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PostPosted: Thu Jan 12, 2012 2:14 am 
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Location: Central Coast NSW Australia
In this clip one of my mates is returning to land to repair the broken aka brace bolt. It was his first trip out and he had just collided with my other AI skippered by another first timer. The bolt, being designed to break and prevent structural damage, did its job well.
This clip demontrates that it is very difficult to capsize an AI, even in strong crosswinds with the lee ama folding in.
It seems the windward ama plays more of a role than I thought in stabilizing the AI.

I'd recommend everyone try sailing with a disconnected aka brace and holding the aka out so that if it does really happen you're prepared. :)

PS:
After seeing this clip I've also been thinking about having an adjustable aka rake fore/aft as a way of preventing nose diving. Adding a couple of extra brace balls would allow the ama to be pushed forward or back which may get the bow up a bit? You couldn't do it with tramps on but I think its worth further investigation! :wink:


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PostPosted: Thu Jan 12, 2012 6:40 am 
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You did keep flying the F-111 for the longest time.
It will be interesting to see a variable AI.
Are you going to make your own nut plates or bolt thru the deck?

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PostPosted: Thu Jan 12, 2012 8:21 am 
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Ive only had my AI out once since I bough it, but I doubt the wind could ever capsize it. It does not have a big enough sail, and the further over it leans the more air the sail dumps over the top. So its a two fold effect.. the further over it goes the wind has less and less effect pushing it over, and the further it goes over the buoyancy has more and more effect pushing it back up.


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PostPosted: Thu Jan 12, 2012 9:20 am 
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Location: CLEARWATER, MN
I ended up putting a 'leash' on the padeyes located on the front of the amas.
They normally run along the ama and are clipped to the rear. If a brace is broken rather than the sheer bolt...I can release the leash at the rear and pull it across and clip it to an anchor point on the gunwale. It may not be as sturdy as a brace but at least it will help stabilize my TI.
I also found the leash to be a good lead when I need to temporarily tie the TI parallel to a dock. A line running from the bow pulls the bow into a dock rather than parallel to the dock.


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PostPosted: Thu Jan 12, 2012 2:48 pm 
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Wingnutt wrote:
but I doubt the wind could ever capsize it.

Your not trying hard enough.
Wind combined with opposite wave action and tramps.
Very easy to exceed the critical angle and roll.

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PostPosted: Thu Jan 12, 2012 4:02 pm 
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Regarding the tramps, I'm not a fan of suddenly having a second sail when I least want one.
Does anyone make an alternative that is more like a nice taught cargo net. I don't want anything I can sit on, just a place to set things from time to time.


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PostPosted: Thu Jan 12, 2012 6:12 pm 
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Location: Southwest Calif.
After watching this, I'm wondering if having some bungee cords as additional braces would help insure against a total collapse of an ama. The shear pin could still do it's job but the elasticity of the cord would still help it keep some of it's intended position and not do any damage to the main hull like a solid brace would do.

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PostPosted: Thu Jan 12, 2012 6:43 pm 
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Location: Maui, Hawaii
Sprayskirts, fully, securely attached to the hull will stop a total ama collapse in most situations unless there is so much stress as to break their lines. I don't think a bungee would hold up.

When Aloha Dan and my dealer Kelly from P&P Kayaks sailed AI's from the Big Island to Maui and then back, they added lines from the bow to the front eye on each aka to protect from collapse, but they didn't have any issues to test it.

On Tramps, I use a home-made 1/2 tramp for fishing made out of shade cloth and 1" straps on a frame made from PVC pipe and wind-surf masts, that lets air and water through, but can hold over 200#.

I also have split a Hobie tramp in half to make 2 half tramps that work well, but I rarely use them.

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PostPosted: Thu Jan 12, 2012 7:36 pm 
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[quote="Wingnutt" Does anyone make an alternative that is more like a nice taught cargo net. [/quote]
An OD cargo net/hammock multi-purpose thing that I got about a decade ago. Don't know where it is or what the NSN was but it would have been perfect with some minor mods.
Kind of like the safety nets on the side of a Frigate or Destroyer along the flight deck.... and just like them it would support your weight until too much salt and sun got to it.
I'll dig through my kit and put it on my AI if I can find it.

