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Old 04-08-2010, 19:33   #91
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Originally Posted by mikereed100 View Post
Not to distract from the always informative mono/muti debate, but here's an interesting article on microbursts.

Microburst Handbook

It's more geared towards aviation but the basics are interesting.
Good link. Scary stuff. I thought the last section of the article was the most useful. It is kind of mind blowing to read that this picture
might represent 100+ mile an hour burst winds... Or maybe just your typical rain showers... Or a combination of both...

Is this sky a hint that it's time to strike your sails?



Tom
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Old 05-08-2010, 06:03   #92
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Good link. Scary stuff. I
Tom
I agree with your sentiments.

As the proud owner of an Atlantic design, maybe you can inform the forum of what wind strength is required to capsize your vessel with say a triple reefed main and working jib. For ease of calc maybe you can ignore the windage of the spar and rigging sticking up above the main headboard.( in 60 knots this will be significant however)

You may surprise some.

Crunching the numbers for the A55/57 from the designers web page it appears this is less than the 60 knots + they experienced.

Scary stuff indeed. When does one pull all sail down on a cat? This isn't going to be quick or a lot of fun with only two crew with a 70' rig in 25 odd knots.
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Old 05-08-2010, 06:07   #93
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There was this incident, about two years ago, in which a charter yacht sank in a heavy squall in the BVI. I was out in the same weather as it passed through the Nevis area, and it was a hell of a blow. I'm glad I saw it coming and had everything battened down tight.

BVI Charter Sailboat Sinks in a Squall

Monos can go down in squalls, but it generally requires a mistake on the part of the skipper (leaving hatches and portlights open) or structural damage allowing water in.
I agree, but I still would be surprised if the boat actually capsized (i.e, went > 90 degrees) unless waves assisted or, as you point out, there was some massive downflooding. The physics of wind on even a full-canvassed ballasted mono just don't make it likely.
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Old 05-08-2010, 06:12   #94
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They were in the Sir Francis Drake Channel. Max waves 3-4', I would suppose. There was no northerly swell running that day.
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Old 05-08-2010, 06:15   #95
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I agree, but I still would be surprised if the boat actually capsized (i.e, went > 90 degrees) unless waves assisted or, as you point out, there was some massive downflooding. The physics of wind on even a full-canvassed ballasted mono just don't make it likely.
One thing that can be pretty much guaranteed is that the skipper was not 100% familiar with that specific boat. I would class that as the principle cause, notwithstanding the actual mechanics of the event (including that the hatches were open).

A lesson that translates no matter the vessel, size, shape.........or hull configuration.
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Old 05-08-2010, 07:07   #96
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Over the course of 35 years and 100k miles of racing sailboats I've probably sailed through 100's of these squalls. During these times we've been suprised maybe 6~10 times with very high winds that seemed to come out of no where. After you recover and pull the spreaders back up out of the water you look at each other and say where the hell did that come from.

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Originally Posted by tsmwebb View Post
Good link. Scary stuff. I thought the last section of the article was the most useful. It is kind of mind blowing to read that this picture
might represent 100+ mile an hour burst winds... Or maybe just your typical rain showers... Or a combination of both...

Is this sky a hint that it's time to strike your sails?



Tom
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Old 05-08-2010, 07:11   #97
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Well, cruisers cleat off the sheets and let the auto drive. It is simply impossible for a small crew sailing a largish boat to be able to drive and adjust sails like racing with a full crew.

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In previous discussions about cats and squalls (and when to reef), forum members like maxingout have pointed out the tactic of adding a reef or dropping the sails completely.

From the description of what happened to Anna, I have to wonder why a crew member wasn't outside, clipped in and wearing FW gear in the forward cockpit ready to at least blow the sheets.

While the squall that caused the flip looked "the same" as previous squalls, it sadly wasn't.

