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Re: Mega Post for Rick and All

protek@shreve.net wrote:
Here goes!!
OOOhhhh . . . I just crossed my knees  - I feel a flux in the Force, ObiWan!
It is now time for my rebuttal.  Since many of my own words were used
here in Rick's letter, I feel free to quote Rick.
Please do!  That's what I love about email!
Now this is likely to
get me flammed in the worst way
Moi?
but, I want make a few comments and then go
on to use these quotes of Ricks's to demonstrate what we are saying on this
safety issue.
I've come to the conclusion that we are all agreeing on the same thing - we are just approaching it from different angles.

>Basic misunderstanding: design experimentation is being promoted at the expense of safety.

>Wrong!

The "design experimentation" you are looking at and that I have seen in many,
not all, cases on psubs is way out there compared to the knowledge and skill
level of those proposing.

Agreed.
Perhaps this lends to a subjective evaluation, but
my experience in 14 years of teaching technical subjects at university level
sets off a neon sign for me when I listen to some of the proposals.
Agreed.  Likewise for me.
>my technical engineering background is minimal;
>however, my training included DISCUSSION and DEBATE.

I respect the field of debate and the logic that it is based on.  However, I
do not take much technical input from the English Department either.  I
respect
them highly for their knowledge base.  My knowledge base in English almost
caused
me to repeat the subject in college.

Repeat as in "throw up"?          :-)
>Do they not ENGAGE
>at MIT?; Princeton?

Sure they do!  But the PhD's seldom call in a new freshman to help with
design
ideas.  Undergrad and professor conversations are usually more to shape the
student's path, not to establish design criterion.

True.  However, the simple act of "shaping the student's path" is precisely the argument that I'm using.

In the actual design of the sub, I certaily would hope that it was the PhD's that would sign off.

>That having been said, let's take a real look at what an experienced,
>field tested psubber has to say.
>protek@shreve.net (Gary Boucher) wrote:

>I am interested in the safety issue after seeing SO many posts that are
>asking questions about things that just shouldn't be done in the first place.

>Shouldn't; Perhaps the caveat "should" be to go ahead and DO IT --
>with the understanding that you do not climb into an untested vehicle in
>order to test it.; It's not the errors, or the poor design, or the
>wrong materials that kill/maim psubbers.  It's the violation of the
>primary principle of both engineering and science: never use humans as
>guinea pigs.; The fatal flaw is NOT the building of a dud - it is
>the completely stupid (judgemental term - I apologize) and blinded (by
>ego?) method of testing that will kill.

Your response in the "DO IT" comment is an example of non-engineering thinking
in its clearest form.  It is obvious that you believe that if you use any idea
and then test it then it is OK.  You talk about not climbing into a sub on the
initial testing phase.  Would you suggest lowering it to a depth 50% deeper
than
you plan to operate it.

Would you suggest maybe limiting your operating depth
to 25% of test depth.  This seems feasable to the average person.  But more
than
just a test or two or three may be needed for safety.
Excellent point and I'm glad you agree and support my suggestions from a parallel post!  You are indeed a gentleman and a scholar!
[snip]        You
deviate in materials or technique and you are stepping onto uncharted ground.
I completely agree.
I once knew of a fellow that owned an F-8 Bearcat from WWII.  He flew it hard
flying airshows and pulling high G loads.  One day he was flying back from an
airshow straight and level and the plane came apart in mid air.  The Comet, a
british airliner, killed many people before they realized that a few loading
and unloading cycles of the cabin pressure did not indicate that repeated
cycles would be safe.
Ref. the little tale I told of the home builder who neglected to peel the factory installed protective plastic sheet before he laminated his main wing.  Again, we are in agreement.
My point is that just because something holds out water and will test to
twice the operating depth does not mean it is safe.  Materials vary and this
simple "DO IT" approach, BY ITSELF, is not good engineering practice at all.
Again, ref. my parallel post.  I'll say that I even outdid myself on that one  ;-)   Somewhere around 0345h I think I lost my sense of humour.  But, you'll see that I'm ditto'ing what you are stating here.
Lets say you do test your sub using some exotic materials.  Are you going
to build two so that the second one does not have problems possibly caused by
the testing of the first?  Would you have thought of this?  Did you think
about
the fatigue factor?
Ref. parallel post.
>When there is a question, everyone jumps in till it becomes a question
>on philosophy rather than a technical question.
>Design Philosophy 101 is the mainstay to your argument and the arguments
>of all who promote safety.  Without a design philosophy, there would
>be no focus, no results - and no safety.; Your "philosophy of safety"
>is built-in to your argument by default.

