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Re: [PSUBS-MAILIST] Pressure hull
Hi Thijs,
this is an interesting design. I tried working out something similar
(a two man fish shaped sub), my main conclusion was that an end cap
sub isn't very scalible for depths. Going by the ABS standard, if I
was to double the thickness of the pressure, I got an extra 15 feet
of usable depth. The main reason for this is that the main surfaces
of the sub have a curve radius far larger than the submarine.
Still, even with the depth limitation, it's probablya good design
if you're not going for a deep diving sub.
Ian.
On Sun, 9 Feb 2003 18:02:15 +0100
"Thijs Struijs" <thijs-struijs@planet.nl> wrote:
> To all,
>
> I would like some reactions on a drawing i made a while ago. You can find it at: http://www.prismnet.com/~moki/20030126.073208/doubleXendXcapX.jpg .
> The idea is to construct a very simple pressure hull out of two torispherical endcaps. The conning "tower" is made out of a standard line pipe with a little overdimensioned wallthickness and the smallest possible diameter. The endcaps are made with a small cilindrical section on it but i am afraid that the tower will intersect with the torispherical part.
> In order to keep it simple i chose a very common steel for the endcaps. It is P265GH (yield strenght 265 n/mm^2, 38500 psi, tensile strenght 410 n/mm^2, 59500 psi). This is an "off the shelf" material at Afflerbach, the german manufacturer. I think you could call it soft boiler steel.
> To calculate the strenght of it (apart from the conningtower and viewports) one can use the formulas for a sphere, using the dishing radius of the endcap (in this case 1040 mm). Maybe it is my age, to much alcohol or lack of intelligence but watever method i use (ABS, Lloyd's or an old pressure vessel codebook) i get different outcommings. Can anyone of you say something sensible on this? I am considdering a wallthickness of 12 mm, divingdepth 100 mtr?
> If it is ever going to be build it will be tested unmanned to a depth 50% more than its safe working depth. Should it collapse i will hold no one responsible for that. So please be free to give your advise.
>
> Thank you very much,
>
> Thijs Struijs
>