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Old 27-08-2010, 08:59   #316
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I've not sailed that part of the world, but agree with Agility's take.

If you design something to fail (fuse), then where do you draw the line? Do you want to be dealing with a lose clew in 70K gusts, and how much other damage could that do?

I'm more in line with the conservative side - Hope for the best, but be prepared for the worst. I'd rather be taking deep reefs or dousing in 30 to 40K , than fighting to reef/douse in 50-60K. As CW had noted in is review, the force goes up by the square, and some believe that shock load and hydro forces can go up by the cube.

One disturbing note from Kelly's excerpts was the apparant difficulty in opening the escape hatch once capsized.
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Old 27-08-2010, 09:10   #317
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I'd be tempted to start with a double reef in that part of the world with squally weather, and motor at ~7 kts (cruising speed) on one engine during the lull.

One of the benefits of such a light high performance catamaran is that she makes a great motor sailor too.
The Pacific has some long passages. And high fuel costs. Duty Free deisel in Tonga was US$2.64 per LITRE = US$9.97 per gallon.

We generally only used the engine to head towards squalls when becalmed for long periods.

I think this, and other accidents are useful discussion for both multihullers and monohullers. I fear if we start to not take others disasters as being relevant.




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Old 27-08-2010, 09:57   #318
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We're heading to the Galapagos in October.

Great fun . . . wonderful sailing conditions going up that coast (pretty miserable coming south).

This area of the pacific is treacherous if you read the first hand accounts.

We have spent quite a bit of time there. The weather is pretty unsettled! But the scenery spectacular. Do try to get to see Ian and Maggy Staples if you have not yet.

As for the fuse idea . . . I want to have highly reliable systems and not worry about an accidental fuse-break that could do more harm than good. I'd be tempted to start with a double reef in that part of the world with squally weather, and motor at ~7 kts (cruising speed) on one engine during the lull. One of the benefits of such a light high performance catamaran is that she makes a great motor sailor too

OK, thanks. I (am with MarkJ) am reluctant to accept the answer is to use the motor more. On some ocean passages (say for example an early season tropical e to w Atlantic) there is light wind with squalls almost EVERY NIGHT. I would prefer not to motor every night. Poor beth has the 2am watch, and I often have a wonderful watch and she comes on and the squalls start to build and she is setting and unsetting the reefs until I get up and then the squalls stop

I had dinner last night with two cruising cat owners ( Dolphin 46 and M&M custom 52), both decent performance but neither quite in the a57 class. Interestingly both said their cap shrouds were designed to come off just before max righting moment to prevent capsize. I thought that sounded rather worse than just the clew coming loose!
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If you design something to fail (fuse), then where do you draw the line?

Easy - at the maximum possible load that would still prevent capsize . . max righting moment (assuming as previously discussed that is high enough to not break in 'normal' sailing shock loading with this particular design)

Do you want to be dealing with a lose clew in 70K gusts, and how much other damage could that do?

No . . . but I surely would prefer that to capsize. looking at the numbers, I think I would only fuse full hoist and 1st reef. That way you can always recover the sail by pulling in the second reef - and remember even when the fuse has blown and it's 'loose' it is still in fact somewhat held/restrained by the above reef lines and the lazy jacks and the full battens so it would not be a complete wild animal.

I'd rather be taking deep reefs or dousing in 30 to 40K , than fighting to reef/douse in 50-60K.

Yes, of course. . . . reef early and to the expected gusts.

The only part of your and agility's program I have trouble with is the extra motoring. I can't wrap my head around getting a light HP boat with the advance plan to motor more, so I am still looking for a different 'solution' than that.
OK, I find it quite useful/interesting that you A55/A57 owners don't think fuses fit with your concept/vision of the boat (as not 'reliable enough') and that motoring with reduced sail area in squally conditions is more consistent with your purpose. I understand that program/plan, but I guess my tri/multi vision is rather different than that.
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Old 27-08-2010, 10:10   #319
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The hatch on Anna was a non opening type, it was designed to be broken.
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Old 27-08-2010, 10:24   #320
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OK, I find it quite useful/interesting that you A55/A57 owners don't think fuses fit with your concept/vision of the boat (as not 'reliable enough') and that motoring with reduced sail area in squally conditions is more consistent with your purpose.
I didn't exactly say motor in squally weather. I said motor in the lulls and double reef in squally weather. I think Mark and I said that same thing. I don't have the polars, but from first hand accounts a double reef on a A57 is still plenty fast given the light weight of the cat.

