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Brian-
My through-hulls all have valves. Cheap easy insurance. Even
electrical. A gate valve can cut wire... just in case.
I saw Deepflight a couple weeks ago and heard nothing about
"decommissioning". I suspect someone's confusing it with the embolism machine,
Wet Flight.
Peter "1 atm" K
Paul,
What is
this about deepflight being "decommisioned" ? Do you mean
that they are just not running the sub anymore or what?
My sub is loosely based on deepflight's
design.
Brian
----- Original Message -----
Sent: Monday, November 07, 2005
10:01
Subject: Re: [PSUBS-MAILIST] Re: Some
issues
Joe,
So mainly there's that one unpleasant reality of
submerging a volume of air: it has a lot of buoyancy! 63 lbs/cf of
seawater adds up pretty quickly into a too-heavy-to-trailer submarine.
And the fact that you're considering an ambient sub doesn't really help your
displacement, right? The construction is easier in that you don't need
a 1 inch thick pressure hull but unfortunately the boat needs to weigh just
as much as if you did.
I've liked the DeepFlight two person
sub (model 502) which has a separate pressure compartment for each
occupant. It really helps to reduce the cabin air volume but it also
locks you into a small space which is very different from your original
dream. And does anyone know why it's been decommisioned now? I
think they built that one for their pilot training program. Maybe they
didn't get many people buying the training? http://deepflight.com/subs/dfa.htm
What
we need is a clever trick like that used in water ballasted sailboats - just
fill the tanks before sailing to increase your displacement. But of
course that doesn't help a sub, unless you look at flooding most of your
crew compartment while diving. Maybe you need a sand ballast
keel system. :-) Run along in shallow water scooping up sand
until you've got the two tons or so that you need...
take
care-
Paul
On 11/7/05, Joseph
Perkel <joeperkel@hotmail.com>
wrote:
Rick,
Thank you for the info and support. With further research my initial
exuberance has now been tempered a bit by reality. Something I am
quite sure all of the newbie's must experience at the beginning.
My main issue at the moment is material density and it's effects on
buoyancy and ballast requirements, in this case of course, ply composites
for this ambient design. Lead is my friend in this case but still there
are some hurdles to overcome.
Pat Regans boat has a "proper" pressure hull underneath but it is tiny.
I want a compromise between size and the necessity of having to be
launched by crane, so my belief is that an ambient design could be light
enough to be trailer able and still give some reasonable interior volume
but therein lies the technical hurdles.
I am looking at aluminum again as I did last year for a surface yacht
(see the attachment for the quote)...outrageous! This could quite possibly
be riveted as in the old 'R" boats but that of course presents it's own
problems. One would use lighter gauge alloy than what you see in the quote
so welding would not really be an option.
I must admit though all these technical hurdles are quite fun to try to
figure out.
Joe
From:
"Rick and Marcia" <empiricus@telus.net
>
Reply-To: personal_submersibles@psubs.org
To: <
personal_submersibles@psubs.org>
Subject: Re:
[PSUBS-MAILIST] Some issues
Date: Mon, 7 Nov 2005 02:47:37
-0800
Hi, Joe - 560 cu.ft. is about 35,800 lb. of
buoyancy. That's quite a bit. :-)
Once neutral buoyancy was achieved, dynamic control
(i.e.: planes) maintained depth. The HP air was more than
enough to get the boats back up in case of planes failure or even
partial flooding.
As far as limiting your posts to a time when
"flatter curves" would be appropriate, keep in mind that, as far
as I know, our archives are listed by date and by thread, not by key
word search. As long as we, the "pro's", neglect to label our
subject headings appropriately, please feel free to ask all the
ridiculous questions you want.
As far as archival searches are concerned, I'm sure
Ray would love to spend thousands of hours (!?) labeling each and every
post from the past six or seven years according to design ethic, systems
analysis, materials science, commercial suppliers, fluid dynamics, parts
availability, hydrodynamics, conceptual rationale, human engineering,
etc.
I hope everyone realises that, besides being
impossible, the only thing almost as hard as codifiying the archives is
finding the proverbial needle in the haystack.
Again, as above, please feel free to ask all the
ridiculous questions you want.
Rick
Vancouver
----- Original
Message -----
Sent:
Friday, November 04, 2005 8:02 AM
Subject:
[PSUBS-MAILIST] Some issues
Group
I am discovering material density issues
along with the air supply, buoyancy and control issues inherent to a
dry ambient design. In that regard the following excerpt is from the
NAVPERS manual for air systems aboard WWII fleet boats, specifically
the 3000 lb system.
2A3. Air banks.
Each of the five air banks consists of seven flasks, with the
exception of the No. 1 air bank, which has eight. Each flask is
provided with a drain valve. The total capacity of the air banks is
560 cubic feet. The No 1 air bank is located inside the pressure hull,
with four flasks in each battery compartment. The other four air banks
are located in the main ballast tanks
The 560 total cubic feet caught
my eye and I wondered if this could possibly be correct? Since
this is equivalent of seven 80 SCUBA tanks on such a large
vessel to blow tons of seawater. I understand the concept of the
low-pressure blowers on the surface and would employ that feature. But
I am still trying to make sense of buoyancy tankage and air supply
issues for a dry ambient design.
Incidentally, I have been dealing with
post Hurricane issues (somewhat "irritating") but was distressed to
see the recent posts, as the animosity was palpable. If as a "new guy"
some of my previous posts were somewhat "irritating" to some, I did so
in ignorance of the culture within this community however, I cannot
offer any apologies for this reason. Although I am a neophyte in this
field, I am an expert in others where the basics were once complex
issues to me.
That having been said, I will respect
the house "rules" and limit my posts to those times when the learning
curve has flattened a bit as above.
Thank You
Joe ************************************************************************
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