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  #106  
Old 06-11-2009, 07:59 PM
BeauVrolyk's Avatar
BeauVrolyk BeauVrolyk is offline
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Quote:
Originally Posted by rayaldridge View Post
A) That's probably why I said, "...because Westerners have been building monos long enough that there is even less excuse for such flaws."

B) Since for every cruising multihull that has existed, more than a thousand cruising monohulls has existed, I think it's a pretty good bet that statistically, I am correct. Of course, I'm referring to the Western world, once again.

Ray - why would one limit what man has learned about sailing to "western" sailors??? If we did, we'd probably have avoided multi-hulls altogether as until recently "western" sailors didn't use them much. I don't understand this concept of blame for flaws at all. There are loads of terrible boats of both times, all of which should be painfully embarrassing to the designers. But, to say that because there are many more monohulls than multihulls and that therefore there are more flaws is pretty weird. How do you know? Are you guessing, or are you assuming that some fixed percentage of all boats are bad?

BTW - I agree, there are a lot crappy monohulls around, there are also a lot of crapy multihulls like those plywood pieces of junk sitting in Redwood city marina.

Quote:

I thought you said said you were familiar with multihulls-- you claim to have raced them a lot. How could you not know that few if any commercially produced multis are now single-skinned glass? (Though some were built in the early years of the multihull movement.) No performance cruising multihulls or racers are produced in single-skin glass-- all are cored, because single-skin glass has a very unfavorable weight-to-stiffness ratio. Only light multis are fast. But even cored monohulls will sink, due to that massive lump of lead they have to keep afloat. Multis don't have that andicap, so they can be unsinkable with a lot less flotation.
I'll simply ignore the implied insult and say that while there are a lot of cored boats (I didn't know, BTW, that you were only talking about production boats) do you really "know" this? That there is not one single product multihull built anywhere in the world that is not cored? Are you certain? Really?? Care to check??? Given you put it in bold, you must be. B-))

As to my "claims", I'm happy to chat about loads of multihulls, but I must say the ones I have raced upon were not "production" boats. They were racing boats. Some were cored and some were not. Same as monohulls.

Quote:

As to gear weight-- this is one area in which the monohull cruiser is superior to the multihull cruiser. You can dump a lot more stuff into the former without making it unsafe-- though you will make it slow(er). In fact, this is a problem with a lot of condomaran cats. By the time they're loaded up with all the goodies, they are no longer unsinkable. There's no way to make a boat foolproof. If you don't understand the limitations of your boat, you probably shouldn't go to sea.
The amount of junk a group of cruising sailors carry doesn't seem to have much to do with the sort of boat they choose to go cruising upon. It seems to correlate to the amount of stuff they want to have with them, the things they think it will take to keep the boat working the way they'd like it to, and their personal tastes.

As to unsinkable.... I'm still wondering how a cat with two engines, big old mast etc... is actually unsinkable once flooded. I'll have to do some calculations based on core thickness etc... It'll be fun to see if it's possible.

Engine - 300 pounds each, Mast & Rig- 250 pounds, boom 70 pounds.....

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You must have very odd waves on your ocean. On mine, by the time they get big enough to do more than joggle the boat slightly, their period has grown much longer than any cat I'm ever likely to sail.
Really simple. Go out the Golden Gate and turn left. The "swell" has a very long period, the "chop" does not. On a typical day the swell will be about 8 to 10 feet tall and the wind chop, which has a very short wavelength, will be an additional 5 to 7 feet when it's blowing 25 to 30 for a few days running. Happens all the time. I've been out there on a 40' cat that did exactly what I've described.

Tom Blackhauler and Zan set the Farallon's Race record in this 40' cat and Zan still talks about the boat burying its leeward bow, then punching through the wave and leaping. It nearly tossed them off the tramp.

By contrast, a much slower but stable boat, the Santa Cruz 50, simply sits on a wave and surfs down it. No jumping, no one getting tossed around.

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I mean no disrespect, but I really can't understand how anyone who claims to have been offshore in both multis and monos can say they prefer the motion of a mono, though I know lots of folks who do say that. I can only conclude that they love monos so much that their perceptions have lined up with their beliefs. For one thing, the "smooth steady roll" of a mono is far more likely to make the crew seasick than the quicker but lesser amplitude motion of a multi. I've taken folks out in monos and they fed the fishes for days. Same folks in a cat don't get sick at all. What does that tell you?

Many of the safety advantages of multihulls stem from their stability. A boat that takes better care of its crew is less likely to come to grief due to crew fatigue and bad decisions. The greatest risk offshore, in terms of total fatalities, is man overboard. Multis are far safer than monos in this regard, because of their wide flat stable decks, with mast well inboard.
Well, weather you mean no disrespect or not, I hardly think that most sailors agree with you, except in pretty flat water. I think you're closer to the mark when you say you simply "can't understand" and that you "know lots of folks who say so". Rather than hold that all those folks are wrong or misguided by their love of monohulls, isn't it just as likely that you're misguided by your love of multihulls.

