Re: [PSUBS-MAILIST] Is ABS Reliable?

[Adam <submadman@gmail.com>]

The ABS is reliable.

 

I discovered a couple mistakes a few years back, but they were soon corrected and the corrections were released in the ABS corrigenda. These mistakes were actually typos. I found the mistakes through unit analysis, in other words, by making sure all the units worked out.

 

The ABS will not certify your design based purely on the equations they provide. Strain gauging and FEA is typically needed because some shapes are not easily described by hand written equations. And, at the same time, they also require a hydrostatic test, this test is usually done in conjunction with a strain gauging and/or with something that monitors the change in volume as pressure increases.

 

So, I believe the ABS is reliable but in the business of making money and at least they are covering their butt. It is still up to you to cover yours.

 

Regards,

 

Adam Lawrence

 

 

 

 

On 9/5/06, Joseph Perkel <joeperkel@hotmail.com> wrote:

As ABS and Lloyds are the premier certification agencies for manned
submersibles, their standards, calculations and publications are the
standards to emulate.

However, that having been said. I myself have been warned on several
occasions to "be careful' where calculations are concerned as you may be
"right on the money" in theory but, still end up on the wrong side of the
performance envelope once the thing hits the water.

Here is where things like hydrodynamics and tank testing come in.

Joe


>From: "Stephen Pearce" < sjpearceqld@bigpond.com>
>Reply-To: personal_submersibles@psubs.org
>To: <personal_submersibles@psubs.org >
>Subject: [PSUBS-MAILIST] Is ABS Reliable?
>Date: Wed, 6 Sep 2006 10:01:03 +1000
>
>Is ABS Reliable?
>Dear Members
>I have been made aware of a situation where the ABS calculations for
>predicting the collapse of a pressure hull were wrong or
>inappropriate.Is there anyone who has any information about any instance
>like this or can clarify under what circumstances ABS can be relied on?
>Are there any alterative standards that could be used that are readily
>available?
>Regards and thanks
>
>Steve P
>





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