Re: [PSUBS-MAILIST] Syntactic Foam used to give extra strength to a pressure hull

I just found this data on some externally-applied hydrostatic pressure test done on fiberglass filament wound cylinders covered in syntactic foam. What if you covered a steel,or other type pressure hull of a sub in a even layer of syntactic foam?? If you hit something with your sub it would also give some protection to the interior pressure hull. Also it would insulate your sub from hot and cold temperatures as well as from noise. You would also have a none flood-able buoyancy safety factor.

http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0605963

"Title : SYNTACTIC-FOAM, FILAMENT-WOUND COMPOSITE PRESSURE HULLS.

Descriptive Note : Final rept.,

Corporate Author : GM DEFENSE RESEARCH LABS SANTA BARBARA CALIF

Personal Author(s) : Robertson,R. M.

Report Date : SEP 1964

Pagination or Media Count : 73

Abstract : External hydrostatic pressure tests were conducted on 12 fiberglass filament-wound cylinders, each 12 in. Long with an ID of 5 in. Six of these had a wall thickness of 0.210 in., designed to fail by buckling at 2000 psi; the other six had a wall thickness of 0.305 in., designed to fail by buckling at 5000 psi. Three of each type were covered with an external coating of INLYTE (a buoyant syntactic foam previously developed by the contractor in an effort to stabilize the G. R. P. Against buckling. The syntactic foam density was 44 lb/cu. Ft. The six uncoated cylinders were used as controls. Long cylinders of fiberglass exhibit collapse characteristics under external hydrostatic pressures. The compressive stresses are not developed to their full potential. The tests were conducted to determine if a coating of syntactic foam would stabilize the units to allow more efficient use of the compressive stress. Conclusions: By coating cylinders with a layer of low-density syntactic foam, such as INLYTE, the unit is stabilized in the buckling mode, and a great increase in strength is achieved before rupture from externally-applied hydrostatic pressure. Also, the buoyancy of the composite structure is significantly increased. (Author)"

Regards Brent

From:  Ian Roxborough <irox@ix.netcom.com>
Reply-To:  personal_submersibles@psubs.org
To:  personal_submersibles@psubs.org
Subject:  Re: [PSUBS-MAILIST] Concrete submarine
Date:  Thu, 18 Jan 2007 10:04:48 -0800
>
>Yeah the website is new (to me anyway).  I think this guy was
>posting to the psubs mailing list a couple of years back (and
>also shared some pictures then).  But the website has better
>pictures.  Hope we gave him a better welcome than he's getting on
>rec.boats.building, one reply accusing him of faking the
>pictures.... moron...
>
>Ian.
>
>On Thu, 18 Jan 2007 10:35:34 -0500
>Michael Holt <mholt@ohiohills.com> wrote:
>
> > I think we've seen this before, but I don't recall having access to a
> > website.  A note was placed here:
> >
> > http://groups.google.com/group/rec.boats.building/browse_thread/thread/4d063f6278116dfb?hl=en
> >
> > It led to this website:
> >
> > http://www.tolimared.com/submarine
> >
> >
> > M
> >
> > --
> > It's amazing, really, how much people think you must know if you know about something nobody else much cares about.  -Tommy Whittaker
> >
> >
> >
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