With respect to people getting seasick, in flat water multi's are stable, so are monohulls. Sure, people get sick, but after having been out and around a bit I certainly don't see much difference between the two. This is not anything statistically relevant, nothing in this entire thread is, it (like everything in this silly thread) is opinion.

Do you have any data that supports that fewer people fall off of multihulls? Or, for that matter that falling overboard is actually the greatest risk? So far as I can gather, from the deaths here around the San Francisco Bay, the greatest risk of injury has been things breaking and boats hitting each other. We had a boat where the keel fell of, that's bad. We had a tri where the thing pitch poled just outside the bay, that was bad too. Out of about 20 people who've died around here there are only two I can think of that actually fell of the boat. Indeed, in the last three years we've had four guys die of heart attacks. I don't think the facts actually support that going overboard is actually the largest danger.

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Their initial stability is so much greater than any ballasted monohull of similar size that it takes vastly more energy to capsize them, and a monohull that capsizes in violent conditions may come up without its rig and/or hatches. Waves that can capsize a monohull are far more common than waves that can capsize a multi of equivalent size. Even if a monohull comes up in one piece, crew injuries may be severe. In addition, a monohull that finds itself in a bad position relative to a breaking wave can trip over its keel, giving enough leverage to roll the boat over. A multihull with boards up has much less underwater structure over which the boat can rotate.
I simply disagree with: "Waves that can capsize a monohull are far more common..." First, the reasons that boats capsize are numerous, but waves are actually a relatively rare cause. Have a look at the multihulls that have ended up wrong side up, it isn't waves, it's wind. Have a look at the monohulls that have ended up wrong side up, it's usually gigantic waves not wind. Monohulls don't capsize from a big gust of wind, they may put their mast in the water and be held down for a little while but they don't flip.

Further up in this thread is a perfect example, the quasi beach cat that flipped in a 40 knot guys. A 40 knot guys will simply lean a monohull over, it will not flip it.

There are very few pieces of the ocean that generate waves big enough to capsize a monohull boat of any reasonable design. Sure, it happens, it did happen right under the Golden Gate bridge when an idiot sailed over a breaking shoal. But, even around Point Conception, with sustained winds of 30 to 40 knots and seas over 18 feet and breaking, very few boats ever capsize. However, one of the best racing Multis in the world, LAKOTA, flipped going downwind in relatively small waves when it was hit by a gust. These were conditions that did no damage at all to an entire fleet of monohulls who were racing a few miles behind her.

Quote:

One disaster even more common than sinking is dismasting. Because of their light weight and wide staying platform, multis are much easier to jury rig than monos, and their easily-driven hulls are far more efficient under jury rig.

I could go on, but I hope now that you'll do me the courtesy of grasping that I've thought seriously about these matters.
I don't doubt that you've thought about these things, but through your thinking there are a set of errors I'm trying to point out. The errors have to do with the basic assumption that multihulls are lighter than monohulls. In some cases they are, in many cases they are not. Here are some facts:

a Lagoon 440 Cat is 44' long and weighs 29,000 pounds.
a Santa Cruz 40 Mono is 40' long and weighs 10,500 pounds.

Sure the Lagoon has more deck space and room in it. But, it's also nearly three times the weight. How about the Orana 44 which is marketed as an ultra light Cat (their literature says it not me), it weighs 19,600 pounds, still almost twice the 40' sloops weight. Why do you believe these are "light" boats or that they are "easily driven".

Do you really believe that these are unsinkable, at these weights?

Production Multihulls that normal people buy to go cruising are neither light nor easily driven, I sail by them all the time on ultra light monohulls, I chose the Santa Cruz 40 as a comparison because it is not a ultra light by today's standards and because a couple of them have sailed around the world quite nicely. To get a monohull that weighs what a Lagoon 440 weighs you have to go all the way up to the 52' cruising sloop Tom Wylie's Persuasion which has all manner of junk aboard and is a big boat. Having sailed on both the Lagoon and these monohulls, I am pretty sure the Wylie 52 is actually faster.

I think this is about all I've got to say on this topic.

Beau
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  #107  
Old 06-11-2009, 10:13 PM
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A long post, so just a couple of quick comments.

The specific gravity of solid fibreglass is about 1.2 So it doesn't need much buoyancy to keep the boat afloat. Unlike most production monohulls, which use the complete hull for accommodation, many multihulls have built-in buoyancy compartments. In Europe (as of today, but that may well change shortly) by law all multihulls have to be unsinkable.

I actually raced against Persuasion a couple of weeks ago in the day race part of the Swiftsure. It was about the same speed as a well sailed F24.

Sadly a bit quicker than me, but then the winds were light to non-existent, conditions where monos and tris do better than cats.

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  #108  
Old 06-11-2009, 11:01 PM
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Quote:
Originally Posted by BeauVrolyk View Post
Ray - why would one limit what man has learned about sailing to "western" sailors???
Why indeed? The millenia-long safety record for multihulls is surely better than for monohulls, so I'm not sure why you think this enhances your argument. After all, Polynesians with their multihulls achieved much longer voyages much earlier than Europeans did with their monohulls. There might be a lesson here.


