Another Big Canting Keel Boat has Blown-up its Mast

Discussion in 'Sailboats' started by Chris Ostlind, Sep 5, 2007.

  1. usa2
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    usa2 Senior Member

    Honest to god Chris, this is the stupidest thread ever posted on this forum.
    It's obvious you're just trying to bait Doug into making a fool of himself with regards to being objectional towards canting keel boats. But I think that this is making you look bad, because if you were to display any sort of common sense, you would understand that there hasnt been enough RECORDED DATA taken from these boats to even think about starting to question their structural intergrity.

    Q: How many boats have rigging failures?

    A: Many, and most you won't hear about because they are not high profile yachts like the canting keel boats. I believe that all the mast breakages on canting keel boats have been due to a rigging fitting breaking, and not the actual tube being underspecification, so this leads me to believe that the rigging suppliers are being told breaking strain estimate that is too low to match the loads generated on the supermaxis. All of the failures except Nicorette's in 2004 after winning the Hobart have been due to a diagonal or the forestay letting go.

    So get over it, rigging failure really isnt that uncommon.
     
  2. Chris Ostlind

    Chris Ostlind Previous Member

    And, so, you now join the class at Doug Lord's school of charm and personal invective, do you?

    The thread is my opinion based on the argument as put forward. If you don't agree, that's fine with me. Make your own argument and we'll see what you have to support the position. Do try to keep it reasonably civil, won't you?
     
  3. usa2
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    usa2 Senior Member

    No, i almost never agree with Doug, and you can ask him about that if you dont believe me.

    I would generally try to keep it civil, except it seems like you are deliberately looking for an argument here, and even though Doug may be extremely biased nearly all the time, he has a point and i havent posted on this board in about half a year or so because i normally have better things to do. But I got a bit annoyed when i saw the way you presented your opinion.
     
  4. Chris Ostlind

    Chris Ostlind Previous Member

    A bit annoyed is fine with me.

    And I wasn't baiting Doug. It's been an on-going discussion over many months and another big boat rig took a dive from the same type of craft. Maybe you see it otherwise, but the whole deal looks to be slipping into a very predictable pattern.

    It bothers Doug when his chosen White Rabbit boats and technology are having problems. Typically, he pretends it isn't happening and in this thread you can see some of that in evidence.

    Perhaps you have some inside info on the whole story of big canters dropping their rigs and would be willing to share that with us?

    Tell me something... if you were an owner of one of these boats and you were routinely dropping MILLION dollar rigs as well as the accompanying DNF's in the races in which you entered, would you want to know why it is happening to your boat and not to the fixed keel entries in the same event? Would you be in the face of the designers, engineers, composite shops and riggers in order to get a fix in place?

    Or, would you just go, "oh well, that friggin' racing". It's perfectly alright with me to drop big dough on something that should be taking care of itself?

    A million bucks and a DNF is still a big deal to anybody, no matter how much cash they have on hand.
     
  5. usa2
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    usa2 Senior Member

    If i was the owner of one of these boats, i would understand that this is relatively uncharted waters and stuff is going to go wrong. These boats are NOT routinely dropping rigs (except for Maximus, and even that isnt by design), and with their high loads and high speeds, i would be pleased to have gotten 2 Hobarts and much more sailing out of a rig that, quite frankly, the designers and builders didnt know whether it would survive its first race.

    That said, if anyone is in a position to be an owner of one of these beasts, your normal perception of cost effective purchases doesnt matter. You dont build a 45 meter rig out of carbon fibre as light as you can build it and then expect it to last forever.

    You cannot compare a fixed keel boat's rig to one of these, because the loads are magnified greatly. Just like you cannot compare fixed keel boat's times or speeds, because they are different craft, and should be rated as such.
     
  6. Chris Ostlind

    Chris Ostlind Previous Member



    And with that, you have just made my argument.
     
  7. usa2
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    usa2 Senior Member

    It is not that complicated to understand. Its rather obvious that the loading is increased, and the rigging components either are not up to the job in the first place, or they are wearing faster than expected. Its not the end of the world.
     
