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Bill,
I'm glad my brain is on the right page
here. I guess my next question would be, can those valves and piping
function the same as the compressed air system ? What I mean is, do I
install my piping at the bottom of the ballast tank, route the pipe up to the
conning tower, install my valve, and then route the piping back to the bottom of
the ballast tank so that the valve to control the inlet of water is in
a reasonable and convenient location (in the tower). Will the water flow
in this circuit of going up to the tower, and back down to the tank ? I'm
assuming it will since it will be under a bit of pressure and increasingly so as
the sub takes on water and decends. I'm not sure how you would gain
control of the valve letting in water otherwise.
Myles.
----- Original Message -----
Sent: Sunday, October 30, 2005 12:17
PM
Subject: Re: [PSUBS-MAILIST] Hard / soft
ballast tanks.
Hi Myles.
Yes, you are right. By installing a valve you
stop the water from being able to compress the air in the tank as you
decend
as Brian said. Then you have a hard ballast
tank.
Bill.
----- Original Message -----
Sent: Saturday, October 29, 2005 5:56
PM
Subject: Re: [PSUBS-MAILIST] Hard /
soft ballast tanks.
Bill,
To make a "soft" tank into a
"hard" tank, do I simply need to install a valve to let in the water as
opposed to just an open flood hole ? This valve, of course, would keep
the water from coming in while the sub gains depth (pressure).
Myles.
----- Original Message -----
Sent: Saturday, October 29, 2005 1:54
PM
Subject: Re: [PSUBS-MAILIST] Hard /
soft ballast tanks.
Ah yes! Brian is right Myles. I totally
forgot about the compression of the air by the water at depth in the open
bottom ballast tanks. That is another reason to use non open to the water
hard ballast trim tanks
to adjust the attitude and neutral buoyancy
of the sub at depth.
Bill.
----- Original Message -----
Sent: Saturday, October 29, 2005
9:20 AM
Subject: Re: [PSUBS-MAILIST] Hard /
soft ballast tanks.
The reason is that as the air gets
compressed ( in a soft ballast) as you descend the volume shrinks
and you have less lift, making you sink faster. This gets you into
a situation where you are constantly readjusting to maintain a steady
accent or descent. I believe this is all in the busby book which
can be bought on the psubs web store.
Thank you
Brian
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