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PostPosted: Thu Jan 12, 2012 7:46 pm 
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Wingnut, I know this is not what I have/had but it would be a real close second and for the price worth experimenting with.

http://www.amazon.com/Ultra-Force-Olive ... m_sbs_sg_6

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PostPosted: Thu Jan 12, 2012 9:03 pm 
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Well done to catch the action as it happened Stringy. Next time we all get together perhaps we should have a match race around a course without amas. Last one still standing wins. You may have the edge though with your practice going to work with the small sail.

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PostPosted: Tue Jan 17, 2012 2:02 am 
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Gotta love it. Nice video of the "Oh s---!" moment.

Interesting, the folding forward. I and others would have expected a collapse to the rear.

Thoughts on fhis?

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PostPosted: Tue Jan 17, 2012 9:21 am 
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Location: Southwest Calif.
NOHUHU wrote:
Gotta love it. Nice video of the "Oh s---!" moment.

Interesting, the folding forward. I and others would have expected a collapse to the rear.

Thoughts on fhis?


I totally agree with your normal expectations about a collapse towards the aft end but this was under a unique circumstance that actually has a higher probability of happening when you are sailing among a group of aggressive sailors who may be "buzzing" the boat in a display of speed and realize at the last moment that the break pedal doesn't exist on a Hobie to avoid a rear end collision.

Quote:
In this clip one of my mates is returning to land to repair the broken aka brace bolt.
It was his first trip out and he had just collided with my other AI skippered by another first timer. The bolt, being designed to break and prevent structural damage, did its job well.

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PostPosted: Tue Jan 17, 2012 8:20 pm 
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Location: Central Coast NSW Australia
I asked my workmate about the aka/ama.
He said the tendency was for it to fold back but as he was holding it and pushing it forward wave action caused it to fold too far forward at times.
The greatest risk of breaking a brace bolt is when sailing with others. All three of my breaks have been in collisions with other AI's.
I'm a big fan of the tramps which would have prevented this collapse. At the time I only had one set of AI tramps and they were on my TI.
It is very difficult to roll an AI/TI. I know others have reported capsizes but in 4 years of AI sailing often in 25+knot winds on open water I have yet to flip one.
Just two weekends ago we were out in 20+knots with a decent swell. Jason my mate with cerebral palsy ( viewtopic.php?f=71&t=11745 ) was solo in my AI and having a great time under full sail. He wouldn't get on a boat that could capsize easily. Admittedly I didn't have the tramps on his AI but if I had all he would have had to do to remain stable was furl the sail a bit. The beauty of the tramps is that they can be rolled up or hiked out on if stability becomes an issue.

I posted this clip to:
1)-demonstrate that breaking an aka brace bolt does not mean you will end up capsizing. Hobie have produced one of the most stable and versatile of sailing craft that will continue to perform well even with an aka collapse. 8)
2)-Investigate the possibility of raking the aka's to lessen nose diving. My initial thoughts were to push them forward to improve flotation through a wave but after reading of the effect of the rearward aka's on the "Batboat" maybe pushing them back and shifting the weight rearwards might lift the nose? Just got to find the time to begin the trials!

PS
Fly4v,
I intend bolting the brace balls through the hull using shaped backing washers or even a short half pipe.

Slaughter,
About that ama-less match race. Let's make it a time trial.
You go first! :wink: :lol:


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PostPosted: Wed Jan 18, 2012 11:54 am 
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Excellent food for thought. Thanks for posting this.

Havng three braceball positions is a fast and cheap way to see if this works to trim the boat. Extending the brace bar (for the forward rake) is a better engineering choice, but less practical.

I suspect that the forward rake would work if you moved the Amas about a foot forward, but with some decrease in side stability. Sailing a long run like this in gusts and side swells may have rethinking those "hard to huli an AI" observations.

Adding TI Amas, like on tbe Batboat, is not cheap, but will defnitely add front lift, stability and capacity to the AI.

But extra braceballs are easy, and now that it's out there, someone has to try it.

To quote a wise man - "You first!" :lol:

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