ask any conservative expert in anything for an opinion of something new and different and you're likely to get conventional wisdom and reasons why something new would not work. And that applies to very old ideas that never worked, because today with our technology much more is possible. :idea:
     
  7. upchurchmr
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    upchurchmr Senior Member

    Conventional wisdom has something going for it. Hard won experience paid for by lots of money, trials of new ideas, and lives.

    Fantasies that can't pass the first test - the ability to explain the idea - deserve to be challanged.

    Not everyone is as delicate as might be wished for by some.

    Please answer the first challange, how are you going to keep the passanger capsule upright from the force of the sails? That implies the basic question, where are you attaching the mast/sails?

    This could be interesting, but there has to be two sides to the give and take.
     
  8. groper
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    groper Senior Member

    the only thing i didnt like about it is that is would feel like you were in a submarine... there is no view from any windows except looking at the side of a hull, the only exception being the forward windsheild...

    Agree with wavewacker, main challenge with making at least an adaptation of this workable, is to engineer the bearing/race mechanism so that its strong and light... any sails/kites etc would have to be attached to the hulls and defeats your capsize proof idea, but i like the idea just to reduce the motion as many people suffer seasickness - perhaps this type of vessel could help many people travel on water more comfortably.

    To reduce the pitch, roll and heave, giant gimbals have been constructed for use in oil drilling platforms and naval salvage vessels. Elaborate hydraulic systems with accumulators support the gimbal to reduce the heave, then the gimbal takes care of the roll and pitch... has already been done, just not in small craft and id suggest the cost complexity and weight being the main issues...
     
  9. rwatson
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    rwatson Senior Member

    If its the uncomfortable rolling motion that you are trying to avoid, maybe its best not to confuse it with non-capsizable catamarans.

    One of the smoothest trips I had on a commercial boat was on one of those wave piercing catamarans. The hulls knifing through the waves made the ride like an luxury car on a bumpy highway.

    Funnily enough, I felt sicker on it than the conventional ferries due to its constant yawing (smoothly) caused by the autopilot.

    As it stands at the moment, the design you have shows hulls that will pound and crash during regular travel in very moderate seas, thereby totally negating any comfort factor from not heeling.
     
  10. yipster
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    yipster designer

    Look up Hereshoff Amarillis with hulls moving transversly
    not a bad idea yet there must be reasons we dont see them
     
  11. rwatson
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    rwatson Senior Member

    I looked up the AMARYLLIS - and read quite a bit a bit, but there was no mention of anything remarkable about it.

    In fact at http://33rd.americascup.com/en/actualite/interview/jacques-taglang-20-2414

    "The concept of the first multihulls dates back more than 2000 years and comes to us from the Polynesians. The modern multihulls for pleasure really started their development around the end of the 19th century. The first catamaran of Nathaniel G Herreshoff Amaryllis was built in 1876 but compared to modern criteria it was pretty basic. The beams were rigid, it did not have any daggerboards and only one rudder and the leeward float submerged for much of the time."

    What point were you trying to put ?
     
  12. yipster
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    yipster designer

    rwatson, i was to vaque and now in a hurry but did like hearing your incat motion experience and my amarillis reply was meant for venomousbird, sorry

    interesing site you brought up i'll check out later, here Hereshoff's Amarilles and correct me if that cat did not twist laterally, another search later ok?
    [​IMG]
    wherein hulls laterally can twist giving better seakeeping, motioncomfort, even stability and what not, thing is, its probably to complicated wouldnt you think?
     
  13. rwatson
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    rwatson Senior Member

    Hi Mr Y.

    Thats OK, I was under the impression that you were replying to the whole thread, with the Hereschoff cat info.

    As far as I can tell, the AMARYLLIS was a non-flexing design from the comments I have come across, although the picture is hard to analyze. I think the clue is the main box beam midships, it doesn't seem to have any flexing joins. I would be surprised if even Herreschoff had gotten into advanced hull flex concepts, all those years ago,.

    James Wharram cats are suppose to flex with their rope lashings on the beams. It is supposed to provide a smoother ride. They also seem pretty 'wave piercing', with very narrow hulls in the traditional designs.

    Any cat, with the wide beam, is more comfortable than a monohull's heel I guess.
     
  14. upchurchmr
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    upchurchmr Senior Member

    Rwatson,

    Amaryllis was especially noted for not being rigid, all the joints flexed. It was way ahead of its time.

    Marc
     

  15. yipster
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    yipster designer

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