RiskEverything - 09 June 2013 08:04 AM

Good job on getting your boat out sailing, regardless of the outcome!

My first thought is that you need a net between the end of your seating platform and the ama, which will allow you to move weight out to balance in higher winds. Actually, after looking at your pictures again, a net between the akas all the way from the vakka to the ama would probably be better.

My second is that the ama really needs a pointed bow to reduce drag. What is the length:beam ratio of the ama? Everything I read says it should not be less than 20:1.

Can’t disagree with you RiskEverthing a new ama and full net would be a good direction, I think the concept of the moving leeward works well it is the reused platform that is the issue

Tink

skyl4rk - 09 June 2013 08:20 AM

Great story, thanks for posting.

It sounds like the body position between the vaka and ama needs to be able to be quickly adjusted.  Perhaps a sliding seat?

Is there any flex in the crossbeam that would make the vaka and ama not parallel with eachother?

Dear skyl4rk

The cross beams are very stiff.  A bit like above I am using too many old reused parts, a vaka with a cockpit to sit in and unload the ama would be great along with a new ama and trampoline between the two.

Tink

Skip - 09 June 2013 08:44 AM

Thanks for the report. If it makes you feel any better backwinding ( AMS is an acronym for ?) is a common occurrence in small experimental proas.

http://www.duckworksmagazine.com/04/s/designs/johnson/acdc/index.cfm

Another common thread is they are good in a breeze, much less so in lighter stuff. This led to a long excursion into playing with crab claw rigs, which have a lot of merits….reefability and downwind manners are not among them.

A little slow one handed at the moment, but I’ll think on the issues your having and get back to you. One suggestion is to find some one who is at least sympathetic to your quest to observe, video and swap places while sorting out what’s happening. Texas Proa Championships were always a tremendous learning experience even when the lessons sunk in long after the four of us had left the lake. Miss you Laurent.

Your current experience fills me with both dread and anticipation of travelling the same path with the Broomstick.

Cheers,
Skip

Thanks for you support Skip, I had similar issues with TP02, (same vaka, ama and akas) I wasn’t involved in forums at the time but wish I had investigated backwinded issue in much more detail before adding a new rig and controls an already problematic platform. We live and learn

With regard to Broomstick I am sure it is very feasible to have some way of sitting in close to the vaka as possible in light winds and unload the ama, I am thinking a very low drag ama is critical in light winds but my theory as to cause of backwinding may be wrong.

Thanks again

Tink

gearbox - 08 June 2013 07:59 PM

I’ve been reading all the history of your proa, fascinating process!
It ended up fairly similar to my “Proud Mary”, and I think it will be interesting to compare results of the few different solutions we came up with.
I’m particularly interested in your results with the adjustable leeboard, as I have plans for something similar if I need to reduce leeway on my proa.

I hope you recover quickly, and that soon we can have your reports of the maiden voyage.

Good luck, and have fun in the water!

Reports posted after first voyage, love your videos of Proud Mary especially the butt steering one. The leeboard is the one thing that works well. I dispensed with the control lines, I simply adjusted the board position with my foot.

Cheers Tink

I am thinking a very low drag ama is critical in light winds

I think soo to. There should be as little “fight” between the ama and vaka as possible. The vaka should be the dominant hull in every aspect except righting moment. The ama is a keel sticking out to the side where it actually does something useful (whereas the mono has the keel straight down where it does most damage to the usefullness of the boat at the same time as it is not adding to the RM until the boat heels over to a uncomfortable angle). The proa is a monohull without the stupidity of fat hulls and RM optimized for a useless range of angles.

I am sorry to hear about your very harsh lesson today. Sometime nature has a way of correcting our mistakes a little to hard and without any empathy. I think your analysis of what happend and what you can do about it makes a lot of sense. Try a longer and more slender low drag ama.
A failure is only a failure if you stop trying.

Cheers,
Johannes

Thanks for posting your account - both the agony and the ecstasy! As you suggest, the venue for your proa testing sails may not be the best, sort of like trying to test a drag racer in the Costco parking lot. The fact that you had some good stretches of high speed, easy shunts and good control was a great success indeed - many first tries fare far worse. Finding a helpful crew member might be nice, someone to send out to the ama in the puffs and also to tend one of the sails during shunts.

I’m always interested by accounts of schooner proas that have difficulty falling off and gaining way during a shunt. The CLR appears to be much further forward than what we would think. This may have something to do with the hard chines on the hull and ama - since they are responsible for a considerable portion of the over-all lateral resistance, and it would be interesting to know just how far forward that lateral resistance is centered, without the board.

I’m sorry to hear about the cracked hull, but I do hope you repair and carry on.

Editor - 09 June 2013 06:21 PM

Thanks for posting your account - both the agony and the ecstasy! As you suggest, the venue for your proa testing sails may not be the best, sort of like trying to test a drag racer in the Costco parking lot. The fact that you had some good stretches of high speed, easy shunts and good control was a great success indeed - many first tries fare far worse. Finding a helpful crew member might be nice, someone to send out to the ama in the puffs and also to tend one of the sails during shunts.

I agree with the above, try to get a crew member, it makes it much easier to deal with all the unexpected problems.

For the moment I can only share my experience of the platform and balancing the ama. Again, easier with two…
On proud mary I find that having a big platform allows me to balance it much easier (also for steer). I find it hard to control the ama in a steady fly, but ok to just let it skim or lift very little from the water.
It might be worth it checking your lines can all be ready and untangled at all times. That was a problem in the first version of proud mary, and it really made it easier and safer once I fixed it.