Maybe it's just me, but the idea of a designed breaking point when fully loaded up kind of scares me. You can optimize for all sorts of things on a boat. I'm more concerned about reliability on this particular feature. If someone out there starts building/designing fuses and it's sea tested on a big carbon rig on a big cruising cat I'd consider it but putting a premature breaking point on a 1,000 sq/ft sail scares me a lot more than the thought of a capsize. It's an interesting idea and I truly hope folks try it and we come up with a new option, it just won't be me at this point.
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Old 27-08-2010, 10:30   #321
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At the risk of putting words into someone else's mouth (a mouth that is already very well spoken) I think what Evans is driving at is that a monohull has some built in safety valves that spill excess wind in a sudden and unexpected gust that in turn prevents a capsize or knockdown: the boat heels, the boat rounds up, the wind spills. Most catamarans do not have these safety valves, and therefore isn't it prudent to think about how one might be created? It is all well and good to talk about prudent reefing, seamanship, and all that, but we all know that when the sh** really hits the fan is the moment that the gremlins have been at work: you've spilled the coffee and are crawling around on the cabin sole mopping it up; you've lost your glasses and are looking for them; the sheet is jammed on the winch; the autopilot refuses to turn off; etc. Stuff happens. Safety valves might save us when this stuff happens.
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Old 27-08-2010, 11:04   #322
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I didn't exactly say motor in squally weather. I said motor in the lulls and double reef in squally weather. I think Mark and I said that same thing. I don't have the polars, but from first hand accounts a double reef on a A57 is still plenty fast given the light weight of the cat.

ok, I am just trying to envision this in real world practice.

Just just take an actual example . . . sailing from St Helena to Antigua, normally truly lovely sailng conditions during the day (but it would be even more wonderful on your new boat) . . . flat seas and 5 -15kts from close to right up the course, so sailing gibes at 140 true angle in the light and switching to double big headsails when it was stronger (which you probably would not do). But from mid-night to about 4am it was lighter (5-8kts) with occasional squalls, say every hour. Some of the 'squalls' would be 15kts and the occasional would be 40.

We would be using code zero (because its much easier/faster to roll up than the chute is to drop) and full main. We have to sail a little broader with the zero than the chute. When we started to feel any sort of build, gust or temp drop or rain from a squall, roll up the zero and sail full mainsail alone, and then immediately drop to second reef if it shows any sign of continuing to build. We have and can handle +50 with the second reef with no problem. We keep pretty decent boat speed thru-out that process.

Perhaps this is not a fair question because you don't know your new boat well yet . . . but what I hear you saying is that you will sail thru-out this with double reefed main (If your reef points are sized like Anna's I would think a double reef would leave you with a bit less than 600 sq ft) - and not sure what headsail (but I would think you would need a zero/screacher to make any sort of speed jibing in 5-8kts true downwind), and will roll the jib and drop the main entirely and motor when the squalls come close - does that accurately describe your plan?

If someone out there starts building/designing fuses and it's sea tested on a big carbon rig on a big cruising cat I'd consider it but . . . it just won't be me at this point.

Yes, I completely understand that . . . tried and tested by someone else is always better.

. . . . . .
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Old 27-08-2010, 11:47   #323
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Based on my experience sailing the Atlantic 55, I have a slightly different view of the lessons learned from the Anna capsize than some others. My comments are in Post #241, if you wish to read them, but one thing that I said, which may be controvertial and speaks to Evans' comments, is the following:

"That said, I don't believe that Anna was over canvassed beating with one reef and the staysail up in 12 to 20 knots of apparent wind with squalls around (as I interpret his account). Nor do I find it inappropriate that they were on autopilot and in the wheel house."

