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Old 27-07-2003, 09:09   #1
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righting a multi gone turtle

Trimarans have a great draw for me as a world cruiser.

I have righted a few monohulls in sailing school.

My one sailboat ( a cat) thank God never turned turtle despite myself. I was a hellion as a sailor but a very safe teen driver. Go figure. That said here is my question.

Will a big enough ballon at the top of a mast right a cat or tri? Anybody every dealt with the situation?

Personally I think even the turtle issue aside multis are safer than a monohull in most situations Your stores and equipment aren't on the bottom of the ocean.

Also, does anybody have any suggestions on "turtle-proofing" equipment and other stuff on a boat? (Such as straps on batteries or venting for engines and generators) If you could right the boat it sure would be great that the boat survived with minimum damage.

PAUL
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Old 28-07-2003, 01:51   #2
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There have been a lot of ideas exploring methods of righting a turtled multihull at sea. Generally the ones that I know of gave focused on Tris which are much easier to right than a catamaran. One of the most plausable involved flooding one ama (that was also weighted) so that it rolled under the boat allowing the other ama to go skyward. Then an inflatable blatter was expanded within the ama and the mast which in theory allowed the tri to right itself. In reality, a tri would not achieve a sufficiently upright position to allow it to return to right side up. Most multihulls have limit of positive stability that is roughly 80 degrees with a rare exception of a heavily balasted cat with deep keels perhaps hitting 90 degrees. A multihull with a mast float or the tri with a mast float and submersable ama, normally would not float at much above 120 or so degrees making righting very difficult.

At least with a monohull you have a chance to recover from a major knockdown. 8^)

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Old 28-07-2003, 09:47   #3
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Would a tank of helium to fill the bladder increase the chance of full unassisted capsize recovery? With the right type of bladder?

As far as I can see a properly built trihull beats any monohull of the same length in most or all points except capsize recovery(WARNING amatuer opinion here).

What are the odds of unavoidable capsize in an open ocean situation? I can't imagine it would be easy to calculate; calculus and statistics combined. It depends on many factors. I doubt anybody has even been able to do it.

Would the unlikeliness of the event tip the question into the favor of a trihull as an "educated gamble"?

It might if said sailor DIDN'T have a desire to sail in the Artic and Antartic oceans. I have that desire.

Capsize recovery is a huge issue, then? The intenisty of storms in the regions is intensely constant. Also,wouldn't a multihull trapped in ice be destroyed more easily, too?

I am safer with a monohull, aren't I?

Multihulls sure are beautiful though.

PAUL
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Old 28-07-2003, 11:22   #4
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Capsize Recovery ?

I think a Multi', prepared for capsize recovery, would be much like a Mono',prepared for refloating.
OMO
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Old 20-09-2003, 01:42   #5
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multihull righting

Jim Brown and some others experimented with the tow over method of righting trimarans. One method was to attach the tow lines to the stern floats and lead the lines forward to the tow. The bows would dig in as power was applied and over it would go. They also had success with flooding one float and pulling from the side through the centerboard trunk. The only problem is you need outside assistance.
Self rescue in a large cruising multihull is probably not practical and the complications and weight aloft of some type of float at the masthead does not make any sense to me. Capsizing a cruising multihull is such a rare occurance that it is way down my list of dangers to worry about. You would be far better off making sure your boat was habitable in a capsized state with access to tools, food, water, and sleeping areas out of the water. A trimaran may have the advantage over a cat in this situation as you can cut a hole in the main hull for access and the airlock in the floats will hold you quite high in the water. There was the instance of the trimaran Rose Noelle that flipped off of New Zealand and the four crew survived 117 days in good shape. Conditions that will capsize a well handled cruising multihull would have a good chance rolling and or sinking a monohull. I will take my chances in an upturned tri over a liferaft anyday.
There are other more important saftey factors that favor multhulls such as lack of healing (less chance of going overboard), better motion(easier to sail less fatigue), faster speed(lessens your exposure to bad weather). I got into trimarans for the safety factor. To tell the truth going offshore in a monohull scares the #@%& out of me, I always keep one eye on the liferaft, one eye on the thru hull fittings, and the third eye on the underwater repair kit.

You mention a desire to sail in the polar regions. I don't think a multi would be the best choice for that. They are not heavy enough to muscle there way through ice fields and bounce off bergy bits. You need a nice heavy steel or aluminum monohull for that.

