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 Post subject: Re: capsize recover
PostPosted: Sun Jul 06, 2014 9:23 am 
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Joined: Thu Jun 01, 2006 1:16 pm
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Location: Colorado
I have an AI now and am probably going to get a TI in the future so the extra clip on tether (or whatever its called) to prevent the ama from a total collapse seems like a great idea - one that I will do.

From the capsizes I have heard about, the TI capsize seems to be more from an ama collapsing and the AI capsize is just flipping the whole boat - amas all still intact.. An ama collapse might be easier to deal with since you may have slightly more time to keep the mast from sinking.

It sounded like people have done self recovery with the TI with one of the Amas collapsed - but I couldn’t tell for sure.

Quote:
About turtleing my AI upside down, I am prepared for that I will NOT be able to right it up in conditions when it will happen


One comment (quote above) looks like if you have an AI and it gets turtled, sounds like self rescue might be very difficult. Has anyone been able to self rescue an AI from after turtled? As someone else said, when you capsize, its usually in high winds where doing anything at all can be difficult.

Also, I know on my dingy (C15) that if the mast doesn’t sink, the self rescue is fairly easy. If the mast sinks, you will almost for sure need help. Since I sail the AI alone (but generally on inland lakes where there are at least power boats around), which I completely enjoy and sometimes it involves windier conditions, I might think a little about keeping the mast tip from sinking. I would guess that it doesn’t take much floatation at all - maybe even 5 pounds of water displacement. It would create a bulge at the top of the sail when rolled up which wouldn’t be good.. but it seems to me that it would not take much floatation at all.. the picture below has a yellow line drawn in where some sort of floatation strip could be sewn on. ???


Image


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 Post subject: Re: capsize recover
PostPosted: Sun Jul 06, 2014 12:58 pm 
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Joined: Fri Sep 19, 2008 4:07 pm
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Location: CLEARWATER, MN
Following the advise of several forum members, I purposefully capsized my TI off my dock in deep water. I let it 'turtle'. I could not get it to come back up. Wearing a a dive mask to see what I was doing, I eventually was able to pop the mast out of the hull, making sure that the furling and main sheet lines were not too tangled. The lines also kept the loose mast from heading to the bottom. I was then able to flop the three hulls over. I rolled the sail onto the mast, knowing that it would be nearly impossible to bring the mast up if the sail were acting as a drogue.
This was done over a 30 minute period in calm conditions.

I now carry my dive mask bungeed behind my seat. There is no way that I could right the TI, if I couldn't release the mast.


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 Post subject: Re: capsize recover
PostPosted: Sun Jul 06, 2014 2:26 pm 
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Location: Colorado
Hmm... Ive owned a Hobie 14 and 16 and both of these had the Hobie Bob float.. I dont know if Ill try this but maybe something like a Hobie Bob? But in this case it would be a fat flying saucer shape to give the least wind resistance no matter which way it was pointed. Im fairly sure the mast on the AI is water tight so it might not take a whole lot of boyancy at the end of the mast to hold it up. A liter of water is 1Kg or 2.2 pounds, I think even as small as 2 liters of volume might be all you would need?? A simple float test would tell (tip the boat on its side and see what it takes to hold up the mast. It seems to me that if the mast tip were floating, either the AI or the TI would be fairly easy to self rescue by just collapsing one ama. The mask idea wouldnt do me much good, the lake in the first pictures in this thread gets up to maybe the low 60's F at its warmest (8600 ft elevation).

As I mentioned, despite all the sailing Ive done with the AI, I have never capsized it so you have to question how big of an issue this really is.. but..

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 Post subject: Re: capsize recover
PostPosted: Sun Jul 06, 2014 2:51 pm 
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Posts: 181
Location: Delaware Coast
walt wrote:
Im fairly sure the mast on the AI is water tight

My TI is far from such. I smeared silicon all over the base and it still fills with water somehow (judging by what I dump out of it, it fills to around deck height). The worst part of this is that even if my sail dries before load up time, the water drains out of the mast and wets the sail after stowing.

As far as a "bob", I have been hoping one of the more inventive members would come up with something for the islands. The average depth I sail in is around 6 feet and I don't sail anywhere where the TI could turtle without the mast contacting the bottom. I had a bad experience in a rented cat after pitch poling and having the mast stick in the mud. I know a pitch pole is very unlikely to happen on my TI, but it would be reassuring to have a device to stop it from turtling and finding out how the mast contacting the bottom would complicate recovery.

