<font color='black' size='2' face='arial'>
<div><font face="Arial, Helvetica, sans-serif" size="3">Jon & Alan,</font></div>
<div><font size="3"></font> </div>
<div><font size="3">I have only been familiar with 1.25 test and 2.0 collapse standard, however the stepped requirements per GL make logical sense. Percentage margins at shallow depths could be a little thin compared to absolute margins as you illustrated, Alan.</font></div>
<div><font face="Arial, Helvetica, sans-serif" size="3"></font> </div>
<div><font size="3">Jim</font></div>
<div></div>
<div></div>
<div style="color: black; font-family: arial,helvetica; font-size: 10pt;">-----Original Message-----<br>
From: Alan <alanlindsayjames@yahoo.com><br>
To: Personal Submersibles General Discussion <personal_submersibles@psubs.org><br>
Sent: Fri, Dec 6, 2013 10:38 am<br>
Subject: Re: [PSUBS-MAILIST] G.L. summary Design Loads<br>
<br>
<div id="AOLMsgPart_2_c8074f35-92c4-4fac-80b6-ac5b803a8295">
<div class="aolReplacedBody" dir="auto">
<div>Hi Jim,</div>
<div>Yes you are right.</div>
<div>I used feet as an illustration, where they use metric pressure</div>
<div>in their table. </div>
<div>I like their scale system, because if you are building for a</div>
<div>shallow depth, with a thin sectioned hull, then any small margin of</div>
<div>error will have a bigger impact than on a thicker hull.<br>
As a simple illustration, if you were building 3mm thick & ended up</div>
<div>2 mm that's a 33% error, whereas if you built 10mm thick & were out</div>
<div>by the same 1mm, that's only a 10% error.</div>
<div>Alan<br>
Sent from my iPad</div>
<div><br>
On 7/12/2013, at 5:11 AM, Jon Wallace <<a href="mailto:jonw@psubs.org">jonw@psubs.org</a>> wrote:<br>
<br>
</div>
<blockquote type="cite">
<div>
<div class="moz-cite-prefix"><br>
Jim,<br>
<br>
Yes, there's certainly a point in all brackets where it would
behoove the owner to bump up the nominal dive depth (operating
depth) to take advantage of lower ratios. I believe ABS uses a
static 1.25 ratio for all vessels regardless of operating depth.
GL would appear to be more conservative than ABS in this category.<br>
<br>
Jon<br>
<br>
<br>
On 12/6/2013 6:03 AM, <a class="moz-txt-link-abbreviated" href="mailto:jimtoddpsub@aol.com">jimtoddpsub@aol.com</a> wrote:<br>
</div>
<blockquote type="cite"><font color="black" face="arial" size="2">
<div><font face="Arial, Helvetica, sans-serif" size="3" style="background-color: transparent;">Hi Alan,</font></div>
<div> </div>
<div><font size="3">If I understand the requirements correctly,
then for designed maximum operating depths of 320 feet and
the 340 feet respectively the test depths would be as
follows:</font></div>
<div><font size="3">320' x 1.4 = 448' test depth</font></div>
<div><font size="3">340' x 1.25 = 425' test depth</font></div>
<div> </div>
<div><font face="Arial, Helvetica, sans-serif" size="3">And the
designed collapse depths would be:</font></div>
<div><font size="3">320' x 2.4 = 768' collapse</font></div>
<div><font size="3">340' x 2.0 = 680' collapse</font></div>
<div> </div>
<div><font size="3">Therefore if my designed operating depth is
near the lower limit <font face="Arial, Helvetica, sans-serif">of a bracket, increasing the stated operating
depth enough to push it into a deeper bracket would
actually <em>lessen</em> </font>the requirements for
test depth and collapse. Do I understand correctly?</font></div>
<div> </div>
<div><font size="3">Thanks,</font></div>
<div><font size="3">Jim</font></div>
</font><br>
</blockquote>
<br>
</div>
</blockquote><blockquote type="cite">
<div><span>_______________________________________________</span><br>
<span>Personal_Submersibles mailing list</span><br>
<span><a href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a></span><br>
<span><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a></span><br>
</div>
</blockquote></div>
</div>
<div id="AOLMsgPart_3_c8074f35-92c4-4fac-80b6-ac5b803a8295" style="margin: 0px; color: rgb(0, 0, 0); font-family: Tahoma, Verdana, Arial, Sans-Serif; font-size: 12px; background-color: rgb(255, 255, 255);">
<pre style="font-size: 9pt;"><tt>_______________________________________________
Personal_Submersibles mailing list
<a href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a>
<a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a>
</tt></pre>
</div>
<!-- end of AOLMsgPart_3_c8074f35-92c4-4fac-80b6-ac5b803a8295 -->
</div>
</font>