I think we can define "minor" as "very small", which is what the pressure difference is at the surface where the Hunley took on water to submerge.
I think I understand the basis of your theory that the Hunley was a hybrid; but to me the internal pressure variable caused while flooding the tanks at or near the surface seems too insignificant to offset the fact that she was, in most respects, a 1-ATM submarine designed to protect the crew from pressure at greater depths. Ambient subs do not offer the crew anything near that level of protection from pressure, so to me, the Hunley seems to be a 1-ATM sub.
But we're all entitled to an opinion, and while I might not be able to fully agree with yours, I do respect your right to it.
Hi Jim.
How do we define "minor"?
True "IF" the Hunley had been a COMPLETELY ambient sub they could have opened the hatch and escaped if the conning tower glass had not been shot out by a union rifleman as the archaeologists claim is possible and water either entered the hull that way or from
the Hunley having her hatch open when she attacked and too much water came in before they closed the hatch and they submerged. They actually do not know for sure what swamped her, but it is a fact that when they found her the glass in the conning tower had
been broken out, possibly by a union rifle bullet.
But then again the Hunley was not a COMPLETELY ambient sub. She had attributes of being both ambient and pressure hull. At different times the Hunley was acting as ambient, at other times she acted as a pressure hull. When her ballast tank valves were
closed she acted as a pressure hull. I am sure they would have closed the ballast tank valves AFTER they submerged right after sinking the Housatonic, so she would have been acting as a pressure hull at that time and therefore they would not have been able to
open the hatch to escape.
Once again, the Hunley took water into her hull INTERIOR like MANY common ambient subs do to submerge. She had her atmosphere compressed like MANY common ambient subs do by the water pressure coming into her. Although she did not have
compressed air tanks, her compressed atmosphere ALLOWED them to pump the water out of her or else there would have been air loss for the water to be there in the first place and therefore pumping out water then would have been impossible since that would have
created a vacumn. . She was only a 1 atm sub when her ballast tanks were totally dry which means she was not a 1 atm sub all the time. And finally, had she had compressed air tanks and left her ballast tank valves open she would have been a COMPLETELY
ambient sub, so she was only ONE item away from being a TOTAL ambient sub. Just compressed air tanks were all that was missing for her DESIGN to be COMPLETELY ambient. Do you still think she had more in common with a 1 atm pressure vessel than an
ambient sub? She was both at different times. A hybrid as I have said.
Kindest regards,
Bill Akins.
----- Original Message -----
Sent: Monday, June 13, 2005 7:29 AM
Subject: Re: [PSUBS-MAILIST] inaccurate terms & inescapable that the Hunley was a hybrid.
Please correct me if I'm wrong:
In a 1-ATM sub, the pressure inside the hull is about the same as it is on the surface, give or take minor variables of the type already described.
In an Ambient sub, the pressure inside the hull is about the same as the outside water pressure at any given depth, more or less.
So it seems to me the Hunley was basically a 1-ATM sub (with a pressure hull) that might have had some of those "minor variables" in pressure due to the open ballast tank design.
If the atmosphere were at ambient pressure inside the hull, wouldn't the crew have been able to open the hatch and escape? That's something three perished crews were apparently unable to do. And that's why, to me, the Hunley seems much closer to being a 1-ATM sub than it does an Ambient sub.
Does this make sense to anyone?
Jim
Ian Roxborough <irox@ix.netcom.com> wrote:
On Mon, 13 Jun 2005 02:29:36 -0400
"Akins" wrote:
> 1. An ambient sub allows water to enter its INTERIOR to dive.
> The Hunley did this with her open top and open to the hull
> interior ballast tanks.
This is wrong, any sub which has VBT inside the pressure hull could
meet this discription. And you you could build an ambient sub which
doesn't let water into it's interior, so this seems irrelavent.
> 2. The water pressure entering the sub's interior when an ambient
> sub dives, compresses the atmosphere in the sub's interior just
> as it did with the Hunley.
Yes, there would be a minor internal pressure increase from venting
the tanks. (Also note water does NOT have to enter an ambient sub's
interior for it to dive.)
> 3. An ambient sub uses air to force water out of the sub! 's
INTERIOR
> to surface, just as they did with the Hunley.
I don't believe this for a minute. How did they use air to force water
out? Sailers breaking wind maybe? The bits about the Hunley's operation
I've read about claim that they used a HAND PUMP to empty the ballast tanks.
Well there you go, you got 1 out 3.
There where a few other error in your text , but I can't bothered
point them out at this point - most of them have been address in my
other emails, as have most of your questions.
I'm sorry you don't understand the ambient vs 1ATM, and I'm sorry I can't
explain it in a way you can understand. But I don't want to continue this
exchange, I feel like I'm banging my head on a brick wall. Maybe somebody
else has some way of putting that's better.
Some of your claims of what I've said and defined are VERY inaccurate
(in fact the complete opposite of what I said), this is not very nice.
I will not resp! ond to
any more of these "Hunley is ambient/hybrid" emails.
Ian.
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