Quote:
Originally Posted by BeauVrolyk View Post
I'll simply ignore the implied insult and say that while there are a lot of cored boats (I didn't know, BTW, that you were only talking about production boats) do you really "know" this? That there is not one single product multihull built anywhere in the world that is not cored? Are you certain? Really?? Care to check??? Given you put it in bold, you must be.
Beau, I didn't claim that all glass production boats were cored, because I don't know. I said "few if any" are uncored. I did claim that all production performance oriented cruising boats and racers were cored, if they were glass. This is engineering 101 for folks who know anything about multis You can prove me wrong very easily. Just find one in current production that utilizes single skin glass.

Maybe I am wrong, who knows, but as a guy who tries to keep up with the multihull world, I'm not aware of any single-skinned glass multis still in production. Your argument was that fiberglass is heavier than water, which is true, but for modern glass boats, irrelevant. Certainly, there is no greater design flaw for a multihull than sinkability, and this has been known for decades.


Quote:
Originally Posted by BeauVrolyk View Post
As to my "claims", I'm happy to chat about loads of multihulls, but I must say the ones I have raced upon were not "production" boats. They were racing boats. Some were cored and some were not. Same as monohulls.
Are you claiming that any glass racing multihulls built in the last 20 years were not cored? Which ones?

Cold-molded or strip-planked wood isn't foam or balsa cored, of course, but it doesn't need to be in order to be unsinkable.



Quote:
Originally Posted by BeauVrolyk View Post
As to unsinkable.... I'm still wondering how a cat with two engines, big old mast etc... is actually unsinkable once flooded. I'll have to do some calculations based on core thickness etc... It'll be fun to see if it's possible.
Well, bear in mind that a multi will have a lot more skin than a mono, in most cases.

In fact, one of the condomarans built for the Caribbean charter trade recently sank, so it is indeed possible to overload them. But the fact remains that most modern multis are unsinkable and most ballasted monohulls are eminently sinkable.

Quote:
Originally Posted by BeauVrolyk View Post
Well, weather you mean no disrespect or not, I hardly think that most sailors agree with you, except in pretty flat water. I think you're closer to the mark when you say you simply "can't understand" and that you "know lots of folks who say so". Rather than hold that all those folks are wrong or misguided by their love of monohulls, isn't it just as likely that you're misguided by your love of multihulls..
It's possible, I suppose, but there's a small problem with this analysis. Many sailors switch to multihulls from monohulls, but few switch back from multihulls to monos. Could just be a coincidence, I guess. Honesty compels me to admit that I'm one of the latter, but this had little to do with comfort per se. When we had no children, we had a Wharram cat, and it was a great boat. Suddenly we had three small children, and there wasn't enough room in the cat for them to play safely below. We couldn't afford a bigger multi, but we could afford a bigger mono, so we went with monos for a few years. Now the kids are big, and I'm back to multis.

My experience has been that the vast majority of folks who have gone offshore in a multi find it more comfortable than a mono. However, I will admit that this is a self-selecting group.


Quote:
Originally Posted by BeauVrolyk View Post
Do you have any data that supports that fewer people fall off of multihulls?
Can you think of any ways it might be easier to fall off a cabin top heeled at 35 to 50 degrees and rolling like a pig than it would be to fall off a much wider, level, stable platform?




Quote:
Originally Posted by BeauVrolyk View Post
Or, for that matter that falling overboard is actually the greatest risk? So far as I can gather, from the deaths here around the San Francisco Bay, the greatest risk of injury has been things breaking and boats hitting each other. We had a boat where the keel fell of, that's bad. We had a tri where the thing pitch poled just outside the bay, that was bad too. Out of about 20 people who've died around here there are only two I can think of that actually fell of the boat. Indeed, in the last three years we've had four guys die of heart attacks. I don't think the facts actually support that going overboard is actually the largest danger.
Chris White once attempted an analysis of cruising boat safety. He found that, according to the Coast Guard, of the 36 fatalities in auxiliary sailboats over 25 feet reported to them from 1983 to 1987, 29 were attributed to man overboard. That's 80 percent.

Here are a hundred or so case studies of man overboard situations, if you're interested:

http://www.ussailing.org/safety/Stud...ng_history.htm

This is largely a plea for the Lifesling MOB recovery system, but it makes for interesting reading. I own a Lifesling myself-- it's a good thing to have aboard.





Quote:
Originally Posted by BeauVrolyk View Post
I simply disagree with: "Waves that can capsize a monohull are far more common..." First, the reasons that boats capsize are numerous, but waves are actually a relatively rare cause. Have a look at the multihulls that have ended up wrong side up, it isn't waves, it's wind. Have a look at the monohulls that have ended up wrong side up, it's usually gigantic waves not wind. Monohulls don't capsize from a big gust of wind, they may put their mast in the water and be held down for a little while but they don't flip.
Beau, the price of speed is accidents. Racing multis overturn because they keep racing with too much sail up. Cruising multis under bare poles will not be capsized by wind, unless they have wing masts, a very poor idea for an offshore cruising boat. So, in a survival storm, with both multi and mono sailed prudently, the mono is far likelier to find a wave capable of capsizing it than the multi, because so much more energy (bigger wave) is required to capsize the multi.


