Canting Keel Monos vs Multihulls

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

  1. rayaldridge
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    rayaldridge Senior Member

    By an odd coincidence, I'm building just such a boat, except that it's slightly under 16' LOA and a lot lighter than anything with a cabin.

    I think in the EC (and perhaps other endurance-oriented small boat races) it's essential to be able to sail from inside the boat rather than on the boat.

    Ah well. Another thread, no doubt.
     
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  2. Chris Ostlind

    Chris Ostlind Previous Member

    Concluding with this post, this derivative journey will now be shifted to a new thread of its own. I ask the followers of this thread for their indulgence.

    New Thread for Minimalist Coastal Cruising under Boat Design Sub-Forum


    I'm of the opinion that most of the people who would enjoy such a cruising cat would not be concerning themselves with the imposed EC requirement not being able to use an outboard motor.

    That ruling is crucial for a boat of this size. The weight of a typical fast cat with anything like a beachcat sail area, quickly becomes very tiresome when paddled or Yuloh'd or rowed, or anything by the puny potential of a human being as propulsion element.

    That immediately limits the boat weight and that limit, in turn, limits the accommodation potential for comfort and rest on board. For a pure cruiser, this isn't such an issue. For a racer, it is. That is where I think the EC formula fails as it is highly prejudiced towards certain types of boats.

    Most people in coastal cruising adventure applications, using non-kayak or canoe sized boats, would more than likely choose a small outboard for their non-wind propulsion. An internal combustion gas engine packs more potential power into a much lighter and smaller unit than anything available. The newer fourstroke engines are so dependable and quiet that they are without question, the best solution for windless periods.

    For events like the EC, I'd rather see an allowance for outboards with a severe ration of fuel with a kicker attached. Sure, take along a 50-lb. outboard... You get one gallon of gas as your ration and it will be weighed at the end. For every fluid ounce you use, you will be assessed a period of time to your finishing position. Sort of a racer handicap. For a cruiser, this is no big deal as it allows you to dedicate your boat to sailing and you can use the engine to get in and out of the checkpoints against the tide if desired and you'll get socked at the finish line... but who cares, you're only cruising.

    Let's face it, if I were going to Belize and wanted to sail down the coast of Central America and explore the inlets and river mouths, I would have an outboard on my multihull and I wouldn't think twice about violating the rules of the Watertribe. If outboards are taboo in the EC, then GPS units should be taboo as well. If you have to paddle like a man, why not navigate like one too?
     
    Last edited: Oct 4, 2006
  3. ActionPotential
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    ActionPotential Junior Member

    Ballast vs Buoyancy

    Such as a proa. If it constantly flies one or more hulls, that is always sails on one hull (always the same hull) is it a mono or a multi?
    I think the arguement is rather Ballast vs Buoyancy and that the future of carrying weight simply for ballast is limited.
    When the canting keel carries buoyancy rather than ballast then it will become a multihull until it can sail on the buoyancy, then it can be a mono again.

    Why is the ballast bulb on the end of the canting keel not currently classified as a hull, just because it doesn't break the surface?
    As soon as it does will it become a proa?

    Is it really only the 'self righting' that keeps the multi's out while the canting keels are in? Do they really 'self right' when the canting mechanism is broken?

    Perhaps the 'traditional' monohull proponents will be able to rid their races of canting keels on this basis?
     
  4. Doug Lord

    Doug Lord Guest

    Canting Keel Mono's vs Multi's

    "Perhaps the 'traditional" monohull proponents will be able to rid their races of canting keels on this basis?" Lets hope not; there is enough exclusionary BS running loose as it is. It's a disgrace that multi's are still excluded from many major ocean races.
    Movable ballast- on-deck + canting keel has a much greater future than most people seem to realize both on mono's and multi's. Spitfire, an Australian surface piercing bi-plane rig foiler used ballast instead of developing RM from the foils. The designer said that with ballast you only have to lift it once....Even Orma 60 tri's are allowed to use ballast.
    Movable ballast on self-righting monohull foilers will allow those boats to be competitive with foil assist multihulls and that IS the future of canting/movable ballast.....
     
  5. ActionPotential
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    ActionPotential Junior Member

    Ballast vs buoyancy

    I think traditional monohull racers should have the right to race like with like.
    They should exclude anything that makes a competitor significantly different.
    Perhaps the answer for S-H is to have a race starting on boxing day, for traditional monohulls, then another race, starting new years day, for 'anything goes' Multi including Proa, Mono including canting keels, movable ballast, canting rigs etc.

