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Hi Cliff.
Your scenereo made me think of two days ago. My
dive buddy and I were out on his boat looking for a freshwater spring located
about 300 yards out in the Gulf of mexico just south of Hudson, Fl. in Lighter
bayou.
We dropped anchor while we were grilling some
burgers on his boat grill. The anchor kept
dragging across the bottom and we were slowly drifting with the current. The
bottom here is very sandy
like a submerged desert, and there is very little
structure for an anchor to catch on. Of course we were topside affected by
the current. But there are underwater currents you would have to deal with
too.
Would a relatively smooth drum filled with concrete
drag along the bottom if your sub was in an underwater current, and would it be
of much use doing that? Our anchor had pointed ends designed to dig into
the
bottom but it still dragged right thru the sand. Is
the bottom sandy or rocky where you are Cliff? What is the average depth to the
bottom where you are? Would you be able to put the sub itself on the
bottom
(if it's not over scuba depth) and then exit thru
the lockout and secure an anchor line so you knew it was secure and not
dragging? Then you could go back into the lockout and decompress inside the sub.
When you wound up the line to resecure the drum
into the sub's bottom, you would need at least two line secure points on the
drum or else it might spin on the line and jam sideways against the cavity
under
the sub.
It sounds like a good idea Cliff, but I think it
depends on whether the bottom where you plan to dive has suitable structure for
an anchor to grab sufficiently, and would a smooth drum drag along in a heavy
underwater
current even if you did have structure on the bottom? I guess it would depend on the weight of
your sub and how much an underwater current would affect your sub and
therefore the line and drum.
I guess even a dragging weight would be better than
no anchor at all though.
Hmmm. This one sounds like a toughie. Sorry I can't
think of a good answer to help you Cliff.
Kindest regards,
Bill Akins.
----- Original Message -----
Sent: Thursday, June 09, 2005 9:22
AM
Subject: [PSUBS-MAILIST] Anchor for
Sub
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
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