  8. water addict
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    water addict Naval Architect

    I'll weigh in with usa2 here, Chris. You sure as hell sound to me like you're just looking for an argument for argument's sake.
     
  9. RHough
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    RHough Retro Dude

    The first place I'd look is at heave accelerations and their effect. In a fixed keel boat, heave motions impart next to no change in RM. On a canter, with the CG so far off to one side, heave motion creates a heeling couple that changes the RM at the end of each cycle.

    Rigging and fittings have a finite service life WRT stress cycles. The greater the change in stress during each cycle, the shorter the service life becomes. A component that might be expected to last 30,000 sea miles on a "standard" boat may well be at the end of it's service life in 5,000 - 10,000 miles on a canter.

    If we assume a 10 knot average speed, expect to start replacing things in 3000 hours. At a wave frequency of 6 sec, that's 18,000,000 cycles. Factor in an exponential reduction in service life to the increased loads from a canted keel and you might see failures at 750-1000 hours. The difference is 32-42 days of racing on the canter vs 125 days for a "standard" boat.

    I don't think there is anything wrong with the rig design, just that the same "safety factors" that have worked for years did not include canting keel boat data. The situation is not as simple as just factoring in the high RM as you would for a multi, the multi does not have 20,000 pounds of lead adding to the RM at the bottom of each wave.

    The "fix" is easy. Increase the margins and start by doing test to failure on parts sooner. You have the choice of extremely high maintenance costs or a much heavier rig. Not a big deal. :)
     
  10. Guillermo
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    Guillermo Ingeniero Naval

    Respectfully guys: aren't you turning around in circles...?
     
  11. DGreenwood
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    DGreenwood Senior Member

    No one is turning in circles...it is a very good question.
    Isn't it possible the fault does not necessarily lie in the machine ...it could be the pilots learning to control so much power that is often the cause.
    The results of exceedingly light structures capable of generating so much power in nearly all conditions has obliged the crew to develop a much keener sense for where that breaking point really is.
    We can build boats with muscles that are stronger than their tendons---requiring much discretion in the application of those muscles.
    Multi-hulls went through a similar phase (it isn't over). Their rigs were snapping when designers were a little drunk with all that available stability. And multis have a much bigger platform to tie the rig down to!
    Suddenly the canting keel allowed significantly lighter boats with a control knob on the stability The temptation to design for ideal conditions and leave it to the crew to back it off when necessary, is almost as strong as the crews temptation to push it a little harder.
    For all the things a good Vendee sailor must know, knowing when to apply available resources is the greatest and hardest won talent. If you expect to be competitive, you will break some gear learning that...period.
     
  12. Guillermo
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    Guillermo Ingeniero Naval

    Yes, the question is good, of course. But what I mean is that everybody seems to have arrived to the same conclusions, yet the sturggle continues. Anyhow, it's OK to me. Just a comment. :)
    Cheers.
     
  13. Chris Ostlind

    Chris Ostlind Previous Member

    Yet another big canter has gone the same route

    This time it's the brand new, Pindar, Open 60 design from Juan K and it wasn't even in a full tilt race mode when it sucked down another mast. This is Pindar's second time down this road after the first dismasting back in early August.

    http://www.pindar.com:80/teampindar/news.asp?navID=273&d=848&i=5

    One can only wonder as to the conversations between the owners, skipper, designer and the comp mast builder, Southern Spars.
     

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  14. lazeyjack

    lazeyjack Guest

    is there such a thing as carbon fatigue> like an axle, you twist it, , you twist it again many times, then one day it brakes, under little stress, A mast moves (even if it can not be seen) through many cycles per minute, so why could it not just give up, when it became tired?
    Anyways I don't dig anything thats made of sticky juz737744ne 55 4 ws22 sh----t Suffice to say they did not make the 380 from Carbon fibre
     

  15. DanishBagger
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    DanishBagger Never Again

    Is it just me, but since a part failed/broke/collapsed/compressed when it shouldn't, doesn't that mean that the structural integrity wasn't god enough (that the structural integrity was "compromised")?

    I'm not talking about the mathematics behind it and whether the structure was fine according to that. But in real life, the structurel integrity wasn't there – am I wrong?
     
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