Is expanding foam bouyant? Could filling the mast with it stop both water entry and provide enough flotation to keep from turtling? Doh, after thinking about that for 10 seconds I realize that nothing would be more bouyant that plain old air in the mast :oops: I have been thinking about pouring something into the bottom half of the mast to seal it though.


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 Post subject: Re: capsize recover
PostPosted: Sun Jul 06, 2014 10:52 pm 
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Joined: Sun Sep 11, 2011 9:35 pm
Posts: 77
Location: Mt Kuring-Gai, NSW, Australia
noon the subject of a support line to stop the ama folding back, I've had the following spray skirts
for a while now, which I install each outing, they appear to help prevent folding back at least
to some extent. Do you think they stand up to much force ?
http://www.kayakingbob.com/sprayskirt


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 Post subject: Re: capsize recover
PostPosted: Sun Jul 06, 2014 11:14 pm 
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Joined: Fri Jan 05, 2007 9:21 pm
Posts: 2231
Location: Maui, Hawaii
Aloha oceanmoves,

The Sprayskirts will slow the folding of the aka/ama giving more time to react, but not completely stop it in strong conditions. It will stop the forward aka from disconnecting from the hull. I just add leashes on my rear aka to complete the set.

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http://KayakingBob.com - - - - - Hobie Island Sailing since 2006 - - - - - 2011 & 2012 Hobie AIs and a 2012 TI


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 Post subject: Re: capsize recover
PostPosted: Mon Jul 07, 2014 2:46 am 
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Joined: Wed Dec 19, 2007 4:07 am
Posts: 598
Location: Punta Gorda, FL
fusioneng wrote:
...
I hate to burst everyone's bubble but most of my shear pin breaks have occurred while underway out in open water, with the result always being the same ( the AMA folds and you capsize for sure if you don't have the brace ropes ( I think it's call floundering LOL)). It's simple math, if your barreling along at over 12 mph and a funny gust comes along and buries the AMA, the resistance of the water pushing back on the AMA is more than the shear bolt can take and the AMA folds, and you capsize. ...


I never broke a shear pin but did knock my aka brace free with my elbow once.

I actually knocked it loose, not free, but it freed itself in the next gust.

I figured I was going swimming for sure, but managed to ease off the sheet in time and stayed upright.


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 Post subject: Re: capsize recover
PostPosted: Mon Jul 07, 2014 3:57 am 
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Location: Sarasota,Key West FL
Tom:
I think there is a direct correlation between the shear pin breaking and speed. I think your pretty safe up to around ten mph even if a gust comes and the AMA buries, typically this almost stops the boat anyway. That little clip and rope makes sure you don't capsize from the pin break that's all it does.


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 Post subject: Re: capsize recover
PostPosted: Mon Jul 07, 2014 9:31 am 
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Joined: Tue Jun 19, 2007 6:14 pm
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Location: South Florida
Tom Ray wrote:
I never broke a shear pin but did knock my aka brace free with my elbow once.

I actually knocked it loose, not free, but it freed itself in the next gust.

I figured I was going swimming for sure, but managed to ease off the sheet in time and stayed upright.


I've never broken a shear pin (both Tom & I use AIs, not TIs--there are differences!), but like Tom, I did accidentally release an aka brace once in very heavy winds as I was trying to save a paddle--it is a long story. You can read about it here http://www.hobiecat.com/forums/viewtopic.php?f=70&t=7276&start=75 Scroll down to the Chok-Pavilion Key trip and then to the very end of that.

In my case, the brace that I accidentally released, was on the windward side, so capsize did not occur although it was an extremely dicey situation--trying to save my paddle (held by precariously stretched bungee cord) while also trying to re-attach the brace in 25 mph plus winds. This was before hakas.

I usually have my hakas installed. They would certainly prevent the ama/akas folding back. My guess is the hakas would greatly firm up the ama/aka structure, but, if you rammed into something, would the shear pin break or would something else be put at risk?

Keith

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I sail: Biscayne Bay, Everglades to Cape Romano, Ft Desoto, Cedar Key

"Any intelligent fool can make things bigger and more complex ... It takes a touch of genius and a lot of courage to move in the opposite direction." A. Einstein


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 Post subject: Re: capsize recover
PostPosted: Mon Jul 07, 2014 6:51 pm 
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Joined: Sun Sep 11, 2011 9:35 pm
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Location: Mt Kuring-Gai, NSW, Australia
KayakingBob wrote:
Aloha oceanmoves,

The Sprayskirts will slow the folding of the aka/ama giving more time to react, but not completely stop it in strong conditions. It will stop the forward aka from disconnecting from the hull. I just add leashes on my rear aka to complete the set.


thanks. where do you attach the leashes on your rear aka & hull ?