In these conditions, we would have been sailing at 9 to 10 knots, so the TRUE wind was pretty tame. We wouldn't have been complacent, but we wouldn't have been hand steering with two reefs pulled down and the main sheet in our hand for the last 24 hours either (or with the motor running). Of course, we would have evaluated every squall as it approached and planned our next steps. Without being there I won't speculate on how we would have reacted to the sky and conditions that they saw, so I just take it face value that we would have been rigged as they were; it seems pretty reasonable based on what they said about conditions. As I noted earlier, my different actions would have been well before and as it started to happen.

With the above in mind and recognizing my own fallability, I like the idea of a clew fuse, but would suggest one addition. You really don't need to ease the main alot to improve your situation significantly. If the "flogging clew" issue is a concern, you could design in a tether that takes up after a certain number of feet to control the flogging. You could even put a second fuse at the end of the tether, if you wanted a second level of security. As others have said, after the fuse blows, I would pull down the next reef to further control the sail.

P.S. It helps to have an atmospheric scientist on board (my wife)! I based my first comment in my earlier post (e.g. that we likely wouldn't have left in these conditions) on this analysis and the knowledge that we like easy, quick passages.
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Old 27-08-2010, 12:22   #324
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P.S. It helps to have an atmospheric scientist on board (my wife)!
I think the key lesson is just to leave it to the wife to either pick the weather window (you) or to keep the squally watch (me). None of us need fuses if we have the right wives!



More seriously, I would love your wife to start a thread, in very practical detail, on what she looks at in port and at sea to follow the weather?
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Old 27-08-2010, 12:43   #325
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More seriously, I would love your wife to start a thread, in very practical detail, on what she looks at in port and at sea to follow the weather?
I have suggested that she write this up and she is willing, but hasn't had the time yet to do so. If you want to see her views on the Anna situation, check out Chris White's website -- that is her analysis.
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Old 27-08-2010, 22:33   #326
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Sorry, every time the fuse thing comes up I try to keep my mouth shut cause it's off topic...but it's right down my professional alley so forgive me but:

If you asked to me design your fuse, here is how I'd do it. Small sensor at the end of each mini-keel or deepest part of the hull that would simply sense "am I under water?" The sensor cause be incredibly simple, such as a circuit completed by the water. Hook that up to an electronically triggered release and you're finished.

The force at the clew isn't a reliable indicator of capsize...or at the very least, not nearly as reliable as "is one hull out of the water?" The electronic design would reduce or eliminate false positives (fuse blowing when boat wasn't flipping). It can be made extremely robust and very simple, and my favorite...could be turned off with the flick of a switch. You know, in-case you got all jazzed up with high winds and smooth seas wanted to go nuts and fly a hull.

Doesn't quite have the same DIY charm of an undersized spectra line. But I think it would be safer, more reliable, and potential to be far less of an annoyance. It would also make the performance boaters feel better because nothing on their sturdy expensive boats would be constantly teetering on the verge of failure.
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Old 28-08-2010, 00:33   #327
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Sorry, every time the fuse thing comes up I try to keep my mouth shut cause it's off topic...but it's right down my professional alley so forgive me but:

If you asked to me design your fuse, here is how I'd do it. Small sensor at the end of each mini-keel or deepest part of the hull that would simply sense "am I under water?" The sensor cause be incredibly simple, such as a circuit completed by the water. Hook that up to an electronically triggered release and you're finished.

The force at the clew isn't a reliable indicator of capsize...or at the very least, not nearly as reliable as "is one hull out of the water?" The electronic design would reduce or eliminate false positives (fuse blowing when boat wasn't flipping). It can be made extremely robust and very simple, and my favorite...could be turned off with the flick of a switch. You know, in-case you got all jazzed up with high winds and smooth seas wanted to go nuts and fly a hull.

Doesn't quite have the same DIY charm of an undersized spectra line. But I think it would be safer, more reliable, and potential to be far less of an annoyance. It would also make the performance boaters feel better because nothing on their sturdy expensive boats would be constantly teetering on the verge of failure.
Thank you for saying that EH...I have no credentials for saying so, but I felt the same way....I still think the Incimeter to be the best solution.
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Old 28-08-2010, 05:19   #328
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Sorry, every time the fuse thing comes up I try to keep my mouth shut cause it's off topic...but it's right down my professional alley so forgive me but:

If you asked to me design your fuse, here is how I'd do it. Small sensor at the end of each mini-keel or deepest part of the hull that would simply sense "am I under water?" The sensor cause be incredibly simple, such as a circuit completed by the water. Hook that up to an electronically triggered release and you're finished.