Quote:
Originally Posted by BeauVrolyk View Post
a Lagoon 440 Cat is 44' long and weighs 29,000 pounds.
a Santa Cruz 40 Mono is 40' long and weighs 10,500 pounds.

Sure the Lagoon has more deck space and room in it. But, it's also nearly three times the weight. How about the Orana 44 which is marketed as an ultra light Cat (their literature says it not me), it weighs 19,600 pounds, still almost twice the 40' sloops weight. Why do you believe these are "light" boats or that they are "easily driven".

Do you really believe that these are unsinkable, at these weights?
Yes, if they are not grossly overloaded. It's hard for me to believe that you really don't grasp the fact that as heavy as these multihulls are, they do not have the high ballast ratios of the lighter ULDBs. If you're claiming that because of their heaviness, these multihulls will sink, are you also claiming that because of their lightness, these monohulls won't sink? I'm not getting your point. A five pound hunk of lead will sink a lot faster than a 500 pound cedar log. In any case, what percentage of cruisers go cruising in a ULDB?

Quote:
Originally Posted by BeauVrolyk View Post
Production Multihulls that normal people buy to go cruising are neither light nor easily driven, I sail by them all the time on ultra light monohulls, I chose the Santa Cruz 40 as a comparison because it is not a ultra light by today's standards and because a couple of them have sailed around the world quite nicely. To get a monohull that weighs what a Lagoon 440 weighs you have to go all the way up to the 52' cruising sloop Tom Wylie's Persuasion which has all manner of junk aboard and is a big boat. Having sailed on both the Lagoon and these monohulls, I am pretty sure the Wylie 52 is actually faster.
For a guy who sails on racing multihulls, you sure do make a lot of references to the condomarans developed for the Caribbean charter trade, where number of bunks is a lot more important than performance. You do know that these are not the only choices, right? I see a lot of Farrier tris where I live, for example; they will in most circumstances outrun monohull racers much larger than they are. All significant ocean racing records are held by multihulls, except for those where multihulls are not allowed to compete.

People buy the condomarans for their space and... what was that thing we were debating? Oh, right. Comfort. And still, the condomarans are faster than the monohulls built for the bareboat trade in the Caribbean-- if you're interested in comparing apples to apples.

My 16 foot cat is a lot faster than a Tahiti ketch, but I'm not sure what that proves.

It's a lot less sinkable, too.
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  #109  
Old 06-12-2009, 12:13 AM
ancient kayaker ancient kayaker is offline
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I don't understand this need to prove which are better, monos or multis. They're different and that's all anyone will ever be able to prove. A good mono will be better than a poor multi and vice versa. The earlier parts of this thread were more interesting with lots of info and technical discussions.

I think the impact of size has not been adequately recognized in this discussion. For a small boat (other than a lifeboat) self-righting is not important since the crew constitutes movable ballast. I'm not so sure it's desirable for a sailing dinghy to self-right, it might sail off on it's own; I'd prefer to have the events following a capsize follow my own schedule. Also, the best way to deal with a capsize in a multi of any size is to make damn sure it doesn't happen.

In my experience, small multis tend to be less comfortable at the dock than a mono of the same displacement, although a multi will have more space than a mono of the same displacement. For trailer and car-topper folk displacement is much the more important of the two. Under sail, this comfort advantage endures until the weather is bad enough to turn me back to port. For others of a more adventurous nature there will come a point, no doubt, where the multi starts to score in that deparment. However, at that point comfort is a relative thing and survival has assmed greater importance. If things progress to the point of capsize there is no doubt which type I would prefer to have.

In larger boats, self-right capability is a must if you plan to sail a mono in sufficiently demanding conditions, otherwise it's a pointless waste of the convenience and utility that has to be sacrificed to get it. There's no way a multi is going to self-right unless it's a design freak sorely compromized in other areas, but on the other hand it is a lot harder to capsize than a mono.

There will always be extreme conditions that will threaten the best found vessel. As anyone who's survived a wreck and been rescued after bobbing around in a lifeboat will tell you, large size is not always a guarantee of seaworthiness; I bet all the champagne corks survived the sinking of the titannic.
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  #110  
Old 06-12-2009, 11:58 AM
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It is interesting that since I wrote the first post in this thread at least three live-aboard sailing monohulls have sunk unexpectedly. All three boats were well maintained and all owned by experienced sailors.

By "unexpectedly" I mean not in a storm, not hitting a reef, just sailing along minding their own business.

