|
Gee, almost four weeks of deafening silence on this one. I
don't have a mooring, but get involved in the rebuilding and tying
down of the raft at the place we go to in the summer, so the subject
interests me somewhat. The sailing conference (which I KNOW you
visit from time to time:-^) has a very extensive anchoring topic,
all the lurid details of wind and wave forces acting on hulls and
chain catenaries (sp ?) and elasticity of rope and such. I think
I'd review that, decide how much strength is "plenty strong enough"
and then look to other factors, such as corrosion resistance and
expected strength loss due to corrosion. In the fresh water lake
that I use the raft's chain looks pretty good from a couple of inches
above the surface up and from about 6 inches below the surface down,
but the 4 or so ft that spends half its time wet and the other half
dry gets rusted very quickly, probably should be replaced three
or four times as often as the rest of it.
I'd like to know more about the proper placement of swivels
on mooring chains, that raft sails around and around winding up
the chain, *I* didn't do the chain this time, just the iron on the
bottom. It seems that a swivel at the raft, another about where
the chain would hit the bottom on a straight fall, and another where
it connects to the mooring's main mass would be "about right",
but that's just intuitive and I'd like better guidance for putting
the thing out next year.
BTW, this years's "piece of IRON" is a huge truck brake drum,
somewhere around 2 ft diameter weighing 250 or so pounds, it has a 3 ft
by 3 ft T of 3/4 inch black pipe through it, then 3/8 chain (which I
think it needs another 8 or so ft of). When lowered to the bottom it
stands like a mushroom anchor, when pulled on it tips and digs into the
sand/silt bottom, again like a mushroom anchor. We havn't tried to
break it out, though I suspect that it would be tougher than a real
mushroom anchor due to its greater depth, hopefully it can stay put for
a while.
Reg
|