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Old 15-05-2015, 11:53   #1
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Is there a catamaran of cruising size that can self right unaided?

I do not know a great deal about catamarans except that they make me a little nervous.

I have read the pro catamaran argument that says a cat will not sink if capsized which is all well and good but the probability of a catamaran capsizing far outweighs that of a mono sinking.

I wondered if there is any technology that has dealt with and solved the problem of righting a catamaran hull unaided by external assistance while at sea.
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Old 15-05-2015, 12:36   #2
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Re: Is there a catamaran of cruising size that can self right unaided?

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Originally Posted by paulanthony View Post
I have read the pro catamaran argument that says a cat will not sink if capsized which is all well and good but the probability of a catamaran capsizing far outweighs that of a mono sinking.
Not sure why you would say this. In the past 15 years there have only been a hand full of capsizes and most due to human error. I think you should spend some time on a cruising cat and see for yourself. The odds of a cat flipping are super low.

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Old 15-05-2015, 12:39   #3
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Re: Is there a catamaran of cruising size that can self right unaided?

I'll bite... I think your basic premise is off.

The probability of a catamaran capsizing is greater than that of a monohull sinking if the catamaran operator is an idiot, or if the cat is regularly sailing in the very high latitudes (idiotic as well, I suppose). Otherwise, you have to go pretty far out of your way to flip a cruising cat.

That said, I am not aware of any available solution to self right a cruising cat.

OK y'all; troll's been fed.
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Old 15-05-2015, 12:42   #4
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Re: Is there a catamaran of cruising size that can self right unaided?

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Originally Posted by paulanthony View Post
I do not know a great deal about catamarans except that they make me a little nervous.

I have read the pro catamaran argument that says a cat will not sink if capsized which is all well and good but the probability of a catamaran capsizing far outweighs that of a mono sinking.

I wondered if there is any technology that has dealt with and solved the problem of righting a catamaran hull unaided by external assistance while at sea.
Smaller catamarans have methods to right them by having crew haul on lines from outside the boat. Anything big enough to live aboard is not rightable without outside assistance, and there is no system to do so.

The force required to capsize a catamaran is large; an equal amount of force must be applied in order to right it.

One could imagine a system of watertight compartments and pumps which could be rigged in such a way as to slowly rotate a catamaran by flooding both amas to stern until the boat is pointed straight up and then over, and then pumping out those compartments to right the boat. The entire system would of course have to be waterproof. I don't believe anything like that has ever been done.
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Old 15-05-2015, 12:49   #5
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Re: Is there a catamaran of cruising size that can self right unaided?

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I'll bite... I think your basic premise is off.

The probability of a catamaran capsizing is greater than that of a monohull sinking if the catamaran operator is an idiot, or if the cat is regularly sailing in the very high latitudes (idiotic as well, I suppose). Otherwise, you have to go pretty far out of your way to flip a cruising cat.

That said, I am not aware of any available solution to self right a cruising cat.

OK y'all; troll's been fed.
If you do your homework properly you will see that I am right. Get the values for all the mono's in the world v's cats. Then narrow down the cruising ranges to include places common to cats and mono's and then determine the number of losses via sinking compared to cats flipping. Then extrapolate the numbers of cats to that of mono's, determine like for like probability then come back and say sorry. - Or just answer the question as I asked and leave the biting for kids, lesser animals and insects.
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Old 15-05-2015, 12:59   #6
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Re: Is there a catamaran of cruising size that can self right unaided?

As far i know there is not a cruising cat that can be self righted

I won't argue the other points but i can assure i have done my homework. Looks like you have made your mind up.. Mono for you...

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Old 15-05-2015, 13:02   #7
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Re: Is there a catamaran of cruising size that can self right unaided?

P.S. if you want to throw out strong statements like that, then back it up with the numbers from "your" homework and references to sources. Otherwise you are just blowing hot air.

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Old 15-05-2015, 13:04   #8
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Re: Is there a catamaran of cruising size that can self right unaided?

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If you do your homework properly you will see that I am right. Get the values for all the mono's in the world v's cats. Then narrow down the cruising ranges to include places common to cats and mono's and then determine the number of losses via sinking compared to cats flipping. Then extrapolate the numbers of cats to that of mono's, determine like for like probability then come back and say sorry. - Or just answer the question as I asked and leave the biting for kids, lesser animals and insects.

I think the vast majority of cats flipping, however, are racing catamarans, which are usually overcanvassed ultralight monstrosities that the crew is pushing to the limit. That doesn't apply to cruisers.

To answer your original question, though, I don't think there's a way it can be done. Even folding trimarans, like the Dragonfly, have no ballast, so no easy way to flip them back over, even with the amas folded in.

BTW, I remember reading somewhere that cruising cats would lose their mast before they would flip it over from wind alone. That's how stable they are. I think that was in reference to Lagoon catamarans, but would probably apply to all.
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Old 15-05-2015, 13:12   #9
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Re: Is there a catamaran of cruising size that can self right unaided?

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I think the vast majority of cats flipping, however, are racing catamarans, which are usually overcanvassed ultralight monstrosities that the crew is pushing to the limit. That doesn't apply to cruisers.
I notice this also but I also notice the heavy ones are not going very far north or south either so the risk must still be there.

If I was to ever have one it would be heavy. There is merit in the cat but for me I think the #1 gain would have to be comfort.