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  #111  
Old 06-12-2009, 12:01 PM
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just sailing along minding their own business
That proves it then. You CAN get into trouble minding your own business
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  #112  
Old 06-12-2009, 12:57 PM
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SECONDS before death (CHILLING)

WARNING !! GRAPHIC BOATING PHOTO

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JUST SECONDS LEFT TO LIVE

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  #113  
Old 06-12-2009, 12:59 PM
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And it's yet another monohull involved






.









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  #114  
Old 06-12-2009, 02:03 PM
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That proves it then. You CAN get into trouble minding your own business
Maybe that explains my behavior. I'm just trying to avoid getting into trouble.

Terry: it's not that I feel the need to prove that multis are "better" than monos. But... take any two boats, and I don't care how many hulls they have. Would you not agree that, even if they are sisterships, there will be differences in them, if only in how they are fitted out and maintained? As a consequence, one will be better than the other, if only in some minor respects. Perhaps one has a more powerful engine, which allows it to motor faster than the other. But maybe the more powerful engine weighs more, so its boat is slightly slower under sail. Is "they are different" the best and most informative thing that we can say about these two boats?

Now take two boats that are not sisterships, but which are still similar in many respects. Now there will be more differences. One may be slightly faster under sail, have a slightly more comfortable motion, and so forth.

By the time we get to boats as different as monohulls and catamarans, the differences have become very large. Surely we can do better in evaluating these differences than just saying "they are different."

I contend that a well-designed cruising multi will be faster, more comfortable, and safer, than a well designed cruising monohull of similar size. (Note: not of similar displacement. a 30 foot cruising mono may have 2 or 3 times the displacement of a 30 foot cruising multi.) The mono will also have advantages over the multi. It can carry a lot more stuff, it will be cheaper to buy or build, it will be cheaper to keep in the water because it doesn't require an enormously wide slip at the marina, it will be much easier to find a place to haul and maintain it. It is also a more traditional type of craft, at least to the Western mind, and there's nothing wrong with liking tradition. We're out here to have fun, after all. Though the mono will be much easier to capsize than a multi, it will self-right after a capsize. This is sort of a two-sided advantage, since it's probably better not to capsize in the first place.

Also, I think you should understand the context of this debate. Those who see multihulls as a threat to the kind of boat they love have been quite unfair and even unscrupulous in attacking multihulls. This started a long time ago, well over a hundred and thirty years back, when Nathaniel Herreshoff fielded a weird little boat called Amaryllis against the cream of the New York sandbagger fleet. Some of the owners thought about protesting this boat as a nonboat before the race, but, hoping to be amused, did not bother. They were not very amused when Amaryllis trounced the fleet. They raised a hue and cry, had the little cat disqualified, took her trophy, and banned cats from competing-- and many bitter defamatory words were spoken by these sore losers. Herreshoff continued for a while, building a boat named Tarantelle that achieved a speed of 17 knots-- this in an era before epoxy, plywood, dacron... and under gaff rig. But eventually he was driven out of the multihull business by the prejudice and childishness of the wealthy men who went racing in those days.

The trend continues today. Take Don Street, a great sailor who wrote some great books-- I have both Ocean Sailing Yachts, and refer to them often. But Street hates multihulls with the fire of a thousand suns, so much so that he was dishonest in evaluating them. He basically claimed that multihulls were death traps, and to support his argument, presented a stability curve comparison that did not quantify the vast stability advantage multis have over monohulls at low angles of heel. Yes, once both kinds of boats are heeled at an
angle of 35 degree, the multi's stability declines rapidly and the mono stiffens up. But by leaving out the actual righting arm data, Street prevented his readers from understanding that at 5 degrees of heel, the cat will have ten times the stability of the mono, and that three times as much energy will be required for the cat to lift a hull than will be required for the mono to lay its mast in the water. And of course, he completely ignored another reason why multis, and especially cats, are so much harder to capsize than monos-- their extremely high roll moment of inertia.

This institutional unfairness continues in almost every exchange of views on the subject. I don't mean to pick on Beau, because he was polite and civilized in his responses, traits I respect greatly, but.... did you notice how he continually compared ULDB racing monohulls with condomarans built for the Caribbean charter trade? He explicitly compared a heavy, sleeps-a-dozen, 44 foot cat loaded to the gills with amenities, to a 52 foot performance monohull that is far more suited to carrying that sort of weight. He even referred to old Piver tris rotting away in Sausalito boatyards, without mentioning that these boats were built of substandard materials by unskilled flower children to a poor design over 40 years ago-- and also forgot to mention that some of these ugly hulks had once taken their owners across oceans in safety and comfort. Were any of these fair comparisons to make?

Anyway, I hope this may explain why those of us who like multihulls react somewhat stridently when some brave seafaring monohull man asserts, apparently without any fear of contradiction, that of course, multihulls are unsafe offshore. Everyone knows this, after all.

I think most fair-minded folks will understand that over the history of the human race, what everyone knows to be true has often turned out to be complete nonsense.

Anyway, sorry for writing a book. I'll shut up now.
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  #115  
Old 06-12-2009, 06:38 PM
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Originally Posted by rayaldridge View Post
Maybe that explains my behavior. I'm just trying to avoid getting into trouble.