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 Post subject: Re: capsize recover
PostPosted: Mon Jul 07, 2014 7:05 pm 
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Location: Maui, Hawaii
Here you go: http://www.hobiecat.com/forums/viewtopic.php?f=72&t=46033&p=203879&hilit=leash#p203879Image

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http://KayakingBob.com - - - - - Hobie Island Sailing since 2006 - - - - - 2011 & 2012 Hobie AIs and a 2012 TI


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 Post subject: Re: capsize recover
PostPosted: Sat Jul 12, 2014 7:19 am 
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Joined: Thu Jun 01, 2006 1:16 pm
Posts: 150
Location: Colorado
Data point for the AI..

I wanted to see how much floatation would be required on the AI mast tip to keep the mast from sinking so tried a little experiment.

I first tried to tip the boat over with the ama's out - could not do it. This is a good thing as it shows how stable the boat is - and why Ive never flipped it. So I collapsed one ama and roled the boat over on its side (pictures below). In the second picture, there are some foam blocks at the mast tip and the total volume of all the foam at the mast tip is 511.4 inch cubed - or just over 2 gallons.

From the bottom picture, it looks like it took about half the floatation I put on to keep the mast up. In high winds, the there is additional force trying to push the mast under so you need some margin plus if the ama were extended, the angle would be worse. If I were to make something (not sure I will), I think it would have at least 1.5 gallons displacement..

Image

Image


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 Post subject: Re: capsize recover
PostPosted: Sat Jul 12, 2014 7:44 am 
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Joined: Tue Jul 19, 2005 6:29 pm
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Location: High Point, NC
Generally, when a trimaran capsizes, it goes turtle very quickly, unlike a catamaran which can take a few minutes. The difference is that the submerged hull (ama) on the trimaran then pushes the boat upside down as it attempts to return to the surface, on the other side! Mast floats typically do not work well on trimarans.

But the difference on the AI and TI is that most (not all) capsizes happen due to an aka brace giving way and the leeward ama folding in. So once over, what you then have is a sort of catamaran, rather than a trimaran. So mast floatation of some sort may indeed be beneficial on the AI and TI in the event of a capsize.


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 Post subject: Re: capsize recover
PostPosted: Sat Jul 12, 2014 10:00 am 
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Joined: Tue Jun 19, 2007 6:14 pm
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Location: South Florida
It reminds me of when my wife asked the Ranger at the Glacier Bay NP headquarters "What people did if they capsized?" at the beginning of our 2-week kayak trip. The water in the area is 38-39 deg F (3.3-3.9 deg C). He responded, "Don't capsize."

I've never broken a pin on my AI even though I frequently bury an ama. Maybe I don't sail fast enough! But, I've carried heavy loads in strong winds with 2' plus chop, buried the bow, buried amas. Now, I usually sail with hakas, which I believe will prevent any collapse of the aka.

This is not going to happen to many people, but the time I flooded my hull in 15 mph winds, gusting to 20, I came very near to capsizing with the akas/akas deployed normally but w/o hakas. I was leading a group of people and not paying attention to my own boat. Nevertheless, when that little gust almost capsized me, it definitely got my attention. I immediately reduced sail to a square meter or so, closed the partially open hatch, and sailed/pedaled the mile to our destination. It was a close call. You can read about that trip at http://www.hobiecat.com/forums/viewtopic.php?f=70&t=7276&start=180 Scroll down to the "Chokoloskee to Flamingo" trip.

Keith

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I sail: Biscayne Bay, Everglades to Cape Romano, Ft Desoto, Cedar Key

"Any intelligent fool can make things bigger and more complex ... It takes a touch of genius and a lot of courage to move in the opposite direction." A. Einstein


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 Post subject: Re: capsize recover
PostPosted: Sat Jul 12, 2014 12:05 pm 
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Location: Forster, NSW, Australia
Walt, thanks for going to the trouble, as well as documenting the outcome. We can all learn from it.

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2012 Tandem Island "SIC EM"
www.scenefromabove.com.au


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