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Thanks
Alec. I think I’m more focused on
the sub vs. anchor relationship.
Let’s say you drop a 500 lb. weight to the bottom and take on 100 lbs of
water in the sub. The sub would
still be very positive and not as likely to pick up the anchor. Making the sub 500 lbs more negative to
get maximum effective weight on the bottom would be possible, but I kind of
like the idea of having the sub positive on the other end of the line. I know the times
and distances are a challenge but I’ve got a few things up my sleeve to make it
“bearable”. Spending the night on
the water is something I love to do anyway, but you can only do that fairly
close to shore for the same reasons (unless you happen to get that once or
twice per year exceptional weather forecast). Plus I’m kind of liking the fact that it’s going to have to
be a bit more “robust” than a sub that is in & out in a few hours. I tend to overkill my projects anyway
so it’s the right kind of challenge. Best
Regards, Cliff -----Original
Message----- Essentially the
sub and anchor combination would still be neutrally buoyant, which means the
anchor would rest on the bottom but have no purchase. In principle this would
be equivalent to simply maintaining depth control by conventional means. If
there isn’t a current, you won’t go anywhere, but if there is a current you’ll
go with it. I must say though that the idea of wanting to go such distances in
a PSUB, ride out storms, etc. sounds daunting, to put it mildly. Rgds, Alec -----Original
Message----- I’ve been tossing an idea around for a sub that some may find useful. It would be nice to get some input as
far as possible “snags” (pun intended) in the design. The sub I intend to build will have to spend many hours
offshore on a single trip in order to get far enough out to become useful. Inshore water is near-zero
visibility. I’m worried about seas
changing for the worse while out and need a way to submerge to a “calmer” depth
in order to ride-out a storm. To
keep from drifting about at 60 fsw or thereabouts, I was thinking to make my
drop weight tetherable (is that a word?).
If things get rough, I plan to submerge to the desired depth and release
a tethered drop weight to the bottom.
Once it hits bottom, the sub will be buoyant by however much the drop
weight weighs and should remain suspended by the length of cable connected to
the drop weight. I am hoping that
submerged to a calm enough depth this will sufficiently anchor the sub in place
until such time that conditions at the surface become more favorable. If this is workable, it would be very
nice for a lot of other things such as compensating for buoyancy changes that
occcur when a diver lockout chamber is flooded, holding divers at 1A for
appropriate “surface intervals” without having to ride a rocking and rolling
surface vessel, etc.. Not to
mention that it will keep me very close to my last known GPS location before
submerging and prevent me from drifiting into shipping lanes, oil platforms,
using up battery capacity keeping the sub on station, etc.. My idea is keep the drop weight as
simple and inexpensive as possible, since it may not be easily retracted when
ready (snagged, malfunction, stuck in the bottom, etc.). Of course there would have to be a way
to break it off or at least cut the line.
I had thought I might simply continue unwinding it until the end of the
cable simply slipped from the spool.
The weight would simply be a concrete-filled drum with an eye bolt in
it. The sub would have a similar
shaped cavity in the bottom so that it could be wound up and neatly tucked in
for running. Input appreciated, as always. Best Regards, Cliff |