Terry: it's not that I feel the need to prove that multis are "better" than monos. But...

...snip...

This institutional unfairness continues in almost every exchange of views on the subject. I don't mean to pick on Beau, because he was polite and civilized in his responses, traits I respect greatly, but.... did you notice how he continually compared ULDB racing monohulls with condomarans built for the Caribbean charter trade? He explicitly compared a heavy, sleeps-a-dozen, 44 foot cat loaded to the gills with amenities, to a 52 foot performance monohull that is far more suited to carrying that sort of weight. He even referred to old Piver tris rotting away in Sausalito boatyards, without mentioning that these boats were built of substandard materials by unskilled flower children to a poor design over 40 years ago-- and also forgot to mention that some of these ugly hulks had once taken their owners across oceans in safety and comfort. Were any of these fair comparisons to make?
All,

Let me provide a few comments that might be helpful:

1) I actually adore sailing on multihulls, I spend five years campaigning a Tornado cat back in the '70s and I've sailed aboard as many of 'em as I can catch a ride with. They are a blast. So, please do not assume I don't like them in some way, because that's not at all what I was meaning to imply. I compared the Condo style multi hulls to a Santa Cruz 40 (which is not a ULDB boat by today's standards) because they were about the same length. I also compared the Lagoon to the Persuasion, which is expressly built to haul stuff, is not an ULDB in anyone's definition, and is still lighter than the Lagoon. Just for grins I looked up the weight of a "Benaslow" Oceanus 500, a 50' cruising charter pig - guess what, even it is lighter than the Lagoon 440. (Actually, they're almost identical.)

This is not an issue of ULDB or not as the item of comparison, the simple point is that Production multihulls like the Lagoon are vastly overweight and examples of terrible multihulls. Yet, these are the dominant examples of "cruising multihulls". Sure, there are better boats in the world, but what I was trying to do is point out that for a normal cruising multihull and a normal cruising monohull, the monohull is actually lighter weight. These are simply facts not opinions and you can verify them on the web.

2) Like others on this thread, I feel strongly that there are "horses for courses". If one were sailing from California to New Zealand, which is an area of generally calm seas and lovely weather, I would strongly suggest taking a nice big multihull. It's problems, like being upside down permanently and not being easy to berth in a marina, simply won't come up very often if at all; as a results its advantages cause it to win out. If, however, one were headed around Cape Horn or off to the Bearing Sea I would think a monohull built of double hulled steel would make the most sense. I find the people who cruise the calm waters of the South Pacific in a double ended double planked Colin Archer design just as goofy as those who try to sail a cruising cat like the Lagoon up to Prince Rupert Sound in BC Canada from Los Angeles. Which takes me to item 3.

3) There seems to be the general assumption that monohulls capsize more easily than multihulls, which I find really odd. Let's discuss what causes capsizes and then ask if this is true. I would suggest the following circumstances where a capsize might happen as a candidate:

A boat is sailing in extremely large breaking waves, beam on, where the waves are large enough to roll a monohull over. For the Beneslow Oceanus, which has a beam of 14' 5" and a draft of 6', that I was mentioning earlier, these are waves of at least 30 to 35 feet and breaking, probably larger. The face angle of the wave is going to be 90 degrees or more from horizontal at its top (the definition of a breaking wave) and probably 50 to 55 degrees 2/3 of the way up the wave, which is the point at which most boats start to roll over. When our imaginary wave strikes the Beneslow it will roll her on her beam ends and as the boat starts to fall down the wave face its mast will typically dig into the water causing the boat to trip on the rig (note: it doesn't trip on the keel in my observation, I've watched it happen.). While the boat is turned with the mast parallel to the horizon the keel is actually attempting to right the boat, but for the sake of our discussion we'll say it fails.

Now, let's take the Lagoon 440, which has a beam of 25' 3", as it is struck by the same 30 to 35 foot wave. As the Lagoon is 2/3 of the way up the wave face it too is heeled to the angle of the surface of the water, about 50 to 55 degrees in our example. Then, as the top of the wave (the breaking bit) hits the windward hull that hull tries to rise with the water, and probably fails, punching through some of the wave if it's not really gigantic. some of the windward hull is probably submerged and the Lagoon, which was already heeled something like 50 to 55 degrees by the first bit of the wave is tipped a bit more, perhaps to 65 to 75 degrees? The question is: "Is the Lagoon self righting at 70 degrees of heel? I don't know the answer to that, and it's not on the web anywhere that I could find. But, it is the critical question. I suppose it depends upon the weight of its rig plus any windage the boat might have. But, I think its safe to say that the Lagoon at 70 degrees of heel has a heck of a lot better chance of standing up to the wave beam on than the Beneslow at 90 degrees. The Lagoon stays more upright simply because of its larger beam.