Fair Winds,
Mike
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Old 05-08-2010, 07:11   #98
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Meyermm, "mulit owners believe it regardless" (that cats can't capsize or sink)????? Thanks for the sweeping generalization in your attack on the intelligence of owners of mulithulls - your prejudice is showing and it in no way advances the debate here.

I (and all owners of mulits that I know) do not maintain the multis cannot capsize or sink; only that there is ZERO evidence to support the proposition that it occurs any more often than monohulls sink. Some multis can sink -although it is noteworthy that none of the ones referred to did. However, virtually all ballasted monohulls can sink.

The Atlantic is a very high performance catamaran with relatively light displacement and a huge SA/D ratio. It is a cruising boat in the same way that a Ferrari is a street car. Neither is any less safe than their more pedestrian cousins, so long as one realizes that with all that 'horsepower' on tap, one has to let up on the gas pedal far more frequently. With the forecast they had and in the area they were sailing, pushing the envelope so close with respect to sail area is akin to putting your foot to the floor in a Ferrari while approaching a blind curve - and a blind curve that may be covered in loose gravel or oil. Keep the pedal to the metal in that kind of boat in those circumstances and you takes your chances......

The PDQ 32 is a smaller, light displacment catamaran that was never really intended as a 'bluewater' boat and which left port with a gale in the forecast and a crew that were inexperienced in her operation. It is a miracle that all hands were not lost.

In any event, agree with me or not, the above is at least an attempt to express a meaningful opinion on the root causes of the two capsizes about which we have any real detailed information. And your opinion was what?

Brad
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Old 05-08-2010, 07:18   #99
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AHEM Meyermm. Unless they have changed the laws of physics recently it is effectively impossible for my boat to sink. even with holes in the bottom it will displace more than it weighs.

Catch fire and burn to the water line - Possible,
get hit by whale & break into bits - less probable - but possible
sink, virtually impossible.

Capsize, highly unlikely if you sail prudently, which of course every mariner should do.

Oh and Joli - cruising alone, or with my lovely lady, the main sheet is always at someones hand and its in a cam cleat that is easy to release.. I admit to having the auto do the steering most of the time. Its prudent sailing. For me - two people is a full crew. Thats why I reef early and often.
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Old 05-08-2010, 07:31   #100
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Vasco the point is driven again and again because of how cruising boats are sailed. Cruisers simple "can't be at the ready" all the time. Some types of boats (monos) handle "can't be at the ready" all the time better then others (multis).

Regarding Anna, I don't blame the sailors, I don't blame the boat designer, I place full blame on the concept. The sailors did nothing wrong, they did not loose the boat because of inaction, they lost the boat because of the concept. If I loose my boat because I allowed the hoses to deteriorate until they ruptured and I did not stop the leak it was my inaction that caused the loss, if I loose my boat because I failed to secure the hatches and it down floods it is again my inaction that causes the loss. If the boat suffers a knockdown from a micro burst and is lost it will be from my inaction.

I fell very sorry for them, I am glad they are rescued and I hope the insurance company finds in there favor and they are made whole.

I'm sorry if this ruffles feathers but there are alot new sailors buying multis with limited experiences talking to sales people that are less then honest.

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This thread was interesting until it deteriorated into the cats vs monos debate. A boring, oft repeated discussion that changes no minds. They're all sailboats. Who can say which is safer and, anyway, how many of us buy a certain boat because it is "safer". Small boats will founder, big boats founder. That's a risk all of us take when going to sea. The posts on possible capsize prevention were interesting but the cats vs monos thing gets us nowhere. I cannot understand why certain sailors get so worked up about it. Sail what you want and let others sail what they want.
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Old 05-08-2010, 07:32   #101
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One of the better pieces of advice I received about multihull seamanship was: "If you think you need to reef start by putting in the SECOND reef. It won't slow the boat much, but it allows the boat to deal with much higher gusts."

Let's stop the mono/cat/tri squabble. A properly designed/equipped/sailed cruising multi has about as much chance of capsizing as a properly designed/equipped/sailed cruising mono does of sinking.

