RE: [PSUBS-MAILIST] Hull Penetration and Reinforcement

["Hugh Fulton" <hc.fulton@gmail.com>]

Jon, the hull thickness has an effect on the height of the reinforcing
allowed in the calc which is 6 times the hull thickness( i.e. 5 times plus
the hull thickness)  But according to ASME/ABS you are replacing the area
cut out.  I.e. thicker hull equals higher reinforcing allowed. Because it is
external pressure it is 1/2 what is required for internal pressure. How
about running it past Cliff et co.for comment. I could be digging myself a
hole here. I just think that it needs some simple guidance as it is a trap
that a few have fallen into.  The ASME code is a bit scary for some to look
at and I am offering a simplified approach for checking. It should always
have a disclaimer and it should be checked out by a professional engineer
but it would save people getting into a situation where they have assumed
the wrong approach. I know that I almost fell into the trap myself before I
went through chapter and verse of the code.  We have the hull thickness and
stiffener calc and we have the calc for the flat windows but we have no
guide for the window rings or hatch rings. Don't you think we should have?
Regards, Hugh.
 



-----Original Message-----
From: owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org] On Behalf Of Jon Wallace
Sent: Monday, 5 April 2010 12:34 p.m.
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Hull Penetration and Reinforcement


Hugh,

It sounds like there should be some adjustment for the hull thickness 
when calculating the minimum radial thickness, otherwise you've got a 
constant that does not take operating depth (required thickness (Tr)) 
into account (as the height calculation does). Should it be 5% of the 
hole diameter plus the thickness of the hull?

Jon



Hugh Fulton wrote:
>
> Jon, I have been thinking about hull penetrations for hatches and 
> windows and looking at ASME / ABS. There is a very simple rule of 
> thumb that the reinforcing ring should be a */minimum/* radial 
> thickness of 5% of the hole diameter and the height of the reinforcing 
> should be a */minimum/* of 6 times the shell thickness. Somehow this 
> simple formula should be put into the ABS Hull calc tools. I.e. a 20" 
> diameter hole should have a 1" thick ring 24" should be 1.2". We could 
> also just add a sheet to the existing ABS calcs, I'll send a sample so 
> you can have a play. We need Cliff to check it. Regards, Hugh
>




************************************************************************
************************************************************************
************************************************************************
The personal submersibles mailing list complies with the US Federal
CAN-SPAM Act of 2003.  Your email address appears in our database
because either you, or someone you know, requested you receive messages
from our organization.

If you want to be removed from this mailing list simply click on the
link below or send a blank email message to:
	removeme-personal_submersibles@psubs.org

Removal of your email address from this mailing list occurs by an
automated process and should be complete within five minutes of
our server receiving your request.

PSUBS.ORG
PO Box 53
Weare, NH  03281
603-529-1100
************************************************************************
************************************************************************
************************************************************************
 

__________ Information from ESET NOD32 Antivirus, version of virus signature
database 4999 (20100404) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com
 
 

__________ Information from ESET NOD32 Antivirus, version of virus signature
database 4999 (20100404) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com
 
 

__________ Information from ESET NOD32 Antivirus, version of virus signature
database 4999 (20100404) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com
 




************************************************************************
************************************************************************
************************************************************************
The personal submersibles mailing list complies with the US Federal
CAN-SPAM Act of 2003.  Your email address appears in our database
because either you, or someone you know, requested you receive messages
from our organization.

If you want to be removed from this mailing list simply click on the
link below or send a blank email message to:
	removeme-personal_submersibles@psubs.org

Removal of your email address from this mailing list occurs by an
automated process and should be complete within five minutes of
our server receiving your request.

PSUBS.ORG
PO Box 53
Weare, NH  03281
603-529-1100
************************************************************************
************************************************************************
************************************************************************