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That's what I was kind of wondering about. Much playing is to
come.
Dean
p.s. I am real curious how deep a household light bulb can go
ehheh
In a message dated 7/24/2009 11:22:29 A.M. Central Daylight Time,
vbra676539@aol.com writes:
I would
resist the temptation as the sub will be hard to handle in the vertical axis
with that much ambient air. It will work, sure, but I'd plan on weights for
most of that payload. Use shot bags if you can. They pack wherever you need
them and are much easier on the knuckles than sash weights or
whatever.
Vance
-----Original Message-----
From:
Recon1st@aol.com
To: personal_submersibles@psubs.org
Sent: Fri, Jul 24,
2009 9:18 am
Subject: Re: [PSUBS-MAILIST] water level
Thanks Vance only time will tell.
I was thinking of air. For instance if I decided to take a
passenger down after I had already
weighted for just me. Could it be as simple as just adding enough
air for the passenger
weight?
In a message dated 7/24/2009 4:45:12 A.M. Central Daylight Time, vbra676539@aol.com writes: How
much what? Air? If so, I'd trim to keep the bubble smallish, as that would
be easier to control with shallow water depth changes. Good going on the
dive prep. We'll look forward to a report. Good
luck.
Vance
-----Original Message- ----
From: Recon1st@aol.com
To: personal_submersibles@psubs.org
Sent:
Thu, Jul 23, 2009 2:05 pm
Subject: Re: [PSUBS-MAILIST] water
level
Vance I have not installed a VBT. I am planning on just riding
the bubble.
Are there any limits to how much you could put in a K350 glass
MBT? I guess I can
not think of a reason, but then I am not the brightest bulb on
the tree.
Dean
p.s. I am a week to two from getting wet
In a message dated 7/23/2009 12:56:34 P.M. Central Daylight Time, vbra676539@aol.com writes: Variable ballast is there to fine-tune your dive weight. It is
useful when you dive with changing payloads, or transferring water from
front to back for trim. Generally with a small sub you can do all this
beforeha nd. Mostly it gives you more flexibility. And the mushroom valve
plans are in the works, guys. I promise.
Vance
-----Original
Message--- --
From: Brian Cox <ojaivalleybeefarm@dslextreme.com>
To:
personal_submersibles@psubs.org
Sent:
Thu, Jul 23, 2009 12:14 pm
Subject: RE: [PSUBS-MAILIST] water
level
Why is
it advantages to know the water level in your ballast
tanks?
Brian
Don't you know a guy that
could hook you up with one of those, Vance. ;}
BDH
To: personal_submersibles@psubs.org
Subject:
Re: [PSUBS-MAILIST] water level
Date: Wed, 22 Jul 2009 08:30:01
-0400
From: vbra676539@aol.com
You have
just described the VBT system in a DW 2000. I'd do that myself if I
could find the right hand pump.
Vance
-----Original
Message-----
From: David Bartsch <dbartsch2236@hotmail.com>
To:
personal_submersibles@psubs.org
Sent:
Wed, Jul 22, 2009 3:52 am
Subject: RE: [PSUBS-MAILIST] water
level
#AOLMsgPart_2_0971fa38-fdaf-415e-b4dd-35e0027bdbe3
#AOLMsgPart_2_bcd6b61a-46bb-47f4-a055-be80a9853fc3
#AOLMsgPart_2_7728106f-7db4-46b0-83ee-e72108154fa8 .ExternalClass
#EC_AOLMsgPart_2_6beede8c-9326-411c-91d7-d42cc54c8504 .EC_hmmessage P {
PADDING-BOTTOM: 0px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; PADDING-TOP:
0px}#AOLMsgPart_2_0971fa38-fdaf-415e-b4dd-35e0027bdbe3
#AOLMsgPart_2_bcd6b61a-46bb-47f4-a055-be80a9853fc3
#AOLMsgPart_2_7728106f-7db4-46b0-83ee-e72108154fa8 .ExternalClass
#EC_AOLMsgPart_2_6beede8c-9326-411c-91d7-d42cc54c8504 BODY.EC_hmmessage
{ FONT-FAMILY: Verdana; FONT-SIZE: 10pt} What if
one connected a check valve in a pipe near the boats hull (with the flow
aimed outward) and used a hand operated piston pump with long enough
handle to apply enough force on a short stroke thin diameter piston to
expell water against outside sea pressure while at depth to reduce the
amount of water contained in this tank? When the handle is again drawn
back, additional water from this tank could enter this piston. Once
finished, isolation valves could be closed to prevent additional water
from
transfering.
