Sink or Swim??

Discussion in 'Multihulls' started by Richard Woods, May 5, 2009.

  1. rayaldridge
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    rayaldridge Senior Member

    Here's hot-linked pic of an F-27 with all three hulls flooded completely.

    [​IMG]

    Since it has been understood for decades that a sinkable multihull is guilty of a very serious design flaw, anyone whose modern multihull sank would have a slamdunk lawsuit against the manufacturer. The manufacturers probably know this.

    They did a fairly definitive tank test of the capsize resistance of tris and cats at Southhampton a while back. It should pretty much settle this issue for folks who base their opinions on facts. It's a PDF that you can find by Googling:

    Research Project 427 Capsize and Stability of Sailing Multihulls
     
  2. Manie B
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    Manie B Senior Member

    here is the link

    http://www.mcga.gov.uk/c4mca/mcga-research_report_427.pdf

    be warned - 68 pages of old info March 1999 - test results, thats basically it

    nothing new

    no it wont

    it tells you how far and old Simons design 1995 can lean
     
  3. Richard Woods
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    Richard Woods Woods Designs

    It has now been 6 weeks and 10 pages of posts since I first started this thread. Maybe people should re-read my initial post and see if their opinions have now changed. Incidentally, I see ANOTHER monohull has sunk, so at least four since I first posted. Last week one was hit by a whale while sailing in the Caribbean.

    The west coast of N America is one of the few places in the world where multihulls are rarely seen. For the last few years I have been cruising the Atlantic and counting cruising boats at anchor. On average 15% of boats at anchor are multihulls, a number that excludes obvious charter boats. Clearly these boats are ones actually being used, whereas monohulls in marinas tend to sit there and do still far outnumber multihulls.

    Many cruisers sail older monohulls, while most multihulls are under 10 years old, so it seems likely that 30% of all new ocean cruising boats are now multihulls. So hardly a small number.

    I have been on the ISO (International Standards Organisation) Stability and Buoyancy committee as a multihull expert for around 15 years, a committee which was instrumental in deciding the stability standards for all vessels under 80ft (24m). ISO 12217-2 is the one relevant to sailing vessels. Although using this standard is not a legal requirement (unlike the RCD) it does make life a lot easier when certifying a boat.

    Section 7.6 deals with inverted buoyancy and it is the LOADED condition that must be considered, furthermore trapped air bubbles (apart from dedicated airtanks) are not included.

    Having said that there are a number of large catamarans that cannot meet this requirement, but at the same time their sheer size makes them extremely stable and thus unlikely to capsize. So (as I indicated earlier) we are currently discussing changing the standard to accommodate these large boats. The changes, if ratified, will come into force in 2012.

    I hope this helps the discussion

    Richard Woods of Woods Designs

    www.sailingcatamarans.com
     
  4. Fanie
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    Fanie Fanie

    I get the impression that people are encouraged to buy sinkable mono's. Helps the boating trade some.

    I bet if you contact a manufacturer and ask for a permanent floating mono they are going to rip you double the price, for the one that sink and the one you buy after that. Someone should really try it.

    If I was a boat builder, and one of my boats sink, I would be ashamed.
    Capsize, break, make water, anything but not sink.
     
  5. Fanie
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    Fanie Fanie

    On the issue of floatation, any boat can be made unsinkable. Trapped air should not count as floatation, and is not a given due to many variables. Mono's sink because they make enough water, with the correct built in booyancy they would remain afloat even if flooded to the brim. Be a bugger to catch any multihull then eh :D
     
  6. BeauVrolyk
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    BeauVrolyk Sailor

    Richard,

    Thank you for this post, I'll go have a look at the ISO standard.

    Regarding your estimates of the percentage of multihulls vs monohulls, I think you have at least as weird a sample as I may have in San Francisco Bay. For what it's worth, five years ago in the Marquesas there were about 70 to 80 cruising boats sailing through when I passed that way and only one was a multihull. Similarly, when I passed through Tahiti in 1991 I saw two multihulls and hundreds of monohulls. Granted that was 15 years ago, and I haven't been to Tahiti since. But, I think you might want to have a look at the Pacific to get a different viewpoint. One that doesn't agree at all with your numbers.

    Certainly, on the west coast of the US (as you've said) where the distances are large, the winds are relatively strong and the waves large, there are very very few cruising cats. There are a few F27 type tris that do cruise within the SF Bay and many more multihulls in S. Calif where the wind is much lighter and the seas smaller, but again there are far far fewer than 30% of new boats and far fewer than 15% of all boats - more like about 2% of all boats. I'm certain that the NMMA (www.nmma.org) could probably settle this, as I believe they keep statistics on this.

