|
Hi Brian,
Unless you are building a sub to go really deep,
you should be always adding lead to enable
you to sink. ie the hull won't be substantially
thick enough to give you sufficient weight to sink.
So just add lead untill you are slightly negatively
bouyant, then you will need very little air to
attain neutral bouyancy. If you are adding a large
deisel motor & that is making you too heavy
you can add syntactic foam for
bouyancy.
The deeper you go the less change there is in the
air volume so less need to compensate.
Alan
----- Original Message -----
Sent: Friday, March 04, 2011 6:56
PM
Subject: Re: [PSUBS-MAILIST] riding the
bubble
I have a lot of ballast volume, I think around 150 cu ft. . I was
planning on flooding my ballast tank completely and then be neutral
buoyant, but I think I'm going to be a little bit heavy. I won't
really know until I do some tests. If I am heavy there are some options
I can explore to remedy the situation. In any event if I am
too heavy I could simply not vent any more air out. However,
if I did vent out all my air I may be way too negative an that could
be problematic.
On riding the bubble, I always though that is was very difficult to
maintain a constant depth because you're always fighting your upward or
downward momentum, and with a changing volume of air it was hard to keep
things level.
Brian
On Thu, Mar 3, 2011 at 9:01 AM, <vbra676539@aol.com> wrote:
Lots.
Aquarius, for instance, has a small tank forward of the fwd. MBT which is
utilized for trim. No hard tanks or internal VBTs. Gamma uses a small bubble
in the mains, too, also with no VBT. The Nektons have done lots and lots of
dives that way.
Vance
-----Original Message----- From: ojaivalleybeefarm@dslextreme.comTo:
personal_submersibles Sent: Thu, Mar 3, 2011 6:20 am Subject:
[PSUBS-MAILIST] riding the bubble
Hi All,
Does anyone have experience with trying to control a sub with primarily a
soft ballast tank. I know there is a point where the air becomes
compressed to a point where one starts to lose buoyancy and then you're
headed to the bottom but can it be controlled if you stay slightly positive
and then use your trusters to keep you down?
&n
|