[Member-Forum] Moment of Inertia

[Paul Moorhouse]

Hi Brian

My Triton friends are hugely relieved that the first of their German made spheres arrived last week and  has gone through pressure test already. They have three vehicles that are almost complete apart from the spheres. These 165mm thick spheres proved a step too far for conventional techniques and from three attempts only one serviceable sphere emerged from Stanley’s. It is a task beset with risks from start to finish and it was brave of them to attempt it. One finished sphere was lost on final anneal due to a power failure to the auto-clave over the week-end. 

 

The new spheres are made in a very different way employing thermo forming rather than traditional slush casting techniques. This results in excellent clarity. Keep glued to their web-site for progress. 

 

Paul

 

Paul Moorhouse

Design Engineer

 <mailto:paul at steel-fish.com> paul at steel-fish.com

 <http://www.steel-fish.com/> www.steel-fish.com

#44 7837 542878

 

From: Member-Forum [mailto:member-forum-bounces at psubs.org] On Behalf Of Brian Cox
Sent: 25 March 2014 14:56
To: PSUBS Member Discussion Group
Subject: Re: [Member-Forum] Moment of Inertia

 

Hi Paul,

                 On your web site it says  "The 3300/3 program has been dogged by acrylic manufacturing problems"  , do you mind if I ask what problems you encountered" ?

 

Brian

--- paul at steel-fish.com wrote:

From: "Paul Moorhouse" <paul at steel-fish.com>
To: "'PSUBS Member Discussion Group'" <member-forum at psubs.org>
Subject: Re: [Member-Forum] Moment of Inertia
Date: Tue, 25 Mar 2014 09:10:06 -0000

Joe

As it happens, this is my day job. I have been designing submarine pressure vessels for the last 28 years. I am sure there are others on the forum who do this but I am happy to help if you would like, and others at PSUBS should the need arise. 

Frame size and spacing is inter-related and there is no one answer. I have developed some models based on the European pressure vessel code PD5500 so running a new configuration is easy and surprisingly quick. PD5500 produces much lighter vessels than ASME VIII which is really aimed at chemical plant. In this way it is more similar to military codes but it does rely on quality assurance levels that do not generally come with home construction. So to cater for this, you put a factor in. I apologise in advance for all of the calculations being in metric but give me info in either. 

I would need to know

·        Outside diameter

·        Shell thickness

·        Shell material 

·        Frame material

·        Diving depth

·        Length of parallel body

·        Ends, hemi or 2:1 dished.

·        Preferred frame spacing 

·        Inside or outside frames

I can send you the PDF of the work sheet as the PD5500 sums do look very pretty. 

The next step is to design the hatch penetration and I can help you here also. 

 

This guy can thermo form your acrylic

http://www.airesearch.nl/

 

 

Regards

Paul

 

Paul Moorhouse

www.steel-fish.com

 

 

 

From: Member-Forum [mailto:member-forum-bounces at psubs.org] On Behalf Of Joe Perkel
Sent: 25 March 2014 03:55
To: PSUBS Member Discussion Group
Subject: [Member-Forum] Moment of Inertia

 


Where did I see the rule of thumb for T-section rib sizing relative to shell thickness? I can't seem to find it now.

Joe <http://overview.mail.yahoo.com?.src=iOS> 

Sent from Yahoo Mail for iPad

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