    Meanwhile I believe the future is in not carrying weight just for ballast. Weight will be carried because it is needed for other purposes and used ingeniously to assist RM.
    I expect Rob Denney will prove the superiority of the harryproa configuration and the next step will be the foil borne harryproa.
    Efficiency is the key and weight for ballast only is not efficient.
    Self righting will eventually be by buoyancy rather than ballast.
    Moths don't carry weight for ballast (unless the skipper wears a weight jacket). All the weight they carry is needed for other purposes.
     
  6. Alan M.
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    Alan M. Senior Member

    I wouldn't even guarantee they would self right when the canting keel mechanism IS working. The only self righting tests I have seen done were on boats that had NO RIG on them.
     
  7. marshmat
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    marshmat Senior Member

    Confirmed, at least for the VO 70. Volvo Open 70 rules require that the crew be able to manually right the boat by cranking the keel over from inside, with engine off, but not that the boat right itself without assistance. Nor are they equipped with a mast when the test is performed. Although to be fair, a 180-degree knockdown in a boat with that kind of rigging would have a good chance of tearing the mast right off anyway.
     
  8. ActionPotential
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    ActionPotential Junior Member

    self righting

    All the more reason to throw them in with the multihulls, or to throw the multihulls in with them. Hasn't the argument for excluding multi's always been that they don't self right without assistance?
     
  9. jehardiman
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    jehardiman Senior Member

    Yeah, yeah...I'll take the flack for reopening this wound...uhhh, thread.

    This years (2006) Route de Rhum has some interesting statistics that I think reflect on the original topic starting quote

    While as of this date (Nov 16) not all the multi's or mono's are in, but there seem to be no impediment to the rest finishing except time. The following statistics can be gleaned

    Multihulls
    ORMA (60') 1 abandoned (capsize) in 12
    Class 2 (45-50') 1 abandoned (capsize), 1 retired (rudder failure) in 8
    Class 3 (40-45') 1 abandoned (capsize), 1 retired (dismasting) in 3
    Vessels lost 3 of 23: 13%
    Vessels retired 5 of 23: 21%

    Monohulls
    IMOCA (60') 1 retire (dismasted) in 11 (note 1 retired for family reasons, add in if you wish, but not a boat failure)
    Class 1 (50-60') no failures in 4
    Class 2 (45-50') no failures in 4
    Class 3 (40-45') 1 abandoned (structural failure with leak, sunk), 1 retired (dismasted), and 1 retired (?) in 6
    Class 40 (40') 1 abandoned (knockdown with structural failure in keel, sunk?), 1 retired (boom broke) in 25
    Vessels lost 2 of 50: 4% (or 2 of 51 = 3.9%)
    Vessels retired 6 of 50: 12% (or 7 of 51 = 13%)

    Compare this year to 2002 and a trend begins to emerge. Multis seem twice as likely to fail or abandon/retire. What should we in the design community take away from that observation
     
    Last edited: Nov 17, 2006
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  10. ActionPotential
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    ActionPotential Junior Member

    jehardiman:
    "What should we in the design community take away from that observation?"

    The monohulls aren't really trying. If they were serious they would have more failures. At the leading edge of any competition there will be lots of failures if you are really trying. Conservative, safe, slow will not lead to useful innovation. Radical, dangerous, fast will.
     
  11. RHough
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    RHough Retro Dude

    Trick question right? :)

    That risks increase exponentially with speed?

    That drawing conclusions from small samples is risky?

    That "Multis twice as likely to fail or abandon ocean races" sounds like a Fox News headline on a slow day? :D

    That equating capsized with sunk is a biased viewpoint?

    That stating Mono-hulls are 100% more likely to sink than Multi-hulls (3.9% compared to 0) is equally valid (and equally biased)?

    Have I got it right yet?

    In case the question was not a troll:

    5 of 74 vessels were "lost" (6.7%?)
    12 of 74 vessels retired (16%?)
    17 of 74 vessels failed to finish (23%?)

    Is the failure rate of the multi's (34.7%) significantly higher than that of the fleet (23%)?

    Is the failure rate of the mono's (17.6%) significantly lower than that of the fleet (23%)?

    If the failure rate of a sample is not significantly (2 STD's?) different than the failure rate of the population the the attribute that defines the sample is not proved to be the probable cause.

    My personal opinion is that if you look at each case it will be very hard to prove that hull configuration is a determining factor in anything other than the sinking's. The only boats in the race that had the negative flooded buoyancy required to induce sinking are those that carry lead weight ... the mono's.

    Randy
    -Just having fun.
     
  12. jehardiman
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    jehardiman Senior Member

    OK...there are lies, damn lies, and statistics......:D

    Lets look at the total fleet vice the individual configurations

    Not exponentially, but maybe lineraly (fastest multi was less than half as fast as the fastest mono and slowest multi has yet to finish but will be ~ half as fast as the fastest mono).

