Canting Keel Monos vs Multihulls

Discussion in 'Multihulls' started by brian eiland, Aug 31, 2006.

  1. brian eiland
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    brian eiland Senior Member

    ...... last paragraph of an interesting interview
    with Juan Kouyoumdjian (aka Juan K.) in September Sail magazine.

    He's a naval architect who designed the runaway winner (ABN One) in
    Volvo Ocean Race.

    At end of article they asked: "What is future of canting-ballast
    technology?"

    He replied:
    "It depends on acceptance. I could argue that a canting-keel monohull
    is a very inefficient multihull. Imagine canting a keel to leeward
    and instead of ballast you have air. You would achieve the same
    increase in righting moment in a lighter solution, and in fact you get a
    multihull. Our sailing community is divided, and choices are made on
    style or fashion; otherwise we'd all be sailing multihulls"
     
  2. Figgy
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    Figgy Senior Member

    I saw that, and I agree with him. I love mono's, but I think the future is in multihulls. This is going to be one of those comments that gets picked apart word by word.
    Prepare for a long thread.
     
  3. Tim B
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    Tim B Senior Member

    That's an interesting idea. Why are multihulls the future? Is it just because they are more efficient?

    For Starters:
    There's less interior space,
    they are harder to manouvre
    they take up more space in marinas...

    There are more arguments against them. For going fast in a straight line they're great, but I want a boat that does more than that.

    Tim B.
     
  4. jam007
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    jam007 Junior Member

    Just for the fun of argumentation
    And against monos:
    They heel 20-30 degrees making living in them unatractive
    Less exterior space
    Need deep bays and harbours
    Slow in any line or curve you want to sail in

    Anders M
     
  5. Figgy
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    Figgy Senior Member

    Isnt that one of the fundamentals of cruising, efficency, or am I taking it out of context? We are talking about cruising and not day sailing, yes?
    Now I will agree that they take up more space in marinas, but the comfort level at sea more than makes up for it.
     
  6. yipster
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    yipster designer

    Juan is oK and for all who are gonna say multi's turn upside down sooner or later dont race or look for a motor sailor multi ( and still outsail mono's ( Malcolm Tenant ))
     
  7. jehardiman
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    jehardiman Senior Member

    I think that quote is directed at the around-the-world, extreme racing crowd. There are many reasons why a multi-hull is a poor choice in other situations (and even in around-the-world).

    Remember, the only thing a Naval Architect has to sell is his opinion. Because, in fact, the answer is always " It depends....".;)
     
  8. marshmat
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    marshmat Senior Member

    Well, I find it pretty hard to dislike any fast boat. And at present, the big cats are still beating the big monos on speed (although of course both types thoroughly leave my own boat in the dust).
    There's durability to consider too, though. Could a VO 70 circumnavigate without shore crew at each port to repair it? Perhaps the ABN AMRO boats could if they had to, but most of the fleet underwent pretty extensive repairs. One lost a mast, one sunk, many had keel problems. Could a supercat like Orange II circumnavigate a similar course? Maybe, maybe not. Racing ain't cruising; the priorities are very different.
    Yes, multis do have their shortcomings. But as far as racing is concerned, I think the reason we don't see more of them is political rather than technical. Too many powerful people have too much money tied up in mono racing, and don't want to be embarassed by much faster multis in head-to-head competition. Look at the new America's Cup boats: the difference between $50M and $100M (an order of magnitude more than I would have ever imagined spending on such a yacht) is what, 0.2 knots? The current racing culture is so locked into their old ways that innovation and change are really, really hard to find. Most big-time racing still runs on rules that the technology outstripped decades ago. Why don't we see freestanding wingmasts in the big races? Why no cats and tris? Instead, we mount hydraulics on the old lead/tungsten bulb, so that the result still looks and sails like a mono. If we want to see real progress in sail racing, we need rules that allow progress on a big scale, not just in little niche classes.
     
  9. Figgy
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    Figgy Senior Member

    I think a multi is the ONLY choice in a 'round-the-world race. Why would anyone even consider a mono? Multi's have proven themselves superior. Now we can go rounds about cats vs. tri's, but its moot.
     
  10. yipster
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    yipster designer

    sure you may ad cost and more but "depends on acceptance" Juan K said wisely, his example i liked even better, we all have opinions, here Malcolm Tennant's
     
  11. jehardiman
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    jehardiman Senior Member

    Ok.... lets say I limit the length to 10m and tonnage to 4 tonnes and we go east to west..... now we race. It is the selection of the requirements that drive the selection of the design, not that any one design is better than another. As I said, "It depends..."

    Anyway, the only reason that a cat or a tri has any major ocean ability is due to one thing: Modern composites. Cats and tris are weight limited structures that are very sensitive to wave period and direction. It is only the combination of light weight and high strength of modern materials that allows a cat or tri of the proper size to be built to survive the southern ocean (and some don't because loads increase with size) and carry the weight required (which right now can only be accieved on very large vessels). Which brings up the routes; they are selected to exploit the abilities of the racing vessels, not driven by economic necessity.

    While cats and tris have thier exploitable points, they are not the be-all end-all of marine design.
     
  12. Doug Lord

    Doug Lord Guest

    Movable Ballast Keelboats vs Multi's

    -----------------
    Well, I think there is another option and that is a self-righting mono using buoyancy pods(as backup), fixed or canting keel, on-deck movable ballast and last but not least a bi-foil hydrofoil system. The Moth has shown that a well designed monofoiler can beat well designed cats almost twice it's length. And I think that a Maxi-Skiff type monofoiler will be able to beat a multihull it's own length down the line but with the added advantage of being self-righting.
    I think there is tremendous room for exploration of this design type for high speed ocean sailing.
    Here are design conceptions from Bethwaite and Langman that could, potentialy, be adapted to a bi-foil system:
    LSS_7.jpg
    Address:http://www.sailinganarchy.com/fringe/2005/images/LSS_7.jpg Changed:11:43 PM on Thursday, October 20, 2005
    ----
    billochcut.jpg
    Address:http://www.sailinganarchy.com/fringe/2005/images/billochcut.jpg Changed:7:21 PM on Wednesday, September 28, 2005
    ----
    These guys have built a 30+ ft. proto and expect to use foils on it and the 100 footer they plan to build some day:
    Out and Out Solutions - OUT95 - Extreme Sailing - Extreme Performance Yacht Design
    Address:http://www.out95.com/welcome1.html Changed:8:00 AM on Thursday, June 15, 2006
     
  13. Figgy
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    Figgy Senior Member

    Multi's might not be the end-all of design, but I dont see too many mono's on this list outside of thier own catagory.
    http://www.sailspeedrecords.com/ratified.html
    My point isnt to try to fight about this, its that I agree with Juan K.
     
  14. yipster
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    yipster designer

    reminded me of http://www.boatdesign.net/forums/showthread.php?t=9608&page=3&highlight=canting
    but i like the airbulb much better bulb bulb :D
     

  15. marshmat
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    marshmat Senior Member

    Good point about the records... a close look through there indicates that almost all the prestigious records are held by multis of some form; the few that aren't (Sydney-Hobart for example) are for races that discourage or ban multis in their rules. The few monos on there in open categories hold records on routes that aren't nearly as well publicized or as heavily challenged, or on singlehanded long-distance races.
    I do find it interesting though that the monohull 24 hour record was broken three times in a year, by the VO 70 fleet.
    Multis certainly aren't right for everybody, but I think the current world racing fleet makes pretty clear that they can be bloody fast, especially when compared against monos.
     
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