Capsized trimaran uprights by itself

Roberto

Roberto

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Incredible! At the Route du Rhum, the trimaran Arkema capsized, the skipper was eventually rescued by another participant and the boat abandoned.
A few days later they left from Martinique with a tug, once they arrived on the spot surprise surprise they found the trimaran upright, mast up, it has righted by itself.

The hypothesis is one of the amas filled with water, sank, then a combination of wind and waves brought the mast up again. I recall this was one of the techniques to right a trimaran which were aired some tens year ago, but never thought it might be automatic. :D
 
FROM WIKIPEDIA:

The term ama is a word in the Polynesian and Micronesian languages to describe the outrigger part of a canoe to provide stability.

Today, among the various Polynesian countries, the word ama is often used together with the word vaka (Cook Islands) or waka (Māori) or va'a (Samoa Islands, Tahiti), cognate words in various Polynesian languages to describe a canoe.

In modern sailing, the term is sometimes used to refer to the outrigger on a proa or trimaran, or the two sections of a catamaran.[1] However, calling the two sections of a catamaran by the word ama, is not technically correct since they are of equal size. A catamaran is technically a wa'a wa'a or double canoe connected by an aka.[2]
 
Roberto said:
Incredible! At the Route du Rhum, the trimaran Arkema capsized, the skipper was eventually rescued by another participant and the boat abandoned.
A few days later they left from Martinique with a tug, once they arrived on the spot surprise surprise they found the trimaran upright, mast up, it has righted by itself.

The hypothesis is one of the amas filled with water, sank, then a combination of wind and waves brought the mast up again. I recall this was one of the techniques to right a trimaran which were aired some tens year ago, but never thought it might be automatic. :D
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Donald Crowhurst's "Teignmouth Electron" was fitted with a system which involved an inflatable air bag at the mast head and the ability to flood either of the floats.

(Source: "Voyage for Madmen" Peter Nichols)
 
Poignard said:
Donald Crowhurst's "Teignmouth Electron" was fitted with a system which involved an inflatable air bag at the mast head and the ability to flood either of the floats.

(Source: "Voyage for Madmen" Peter Nichols)
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I wonder if it might be truer to say that Crowhurst planned to fit such systems. But then he was a great planner.
(Read the book two or three times but can't with confidence remember.)
 
Topcat47 said:
Wots an "amas"?
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Sorry I thought it was the name of the two lateral floaters/mini-hulls? :o

They started pumping the water out of the three hulls to decrease the loads during the tow.




I see Wikipedia had that term listed, I did not remember what language were the texts where I read it, probably more French, with their long history with Polynesia, though in official French is "flotteur"
 
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macd said:
I wonder if it might be truer to say that Crowhurst planned to fit such systems. But then he was a great planner.
(Read the book two or three times but can't with confidence remember.)
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I think it was partially installed but not commissioned or tested.
 
Not wishing to doubt the accuracy of the OP's post but equally being reasonably familiar with the forces required to turn a trimaran over I was a bit suspicious of this story.......

Reading through the various reports with the help of Google translate it confirms he did lose his rig in the capsize and that he cut it away afterwards. They also go on to say that one of the causes of the capsize appears to have been water ingress into the starboard float and they believe it continued to flood afterwards resulting in the float "sinking", and they believe this, combined with wind and a wave, may have righted the boat. I'm still not convinced. I'm not familiar with the construction technique used on this vessel but most multihulls are foam core and they have enough structural buoyancy and compartments to make them literally unsinkable.

Ian Farrier, the designer of my F27, made a point of flooding every compartment on the prototype (there are nine) and was still able to sail it around the harbour......

I know the facts around this story are a bit thin at the moment, but I'll be amazed if it transpires it really did right itself without human intervention......
 
Triassic said:
Not wishing to doubt the accuracy of the OP's post but equally being reasonably familiar with the forces required to turn a trimaran over I was a bit suspicious of this story.......

Reading through the various reports with the help of Google translate it confirms he did lose his rig in the capsize and that he cut it away afterwards. They also go on to say that one of the causes of the capsize appears to have been water ingress into the starboard float and they believe it continued to flood afterwards resulting in the float "sinking", and they believe this, combined with wind and a wave, may have righted the boat. I'm still not convinced. I'm not familiar with the construction technique used on this vessel but most multihulls are foam core and they have enough structural buoyancy and compartments to make them literally unsinkable.

Ian Farrier, the designer of my F27, made a point of flooding every compartment on the prototype (there are nine) and was still able to sail it around the harbour......

I know the facts around this story are a bit thin at the moment, but I'll be amazed if it transpires it really did right itself without human intervention......
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May I say I agree, it looks really really strange. Also, I think if lne leaves to look for his own capsized boat, maybe he would bring a phone/camera; ok that is probably a view very much influenced by this modern way of showing everything off, you know sponsors and all..

Anyway I just rewrote the original news, if it turns out to be true it could well be a world premiere, never heard such things happen before.
 
A question mark -in terms of stability and general behaviour- comes from the fact they often use these very light boats in a way where the "traditional" multihull naval architecture risks becoming inadequate to explain what can happen: for example when running downind at highspeed they may use water ballast in the aft parts of the hulls (don t know exactly which of the three, possibly all of them). They often report partial flooding of some compartments.
How can such a geometry react to a weight balance different from the base hypothesis being made? They are racing machines, I doubt very much studies are made as to their likely behaviour in conditions nowhere near "normal".
 
macd said:
I wonder if it might be truer to say that Crowhurst planned to fit such systems. But then he was a great planner.
(Read the book two or three times but can't with confidence remember.)
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According to the book it was never connected as he had left most of the parts behind - the voyage was a disorganised nightmare. It was never tested and might indeed probably wouldn't have worked anyway, and depended on undisturbed electrical systems in an inverted and flooded boat.
 
More uncertainties as to what happened: the boat has been found with the shaft and propeller ripped away, the central hull was partially flooded; among the hypothesis, an attempt by some unofficial salvage unit to right the multihull, they then went away as they could not tow it.
Just an hypothesis of course.
 
ninjod said:
It’s not the first time a tri has been righted without human intervention.

http://vg.sitesalive.com/capsize-near-cape-horn
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Indeed. I said I was reasonably familiar with the forces required to turn a trimaran over. 65' waves with 70mph plus winds should do it........ I do appreciate the weather in the Atlantic during this years Route-du-Rhum was pretty challenging but I don't think it came anywhere even close to that!
 
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