    A capsize or an abandonment (of the boat, not the race) is a constructive total loss. Sunk (i.e. pre-paid) costs of recovery may well exceede replacement (ask about a Lloyds open form or the cost of chartering an air search...see the Aotea loss). Right now I'm not sure how many boats are truely lost...I can't read french that well.

    Again, we don't know how many are truely losses.

    Please, I don't troll...I ask hard questions that require thought. Often I don't like the answers, but the questions must still be asked.

    OK lets look at this another way and since you brought up the standard deviation....STD of the fleet= 0.0045 losses per entry, STD of the multis= 0.0170, STD of the monos= 0.0016...loss of multis= 3.78 sigma, loss of monos = 0.35 sigma for a del sigma of ~10....yes that is significant. PLEASE, any math majors dive in here and please correct this math challanges NA.

    Well all the losses are yet to be tallied..so we will let that go. One thing I like about this race is that the storm hit early, before the fleet had a chance to spread like Fastnet. However, there is still the seperation to contend with. This years winner Gitana 11 and the other first 7 multis to finish (Gitana 11, 6 ORMA and 1 Class 2 multi) got ahead of the storm. All the next (both multis and monos) are in a group that had to ride out the storm and were 2 days behind. Now that the first class 40 has finished (@2300Z Nov 16, 2006), there are still 1 MORA, 2 Class 2's and 1 Class 3 multis left to finish, as well as 1 IMOCA, all the Class 1's (which got hammered), 3 Class 2's , and the 3 surviving Class 3 monos yet to finish.

    If we wish to draw broad conclusion from this race, it is that the waves did not favor vessels between 40+ to 45 feet ( 2 lost, 2 dismasted, 1? for a retirement of 5 out of 9)
     
    Last edited: Nov 17, 2006
  13. Chris Ostlind

    Chris Ostlind Previous Member

    Design Question

    What I take away is that high strung designs with few compromises to the high priestess of performance have routine issues on the race course. This is true for any sport at this level. Ask the boys in Formula 1 or NASCAR how that works.

    I don't fully subscribe to the comment from AC about the monohullers not trying very hard. I think everyone was going at appropriate race speed for the conditions and their skill sets.

    It comes down to this simple line of design thinking when it comes to race boats... you design for the fastest boat you think can be held together for the duration of the event for the potential skills of the person driving. Anything less is not racing. Sometimes that configuration will break, the skipper will make an error or the God's will deal you a bad hand.

    If none of the above negative outcomes come into play, then you watch the opponents recede over the horizon behind. If they do enter the picture, you go to Plan B and that can take on a whole host of realities, depending on vessel and conditions.

    This is about racing, not comfortably tooling around. Racers typically want to win and not circulate at the back of the envelope while they wait for all the fast guys to drop out. The only ones who routinely take part in that strategy are the ones who are under-funded, under-talented, or both.

    And lastly... since when does the designer have a choice in the matter as to style of boat the racer/sponsor wishes to have drawn-up? The only choice we get is whether we take the commission or not. If you are asked, and you agree, then you draw the boat within the limits that the racer/sponsor lays out in the design brief. Or they go elsewhere.

    If you want to design your own boat and go hunting for a talented driver and a deep pocket sponsor, then you get to do what you want with the design. If your monohull effort (and that's where you are going with this component of the discussion, I assume) is entered in a year with good weather, good winds and simple routing, you can watch your dream boat arrive well after the multihullers have gone home with the cash and the cups. If it's all bad, then you may just be the attrition meister and get a series of asterisks next to your effort.

    I guess it just depends on the crowd to whom you are playing.

    Chris
     
  14. RHough
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    RHough Retro Dude

    Lets look at it very simply (I'm a simpleton). :p

    I conclude that speed is a safety factor. The boats fast enough to avoid the storm did well, the slow boats accounted for all the losses. That is a correlation that cannot be statistically manipulated to make a point.

    Sailing to a schedule or racing has always increased risk. Waiting for good weather has always been prudent. It would seem that if you decide to race across an ocean, the wisest choice is a fast boat. Fast boats do not include 40 footers or mono-hulls.

    You can use this data to "prove" that the safest ocean boat is a ORMA multi. One could also conclude that any boat with a keel (canting or otherwise) is a foolhardy risk. :)

    Now if there had been a 60 foot canting foiler in the race the story would be different ... :p
     

  15. jehardiman
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    jehardiman Senior Member

    I believe that conclusion (speed=safety) is wrong. I think they just got lucky, which is something a racer, but not a designer, may hang his hopes on. Of the multis that had to ride out the storm, 5 of 16 retired (31%) and 4 of the remaing 11 are more than 5 days behind the fastest mono, who also had to ride it out. I think that if they had left the day later it would have been like 2002 where 69% of the multi's retired when they sailed into a storm instead of being overtaken by one.

    Anyway, some people like icing, some like cake.
     
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