    Perhaps the reason there are so view cruising multihulls around the Pacific are the distances involved, you need to carry a LOT of stuff with you and most of the Multihulls I've bumped into don't have the load carrying capacity. That said, if I were to do the S. Pacific trip again, as I did in '91, I would personally take a multihull as the seas are pretty darn flat and the winds gentle. I just wouldn't sail along the west coast in one - too many big waves and strong winds.

    Beau
     
  7. Richard Woods
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    Richard Woods Woods Designs

    Things have changed fast. As I wrote on my website, 10 years ago when I first did the ICW trip I saw one other multihull, 5 years ago I saw one every couple of days. Last year there was usually one in sight for the whole 1000 miles.

    The 15% of boats anchored that I counted were in the UK, Canaries, Cape Verdes, Tobago, Grenada, Venezuela, Curaco, Colombia, Bahamas and Panama. Plus the east coast USA.

    In 2006 I crewed on an 33ft Australian catamaran from the Canaries to Panama (it has since completed its circumnavigation by crossing the Pacific last year). The owner reported that there were even MORE multihulls in the Pacific than in the Atlantic.

    I understand your reasons for not sailing the west coast US in a catamaran. I have only sailed from BC to Coos Bay, Oregon and from San Diego to Mexico, both trips in monohulls but both in very light winds.

    Having said that, the Caribbean Sea can be pretty rough, yet the vast majority of charter boats there are multihulls. So I don't think the reason for lack of multihulls is because of the weather. More the shipping costs from Europe, S Africa or Australia.

    Incidentally, I visit the Bay area for about a month every year and usually find time to sail there. Everytime I go out I see IOD's racing, so I guess I've seen you on the water.

    Richard Woods of Woods Designs

    www.sailingcatamarans.com
     
  8. rayaldridge
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    rayaldridge Senior Member

    I'd guess the reason for any scarcity of multihulls in California may have more to do with the scarcity of dockage than the violence of the weather. Northern Europe has some pretty ferocious weather, but quite a large number of multis.
     
  9. catsketcher
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    catsketcher Senior Member

    Our views don't matter much

    As with many emerging and evolving disciplines this debate has people who have experience that now backs up their judgement. Whether this judgement is relevant as the discipline (in this case cat design) moves on is a point to consider.

    People will judge cats on their sea keeping, accommodation, speed. cost etc. If they start to kill people like they did back in the 60s then they might stop building them. As the nasty stories are very rare now I think that they will continue to attract a significant proportion of the newcomers, and a few experienced souls, to our scene. I am always really concerned to apportion conspiracy theories to non acceptance of a minority group. Whether it be the some of the local kids in my disadvantaged school that see brick walls where there are only helping hands or multihullers who see mono sailors as out get them we can always change the facts to suit our story.

    For every argument that BeauV makes I can find a rebuttal - about Antarctica (the designer of my cat sailed his foam 38 footer to Antarctica and back - Ice cat XS) wave capsize (the Southampton wave tank could NOT roll scale models over about 40ft) sea keeping - friends come on to our boat and remark on the lack of roll - you can put a cup on the table and it doesn't move Hell I never even bolted the table down to the floor and it never moved in 15 000 miles!- safety - mums like to bring their kids on our boat as the kids can't slip overboard. But it doesn't matter.

    I like multis and Beau likes his monos. I can't cruise a mono - the draft over 3ft, slow speed of a cruiser, the roll downwind, the heavy sheet loadings (I have a wishbone main) hard to use downwind sails (I can singlehandedly raise and lower the 38 footers kite - no snuffer) but for every one of my points the avid monohuller would find a rebuttal too. That's the way it will be.

    Cats will talk for themselves to those who come WITHOUT preconceptions. Just like tris did in the 60s with Piver. If the boats are good then more newcomers will select cats and the proportion will grow as it has here in Oz - it used to be that I would row over to every cat I would see. Now there are so many we don't have to hang as a club. There is no brotherhood in the face of victimisation any more. All the guys who would sneer at me with my little tri in the early 80s think a cat is a good cruiser now.