I did also capsized once, went turtle, when pushing it too hard and a gust came. I held to the platform and had to swim from under it and Steven flew and landed a few meters ahead. Since then we tend to be a bit more conservative in the way we sail!

By your description I think your main problem might have been just not enough space, crew and time to work it all out before really going for it.
It’s all in your signature;

Nothing is impossible, you just haven’t practiced enough
There are no failures only results

Thanks for your report, it’s great to know the board works, and I’m sure it’s just a matter of time until all the rest does as well!

Cheers,

Hugo

Great account of your trials.  Appreciate hearing about the troubles encountered as these are the things people can learn from.

Your platform could incorporate multiple heel holes along the edges much like a International Canoe sliding seat, allowing you to slide in and out using only your heels/legs to control your position on the slippery seat surface.  Dropping your heels in the holes provides stable positioning, while the slippery seat surface allows you to adjust position instantly for trim.  If you watch videos of good (IC) canoe sailors, they never stop moving on their seating platform - much like the active weight trimming needed on TP03.  Basically, that is what your platform is - a one-sided sliding seat that doesn’t need to change sides like on a canoe.  Good sliding seats also travel fore-aft on wheeled tracks for pitch trim adjustment.

I really like the platform as opposed to netting - although there is a windage problem, moving fast is important and sliding on your bum is a great, low effort method.  Efficient.

Using your leeboard for yaw (directional) trim seems great due to the elimination of the whole rudder issue - but a handy paddle may be needed when trouble arises.

I’m one of those wanting to know what the acronym AMS means?

Bill S.

My assumption is that AMS = Atlantic Mode Sailing

I wasn’t suggesting getting rid of the platform, or adding a trampoline. I meant a more open-weave net that would allow you to climb back aboard more easily and catch any ropes that fall over the inboard or outboard ends of the platform.

A hiking strap and a thicker, more rounded outboard edge to the platform (for comfort) covered in outdoor carpet (for traction) would allow you leverage yourself out a bit further…

Thanks for all your replies, encouragement and advice,

AMS is a typo for my made up acronym Ama Wrong Side, in future I will just use Skip’s ‘backwinded’ - much more logical. I am very lucky to be dyslexic and simple mistakes like this are invisible to me.

I reviewed the hole yesterday, it is worse than I thought but fixable.

I plan to fix the hole this weekend, do a few simple rigging modifications and try again when less people on the lake. If that goes well I will work on a better platform, one step at a time.

Thanks to all again

Tink

TINK - 13 June 2013 12:16 PM

Thanks for all your replies, encouragement and advice,

AMS is a typo for my made up acronym Ama Wrong Side, in future I will just use Skip’s ‘backwinded’ - much more logical. I am very lucky to be dyslexic and simple mistakes like this are invisible to me.

I would think dyslexia would be a huge asset in the proa world - I’ve always thought Lexdisya would be a great name for a proa.  It explains the whole “Which end is the bow?” nonsense quite succinctly to onlookers.

I’m watching your progress with great interest as I’m heading down a very similar road myself (just a few months behind).

—
Bill S.

Bill S. - 13 June 2013 12:37 PM

TINK - 13 June 2013 12:16 PM

Thanks for all your replies, encouragement and advice,

AMS is a typo for my made up acronym Ama Wrong Side, in future I will just use Skip’s ‘backwinded’ - much more logical. I am very lucky to be dyslexic and simple mistakes like this are invisible to me.

I would think dyslexia would be a huge asset in the proa world - I’ve always thought Lexdisya would be a great name for a proa.  It explains the whole “Which end is the bow?” nonsense quite succinctly to onlookers.

I’m watching your progress with great interest as I’m heading down a very similar road myself (just a few months behind).

—
Bill S.

Dyslexia is a great asset for any designer, I find myself approaching the same problem from different directions and shooting off in a new and rewarding heading.

Please post the details your project, there are many subtle improvements I would make if I was building from scratch that might be useful but I have not had chance to bore you all with yet

Tink

Damn Tink,

Left handed/ambidextrous too?
I suspect the members of this forum fall far from the center of the bell curve in a number of aspects.

I’ve given some thought to problem of back-winding and haven’t come up with much (surgery recovery may be involved). At ACDC size everything happens so fast that I think the only solution is to have some video of the event to reflect on.

P52 got back-winded only once, and that was enough. I had plenty of time to reflect on the situation as we drifted across Corpus Christi Bay under small craft warnings. Nothing I tried would turn the boat around. The only solution I’ve come up with is to deploy a drogue from one of the bows probably rigged to help turn the boat more once bow is to the wind.

cheers
Skip

Skip - 13 June 2013 02:46 PM

I’ve given some thought to problem of back-winding and haven’t come up with much (surgery recovery may be involved). At ACDC size everything happens so fast

cheers
Skip

Hope that your recovery is fast, I really feel for you.

You are right about the speed with which the backwinding happens and how frustrating it is to get back to normal. I had the same issues with TP02 (same platform, single sail and counter rotating rudders), it had big struts holding the mast up and in light winds I would sail stood on the rear aka holding the strut. I was fairly obsessed with getting the ama flying and so stood very much inboard to achieve this. This seamed to reduce the problem. Memories are coming back I remember that when the ama was flying everything would go silent and speed would increase. If loosely you equate the noise to drag then the ama seams to be the issue.

Anyway fix it up quick and dirty and get back out there is the plan

Get well soon

Tink

You are right about the speed with which the backwinding happens and how frustrating it is to get back to normal.
Tink

**************************************************************************

I found out that in that case, paddling like a mad man helps…

Swearing in French seemed to have positive effects too….

Laurent