Steve R
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Old 20-09-2003, 08:24   #6
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Don't have much to add on the discussion of righteing an upside down multi-hull, but have a couple of comments for Mr. Steve R,
hardcore Tri guy:

I read the book on the Kiwi tri and their 117 days surviving upside down.
The skipper/owner of that tri was also a hardcore tri guy and he said something like: his boat would never flip or get knocked down.
He sure had a lot of un-realistic confidence in his boat....And it .
was not quite fast enough to outrun the weather that flipped it over either.

"To tell the truth going offshore in a monohull scares the #@%& out of me, I always keep one eye on the liferaft, one eye on the thru hull fittings, and the third eye on the underwater repair kit."

Your quote Mr. Rust.

As for the thru hull fittings, well I don't really keep an eye on them, but rather service and use the sea-cocks frequently..
If they fall apart, sure ya could sink, and if ya take to the highways in a car with bad tires and worn out brakes you could also meet yer maker really fast...That does not however mean that there is something wrong with design of the car, just that some idiot did not maintain it.

Same as going offshore in an old glue-it-yourself plywood and balsa tri, the next gale would break into many small pieces and a life raft would look pretty good right then and there.

Been sailing mono hulls for a few years and never worried too much about life rafts or underwater repair kits, but then again, have always sailed on my own boats, vessels I knew inside out with no doubts about the seaworthiness.

So, just because it is a mono hull does not mean it will sink or is un-safe otherwise...

As for Tris, well they look fun buzzing across a lake in a fresh breeze, just like a sailboard, but going offshore, hmm I will take a proper mono hull anytime....
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Old 21-09-2003, 04:45   #7
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Interesting Article:
"Explosive devices designed for space rockets are being used to provide an emergency capsize-recovery system for an adventurer attempting to windsurf across the Pacific Ocean..."

http://www.newscientist.com/news/news.jsp?id=ns99994042
New Scientist
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Old 22-09-2003, 02:04   #8
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reply to CSYMan

Just to clarify a few things. Let's not turn this into a mono vs multi mud slinging match.

As far as the Kiwi tri I can't control the bombastic claims of someone else. I am fully aware of the fact that capsize is always a remote possibility but I don't worry about it. Just like you don't seem to worry about sinking. The chances of either happening are remote and probably the same for both of us. I would just prefer to float in my unturned tri than float in a liferaft. I am more concerned with lightning( been hit in my Searunner and it made nifty leaks) hitting a log(just missed a telephone pole size log while doing about 10 knots recently),container,whale, or ripping the bottom out on a reef. I take comfort from the fact that my boat will stay afloat.

I did not say there was anything wrong with the basic monohull design. I have always owned boats with positive flotation even the monohull I sailed for 18 years ( and still own and sail) has it. I am just not comfortable offshore in a boat without it.

No cruising boat is going to outrun bad weather what I said was the higher speed of a multihull lessens your exposure. A passage that takes 10 days on a monohull may take 8 or 9 on a multihull.
Less time at sea = less exposure to bad weather.

The crack about plywood tri's was a little over the edge and pretty uninformed. You can go to any corner of the globe and you will find Searunners, Cross and Horstman tri's, Wharram cats, and (gasp) you will even see ancient Pivers. Many of these are plywood and they are not flying apart in the first gale. These boats are out there doing it and have been for 30+ years. These boats may be outdated by modern multihulls but like bowsprits, boomkins, and gaff rigs they still get the job done.

I will post a few humorous cartoons dealing with this subject when I get a chance to scan them. Stay tuned.

SteveR
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Old 22-09-2003, 03:04   #9
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Steve Rust;

I'd be really glad to hear any good things you have heard about the Piver Tristar.

What you said was what I always figured was the best thing about trimarans. It they turn turtle or flood at least they won't sink: you still have access to the whole boat as a liferaft.

By the way: my idea for a balloon "aloft" was one attached after the fact of turtling. It could be attached with the diving gear still accessable in the rest of the overturned boat. Some kind of compressed gas onboard to fill it.