    In a little way Richard was a bit naughty for starting this. (I am not really fit to criticize Richard - I have built far fewer boats than he and designed only two) He and other designers are well aware that the tide is turning in our favour and that cats are a great idea for many sailors - not all - cats don't suit all - probably not even most sailors. But I do think that cats will continue to grow in popularity. Monos will sink and cats will do what they do - sometimes capsize, maybe sink. Richard has even sailed on an Aussie cat from which someone died whilst being rescued (it had capsized after a structural fault - the builder was at fault back in the eighties) - our boats aren't perfect but if they are no more dangerous than monos and we like them better then that is a good enough reason to get one. If other people agree then there will be more cats in the future. Let the future roll on and we will see.

    cheers

    Phil
     
  10. rayaldridge
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    rayaldridge Senior Member

    Phil, as usual a sensible post. I'm sure Richard expected to generate both heat and light in the discussion. I've enjoyed the opportunity to point out the many advantages cats have, and I've appreciated the opportunity to deflate a few of the safety myths that comfort monohull sailors.

    I think that while you are correct that such discussions will not change the minds of anyone who believes strongly one way or the other, they are still very useful. Many of those reading this will not have beliefs that are impervious to facts, and that's why I participate. As you point out, multihullers are no longer a beleaguered minority (if still a minority), but I remember how it was 30 years ago when I bought my first cruising cat. There may have been other cruising multihulls down here on this stretch of the Florida Gulf Coast, but I never saw any. Now there are hundreds.
     
  11. BeauVrolyk
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    BeauVrolyk Sailor

    Richard,

    Stop by the Marina in San Francisco any Wednesday night during the summer, except for July, and catch a ride. Our rule is to never leave anyone on the dock, just bring something warm. Also, if you let me know, I can certainly get you a ride on some of our other boats - that are a bit more modern and less filled with termites.

    Beau
     
  12. BeauVrolyk
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    BeauVrolyk Sailor

    Ray,

    You're probably right on the money. I am trying to add to the Vrolyk fleet (a lovely sloop of 45') and I'll be damned if I can find a place to put it. Most marinas are telling me there's at least a multi-year waiting list. I have one slip in SF, but that holds the IOD for city front racing. Also, there seem to be very few end-ties for Multihulls and all the slips are too narrow. Most around here have a finger on both sides, and as a result even if you want to pay 2X for a slip for a multi you're left without any available.

    What do people do in other places? End ties? Stern to a dock? In France they tie 'em stern to and the width isn't as big a problem, although they did ding me for 2X the normal rate 'cuz I was taking up two parking places at the Queue when I docked there with my rent-a-cat.

    Beau
     
  13. Manie B
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    Manie B Senior Member

    catsketcher thanks for a good post


    HOWEVER

    thank goodness that is changing fast with new designs

    New Monos dont sink and arent that slow anymore

    http://www.pogostructures.com/?m=3&s=1&l=en

    boat design is changing so fast that most people cant keep up

    modern cats are a work of art and ingenuity
    for simplicity i like Bob Oram cats

    but a modern mono is not that bad either
     
  14. Bruce Woods
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    Bruce Woods Junior Member

    The Point Is?

    Great post Catsketcher.

    If the choice for your boat selection rests on this simplistic premise (sink or swim) then you've got problems. Multi-hulls offer so much more.

    Surely the debate has moved on these days. Multis no longer need defending. Their miles speak for themselves.

    I suspect Richards purpose for starting this thread on just about every forum on the net is merely to collect filling for one of his articles. The headline
    "Sink or Swim" is certainly going to attract him some attention.
     

  15. Richard Woods
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    Richard Woods Woods Designs

    Beau

    Thank you for the sail offer. I'd like to take you up on that next year when I am next in Oakland. 8-10 years ago I used to race a First Class 8 pretty competitively, before that it was 1/4tonners etc. So it doesn't have to be a multihull, just a boat that sails well.

    Bruce (no relation)

    Of course I write on this forum in an attempt to make people visit my website. But I always try to promote multihulls in general rather than just my designs.

    Having said that, it does take me time to think about and then write my posts. If readers want me to stop then this can be my last post. And I certainly will stop if I think posting hurts my design business.

    I started this thread (which is quite popular by the way, sorry you've only just joined it) because like many people I was tired of critics saying "I'd rather sink than capsize" without justifying the statement.

    Suppose this forum was titled "Living in California" (bear with me)

    Many people living in Florida would say "I'd never live on the west coast - what about earthquakes" to which those in California reply. "But what about hurricanes - you get those every year, we only get major earthquakes once every 20 years"

    A specific complaint with pros and cons on each side and nothing to do with the advantages of living on either coast.

    Sure its easy to write about the advantages of multihulls, but that wasn't the reason for starting this thread.

    Richard Woods of Woods Designs

    www.sailingcatamarans.com
     
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