Atlantic 57 Catamaran Capsized

[SV DestinyAscen]

Originally Posted by 44'cruisingcat

No big deal on our boat either. We've had it go from 10 knots to 38 knots under full sail. Never lifted a hull, but it certainly got my attention.

Always appreciate your contribution - can't say I have the same experience as you, but agree that it isn't deadly on the 1160 we chartered in Australia but we were going downwind so the apparent was much less. I can't imagine what it must be like going to windward with dagger boards down - still waiting to hear about the daggerboards setup - I recall Anna looked like both boards were down.

[SVNeko]

Originally Posted by TJ D

PS- Neko--We haven't seen you guys since the Haha, we've since sailed to Europe. Baxter still asks about your dog from time to time.

Good sailing, TJ

Hi TJ, good to hear from you. Yea, we got stuck in the Atlantic for a few years. Hope good ole Rocket Science is still rocketing along. Sadly, Lucy passed on about a year ago at the old age of 15.
Cheers,
Pete

[belizesailor]

Neko, my condolences for Lucy...a thoroughbred Belizean Potlikah is hard to find.

My Potlikah was one of the best dogs I ever owned.

[SVNeko]

Originally Posted by belizesailor

Neko, my condolences for Lucy...a thoroughbred Belizean Potlikah is hard to find.

My Potlikah was one of the best dogs I ever owned.

Thanks, Curtis. She was a helluva dog. I think she was smarter than I am.

[poiu]

Originally Posted by Cottontop

The power in wind is a cubic function of velocity. Tremendous amount more power in 25k than 20k (maybe almost double).

I think with a sudden increase in wind the static load is more relevant and so force rather than power is the measure to look at that would be a square relationship. Still a huge increase though for a big change such as we are probably talking about.

[beiland]

Originally Posted by Seaslug Caravan

Yes , but how does one accomplish this in reality?

Does one hand hold the sheet tails? Does one come out of the hermetically sealed cabin and experience the elements and feel the first cool breath of an approaching down draft?

Does one stand by the wheel ready to bear off in that first big puff?

Well if the answer is yes then how on earth does one accomplish this with very small crew. A couple would effectively be taking turns to single hand a 57 footer standing in the elements , highly alert for 24 hours a day.

So the reality is then to be safe you reef right down and slop around going no where fast, or crank up the donks and motor.

The whole concept of a large performance cruising sailing catamaran for a couple then appears totally bizarre

Prudent:
1) Reduce sail area (particularly height) at night.

2) Employ a good capsize prevention device.
(a few discussed here)
Capsize Prevention Devices - Page 2 - Boat Design Forums

3) Maybe consider a lower aspect ratio rig such as a ketch. I've suggested several single-masted ketch rigs with mast heights of 20% less height for the same sail areas found on sloops.

[beiland]

Originally Posted by belizesailor

....
Chris did respond with an analysis of the capsize of Ana. Good response I thought, he just stuck to the facts and ran the numbers: by his calcs 64 knots is the windspeed required for capsize with a single reef in place, owner's account of windspeed was more like 74 knots.

Of course, microbursts can happen in seconds and surprise even the best of crews, but normally they happen in the presence of unsettled weather.

Is that analysis still on line somewhere ? I think it has disappeared from his site.

[SVNeko]

Originally Posted by beiland

Is that analysis still on line somewhere ? I think it has disappeared from his site.

https://www.chriswhitedesigns.com/capsize-of-anna

[Boatguy30]

He has notes on his website about Anna

What is a single mast ketch rig?

[beiland]

Originally Posted by catsketcher

Here is an interesting article that does include large and heavy cats in its talk about rig design. A fair way down is a section on cruising cats. Some of the basics are

- heavy and large cats have huge righting moment - the loads on flying a hull are so large designers can just assume the sails will be doused or blown out before you lift a hull.
- mast designers are not sure if this is a good idea

Info – AES

Phil

Thanks for bring that website up again. I had lost contact with that group under my old bookmarks. The principle has done lots of work on analyzing rig loads.

[beiland]

Originally Posted by SVNeko

https://www.chriswhitedesigns.com/capsize-of-anna

Thanks, don't understand why I had trouble finding that ?

[beiland]

Originally Posted by Boatguy30

What is a single mast ketch rig?

[QUOTE=beiland;715323]

Originally Posted by SkiprJohn

Why is it called a ketch rig? I thought ketch rigs were two-masted with the aft mast being the shortest. Am I wrong?


Quoted right out of my website
Sail Propulsion - Revisiting a Mast-Aft Sailing Rig
"So what did I come up with? Lets call it a marriage between a cutter and a ketch without the mainsail.

...Adding a mizzen sail to one of the backstays turned the boat into a ketch without the addition of another mast and its associated rigging. This increased my total available sail area on this single-masted rig. A ketch rig divides the sail area up into more manageable size sails, and it produces a rig with a lower center of effort (less overturning moment) than a sloop of the same sail area."

And technically even though I don't have a second mast, the mizzen sail is attached to a member that is ahead of the rudder post.

I'll bet you might find this 'ketch rig' easy to use in a 'day-sailing' situation:
http://www.cruisersforum.com/forums/...tml#post171683
"You know I can still imagine sailing a big 65-foot catamaran with this rig right off the mooring, and back to the mooring, without the engine, by myself, with so little effort that I might take it out having only a few spare hours to kill or a daysail."

http://www.cruisersforum.com/forums/...g-21331-2.html

[beiland]

Originally Posted by belizesailor

I dont see the kind of rampant speculation, and vilification of crew/boat, so unfortunately common on CF in Chris' write up (in all fairness its not been bad on this thread). While a water spout is a theory, I think its a good one. Would be interesting to hear more directly from the crew.

Not much you can do about a water spout. Even if you see it early, their movement is very erratic. Even if you got sails down, the wind speeds are in ranges that could still capsize a cat or knock down a mono (had a friend on a mono get knocked down by one at anchor).

I just read Chris' initial report, and I have to agree with him.

As it appears there were no real erratic winds prior to the capsize, and relatively calms winds immediately after. It just had to have been a tornado type event. And the roaring sound, sounds just like reports one hears from survivors of land based tornadoes in USA.

Leopard had the second reef in the mainsail and the smaller self tacking jib rolled to a #2 reef position

https://www.chriswhitedesigns.com/leopard-capsize

That is a safe enough reef for most situations,....just not enough for a waterspout hit

[Cavalier MK2]

In Jerry Heutink's book "A Trimaran Sails the Seven Seas" He gives an account of a massive wave engulfing his Cross 46 with solid water over the boat some way up the mast. What saved him was being headed in the same direction and holding a straight line as it passed over head. He thought he had some divine assistance as well. In checking the charts he felt it was prone to rogue waves because of several converging factors. A wave would have sounded like a roar as well if it was breaking.

[Jim Cate]

You know, if in fact this capsize was due to being struck by a waterspout, Chris W must be wondering how he pissed off the gods! A mean blow to the reputation of his work... Anna's demise could be attributed to crew error on a sensitive boat,but the extremely rare event of waterspout strike is truly the metaphorical "act of god" that the insurers are always on about!

"Why me" would be a reasonable question for him to be asking!

Jim