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Dan,
I'm on the same page as you. A 1
atm might be more expensive, more work, and generally more hastle to get tested
and working to standard.
....but.
once all that is done, you have a sub
that is safe to operate and not so "finnicky". I know I don't want to mess
with internal pressures and all that ambient stuff to worry about. To
me, ambient designs just seem like wearing big, cumbersome SCUBA gear.
I want to get in, dive to 50, 100'...whatever, enjoy what I'm doing,
surface as fast as I want, blow the hatch, cruise around, dive dive
dive.... Dive tables and worrying about internal pressures is not for
me. I'll spend the time in the shop welding.
Myles.
----- Original Message -----
Sent: Wednesday, November 16, 2005 7:26
PM
Subject: Re: Re: [PSUBS-MAILIST] Re:
Variable Ballast Calculations, Bill
Maybe I'm missing something.
Why all the fuss to build a sub that you need to
be careful not to surface all the way before shifting air from one place to
another.
First of all you can't control your depth that
easily. You don't always have the option of stopping your assent as 33
feet or where ever as a diver does. Some times you hardly know your
moving until you see the surface right there a foot above you. If you
put in safety valves to release any positive pressure you had in the hull in
case you rise to close to the surface and they release air, you
won't have the air to put in the tanks later on.
Since your building a pressure hull anyway, why
not use 1/4 inch plate instead of 3/16, or whatever. Build a one
atmosphere sub. You'll have a safer sub and a simpler sub to
operate with no need to take extra precautions with hatches,
viewports, and valves for an internal positive pressure
situation.
Please explain if I'm missing
something.
Dan H.
----- Original Message -----
Sent: Wednesday, November 16, 2005
12:14 PM
Subject: [Norton AntiSpam] Re:
[PSUBS-MAILIST] Re: Variable Ballast Calculations, Bill
On 11/15/05, Akins <lakins1@tampabay.rr.com> wrote:
... So imagine yourself at only 2 atm or 33
ft of pressure on your body, but actually diving to 99 feet and
staying for a maximum of 205
minutes without any deco! Wouldn't we scuba
divers love it if we could do that! A
hybrid like this would allow us to. I would say it would be worth the
extra trouble. What do you think Paul?
I'm with you Bill, sign me up for a pressure-limited cabin!
But I am starting to wonder why not just limit it to 1atm. :-) Once I
start thinking about building a crew compartment that handles 3atm and maybe
1atm of overpressure, well it seems like why not just build a traditional
1atm boat? But this hybrid sub design is fascinating and I'd like to
see it sketched out.
Now I would like to know what hull strength I
would need for a 1 atm pressure vessel to withstand 2 atm of outside water
pressure. Probably have to build it with a safety factor for 3 or so
atm
just to make sure it was safe. I wonder what
steel thickness I would need or if a 1/2 inch thick kevlar wing tank
would withstand 2 or 3 atm with 1 atm inside it? Any help here
fellas?
Well that's the rub, isn't it? My feeling is that many
engineering types would be comfortable designing something for themselves to
use but would be pretty hesitant to give someone else recommendations on
pressure vessel details. Is that right? Sorry I haven't been on
this mailling list long enough to know what's been done and discussed in the
past and I didn't find anything on PSUBS.org or by searching it with
Google.
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