&nb
sp; David Bar tsch
> Date:
Tue, 21 Jul 2009 23:09:04 -0700
> From: cast55@telus.net
> To: personal_submersibles@psubs.org
>
Subject: Re: [PSUBS-MAILIST] water level
>
> Don't forget
to account for the possibility of having to adjust=2 0in the
>
other direction - i.e. adding buoyancy to compensate for reduction in
> volume as the hull deflects at depth. For a small, shallow sub,
this
> won't be significant, but as depth and the size of vehicle
increase, the
> change in volume may become significant.
>
> -Sean
>
>
> ShellyDalg@aol.com wrote:
>
> Hi David. A sight glass is the easiest to read on a tank, but it's
not
> > much use to us for variable ballast tanks. The reason
being, it would
> > need to be able to withstand a lot of
pressure and they are hard to
> > keep clean.
> > The
variable ballast tank, often called "hard ballast tanks" are
>
> pressure vessels that will withstand being opened at depth to
adjust
> > buoyancy when you're at your deepest operating
depth, plus what ever
> > safety factor you wanted.
>
> Although a simple "trim tank" can be used to adjust buoyancy at
> > or near the surfac e, and then valved off with a set
amount of water
0A> > ballast in i t, no adjustment can be
made when you're deep unless the
> > tank is able to withstand
the pressure at your deepest dive.
> > Once you open a hard
ballast tank at depth, and close the valves
> > to maintain
that level of water, the pressure is "locked" into that
> >
tank. Then, when you g et back to the surface, you release that
>
> pressure by opening the valve and letting the pressurized bubble
blow
> > out the tank.
> > If you want to adjust for
more buoyancy at depth, due to changes
> > in salinity or
maybe you picked up something from the bottom, you must
> >
blow high pressure air into the tank until the correct water volume is
> > achieved, then close the tank off to maintain that level
of water.
> > Knowing just how much water is in your hard
ballast tank is a
> > problem.and one that I considered a
while back. The "sight glass"
> > method would require a very
heavy walled clear tube with valves in
> > case it developed a
leak. I'm not sure how risky that would be if it
> > blew out
but it should be fairly easy to build.
> > Another method would
be to use a "see through"tank. There's a
> > filament wound
fiberglass/composite tank available called "Lite"
> > propane
tanks and they come in a few sizes, the largest being about 8
>
> gallons for use on warehouse typ e propane fork lifts. These will
> > withstand 250 psi ( with a safety factor) and you can tell
at a glance
> > how much liquid is in it. They come with
threaded fittings molded in,
> > and a metal "basket" that
protects it from bumps. They run about $300
> > each I
think.
> >=2 0I'm leaning toward the see through tank right
now, and have a
> > place inside designed for it. That only
gives me 64 pounds of variable
> > ballast though. ( 8 gallons
at 8 pounds per). It would be nice to
> > have more
adjustment, like if you found something and wanted to pick
> >
it up and bring it back to the surface. It's possible to blow a little
> > air into the "soft" ballast tank for lifting purposes, but
that bubble
> > will become much larger as you near the
surface, making it difficult
> > to control buoyancy as your
depth changes.
> > Most psubs have a few lead bricks that get
adjusted at the
> > surface for how much payload you're
carrying on any given dive, like
> > an additional passenger,
some added machinery or cargo, or what ever
> > will change
the total weight of the sub.
> > Buoyancy is based on water
displacement and total weight in water,
> > so when you add a
passenger, you must ask them ho w much they weigh and
> >
adjust the lead bricks according ly to achieve " neutral" buoyancy. A
> > hard ballast tank is required for small changes in
buoyancy like
> > salinity and temperature changes. For
instance, if I launch my boat in
> > the harbor, which is a
river mouth with a small amount of dissolved
> > salts, and
then motor out into the ocean where the salini ty level is
> >
higher, the sub is displacing more weight ( the water is saltier so is
> > heavier ) so additional ballast must be added to maintain
"neutral. It
> > runs about 4% from fresh to salt water while
temperature can add about 1%.
> > These are percentages of
"displacement" or the total volume of water
> > displaced by
the submarine. Several "high dollar" subs I've read about
> >
have as much as 240 pounds of "variable" ballast. Not sure how they
> > achieve that, but it's useful if you plan on bringing back
samples or
> > stuff from down deep.
> > Frank D.
> >
> >
------------------------------------------------------------------------
>
> What's for dinner tonight? Find quick and easy dinner ideas
> > <"http://food.aol.com/dinner-tonight?ncid=emlcntusfood00000009>;
for any
> > occasion.
>
&g t;
>
>
>
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