RE: [PSUBS-MAILIST] Hulls, Hulls and More Hulls.....

[Alec Smyth <Asmyth@changepoint.com>]

>At these prices, we could afford to get a big one.
>H.T. steel, with half domed endcaps, that is 1.25"
>thick, 10' O.D., and 35-40' long. Anybody care to take
>a shot at where it may fail? I also need to know how
>much (ballpark) depth can be gained with max
>reinforcement? 

AS: I'd be happy to take a stab at that but need a little info:

- D'you know what material it is specifically? H.T. might be HY80 for
example.
- Are the "half domed" endcaps hemispherical or elliptical? The term sounds
hemi but I just wanted to check.
- How much buoyancy do you need the bare hull to have? This will depend on
your estimate for the total weight of batteries, equipment, supplies, crew,
etc. might be. This will tell me how much material I can invest in
reinforcements without getting too heavy. Bear in mind of course if some of
those things are external, then its only the submerged weight we're talking
about.


>Any reason one cannot use inner rings,
>with cross braces, and also use linear ribs outside,
>with cross-members offset from those inside to add
>extra rigidity?

AS: You could do that and it wouldn't make any difference if they were on
the inside or outside. In fact I believe navy boats do combine internal and
external. Generally this would just be a matter of compromising between how
streamlined you want it (external rings add girth) versus how acceptable it
is to eat up internal space. By "cross braces" d'you mean longitudinal
beams? No need.





-----Original Message-----
From: Dewey Mason [mailto:drmason2001@yahoo.com]
Sent: Monday, July 01, 2002 6:42 PM
To: mail list
Subject: [PSUBS-MAILIST] Hulls, Hulls and More Hulls.....


Hey All,
   I did contact those folks again today. I found
9'8", 1/2' thick aluminum is the size and material on
the spheres. The cylindrical short tanks(8-10' ODx
10-16' lnth) are the S.S. tanks. They also have a
large selection of high tensile carbon tanks(one alloy
was given as 212). All of these are inners, as part of
double walled cryo setups. The lead tech for the Co.
said they are tightly controlled, and that the
pressure is maintained below critical levels that
would stress the metal by a burst disc in every
system. He also stated that the inners are untouched
since their fabrication, due to the outer shell, and a
deep layer of hard insulation. These are H.P.V.s
working at -100 degrees F. They must be shielded from
impact, abrupt temp variances, over pressure stress,
ect. or they will fail, due to the extreme cold. The
strength of the metals falls off at -90 or so, and
working temps go down to -400 and slightly below. He
told me (we talked for an hour)that these are not
subject to the same types of stress and impact
potential as propane tanks, as they are documented in
the checking and maintenance.
   At these prices, we could afford to get a big one.
H.T. steel, with half domed endcaps, that is 1.25"
thick, 10' O.D., and 35-40' long. Anybody care to take
a shot at where it may fail? I also need to know how
much (ballpark) depth can be gained with max
reinforcement? Any reason one cannot use inner rings,
with cross braces, and also use linear ribs outside,
with cross-members offset from those inside to add
extra rigidity?
   Who has thoughts on the difference between these
and propane tanks? They have the material specs, know
stress limits, ect. This does ease my mind (somewhat)
about their possible use as hulls.
   Moreover, would anyone maybe want one? We are
discussing them donating some to T.D.P.F. as a tax
write off. If they do, we would probably be able to
pass some on REALLY! cheap (read well below scrap
price) and still be legal as a fund raising measure.
We can't give them, as the legal aspects won't allow
that, but we can come pretty damned close.
   Enough of my rambling for now.




=====
Dewey R. Mason II
The Deep Past Foundation
deeppastfoundation@yahoo.com

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