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Old 26-01-2013, 00:00   #16
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Re: Knocked down 90 degrees

My reading indicates that the odds of rolling a cat are the same as the odds of sinking a mono. I'd rather be on an upside down floating cat. But yes...a slow day troll for sure
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Old 26-01-2013, 00:02   #17
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Re: Knocked down 90 degrees

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Originally Posted by RabidRabbit View Post
Correct me if I'm wrong. If I plan to sail all over the planet for 40-50 years. At some point it should be expected that a knock down will occur, even with the best weather windows, a storm at sea is unavoidable. So wouldnt the vessel choice for a life at sea be one that pops back up when knocked down 90 degees? Seems like this would be a bigger issue with cruisers, pretty much a deal breaker for me. I cant imagine being in any bad weather and wishing I was in a cat.
Look at Figure 3 in this link:

Multihull Design Considerations for Seaworthiness

The amount of energy required to capsize a multihull compared to a monohull is vastly different. So you can't say I knocked down 90 degrees in a monohull in these conditions, good thing I wasn't in a cat. Are there conditions that will capsize a cat, obviously yes.

Beyond that if you don't want to sail a multihull don't. There are thousands of threads on cats capsize and monohulls sink, if you want to find out the pros and cons there's lots of reading available. Rarely do people change their stance, it's just yelling at each other over an uncrossable fence.

I've been on 2 monohulls with 90 degree knockdowns, yes we were racing. We didn't even have a spinnaker up. The person designated to ease the mainsheet after a jibe should really not forget to do that.

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Old 26-01-2013, 00:20   #18
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Re: Knocked down 90 degrees

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Do you ever wonder why all production Cats have an escape hatch in the hulls? Have you never seen pictures of the crew of a cat clinging to the underside waiting rescue? I happens more than you realize.
Wrong. Not all production cat's have escape hatches, and the European ones have them because dumb EC rules (most likely written by suits who have never been on any kind of boat) require them to.
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Old 26-01-2013, 00:24   #19
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Re: Knocked down 90 degrees

bla bla bla

multis flip and remain stable upside down

monos sink to the bottom and remain stable on the seafloor


here we go... get your popcorn and jaffas, folks


I slept well, Roverhi, during gales when my 10 year old son was on watch by himself in one of those dangerous cats you mention. We have never lifted a hull out of the water yet. It could happen, but it is bloody difficult for a cruising cat. Even when we try to push the limits a bit to see if we can get a hull partly out of the water, everything gets so tensioned up, the boat goes too fast, and we can't even lift the windward hull up 300 mm, before we are winding things back. I get the definite feeling (intuition, not maths) that the something would break before we flip. Flipped beach cats plenty of times and that is lots of fun.

On our cruising cat I thought about using undersized shackles on the main sheet and genoa sheet to create a "fuse". But after pushing her hard to see how difficult it was to lift a hull, I decided not to worry about it.

Go out on a cruising cat, mate, not a racing cat and then come back, sit down in your armchair and write something from first hand experience.
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Old 26-01-2013, 00:28   #20
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Re: Knocked down 90 degrees

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The problems with multi-hulls is they reach a point of negative stability or positive stability but upside down. Have a late friend who proved multi's turn turtle. Found his trimaran floating upside down with crew tangled in the running rigging and drowned, no sign of him. Have put the spreaders in the water in the Bay off of SF in a W32. Wind went from a nice sailing breeze to near 40k instantly and subsided back to a nice breeze in minutes. Got a feeling if it had been a multi, would have been able to get a close look at the bottom paint.

That's the reason I'd never sail a cat offshore unless with a full skilled crew that has the quick reactions to dump the main and/or head off when the feces flies. A multi can be blown over without the help of waves. Since I make passages single handed can't rely on a multi to take care of itself. A Mono cannot be rolled except in conjunction with waves, Even then the boat will right itself though probably missing the rig. Still it will be floating upright. A mono will turn up into the wind and dump the wind pressure all by itself in almost all situations. Some people can live with the inverted possibilities of a multi, I can't. Couldn't afford one in any case.

I doubt there are any production cruising cats that would be worried by a 40 knot gust. As an indicator, we have about the same sail area as a Lagoon 38, but weigh about half as much - not a production boat by any means - yet when we were hit by a sudden 37 knot gust, apart from rapidly accellerating to around 20 knots, nothing really happened.
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Old 26-01-2013, 03:00   #21
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Re: Knocked down 90 degrees

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Originally Posted by RabidRabbit View Post
Correct me if I'm wrong. If I plan to sail all over the planet for 40-50 years. At some point it should be expected that a knock down will occur, even with the best weather windows, a storm at sea is unavoidable. So wouldnt the vessel choice for a life at sea be one that pops back up when knocked down 90 degees? Seems like this would be a bigger issue with cruisers, pretty much a deal breaker for me. I cant imagine being in any bad weather and wishing I was in a cat.