Now, lets consider the much more likely scenario in seas of this size. Most sailors who have spent any time out there are going to either run off or toss out a sea anchor and try to ride bow onto the sorts of seas we're talking about. Let's chat about the stability of the boats going either with the wind or trying to ride bow into it.

First, the length of the two boats, the 50' Beneslow Oceanus 550 and the 44' Lagoon 440 are roughly the same. Second, the reserve buoyancy of each looks (and this is entirely my opinion from looking at pictures of the boat) about the same fore and aft. Meaning that the bow of the Beneslow is about twice as fat as each bow on the Lagoon, so you've got about the same reserve buoyancy. So, I would hold that if both boats were "running off" before waves of this size, they would bury their bows about the same amount. The boats are the same length and with equal reserve buoyancy would rise to the wave the same way. They weigh about the same amount, so the probability of each boat pitch poling and flipping over their bows is about the same because each has the same chance to outrun the wave.

For all of the reasons above I think that the probability of the boats flipping over backwards when trying to ride bow into the wind is about the same also. With two exceptions. When the breaking wave crashes into the cabin suspended between the two hulls on the Lagoon, there will be a tremendous amount of force trying to flip the boat. Indeed, I've been on a 20' cat that sailed over a big wave in Hawaii and flipped over backwards once the wind got under the tramp. The monohull doesn't have this windage and drag problem. The second difference is that when stood on its stern about to flip over backwards the Lagoon has the weight of the mast pulling it over backwards and no counterbalancing keel. The monohull has the same weight (roughly) from the rig, but it has the weight of the keel trying to hold the bow down and keep the boat from going over backwards, just as it tries to keep it from going over sideways. So, at some terminal point, I would hold the Beneslow would be just a bit better riding over waves to a sea anchor.

My final remark on this is that the claim of better stability for the Lagoon, or any multihull is primarily based upon the width of the platform. Not only does this not apply when the boats are either pointed directly at the wave or away from it - where the actual stability of the monohull is probably a little bit better than the multihull, but the difference in beam between the Lagoon and the Beneslow is 11 feet or as viewed another way, the Beneslow is 57% of the width of the Lagoon. This difference in beam may be the critical difference in some waves, but it hardly seems the overwhelming advantage that much of this thread has ascribed to multihulls over monohulls, and it only applies when beam on to the sea; something that I really doubt many good seamen would be doing in these sorts of waves.

Submitted with complete respect for and a deep love of multihulls.

Beau
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  #116  
Old 06-12-2009, 08:30 PM
ancient kayaker ancient kayaker is offline
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I agree with most of Rayís comments. I wasnít criticizing multis, just expressing a personal preference for a mono at the smaller end of the scale, for comfort and convenience reasons. A car topper mono you can sit in, a car topper a multi of similar size is something you scramble around on top of.

My multi experience has been limited to a 52 foot tri in the Med and a Tornado, and the odd beach cat, none owned by me. I am a kayaker at heart, although I confess there is a small sailboat egg incubating in the workshop. I enjoyed them all and they were all great fun. The big one was a luxurious craft, owned by a multi-millionaire who was throwing a fully-catered party for about 20 guests; never raised the sails. The Tornado guy on the other hand felt strongly that sailing time on two hulls was time wasted. I donít think one sails a Tornado or any other performance cat, by the way; one rides it, like a motorbike.

I am not in the least surprised that mono racers see multis as a threat, they are faster under many conditions. Racing them together probably doesnít make a lot of sense, a bit like racing foilers against other types or big boats against little ones. When the difference in technology is so extreme it will hide differences in boat design, construction and crew skill, the measurement of which is surely the true purpose of racing, apart from just having fun. When boats are that different course and conditions will determine the winner, not the relative quality of the boat and the skills of the skipper and crew.

New things get resisted or embraced creating two opposite camps, happens every time. I have a buddy who refers to fiberglass as frozen snot and motorboats as stinkpots. I donít argue with him! I got into a similar discussion to this one with some boarders, who have had their troubles getting their things recognized as boats for record purposes. No doubt there were similar arguments about racing camels against horses, motorbikes against cycles, and kayaks against racing shells.

The claim that multis are inherently less safe than monos offshore is ludicrous. The biggest I ever traveled in was the highspeed ferry from UK to Eire. We stopped to assist the transfer of an injured crewman from a cargo vessel to a helicopter: I hadnít noticed until that moment that we had been tearing through a chop big enough to toss the smaller (but still substantial) vessel around and break bones. Not only was it stable, the ferry was incredibly fast and comfortable to boot, my kind of vessel. However, when I recall an full Atlantic gale I once sailed through, I wonder how the multi would have fared. It is an unfair question of course, it wasnít designed for those conditions. I was looking up at waves towering over the 20,000 tonne ship but never felt anxious, because the ship yielded to natureís fury and seemed like a living thing able to find the easiest path through the storm. Some folk got sick of course, but I won a bet by consuming herrings at breakfast. The guy who bet me was so revolted he rushed off someplace! But I digress. A multi would have experienced far greater stresses being obligated to conform to the angle of the waves, and the people onboard might have had an even rough ride.