Thanks

sail_the_stars
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Old 22-09-2003, 21:30   #10
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I am assuming you meant Piver Lodestar. Tristar is the name Ed Horstman gave to his line of multihulls. The Lodestar was Piver's second cruising design after the Nimble I believe. There are other designs like Victress, AA36, AA40, and alot more. The Piver designs were the first generation and later on Jim Brown, Norm Cross, Ed Horstman and others designed what could be considered the second generation. These boats were more refined with better engineering, construction technique and sailing qualities.
Alot of the early Piver's got a bad rap because the plans were not as thorough as they could have been so some builders cut corners or added "improvements". If the boats were built to plan there is nothing inherantly wrong with them just don't expect them to perform as well as some of the later generation designs. Norm Cross designed keel and rudder modifications for many Piver boats and this did improve their sailing ability. I was in Hawaii a three years ago and walking around the marina in Honolulu I was suprised to see more Piver tri's than any other. I recently saw a Piver 40 foot tri for sale on ebay that from the pictures looked quite nice.
Back to the righting issue. I think it is impractical for many reasons. A capsized multihull is going to be very stable so it would require a very large flotation device and you most likely would have to flood one float or more to get it to rotate. You may get it to lie on it's beam end but how would you get it upright? The mast is filled with water and would be very heavy. If your attempt fails now you have flooded your boat and it is no longer habitable. Not to mention the risk of diving into the tangle of rigging under the boat. As I stated before you would be better off to make sure your boat is habitable in a capsize situation and flip on the epirb and tough it out. The risk of capsize is very small in a cruising design but it is there. You have to be comfortable with the implications.
I have seen a series of photos of someone righting a small 18 foot tri using a derrick jury rigged out of a boom and whisker pole. A large water filled bag was suspended under the bow from the derrick. As he tried to winch the bag out of the water the boat rotated end over end . On a large boat could you generate enough leverage for it to work? You need to have the derrick well stayed but it also has to pivot as the boat rotates and you have to have a winch mounted on the transom or underside of the boat. My gut feeling is that it would be impractical in a large boat. Maybe a combination of the two methods. It would give you something to do while you wait for a ship to find you.

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Old 23-09-2003, 13:26   #11
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Well Mr. Steve Rust, i am certainly not in favor of a mudslinging fight about mono-hulls verus triamarans.

Your are however the one that questioned the safety of mono-hulls as a group.

My comment about home-glued tris coming apart in a gale was indeed over the edge, along the lines of you keeping an eye on the liferaft any time you are on a mono-hull....Duh.

If indeed yu are in favour of tris in particular and multi-hulls in general, and if you own a tri, that is great, fantastic and my hat off to your for doing what you belive in.

Not all of us have the same taste, desires or needs in a boat, so we sail differently vessels to different destinations..

End of story as far as I am concerned.
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Old 31-07-2005, 06:04   #12
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turtle back

Hello from a new user. What a timely conversation. I have sailed monos extensively, and currently own two. I have a deal cooking on a Piver 35 Lodestar. I looked at this vessel about 6 years ago, but the owner wanted too much money for her. Things have changed.
My wife and I, as a result of our original interst in the tri, did a lot of research on the ups and downs (Pun intended), of multihulls. The risk appears to be comparable to that of pitchpoling a mono, and less than that of a dismasting. Pretty good odds.
As for righting the boat, a design, (yet untested) that I came up with is to mount my inflatable on the fore deck, fully inflated. A halyard can be attached to the inflatable, and run aft. Currently, I use diving weightbelt buckles to secure my dinghy. They have never let me down, and release very easily. On a turtled multi, the dinghy can be released, and the halyard hauled in. There is your masthead airbag, no complicated extra gadgets. Will it work? I hope never to find out, but chances are good that it would.
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Old 31-07-2005, 11:45   #13
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you need to do the maths to establish what the righting leverage would be, and I am pretty sure that with such a short sideways lever, you are looking at at least a couple of tons (dependent on size of boat) the air in the average dinghy does not come close to displacing that much weight of seawater.

a cruising cat is unlikely to capsize, but does suffer a risk of pitchpole if driven too hard. this is more of a problem in a tri that is being driven too hard as the float can dig in and cause the pitch. This is one of the problems of multihull design where length and width proportions are crucial to the design's safety.
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Old 31-07-2005, 18:07   #14
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Not being an engineer, my calculations are rather crude, but with a 20' beam, a 40' mast, and a dinghy that displaces 10 cu ft of air, the rough calculations say it will work. I am not including the weight of the mast, or the weight of outer ama (meaning the one out of the water once the boat is brought on her beam).
Of course, as was pointed out before, it will give you something to do while waiting for rescue.
Bottom line, sailing and self reliance go hand in hand. The things that work on paper, usually do not work at sea, and bailing wire and duct tape are often better than the original part.
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Old 31-07-2005, 20:18   #15
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10 cu ft roughly equal to 30 gallons = 300 lb trying to lift 4 ton boat , or at least trying to lift half of it. Aint going to happen.
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