My philosophy is to try to prevent people with limited knowledge from
going off into an area where they do not have the necessary resources and
knowledge.

Now there's an excellent qualifier: "necessary resources and knowledge".

What Gary is saying is absolutely true.  I have been supporting a "go out and do it" philosophy, but, even my posts have been rife with caveats and I'm completely in line with Gary and the other  members of the "safety team".

Proper testing should follow protocols, especially in one atm. boats.  (again, ref. parallel post)  If you do NOT have the resources - intellectual, data, financial, technical or otherwise, then by all means BUILD A PROVEN DESIGN!!! -

I personally do not have the financial resources.  This is one of the reasons I feel much more comfortable with ambient dry subs.  It's an environment I know intimately both from work in the field, technically, and aesthetically.

[snip]        >>discouraging to me personally when someone goes and says that you can
>>build a sub out of anything that keeps out water. You know, this is
>>a true statement.
>
>It was suggested by none other than the foremost, most prolific, field
>experienced and successful submersible designer in the world.

I am not questioning his knowledge, ability, or experience.  I question the
wisdom of suggesting this to many people who do not have the knowledge and
ability at this point to engineer the tests, or to even know what they are
testing for.

As above.  Agreed.  I think you've been reading my mind.

I feel that if design work is to evolve, then stretching parameters is mandatory.  If all of our warnings, however, go unheeded, then at least we can say "We tried to tell you"  Under no circumstances should lack of resources be used as an excuse to kill oneself.  If you can't test it (according to protocol), don't dive it.

[snip]        there is ALWAYS a waiver
>of responsibility that keeps most parties out of court. What is it?
>Simply what all of the "safety" oriented psubbers have been stating all
>along: have your designs, building steps and techniques, drawings and field
>testing evaluated by certified professionals.[snip]
I once worked on my airplanes in a big hangar with a big sign "NOT RESPONSIBLE
FOR PERSONAL INJURY OR THEFT OF PROPERTY" or something like that.  You know
what that was worth?  Not the paint and plywood used for it.  State to state
liability laws are different.  You can not just disclaim liability.  I really
mean it when I say to get a P.E. (Professional Engineer) to check your work.
I would like to meet the P.E. that OK's a plywood sub covered with something
to keep the boards dry.
Up here in Canada we think a little differently.  We view the litigous culture in the US and hope it never comes up here. My concern is the sin of omission.

As I mentioned in my "parallel post" (man I covered a lot of territory!), it is the information we, as a group, neglect to give to others that may kill them.  Using potential litigation as the reason, (nay, the excuse - forsooth!) for avoiding answering questions is tantamount to saying we would rather protect our asses than keep someone alive with some gem we are afraid to impart.

This email list is simply a convenience - a device we use to maintain a round table of interested parties in one particular field.  We can no more be sued successfully IMHO than the pilot in the local airport cafeteria who recommends using Brand X of wing strobe only to have some other pilot's wing burn off due to an electrical malfunction.  Can the family blame the originating source of the information?  I doubt it.

This is, I feel, way beyond even political correctness in its fear mongering.  We give general answers in the assumption, and hope, that the student/questioner/newbie will run down to the local library to protect himself?

Final thought...

[snip]         "ASK ALL THE QUESTIONS YOU WANT OF ANY OF US.  I don't want to
impede the free flow of questions at all.  But if some are answered by "no"
then understand that we are not trying to squelch creativity.

Got that, All?  We love you - but, in many different ways!  As I said above, ultimately we all do agree.  Gary and Others are correct in their technical viewpoints.

To sum up: empirical results are the only thing that matters.  Note my email address.

No flames!  Wasn't I sweet?
--
Rick Lucertini
empiricus@sprint.ca
(Vancouver, Canada)

"Most people die with their dreams still inside them."