Proa with canting (flying) keel why not

Discussion in 'Multihulls' started by Konstanty, Mar 22, 2016.

  1. Konstanty
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    Konstanty Junior Member

    This is a translation with a little help from google translator from the sidi about Mr. Boguslaw Kitowski and his patents:
    This rig has many advantages, significantly facilitate navigation and opening new, not previously known, maneuverability, they do not have boats with existing, traditional rigging.
    • Maximum simplification of handling sail importing to set sail at a right angle to the wind direction. This is accomplished by turning a circle with a suitable angle (manually - small or medium-sized units, mechanically - large units)
    • minimization of the force required to operate the sail (the sail is symmetrical with respect to its vertical axis)
    • The possibility of free sailing and maneuvering forwards and backwards
    • When tacking (with the wind and upwind) the lack occurring in traditional boats, often unpleasant consequences, the phenomenon of shifting the boom and sail from one side to the other
    • The possibility of a very effective braking sail
    • The ability, at any position of the hull to the wind, "taking the wind in the sails" as much as possible as the current wind strength, including parallel to the wind direction setting sail ("flutter")
    • Possibility of application of the new solution in virtually all types of boat, regardless of their size
    • High ease of automation and computerization of sail maneuvering and keeping a designated course (large units).
    Look at this too:
    http://tech.money.pl/przemysl/wynalazki/osprzet-zaglowy-jednostki-plyw-753862.html
     
  2. CT249
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    CT249 Senior Member

    1- Who sets sails at "right angles" to the wind direction?

    2- If you mean setting the sails at the correct angle to the wind direction, why is it simpler to deal with about six sails (in the drawing in post #1) than one or two sails?

    3- How often does anyone sail backwards and forwards? We can do it easily in windsurfers and you can also do it in Lasers and even in keel yachts, but almost no-one ever bothers.

    4- What is unpleasant about a boom shifting from one side to the other? Why is the rotary rig any better?

    5- Any rig can "take the wind in the sails" as much as possible in the current wind strength, apart from sailing very close to the wind (which the rotary rig would be terrible at, from its looks) and square running.

    6- How can this rig work in any size of boat any better than any other rig?

    7 - Why would anyone want an incredibly complex and expensive rig like the one shown in your first post?

    8 - How does the revolving rig get the sail draft in the correct space?

    9- How does the revolving rig get the correct leach twist?

    10- How does the revolving rig get the correct entry profile?

    11- If this rig works, why did people reject the Gallant rig?

    12- If this rig works, why didn't it work when similar rigs were tried in windsurfers?

    13- If this rig works, why not prove it by the very simple process of putting one on something like a Laser or A Class cat, racing it against other boats of similar sail area and hull design, and then showing everyone the official results?

    14- Why should people spend so much more to hire a wider marina berth that would handle the circular frame in the revolving rig?
     
  3. Stumble
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    Stumble Senior Member

    If you really have faith in a new rig then my advice is to buy a beater A-Class Cat and install it as a test platform. Overall nothing has yet proven more effective around the race course than the unirig. But our rules are very simple, it just has to have <150 sq foot of sail area. Everything else is up to you.

    Ben Hall did build a very light weight wing sail that was pretty impressive, but the cost/benefit ratio wasn't there. I think it is the secret hope of the entire class that wing sails don't take off, because we don't want to deal with the logistics of them. Luckily, so far at least, the gains are just theoretical.
     
  4. Timothy
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    Timothy Senior Member

    The 1971 C class cat Patient Lady 2 had a turn table mounted una rig.
     
  5. Konstanty
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    Konstanty Junior Member

    Seaworthiness the Forgotten Factor

    Canting keel is needed for safety and speed proa. One sailor died in the AC during a capsize. That would be good for the show, when the boat after capsizing goes on.
     
  6. Stumble
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    Stumble Senior Member

    Proa' don't have keels they use unweighted center boards. If anything they use water ballast to hold down the windward ama.

    What happened on an AC catamaran has nothing to do with a Proa, completely different design philosophy.
     