The force at the clew isn't a reliable indicator of capsize...or at the very least, not nearly as reliable as "is one hull out of the water?" The electronic design would reduce or eliminate false positives (fuse blowing when boat wasn't flipping). It can be made extremely robust and very simple, and my favorite...could be turned off with the flick of a switch. You know, in-case you got all jazzed up with high winds and smooth seas wanted to go nuts and fly a hull.

Doesn't quite have the same DIY charm of an undersized spectra line. But I think it would be safer, more reliable, and potential to be far less of an annoyance. It would also make the performance boaters feel better because nothing on their sturdy expensive boats would be constantly teetering on the verge of failure.
Just a thought, on a multihull going into sharp seas (not necessary that big )the hulls can rock out of the water exposing the sender , what about breaking waves with all that white water and foam, or what’s going to happen when the sensor starts getting growth on it??
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Old 28-08-2010, 12:54   #329
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Just a thought, on a multihull going into sharp seas (not necessary that big )the hulls can rock out of the water exposing the sender , what about breaking waves with all that white water and foam, or what’s going to happen when the sensor starts getting growth on it??
All valid, design is a process, which I LOVE so if posts like this keep happening you guys will keep egging me on

The immediate solution I see to rocking and white water would be using more than one sensor on each hull, one under the CG, one near the bow, and one near the stern (this would also have the added benefit that you could call it a 'sensor array' which sounds neat and hi-tech so you can impress your friends/family). You could also have some sort of time delay such as: If sensor doesn't feel water for x-amount of time, release trigger. Personally I'd prefer the first idea.

Foam probably couldn't fool the sensor because it's mostly air, but if I were serious about such a system I'd check to make sure.

The sensor anti-fouling is a really interesting issue. I don't know very much about marine sensor design but this is definitely a problem that's plagued them from day one. Thankfully, this means there a bunch of really clever solutions out there I'm unaware of (think long term deployment under oil rigs). In general these sensors wouldn't be measuring anything at high precision which means they are somewhat resilient to fouling. An annual cleaning would probably be necessary and surely recommended. I imagine almost all responsible boat owners clean their hulls at least that often anyways.
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Old 28-08-2010, 20:17   #330
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My general thoughts are:-

- There is no doubt that the capsize of an Atlantic 57 has been a real eye opener for the vast majority if not all of us including cat designers in general.

- A lot of us did not anticipate a cat of this size coming to this fate

At the risk of siding with the Cat folks I don't think (in general?) cat owners were that naive.
I hope that we aren't. As a matter of safety and good multihull seamanship it is critical to understand that wind induced capsize is not a function of size. The 115' Alinghi 5 can be blown over in something like 5 knots true if they work at it and it isn't a great trick to make a 20' cat that can withstand 50 knots without needing to reef. For sea keeping and average speeds size is a great advantage but the wind speed at which a multi will flip has nothing to do with the size of the boat.

I think it would be wonderful if the group would come up with a reliable and affordable safety system that could help with the margin of safety. Certainly it can't hurt to think about such things. But, a multihull is a non-self-righting boat and it needs to be sailed with that in mind. History is full of successful voyages in non-self-righting vessels. I have no doubt that they can be sailed very safely. But there is a level of risk that can not be removed. Generally it can be managed -- you can choose to be rigged to capsize in a 1% event or a .05% event etc. In much the same way that sailing navies had standing orders to reef at night the short handed multihull cruiser is well served by a conservative set of sailing rules. That may well mean that when it is blowing 5 gusting 60 with unpredictable wind shifts that there is no appropriate sailing rig for the boat. If you spend a lot of time in those conditions then a conventional sailing multihull is probably a bad choice. If you meet up with conditions like that occasionally you have some options -- motoring, lying ahull and waiting for better conditions, mixing active sailing with lying ahull an motoring etc. But an understanding that a wind induced capsize is always a possibility regardless of size has to be part of the decision making process.

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