|
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 ************************************************************************
************************************************************************
************************************************************************
The personal submersibles mailing list complies with the US Federal
CAN-SPAM Act of 2003. Your email address appears in our database because
either you, or someone you know, requested you receive messages from our
organization. If you want to be removed from this mailing list simply
click on the link below or send a blank email message to: removeme-personal_submersibles@psubs.org Removal of
your email address from this mailing list occurs by an automated process
and should be complete within five minutes of our server receiving your
request. PSUBS.ORG PO Box 311 Weare, NH
03281 603-529-1100
************************************************************************
************************************************************************
************************************************************************
************************************************************************
************************************************************************
************************************************************************ The
personal submersibles mailing list complies with the US Federal CAN-SPAM Act
of 2003. Your email address appears in our database because either you, or
someone you know, requested you receive messages from our organization. If
you want to be removed from this mailing list simply click on the link below
or send a blank email message to: removeme-personal_submersibles@psubs.org Removal of your
email address from this mailing list occurs by an automated process and
should be complete within five minutes of our server receiving your request.
PSUBS.ORG PO Box 311 Weare, NH
03281 603-529-1100
************************************************************************
************************************************************************
************************************************************************
|