As a kayaker I can share some related experiences with you. My first kayak was a short and beamy one, ridiculously stable, never a worry of tipping, but have a fast, heavy motorboat pass too close and it will rock. Not a big deal, I relax and enjoy it but it would worry a newbie. The canoe I designed and built is damned tippy in comparison, no leaning over the side to watch the fishes, it is and was meant to be fast. I had a police special pass me way too close in full cry, obviously they were dangerously low on donuts, a massive wave I could look up at swept across my beam, and I was worried since a canoe is much easier to swamp than a kayak and it has less than 5 inches of freeboard. No problem though, the boat went straight up and down, virtually no rolling and not a drop came aboard, although the wave was so steep the paddle blade came out of the water. Paddlers are at least as aware as the rest of the boating community that too much stability can, on occasions, be as big a problem as too little.

Durn it: I didnít mean to write a book either!
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  #117  
Old 06-12-2009, 10:29 PM
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rayaldridge rayaldridge is offline
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Quote:
Originally Posted by ancient kayaker View Post
I agree with most of Rayís comments. I wasnít criticizing multis, just expressing a personal preference for a mono at the smaller end of the scale, for comfort and convenience reasons. A car topper mono you can sit in, a car topper a multi of similar size is something you scramble around on top of.
Hey, Terry-- I'm a troublemaker by nature, I guess. The little cat I designed and built, Slider, is a 16 footer that flies in the face of accepted wisdom, which is that you sit on top of a cat that small. The great trimaran designer, Jim Brown wrote a piece for Cruising World in which he predicted that tiny multis, like the Windriders he had design input into, were the Next Big Thing for small boat sailors. He also opined that cats weren't going to be good small cruising boats, because you had to squat on a trampoline. Now Slider is too big and heavy a boat to cartop, but you don't have to squat on a trampoline. It's the most comfortable boat I've ever sailed, in fact.



But... not a cartopper.

I know there are lots of folks who don't have a place to park a trailer, So my next project is a cartopper cat.



It will knock down so it can be carried on a roof rack and put together quickly at the beach. Unlike beach cats, there will be ergonomically correct seating inside the hulls. Compared to beach cats, the rig will be modest and simple-- about half the sail area of a Hobie 16. It's aimed at those who could be content with a modestly rigged 14 foot open monohull sailboat-- but who are willing to try something a lot more comfortable and stable.

Beau, your position is well-supported, and I don't find a lot to argue about there. Have you ever read Fastnet Force Ten, by Rousmaniere? The post-disaster analysis brought into public view a concept that is very helpful in understanding why it's so much harder to capsize a multihull than a monohull (in addition to the much greater amount of energy required.) In brief, the inquest that followed the loss of life and vessels took note of a consistent observation, which was that a capsized monohull that lost its rig in a rollover was far more likely to suffer additional capsizes than boats that retained their rigs. This, the examiners concluded, was because the mast, with its center of mass well away from the boat's center of rotation, provided an inertial resistance to that rotation that was multiplied by its distance from the boat's center of rotation.

Catamarans, and to a lesser extent, trimarans, also have this "roll moment of inertia" resisting rotation, but unlike monohulls, in addition to the stabilizing effect of the mast, they have almost half of their total mass well separated from the boat's center of rotation. When a wave tries to flip them, this inertia strongly resists the rotation, usually long enough for the wave to move under the leeward hull and kick the boat back upright.

For an example of an anti-charter cruising cat, check out Chris White's Atlantic 42. It's fast, with one built in South Africa routinely doing 200 mile days on Atlantic crossings, very stable, with high bridgedeck clearance and reasonable use of space. On Chris White's website,there a report from an owner comparing it to a bareboat cat of similar size.

http://www.chriswhitedesigns.com/atlantic42/index.php



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  #118  
Old 06-13-2009, 07:16 PM
ancient kayaker ancient kayaker is offline
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Nice! I have a design for a cat of similar size, that I have been eyeing for some time. I know I will have to get a trailer sometime and I have space for one but I'm just puting off the inevitable. I am slowly but surely being lured away from the superlight canoe and kayak scene. I have to bear in mind that, one day I will not be able to get into the damn things, tempus fugit and that kind of stuff. So I will be forced to either build or buy a boat that won't car-top and that will be that. Or give up boating - not bloody likely!

The joke thread has a quotation attributed (spuriously) to William Pirrie "uour next boat will be bigger" ... I bear that in mind.
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  #119  
Old 06-13-2009, 07:25 PM
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I have often thought that if I went for the bigger boat the first time round it may have been finished already...
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  #120  
Old 06-13-2009, 08:27 PM
Freenacin Freenacin is offline
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Quote:
Originally Posted by BeauVrolyk View Post
a Lagoon 440 Cat is 44' long and weighs 29,000 pounds.
a Santa Cruz 40 Mono is 40' long and weighs 10,500 pounds.

Beau
Which is heavier, one ounce of lead or one pound of styrofoam? Which is more bouyant?
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