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Brent,
I have had 1031 dives in the submarines Kraka and Freya -
but I have had only one offer to bye Kraka and it was just 100 US doller - so
quite clearly I dont qualify for the new group.
However - I would love to know the answer to the acrylic
question since I have had vindows water jet cut for the UC-3.
Best regards,
Peter
----- Original Message -----
Sent: Wednesday, August 22, 2007 11:10
AM
Subject: [PSUBS-MAILIST] Open
Discussion's Allowed in PSUB's Mailing List
Jay,
I've
heard a number of times in the past how some choose to be blunt with new
comers to the group and/or amateurs in the field of subs. I think one can be
straight forward with important information in a way that doesn't come off as
rude or disrespectful to those that lack or one believes, lacks there
expertise and experience in that area. This group is primarily for, and always
has been for learning and exploring of how to design, build, and safely
operator ones own sub through open discussions and sharing of information
and/or hardware with amateurs and experts alike.
Perhaps there is a need for a
new forum for a select group of individuals that don't wish to deal with
teaching and/or reading what amateurs are talking about, and want only very
serious factually accurate post in there group. To join this group one would
need to have done more then 500 dives in a sub worth more then $100,000,
and/or been in the submarine field professionally for more then ten years,
and/or they have a doctorate in a related field.
I've seen discussions more or
less shut down by a type of intimidation, on subject matter that some were
tired of discussing and/or not interesting in. I think that is wrong for this
group, and that if one doesn't want to read and/or respond to subject
matter(s) they are tired of and/or not interested in, it is very easy to just
delete all messages with said subject matter and/or content. We will hopefully
always get new comers into this group with basic questions and great new
insights to old problems, and they shouldn't be required to read and
understand the whole PSUBS archive before they post a question to the group. I
spend a massive amount of my time researching subs and related data, and I
barely have time to read and try to fully understand the current emails from
the list, let alone read and understand the whole archive. Perhaps I'm slow,
and if that's the case then I'm ok with that. Those are the jeans my parents
gave me, and I'm happy to have what I got.
I once posted a question about
whether or not I needed to anneal acrylic, if I only cut it with a aqua jet
cutter. Since I had reason to believe the aqua jet cutting process wouldn't
put any heat stesses on the acrylic that would need annealing to take care of.
I did a PSUB's archive search before I posted my question. Along with the
speculation that my question wouldn't be answered in a great but slightly
dated $200 book, (I hadn't aquired yet) since I believed aqua jet cutting of
acrylics was basicly a new process, I asked the question. I got the
patt answere of that, all acrylic needs to be annealed after cutting, in such
a way I couldn't tell if they really knew that, with regards to my question,
or if they just didn't want to deal with it. Then they shut the discussion
down by intimidation by being an expert in the group (most
don't want to perturb) and stated that the topic was basicly old and
dead.
When I said, " How about
an non educated guess. ; )' " that was tough and cheek
Jay.
In my opinion, I'm
reasonably well educated and practiced in a fair number of areas, and I worked
very hard to get to where I am today. I have so many skill sets and interest
it's hard to keep on track most days. Almost everything is of interest to me.
Many far more negative people then you, have tried to get me to hide in a
corner because I've chose a very different path then them selves. You can see
the result.
I would guess that
for most of us here in this group, this is a passionate hobby of there's.
Hobby's are supposed to be fun and enriching, not negative things that suck
the life out of you.
We have
talked about using the KISS (Keep It Simple Stupid) principle for sub
design. I agreed with you that one should do that if at all possible. How
simple is simple? The fact is that most subs in order to have the
capabilities one wants them to have, can't have all aspects of there design
be simple.
Just recently
you gave me a link for a book called Simplicity in Design, as a response to
one of my post. Again I ask, how simple is simple? It's all subjective to ones
brain power and understanding of how things work. What makes art beautiful?
It's mostly all in ones head.
During that same period in
your post in response to mine, you made it sound pretty clear that I
shouldn't post to this group until I read and understood the ABS manual and
reams of other technical manuals, science articles, and books relating to sub
design and operations. If I and or others were required to do that, then it
would likely be years before we could post
here.
"Instead of
“guessing” all of the time, please do some real
research."
I do massive amounts
of research almost every day before I send most of my longer post to the
group. But at some point with all the massive amounts of data out there on the
net, one just needs to post a question or two to the group and see if
anyone can, or is willing to give some insight, or even give a guess, that can
help discover the answere.
I'm
not interested in perturbing or annoying anyone on this group. I'm here
primarily to learn and share what I've
learned.
Since many subs are
military or trade secrets for large organizations, many times we are left
guessing why they designed it a certain way. It's a mystery, and who doesn't
love a good mystery. It's like a puzzle that with enough brains but to task
can figure it out or find someone that
can.
I think that if the MIR
subs have one or more very large drop weights, that if dropped could make
vortex shedding a problem that the rear stabilizer would be very helpful in
dealing with.
When I
said I don't know if that is a Kort or Rice nozzle, that was a prompt for
someone that does really know to please speak up and so we could learn more
about the sub.
"I can tell
you from an early proposal for building the Mir subs that they are size
constrained for carrying in aircraft holds and the fins on top are probably a
means for shortening the overall length due to deck housing issues (this is a
factor in a number of submersible designs)…but it is pure speculation on my
part."
