Mega Post for Rick and All

[protek@shreve.net]

Here goes!!

    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.  Now this is likely to
get me flammed in the worst way 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.

>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.  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. 

>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.

>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.


>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.  Windows for example
are 
pressure cycled thousands of times to establish that a certain design is not 
going to fail.  One or two cycles to much greater depth will NOT yield the
info
necessary to make a judgement.  That is why the Navy spent all that money in
testing to just establish the parameters for round flat plate windows!  You 
deviate in materials or technique and you are stepping onto uncharted ground.
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.
    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.
    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?   

>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.

>>Jon, Richard, myself, and several others have tried to suggest avenues of
>>proven technique such as using steel hull design, acrylic window of proper 
>>thickness seated in proper ways, etc. We know that subs have been
constructed with
>>given techniques for years that have been safe and had utility.
>
>An extremely valid point of view - just not an exclusive one. However,
>the key to what you're saying is "proven". How does one go about
>"proving" By testing, of course. Like all who came before you.

When I designed "The Vindicator" I welded in a seat for a rectangular
window.  I
was going to make it 2 inches thick.  That is a thick window for a 200 ft sub.
I actually called Jerry Stachiw, a world class expert, on the phone and
talked to
him about some of my design efforts.  He said "Nothing wrong with a
rectangular
window.  We just have no reliable test data on them.  We do not know how the 
stresses will be set up.  You can use it if you test it.  But after reading
his
book on "How to test it.." I made a round window.  It would have taken
thousands
of extra dollars to test it in the accepted manner.  Beginning to see the
point?

>>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.  How many of these people know the accepted criterion for window
testing?  Most would just dunk it to 150 feet and call it a done deal.
This is the point that we are trying to make.  Sending these people off into
uncharted territory will wind up being fatal.

>However, on every pharmaceutical drug insert, every advert for vitamins
>and herbs, every technical brochure on anything, 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. Period end of story.

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.

Final thought...

At first I thought "Nobody is listening to any of this seriously, and
nobody is
going to take any of this advice.  But I now think that there ARE people
out there
that this is helping, that we have not heard from.  I think that "The safety
committee" as it was called is reaching some people and they are beginning to
see where we are coming from.  I would say this to new people and those
thinking
about psubs "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.

Gary Boucher