  7. Konstanty
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    Konstanty Junior Member

    At The angle of cant 90 degrees ballast water is no longer working. For the safety and good show philosophy can be changed.
     
  8. upchurchmr
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    upchurchmr Senior Member

    I doubt the statement you made has any sense to it at all.
    Check out "Cheers" performance in the OSTAR.

    Didn't look like it needed ballast and that was one of the more famous proas ever built.

    As was said by Stumble - the death in the AC was in a Catamaran, not a proa. I hope you understand the difference.
     
  9. Stumble
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    Stumble Senior Member

    A proa should never get anywhere close to 90 degrees heel. That's what the training wheel is for. Proa' aren't rocket science, nor are they new, adding a ballasted keel, let alone a canting one is just silly. There is no need for it, it's defeated the entire point of a multihull, and would be god awfully slow.

    Adding a canting keel would be even worse.
     
  10. Doug Lord
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    Doug Lord Flight Ready

    Movable Ballast on Multihulls

    Some of the fastest multihulls ever have used ballast-like Hydroptere and Spitfire and others. I think that using ballast-even lead ballast, is worth experimenting with on multihulls. I know it can work on small trimarans and it may be possible and beneficial on other types of multihull. Dismissing it as "just silly" or "defeats the whole purpose of a multihull" isn't necessarily true. In fact, a ballasted multihull around 20' can be made very fast as a foiler and yet be self-righting. I think there is an unfounded prejudice against using movable ballast on multihulls (unless it is alive ,then it's ok!). Modern engineering, design and materials allow things to be possible today that were considered completely impossible when I was a kid.
    There is certainly room for experiment.......

    PS- many people on various forums told me years ago that a foiling keelboat was just ridiculous and ,not only that, impossible! Hugh Welbourn proved those people completely and totally wrong last June with his prototype Quant 23-the worlds first foiling keelboat. http://www.boatdesign.net/forums/sailboats/quant-23-foiler-scow-53468.html

    PS2- not "needing" ballast a qualification for a multihull is nonsense: take the movable ballast off a Hobie 16, Tornado, Flying Phantom etc what happens??!! They NEED movable ballast. So, at what length does a multihull not "need" ballast?? This concept is just nonsense when applied as some have-ruling out ballast on certain boats just because of the idea of it-now that is silly.
     
  11. Stumble
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    Stumble Senior Member

    Doug,

    On a proa water balasting the windward hull is common, on a very powerful proa I could envision a ballasted keel coming horizontally out of the windward hull, but it still wouldn't be a canting keel.

    If you need more RM then you make a multihull wider not heavier. Big multi's principly use water ballast to adjust trim and keep the bow up, not to generate RM.
     
  12. Doug Lord
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    Doug Lord Flight Ready

    Hydroptere uses water ballast in the windward ama for righting moment, Spitfire used ballast to keep the boat level side to side-in other words for righting moment.
    Ballast used in the main hull of a big tri capable of flying the main hull most certainly adds to the RM of the boat. Just making a tri wider in lieu of adding movable ballast can be a real bad idea especially on a boat w/o foil assist.
    There is a lot of potential for the use of movable ballast in multihull design including foilers and the potential of a self-righting trimaran foiler using movable ballast for RM is tremendous.

    Spitfire: http://www.marine.bdg.com.au/spitfire_features.html

    Hydroptere: http://hydroptere.com/en/the-sailing-boats/l-hydroptere-en---3d-view/

    Pictures one and two are Spitfire from Australia. Last picture is Hydroptere:
     

    Attached Files:

  13. pogo
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    pogo ingenious dilletante


    Impractical racers---worthless daydreams.

    pogo
     
  14. Doug Lord
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    Doug Lord Flight Ready

    Flying Canting Keel from Europe:

    [​IMG]

    Flying Canting Keel from the USA:

    [​IMG]

    Flying Canting Keel from Australia:

    [​IMG]
     

  15. NoEyeDeer
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    NoEyeDeer Senior Member

    That reminds me, what happened to Speed Dream? I recall a lot of bluster about how awesome it was going to be, then nothing.
     
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