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I thought "riding the bubble " was having a small amount of air in the soft
tanks while traveling close to the bottom. I like the idea of dragging a length
of anchor chain to maintain a short distance from the bottom. Of course, you'd
need to have a means of dropping the chain if it got hung up on something.
As for the MBT valves being mounted directly on the tanks and having
linkage drive them......What have you gained? You still have a through hull for
the linkage, except it has a rotating rod go through it. You guys are probably
tired of hearing this, but I just don't like the idea of a rotating shaft
penetrating my hull.
ALL of the through hulls on my sub will have a ball valve directly on
the penetrating nipple. Now if your linkage had a socket connection at the point
where it enters the hull, so the linkage could be pulled and the valve shut off,
I'd be more inclined to feel safe with that. Even a small leak at 500 feet could
send a dangerous water jet pouring into the sub. Definitely enough to hurt you
if it squirted into you.
How about an electrical through hull, connected to an electric valve? Or
how about a hydraulically operated valve. This would only need a very small
through hull, ( like 1/4 inch ?) connected to a simple hand pump. Each of
these can have a ball valve where it enters the hull.
My first choice is of course just running the air into the sub, manifolding
the lines together so only one "exit" through hull is needed, and with valves
and piping, pushing the air where you need it. Granted, lots of valves,
but absolute security as far as leak control. You would also be able
to direct air/water with more options when all the piping is accessible from
inside. I know a small drip isn't going to be a big problem, and leave you with
plenty of time to surface and do repairs, but what if
a catastrophic failure of just one seal happens.....You're dead
!
If you want to vent faster, well, you just gotta put in a bigger valve. A 1
inch valve has .785 square inches....a 2 inch valve has 3.14 square inches.....a
3 inch valve has over 7 square inches. You see where I'm going with this? A
hole is a hole, and with a valve to shut it off, you can control that
hole. It doesn't really matter what size it is. If the seal
blows in, and you have no valve there, you're dead. The cost
difference between a 1 inch valve/piping and a 2 inch valve piping isn't that
big. The work is the same, and it takes a little more room for bends and valves,
but the safety is very much improved. An extra valve here and there is cheap
insurance.
Sorry if I sound repetitive, but why make something that COULD be a
problem, when a simpler, safer solution is available. Frank D.
PS. I heard a good quote yesterday.....Don't critisize someone until
you've walked a mile in their shoes. That way, when you do, you're a mile away
from them, and you have their shoes! (Just to end on a light note.)
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