Re: Use of concrete.

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

Just because it's an external pressure vessel, don't be thinking that the
hull is all in compression. The inner wall is in tension, and the failure
mode is actually buckling (WHUMP.) :-o Joe

-----Original Message-----
From: Erik Michael Muller <emm03@uow.edu.au>
To: Personal_Submersibles@psubs.org <Personal_Submersibles@psubs.org>
Date: Friday, April 23, 1999 11:22 PM
Subject: Use of concrete.


>Hi!, I too am new, and have had the thought of small subs in my head for a
>long time, which i think is the best way to have it before you plunge
>straight in!.
>
>I have a question regarding the use of concrete in personal subs, and I
>notice that concrete subs were discussed a little before, so please forgive
>me if i am going over old ground.
>I would have thought that the excellent compressive strength of concrete
>would have been an enormous advantage. Coupled with the kind of 'sealing'
>that you might get from pouring concrete.
>Because i havent bothered to find out the density of concrete and do the
>sums, i am unaware how large a submarine is required to achive some kind of
>boyancy, my guess however is quite large.  Anyone fill me in on this?
>
>I though also that concrete is significantly cheaper than steel/iron per
>ton, and could significantly reduce cost??
>
>Maybe i am all just too ignorant, in which case i apologise for wasting
>peoples time!
>otherwise please set me straight or fill me in etc.
>
>Thanks!
>E.M.
>
>