you wont spend 40-50 years sailing. Most of the time you will be in a marina or sitting on the hook! Plus, If youre only a cruiser, you will pick your weather a little smarter than they did in the days your old books were written.
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Old 26-01-2013, 03:35   #22
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Re: Knocked down 90 degrees

Sometimes its not the bow... its the Indian.
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Old 26-01-2013, 03:50   #23
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Re: Knocked down 90 degrees

Quote:
Originally Posted by RabidRabbit View Post
Correct me if I'm wrong. If I plan to sail all over the planet for 40-50 years. At some point it should be expected that a knock down will occur, even with the best weather windows, a storm at sea is unavoidable. So wouldnt the vessel choice for a life at sea be one that pops back up when knocked down 90 degees? Seems like this would be a bigger issue with cruisers, pretty much a deal breaker for me. I cant imagine being in any bad weather and wishing I was in a cat.
All monos pop back from 90 degrees and more.

But cats are much less like to be in that position in the first place -- they have much greater form stability.

Statistics show that cats and monos are equally safe at sea.
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Old 26-01-2013, 04:04   #24
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My experience as crew on cats is that the captains were very much aware and cautious of getting into the conditions that precede a knockdown. As they should since recovery is far from certain. Rounding promontories, watching gusts on the water, heating up the boat for fun, etc. With monohulls the captains tend to approach the same situation with an attitude more like "I wonder what that coming puff will do, looks big?" Because the probability of a disaster is so low. And on the Queen Mary they don't even watch for puffs ... Different boats, different practice. Confuse them at your peril.
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Old 26-01-2013, 04:17   #25
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Re: Knocked down 90 degrees

Nowhere near the sea miles of many (most?!) folks here - but I would say that whilst a 90 degree knockdown not to be "expected", nonetheless IMO prudent to plan for that possibility - even if simply on the basis that if you "only" acheive 70 or 80 degrees unexpectedly that will spend less time picking stuff (and self?!) off the floor (and ceiling?!).
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Old 26-01-2013, 04:25   #26
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Re: Knocked down 90 degrees

Most monos have a tendency to round up when heeled over. I have never sailed a cat and i was just wondering if they do too. Intuitively I would think not, but I would like to hear from the cat people.
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Old 26-01-2013, 04:32   #27
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A cat may round up when pressed. It may not. Depends. The monos I have crashed went over far faster than they rounded up. Heeling is instant compared to turning.

On a reach, especially on a cat, heading up may not be helpful. It's a subject of much debate after the crash. The apparent wind builds so fast that the loading problem can become worse. Pretty fun stuff while racing on small boats. Not so good with all those pretty seashells and cooking utensils improperly stowed.
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Old 26-01-2013, 05:06   #28
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Quote:
Originally Posted by RabidRabbit View Post
Correct me if I'm wrong. If I plan to sail all over the planet for 40-50 years. At some point it should be expected that a knock down will occur, even with the best weather windows, a storm at sea is unavoidable. So wouldnt the vessel choice for a life at sea be one that pops back up when knocked down 90 degees? Seems like this would be a bigger issue with cruisers, pretty much a deal breaker for me. I cant imagine being in any bad weather and wishing I was in a cat.
Good, dont buy a cat then.
Anyway they are not escape hatches, they are spewholes!
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Old 26-01-2013, 05:45   #29
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Re: Knocked down 90 degrees

I never expected to get knocked down, but we did , by a mini tornado off the coast of africa, with less than half the genoa out and no main, the wind backed that quickly we had no time to react, never mind the golf ball sized hail stones whacking us.

It certainly made me think if we had been in a cat it would have been game over, regardless of any form stability the cat would have turned turtle. we went from 8KN of wind to god knows what (last i saw was 65KN), yes freak events like this do happen, how often they happen i don't know, so far only once in 14,000NM, if it happens again before the end of our journey i may have better statistics.
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Old 26-01-2013, 05:55   #30
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You csnnot even compare the two. In our 31 heavy 13k lb mono we could get laid on our side in a 15-20 knot gust. Wife screaming cocktail spilling crap going everywhere falling off bunks. Surfing down 10' waves in 50kts in the mono felt like any min you could lose it and go sideways. We have had two cats of same or bigger size now. In a gust the cat accellerates. In a huge gust, im talking getting caught with a 30-40kt unexpected "caught u not paying attention w too much sail up " the cat will,, are all you mono sailing armchair quarterbacking... ready for this ,, it will omg Round up!!! They dont just dump over like some beach cat. They also down wind and down huge waves have a much much better sense of control and stability than most of you could imagine. My gosh therez a dozen cats over the years that have flipped boards down at wrong time driver error who knows. At least many of the people were found next to their .......wait for it..... its coming........ thats right still floating vessell.!!!!! My god so much armchair crap here... i need my waders...
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