Re: [PSUBS-MAILIST] Pressure Hulls

[Michael Fodor <hgc_michael_1@yahoo.com>]

hi  I just joined the mailing list and don't know what to do, can you help me ?

          Mike

  Walter Starck <wstarck@ozemail.com.au> wrote:

Two comments.

A 9' sphere seems unnecessarily large for the described purpose. It will
displace about 15 tons and present substantial handling demands,
especially at sea. Even if the sphere costs nothing you will need
$100,000 in lifting gear and a $1,000,000 mother ship to handle it.

A manned ROV seems to obviate the respective advantages and combine the
limitations of both ROVs and manned submersibles. What would an
operator be doing inside the sphere relying on cameras for external
viewing that could not be done just as well by an operator on the
surface?

Walter Starck
Golden Dolphin Video CD Magazine
www.goldendolphin.com

----- Original Message -----
From: "Dewey Mason"
To:
Sent: Tuesday, July 02, 2002 3:25 AM
Subject: Re: [PSUBS-MAILIST] Pressure Hulls


> Hey All,
> I assure you I think highly of you all, HOWEVER,,,,
> I will double check ALL math on my sub, I promise. Not
> that I don't belive you, just that I don't breath
> water, and feel no desire to be smooshed inside a
> steel ball. Sounds unpleasant.So you need not worry
> that I will kill myself and then blame you. As to the
> exact specs for this metal, I am going to try to find
> out more today. I am thinking that if I have it tested
> for micro damage, then calculate the unreinforced
> depth, and use that number even after I DO add
> framing, then I wont die. I will also do several
> UN-manned pressure tests first.
> Does anyone have any data on Stainless alloys? As
> to windows, who needs'um? They are BIG holes in the
> boat, and don't work well with a double hull design.
> Cameras can see in more directions, and safer. This
> critter is going to be a big ROV, with a little man
> living inside at the end of the cable. Or in this
> case, a rather large man living inside. It's purpose
> is to find, and to work. Not a sight seer. I have not
> yet found any formulas for computing reinforcement
> strengths. Anybody know how to do this? Where to find
> such? Which books are better?
>
> Dewey
>
> *****************************************************
> --- Captain Nemo wrote:
> > Hi Ian,
> >
> > Interesting formula. Let me see if I understand it
> > with an example, below.
> >
> >
> > ----- Original Message -----
> > From: "Ian Roxborough"
> > To:
> > Sent: Sunday, June 30, 2002 7:53 PM
> > Subject: Re: [PSUBS-MAILIST] Pressure Hulls
> >
> >
> > > P = 2Ut/R
> > > Where:
> > > U = min yield strength
> > > t = hull thinkness
> > > R = outside radius
> >
> >
> > Let's say we're talking about something a little
> > tougher than mild steel;
> > say 0.4% carbon steel ("boiler plate") with a
> > Tensile Strength of 44,000
> > psi, and a Yield Point of 30,000 psi. Then:
> >
> > U = 30,000 psi.
> >
> > If we have a 9-foot O.D. sphere of one inch thick
> > boiler plate, then:
> >
> > T = 1"
> >
> > R = 54"
> >
> > Then:
> >
> > P = 1,111.11 psi
> >
> > And if D = P multiplied by 2.245, then:
> >
> > D = 2494.444 FSW
> >
> > Und Zo...she pops at about 2,500 feet. Operating
> > depth could be, maybe,
> > 1,250 FSW ; 830 feet would be even safer.
> >
> > I'm asking myself now if I think a 9-foot sphere
> > made out of one-inch boiler
> > plate could go that deep before imploding.
> > Hmmm....it might.
> >
> > Is this how you figure the formula works, Ian?
> >
> > BTW: Dewey, I am NOT saying your sphere is suitable
> > for this depth; I don't
> > know anything about that particular vessel, and
> > there could be a lot of
> > things about it that might throw the numbers right
> > out the door: exact type
> > of metal, imperfections in shape or welding, dents,
> > corrosion, modifications
> > like windows and hatches, etc.. This is just an
> > experiment with the
> > formula, using assumed variables and metal
> > properties.
> >
> > Anybody else wanna take a crack at this? Comments?
> >
> > Pat
> >
> >
> >
> >
> >
>
>
>
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