Carsten,
Understand that beyond a certain depth, lockout
becomes unfeasible plus the decompression times become
excessive.
After sailing as the engineering officer on the
largest ferrocement vessel certified for hire in the US for a year (I
recognize the difference between ferrocement and what is being proposed here)
and having to repair a significant hull breach due to the captain at the
time?s inebriation (drunk), I concur that the hull thickness should be
designed greater than what is required for depth. The vessel?s hull in
the region of the accident was properly laid up with a significant amount of
rebar which held together the crushed concrete but a large amount of water
still flooded into the hull. A freshly tarred piece of canvas pulled
around the hull and over the breach staunched most of the flooding until
repairs could be made. The square-rigger was 130 ft. (40 m.) in length,
displaced about 200 t., and the hull?s ferrocement was about 180 mm in the
region of the hole. The collision was with a channel buoy (a giving
instead of a solid surface) which crushed an area about 20 inches (0.5 m.) in
diameter. The crushed concrete had to be cleared out, the exposed
concrete surface cleaned with muriatic acid, and a VERY EXPENSIVE special
epoxy-sand mixture was used to fill the area which resulted in the patch being
stronger than the surrounding hull.
I am intrigued by what Wilfried has accomplished and
would really like to explore further the possibilities. To lessen the
impact issue, consider metal-skinned, external ballast tanks that vertically
extend down below the greatest breadth of the concrete hull. The metal
acts as a fender and is more forgiving of impacts than the concrete (easier
and cheaper to repair also).
R/Jay
-----Original Message-----
From: owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org]
On Behalf Of MerlinSub@t-online.de
Sent: Wednesday, February 14, 2007 7:56
AM
To: personal_submersibles@psubs.org
Subject: RE:
[PSUBS-MAILIST] stress levels in a concrete submarine yacht hull -
troll
Hi Jay - I was thinking on a concrete realy deep diver
- and for a deep diver a diver exit chamber makes no
sence.
I think a concrete sub should have a minimum wall
thickness to
resistant local impacts like from a kai or an other
ship or so.
So for me it is clear that a concrete sub is someone
"big".
Maybe an autonomus Psub - but clear not K-Size sub.
regards Carsten
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