So why is it you can
speculate and I can't? I had reason to believe I had a couple of
possible good reasons they designed the rear stabilizer the way they did and I
was bouncing them off the group for an open discussion to pool the groups
large knowledge base. I don't know how many times colabortion with
others has produced wonderful things in my life and others. If I had a part of
a good idea, one or more people would come along and fill in the
blanks and make it a whole good
idea.
"Neophyte PSUBers often take as gospel any information that is
found here on the PSUB list and can lead to misconceptions on their part in
the future…some of which may be dangerous if not down right
deadly."
I would expect
anyone with the were-with-all to build, and then operate there own sub
wouldn't believe that this "DISCUSSION" groups postings are all, or even
mostly all the gospel truth. Such a person wouldn't likely able to read and
understand enough of what this group is talking about to hardly get started on
there own sub, let allot survive the walk to the
garage.
Regards,
Brent
Hartwig
From: bottomgun@mindspring.com
To:
personal_submersibles@psubs.org
Subject: RE: [PSUBS-MAILIST] MIR aft
planes
Date: Tue, 21 Aug 2007 15:59:28 -0400
Brent,
Instead
of “guessing” all of the time, please do some real research. Neophyte
PSUBers often take as gospel any information that is found here on the PSUB
list and can lead to misconceptions on their part in the future…some of
which may be dangerous if not down right deadly. You will note that
many of us refrain from making replies here unless we have some expert
knowledge to bring. A number of us have to waste a good deal of time
better spent on other endeavors dispelling misinformation that is either
represented as fact or not clearly labeled speculation by a non-engineer or
scientist.
I did not
respond to this particular request by Joe as I do not know why the Russians
have used this configuration but I can tell you it is not because the water
is not disturbed yet and vortex shedding is not an issue here. Both
issues are related to speed here and speed is not one of Mir’s fine
points. You can not tell whether it is a Kort nozzle, a Rice nozzle,
or simply an entanglement guard without viewing the cross section of the
nozzle or someone more closely associated with the Mir submersibles making a
response. Due to the small size of most all submersibles, there is
little reserve buoyancy that can be effectively designed in…all of them have
handling issues on the surface. While a lot can be learned from images
and visiting various submersibles, hard calculations along with weight and
trim spreadsheets are necessary prerequisites for a successful submersible
with a long, safe lifespan. How do you know you are not looking at a
given submersible’s weak point or a poor design?
I can
tell you from an early proposal for building the Mir subs that they are size
constrained for carrying in aircraft holds and the fins on top are probably
a means for shortening the overall length due to deck housing issues (this
is a factor in a number of submersible designs)…but it is pure speculation
on my part.
A dunce
can appear brilliant if he holds his tongue.
Jay K.
Jeffries
Andros
Is., Bahamas
A
skimmer afloat is but a submarine, so poorly built it will not
plunge…
From:
owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org] On Behalf Of Brent
Hartwig
Sent: Tuesday, August 21, 2007 2:39 PM
To:
personal_submersibles@psubs.org
Subject: RE: [PSUBS-MAILIST] MIR
aft planes
How about a non
educated guess. ; )'
Thanks for the link to the pic
Joe. I would "GUESS" that the aft plane is controlled my the pilot
directly or by hydraulics or the like. The swept-back feature is for
coolness factor Joe. Na for that I would say it helps if you lightly hit
some thing you'll just bounce off and keep going instead of braking the aft
plane, but more importantly I would say its for reducing entanglement
issues. That is why I like to have surfaces on my sub rounded over and swept
back to some degree, with no item protruding forward like the weapons
systems on the Star Wars X-wing fighter.
On another note
since the aft plane is acting like a planes elevator, having the said aft
plane up and out of the way of the swirling water coming off the subs hull,
gives the pilot more control then if its down and directly behind the
sub. This is why allot of ships are now using forward facing props,
that pull instead of push. This is more efficient since the water hasn't be
really disturbed yet and you can get a better directional bit into it.
I would say that
the whole stabilizer assembly also really helps to deal with vortex
shedding. But for that I would use a larger
assembly.
I like the Kort
nozzle on the sub, or is that a Rice nozzle? From what I understand the
Rice nozzle is more efficient.
I wish they would
add some soft saddle tanks to the Muir subs, to give them more freeboard
staybility. Allot of people get really sick in them when at the surface.
Watching the Zodiac cowboys try to attach the crane cables to the subs in
rough water is one of the reasons I started designing trimaran subs. I know
that adding tanks to the subs gives them more hydo drag, but that is another
one of these trade-offs we have been talking
about.
>
From: joeperkel@hotmail.com
> To:
personal_submersibles@psubs.org
> Subject: [PSUBS-MAILIST] MIR aft
planes
> Date: Tue, 21 Aug 2007 12:15:46 +0000
>
>
> Can someone please explain to me the precise function and mechanics
of the
> aft planes / stabilizer on the MIR submersibles?
>
> In this image, you can see it rotated at an exaggerated angle,
which makes
> me wonder if this was done mechanically by the pilot
from within, or the
> unit is "free pivoting" for some reason which
escapes me.
>
>
http://www7430.nrlssc.navy.mil/7432/hydrates/images/Muir_1.jpg
>
> Why then I also wonder, the extreme sweep-back of these planes? You
see this
> in aircraft for aerodynamic purposes in the transonic
flight envelope
> (airliners) but, why here? This is repeated in both
MIR's as well as the
> proposed Alvin replacement.
>
>
Any info is most appreciated, even an educated guess.
>
>
> Joe
>
>
>
>
>
>
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