Re: [PSUBS-MAILIST] concept query

["Marsee Skidmore" <heyred@email.msn.com>]

I went back and read the original message, and by golly if you aren't
correct in every detail. I promise to read more carefully in the future. As
penance, I'm going to use the word "disastrophe" in a sentence at least once
a day for the next week. - Joe

----- Original Message -----
From: Phil Nuytten <72020.572@compuserve.com>
To: <personal_submersibles@psubs.org>
Sent: Saturday, January 29, 2000 9:57 PM
Subject: Re: [PSUBS-MAILIST] concept query


> Hi, Joe:
>         Nope, Dan's proposal is not similar to ring stiffening . .Dan
> proposes a series of concentric hulls with between-hull pressurization, in
> the hope that the internal pressures will add (on a 1:1 ratio) to the
> hull's ability to withstand external pressure. That is, if the monohull
> could tolerate, say, 150 psi - then pressurizing it to 50 psi, internally,
> would allow it to tolerate 200psi externally, and so on. The only way that
> the external or outer hull can 'see' the additional 50 psi, is if it
begins
> to yield or become 'plastic',
> The extra 50 psi will increase the pressure at which the outer hull
yields,
> but only at the cost of having an extra 50 psi on the external portion of
> the next hull.  - No free lunch. The hulls will transmit pressure freely
> only if they are made of a soft, deformable, material. Otherwise, they
will
> resist until they can resist no more . .then they will turn into
> 'deformable material' and transmit big-time!! This is termed 'catastrophic
> failure'  . .or in the biz." a f-ckin' disastrophe !! "
>         Again, I say:  Whatever depth you can achieve by multiple hulls,
> with pressure between, is the same or less than that achievable with a
> single hull of the combined thickness -( for a given one-atmosphere
> internal volume)
>         And, speaking of disastrophe's . .I was BS'ing with Bill Meistrell
> ( Meistrell brothers, owners of 'Body-Glove') - he is an old subslut . .
> .operated 'Sea Snooper' for years . .last week at the NOGI awards banquet.
> He told me that  they had recently built a deepwater sub and didn't want
to
> go the expense and hassle of strain guaging, controlled chamber
> pressurization, etc.. so they lowered it into the sea to the calculated
> test depth of 2800 feet. .whoops! instant halibut!! Darn those pesky
> calculations! (G)
> Phil Nuytten
>