If you are going to sea in small craft (smaller than a ship) you need good equipment, good skills, and good luck -- and sometimes that's not enough.
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Old 05-08-2010, 07:33   #102
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Factor, I have this feeling your a pretty damn good sailor. Tell us, would you have sailed the Atlantic any differently then they did?

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AHEM Meyermm. Unless they have changed the laws of physics recently it is effectively impossible for my boat to sink. even with holes in the bottom it will displace more than it weighs.

Catch fire and burn to the water line - Possible,
get hit by whale & break into bits - less probable - but possible
sink, virtually impossible.

Capsize, highly unlikely if you sail prudently, which of course every mariner should do.

Oh and Joli - cruising alone, or with my lovely lady, the main sheet is always at someones hand and its in a cam cleat that is easy to release.. I admit to having the auto do the steering most of the time. Its prudent sailing. For me - two people is a full crew. Thats why I reef early and often.
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Old 05-08-2010, 07:39   #103
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Mike I listed 5 multis that went over or almost went over in the past 2 months. List 5 mono's that sank in the past 2 months. And the population of monos is ~100 times larger?

Again my apology for ruffling feathers but I feel these are salient points that should be openly discussed by cruisers on a cruisers forum.


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One of the better pieces of advice I received about multihull seamanship was: "If you think you need to reef start by putting in the SECOND reef. It won't slow the boat much, but it allows the boat to deal with much higher gusts."

Let's stop the mono/cat/tri squabble. A properly designed/equipped/sailed cruising multi has about as much chance of capsizing as a properly designed/equipped/sailed cruising mono does of sinking.

If you are going to sea in small craft (smaller than a ship) you need good equipment, good skills, and good luck -- and sometimes that's not enough.
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Old 05-08-2010, 07:44   #104
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Factor, I have this feeling your a pretty damn good sailor. Tell us, would you have sailed the Atlantic any differently then they did?


Dont know yet Joli (and BTW flattery will get you everywhere). I am going to have to hear more about it, but yes I suspect I would have been reefed more and slowing the boat up a bit, but I have read in a few places that the sea state was pretty small, so on that basis I may not have, its usually sea state that makes me want to slow the boat (not that my boat is anything like as fast as an Atlantic 57). My experience and discussions with many multi sailors world wide also tells me that few cats capsize, most pitchpole, same horrible outcome, but its important to know which it was - cause that will tell you different things about design and possibly the sailors mistakes etc.

I also should note that even listening to this sorry tale, if I had the money the Atlantic 57 is probably the boat I would buy.

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And the population of monos is ~100 times larger?
Not in my part of the world it isnt. Not even close. At your average lovcal anchorage on any given weekend its probably more like 2 or 3 to 1 - monos to multis
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Old 05-08-2010, 08:51   #105
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.......Let's stop the mono/cat/tri squabble. A properly designed/equipped/sailed cruising multi has about as much chance of capsizing as a properly designed/equipped/sailed cruising mono does of sinking.
I think the above is well worth repeating.

My condolences to the crew of Anna

When a yacht is lost it is usually because of a combination of different things that will have preyed on that particular yacht’s inherent design or construction weaknesses.... brought on as a result of maintenance neglect or poor seamanship choices on "Judgment Day".


There is no silver bullet that will kill…. that demon boat destroyer.

Cats can capsize and most existing boats will sink if you cannot keep the water out

Factor’s unsinkable Cat could be dashed to pieces on a low lying reef while my sinkable steel hull and full keel might be saved.

Both captains need to focus on the weaknesses of their own boats and come up with precautionary solutions, instead of being distracted or lulled into a false sense of security because of their inherent strengths and the perceived weakness of other designs.

Seems to me a designed weak link or automatic trip in the mainsail at a specific heel would be the precautionary solution for a cruising multi and should be the focus of this thread.
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