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Hi Carsten and Paul and everyone.
Carsten, I have a few questions I wanted
to ask your advice on, about this hybrid ambient/1atm sub idea I
have.
You wrote..."If
you drive dynamicly such a partley ambient boat close to the surface
the hatch will pop up.. Or you have to design an expensive double acting bajonet hatch. " (1). If you filled your hybrid ambient/1atm sub's
ballast tanks as much as they could be filled at the surface,
and the sub was under with just the tower
unsubmerged, (like in the Hunley) and then you CLOSED the water
inlet
valves going to the ballast tanks, so no more water
or pressure for the moment could come in, and next completely
submerged
using only forward motion and the dive planes,
wouldn't that put enough pressure against the hatch, from the outside water
pressure, to keep
it from popping up, especially since you CLOSED the
ballast tank's inlet valves so no more pressure could come into the hull
and
then when you were submerged a few
meters the outside water pressure would keep the hatch shut and THEN you
could
reopen the water inlet valves to further fill the
tanks. Would this work Carsten? Before you answer though, go to this
link....
http://home.att.net/~JVNautilus/Hunley/reconstruction.html
now move your cursor over the sub and when the ballast tanks
appear and highlight, click on them and then in the
popup window scroll down and read " Displacements and Capacities", and
also
"Analysis" where it explains the sub went under
always slightly buoyant (like the Holland) because they could not fill their
tanks FULLY at the surface
(they could only fill about half full)
until under a short distance, and it says
the sub was pushed under using her dive planes only until
superior water pressure allowed water to
fill the tanks more when submerged deeper. So
when she initally dove, with her ballast tank water
inlet valves open, she was acting as an ambient sub but her hatches did not pop off.
You wrote..."If
you install a overpressure vale - you will lost the air you later
need to pump the tank out.. " (2). Carsten. I assumed the only time there
would be an interior overpressure problem would be in accending, so I ask your
advice on
how these situations would work.
a. You shut off your water ballast tank inlet
valves at 2 atm. You continued to dive forcing the sub under with only her dive
planes to 4 atm
because the sub did not want to go past 2 atm in
depth because it was equalized and neutrally buoyant at 2 atm, so now
you decide to
surface from 4 atm with a 2 atm hull interior. If
you didn't force the sub up with your dive planes wouldn't she accend on her own
and once she reached
2 atm wouldn't she become equalized to the now 2atm
outside water pressure and become neutrally buoyant and hang there at 2 atm
without surfacing?
b. You have done everything in (a.) and now you
want to accend to the surface from 2 atm. with a hull that is also 2
atm.
You have two choices to accend. You either pump the
tanks out and accend and have no overpressure
problems because your atmosphere expanded
to 1 atm again, or you use the dive planes only and accend and while doing so forget to
pump your air down and are just powering up using
the planes.
If I installed overpressure valves that would sense
when the inside air pressure was greater than the
outside water pressure so they would automatically
open my ballast tank's inlet valves to
allow the water to be pushed back out and the atmosphere to expand again without me losing any air, would that work?
I never intended to exhaust the air out of the sub
by using an overpressure valve, but for that safety overpressure valve to automatically open the ballast tank valves
(in case I forgot to) and let the expanding air
pressure from accending push the water out of the tanks.
Would this work Carsten?
You wrote....."Small note : According to the class rules for manned submarines
you
should able to blow the soft tanks at the surface 4 times and the hard tanks at the maximum operation deep 3 times... Hmm.. 4 times .. maybe the pilot should wear a Astronauts-suit ? (3). I am unaware of class rules
for non tourist subs here in Florida. When I called the
authorities here about registering a submarine they
told me it would be registered as a normal boat as long as it
had some kind of motor. That appears to be all I
have to do here is register it as a boat.
But if I DID have to blow tanks 3 and 4 times
at the surface I could carry air tanks to do so,
but would not ordinarily
have to use them because I was regenerating my
ballasting as Paul put it, that way I would have
the air tanks
if I needed them but would not ordinarily have to
use them and therefore be less
dependent on ever running out of ballasting air.
Would that work?
You wrote...."and at 2 bars (20m or 60ft) a diver has a "zero" bottom
without decompression of about 40 minutes. At 3 bars (30m or 90ft) of 15 minutes. At 4 bars of 5 minutes." According to my P.A.D.I. dive tables, there is a
slight technical difference between an ata (also known as atm)
and a bar, but it's so minor that for
diving applications it is disregarded because they are almost the
same.
Basically BAR = ATA or ATM.
According to P.A.D.I. dive tables 1
bar/atm is at the surface, 2 bars is 10m or 33ft, NOT (20m or
60ft).
and 3 bars/atm is 20m or 66ft NOT (30m or
90ft).
My P.A.D.I. dive tables read that I can
dive to 2 bars (33ft) for a maximum of 205 minutes without having to
do
any kind of decompression. It reads that I can dive
to 3 bars (66ft) for a maximum of 40 minutes without having
to
do any decompression. It reads that I can dive to 4 bars (99ft) for a maximum of 20
minutes without having to do any
decompression.
So you can see that if I pressurized the hybrid
sub's interior to 2 atm/33ft, and then closed the ballast water inlet
valve
and then further dove her to 4 atm forcing her
under with my dive planes, I could stay at a
depth of 4 atm/99ft, for 205
minutes in my hybrid sub as compared to only 20
minutes in a typical ambient sub because my
interior is pressurized
to 2 atm/33ft while outside it is 4 atm/99ft.
This is not me saying this, this is the
official P.A.D.I. diving tables saying this.
Could you please check your figures for
accuracy that you posted on those depths and times again
Carsten?
Finally, I am asking your
opinion Carsten, if I did all the above things I wrote in
this post.....(automatic overpressure valves to
open the ballast inlet valves, air tanks available even if not normally
necessary,
hull built to withstand at least 2 bar/ata/atm
water pressure with only 1 atm inside it),..... wouldn't this
make a safe and workable ambient/1atm hybrid design
that would enable you to obviously dive to 4 atm
for 205 minutes instead of 20 minutes without
having to decompress at all?
Sorry this post is so long. There was just no short
way to explain and ask these things Carsten.
Your answers and advice would be greatly
appreciated. I highly value your advice Carsten.
Thanks,
Bill.
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