I would like to chase speed but but I just would always be worrying in a light cat.

I have also read about the mast going before the trip but we don't see this happening on light cats. However, I expected to see the mast becoming the solution to self righting but it does not seem to advanced much and I am guessing manufacturers based on the intended use for most cant see a need.
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Old 15-05-2015, 13:19   #10
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Re: Is there a catamaran of cruising size that can self right unaided?

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Smaller catamarans have methods to right them by having crew haul on lines from outside the boat. Anything big enough to live aboard is not rightable without outside assistance, and there is no system to do so.

The force required to capsize a catamaran is large; an equal amount of force must be applied in order to right it.

One could imagine a system of watertight compartments and pumps which could be rigged in such a way as to slowly rotate a catamaran by flooding both amas to stern until the boat is pointed straight up and then over, and then pumping out those compartments to right the boat. The entire system would of course have to be waterproof. I don't believe anything like that has ever been done.
Yeh... I have thought of this.. It could be done but you may have to flood one of the hulls which would add risk to the situation.

I expected there to be a solution offered by the mast as being the principle inversion recovery system if not the complete one. I have seen early prototypes but nothing has been developed that I see. Seems it would be also too risky to rely on mast integrity.
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Old 15-05-2015, 13:23   #11
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Re: Is there a catamaran of cruising size that can self right unaided?

Cruising boats--monohulls or catamarans--aren't typically capsized by winds, they're capsized by waves. Most catamarans are designed to dismast before a large enough torque is applied by winds to flip them. This of course means that the rigging cannot withstand the torque required to right the boat. None of this applies to ultralight racing cats which are routinely capsized by winds.

Both types can be capsized by abeam breaking waves that are larger than 1/3 the LWL of the boat (which is usually very similar to the beam). The natural advantage of cats is that the beam width is typically larger than it is for monos so it takes a bigger wave, and the rarity of large waves decreases by the square such that most people will never see a wave large enough to flip a good sized cruising cat.

A system to flood the stern half of the amas and then pump them out would do the job. Could be done with simple gate valves on the topsides of the gunnels (which would be the bottom sides in a capsize) that a swimmer could open. The stern of both amas then floods, tipping the boat upright. Once the boat is over the half-way mark, the valves would be closed, and they could start pumping (or bailing) in order to eventually right the cat.

But the problem with all of these conjectures is the circumstance: you cannot take any of these measures during a storm. And that's when boats get capsized. The idea that you're going to ride out a 24 hour storm in a capsized boat--catamaran or monohull--is pretty ludicrous. People who point out that monohulls can roll as a safety feature have never been in a monohull that has rolled in a storm. It's not a situation that is very survivable, and frankly it doesn't matter if the boat survives when the people don't.
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Old 15-05-2015, 13:27   #12
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Re: Is there a catamaran of cruising size that can self right unaided?

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As far i know there is not a cruising cat that can be self righted

I won't argue the other points but i can assure i have done my homework. Looks like you have made your mind up.. Mono for you...

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Nor for that matter is there a method for refloating a sunken moonhull without outside assistance.
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Old 15-05-2015, 13:49   #13
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Re: Is there a catamaran of cruising size that can self right unaided?

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Cruising boats--monohulls or catamarans--aren't typically capsized by winds, they're capsized by waves. Most catamarans are designed to dismast before a large enough torque is applied by winds to flip them. This of course means that the rigging cannot withstand the torque required to right the boat. None of this applies to ultralight racing cats which are routinely capsized by winds.

Both types can be capsized by abeam breaking waves that are larger than 1/3 the LWL of the boat (which is usually very similar to the beam). The natural advantage of cats is that the beam width is typically larger than it is for monos so it takes a bigger wave, and the rarity of large waves decreases by the square such that most people will never see a wave large enough to flip a good sized cruising cat.

A system to flood the stern half of the amas and then pump them out would do the job. Could be done with simple gate valves on the topsides of the gunnels (which would be the bottom sides in a capsize) that a swimmer could open. The stern of both amas then floods, tipping the boat upright. Once the boat is over the half-way mark, the valves would be closed, and they could start pumping (or bailing) in order to eventually right the cat.

But the problem with all of these conjectures is the circumstance: you cannot take any of these measures during a storm. And that's when boats get capsized. The idea that you're going to ride out a 24 hour storm in a capsized boat--catamaran or monohull--is pretty ludicrous. People who point out that monohulls can roll as a safety feature have never been in a monohull that has rolled in a storm. It's not a situation that is very survivable, and frankly it doesn't matter if the boat survives when the people don't.
Yeh.. This is very true. You would have to wait for the weather to abate. It does not sound reasonable to try and recover from a total inversion especially if there is a lot of mass involved. Highly dangerous no doubt. In practical terms it does not seem we will see anything and maybe as you point out we don't want anything either. Issue then is moved to prevention instead of recovery but even on that side of the coin I do not see a great deal of technology.
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Old 15-05-2015, 13:51   #14
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Re: Is there a catamaran of cruising size that can self right unaided?

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Nor for that matter is there a method for refloating a sunken moonhull without outside assistance.
If it is a submarine there is.
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Old 15-05-2015, 13:53   #15
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Re: Is there a catamaran of cruising size that can self right unaided?

The only larger twin hull boat that I know that is built to prevent capsize is the pacific proa like the 36 foot with an anticapsize pod (and berth) on the lee hull as seen on this picture.
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