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Vic Smith Vic Smith is offline
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First recorded activity by BoatBanter: Oct 2006
Posts: 4,312
Default Roll Stabilization Tanks

On Mon, 31 Dec 2007 10:36:35 -0500, Wayne.B
wrote:


Yes, the old flopper stopper trick. I built a set for our old boat
and they were quite effective. On the Grand Banks they appear to be
undersized however, with 3x the displacement. Equilateral stoppers,
more than 4 ft on a side, would be quite bulky to stow and deploy.
I'll have to think about it. One trick that I did get some success
with was to leave the inflatable RIB dinghy over the side, half
suspended from the cargo boom. It allowed the boat to roll easily
towards the dinghy but provided 300 lbs of resistance going back the
other way. You could hear the dinghy splashing around at night
however so it was not a big hit with the admiral, and probably tough
on the mast rigging over the long term.

Since I began reading about "roll dampeners" I've wondered about the
stress on attachment points. Read a few accounts of flopper stoppers
breaking their cables, and it seems the forces are significant.
How do you judge what's too much stress for these setups?
Since cats are resistant to rolling I've pondered whether extendable
amas on strong poles - don't know what material - might be a solution.
Storage, cosmetics, and ease of deployment might be the big issues
with this, but less so on a bigger boat like yours than a smaller
boat. There are some interesting engineering questions about
flexibility of the poles, attachment points, ama buoyancy, etc, which
might be fun to work out. Sometimes I wish I were an engineer,
but I don't even do algebra. Still fun to Rube Goldberg it.

--Vic