Subject: Re: [harryproa] Re: mast bouyancy
From: "Chris Ostlind" <>
Date: 2/10/2006, 4:40 PM

One of the big reasons I started looking at passive, functional flotation at the mast head was the complexity factor of anything with moving parts such as an inflatable system at the mast head. Stuff corrodes, bags get holed, and the halyards or electronics to perform the triggering task can be compromised in any of several different ways.
Most importantly, how do you deploy (or is it un-deploy) the air bag once fired-off and full of air. We're talking another mechanism for deflating the bag through a one way valve, aren't we? We're also talking potentially of a mast monkey to ascend the stick in the very serious conditions that caused the capsize and stuff that sucker back into it's hidey hole so it can be used again (providing there is an unlimited supply of charges for the sack in the first place) I wonder what are the physics of a grown-man-moment on the end of the waving stick in lousy seas?
Clearly, there's way more to this than simply flipping switches for air bags.
Personally and ideally, I'd like to see something like the options available in a passive/dynamic system with reloadable capacity while remaining on the deck and out of harm's way, as it were.
I'm not saying the passive endplate system is the do-all, be-all solution. I find the potential as intriguing, without R&D resources, as I do the air bag thingy and it's certainly simpler to use over again... and again, if necessary. If I can muster the cash this summer, I will build something of a prototype for a simple, beach cat sail and mast and go tip it over to see how it works. In the meantime, I'd like to see if someone can run some numbers as to what, if any, performance enhancement there might be from the endplate effect at the top of the sail.
The whole thing could just be a cool pipe dream that goes nowhere, but for my money, I'd rather have a passive device with performance potential than something that will need all sorts of maintenance to make sure it will work when you need it most. At least that is where I'd like to start. If it turns-out that a paintball gun cylinder with an air line up the inside of the mast is the finest solution, it won't bother me in the least as I'd much rather see a nice product that can be used by all my fellow, multihull sailors for a little extra piece of mind.
Lastly, it would flat piss-off about a dozen of my friends who are monohull drivers when I can toss my boat back on its feet before they can sludge their way past me on the ocean. That would be sublime in its purest sense.
Chris Ostlind

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