<font color='black' size='3' face='Arial, Helvetica, sans-serif'><font class="Apple-style-span" size="3">Sean,</font>
<div><font class="Apple-style-span" size="3"><br>
</font></div>
<div><font class="Apple-style-span" size="3">Originally Perry used plain old neoprene o-rings, and then they sent PC-8 to Alaska for a walrus-through-the-ice-off-an-icebreaker mission. The o-rings compressed at depth but would not expand fast enough on surfacing due to the cold. The primary problem was hatch, main viewport and battery pods. Somebody had to scramble up a set of red rubber jobs with low-temp capabilities, then the boys had to tear the sub partly down to install them--on deck under a tarp, of course. Great fun. Not!!! Afterwards, we went back to neoprene with, one assumes, a different temp rating and never really had another problem. Well, okay, there was that other time.....</font></div>
<div><font class="Apple-style-span" size="3"><br>
</font></div>
<div><font class="Apple-style-span" size="3">Vance<br>
</font><br>
<br>
<div style="font-family: helvetica, arial; font-size: 10pt; color: black; ">-----Original Message-----<br>
From: Sean T. Stevenson <cast55@telus.net><br>
To: Personal Submersibles General Discussion <personal_submersibles@psubs.org><br>
Sent: Mon, Feb 10, 2014 2:49 pm<br>
Subject: Re: [PSUBS-MAILIST] cold weather effect on ports<br>
<br>
<div id="AOLMsgPart_2_07d6f7c8-ab77-4e30-a815-98ac68767712">
<div class="aolReplacedBody" link="#000000" vlink="#000000" alink="#000080" topmargin="0" leftmargin="0" marginwidth="0" marginheight="0">
<div dir="ltr">One presumes that there could potentially be an issue with either thermal shock to the acrylic window, or with o-ring compliance when taking a sub at thermal equilibrium on a frigid deck (-30° C) and immersing it in seawater at ~0° C. It takes some time for both acrylic and elastomers to warm up - they are poor conductors of heat. Don't the o-rings stiffen in the cold?</div>
<div dir="ltr">Sean<br>
</div>
<br>
<br>
<div class="gmail_quote"> <<a href="mailto:MerlinSub@t-online.de">MerlinSub@t-online.de</a>> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<font face="Courier New" size="2">Hi Hank,<br>
<br>
the limit
according to GL is -18 celius degree <br>
- a temp seawater can not
reach. <br>
<br>
The max temp to GL is 66
degree.<br>
<br>
In general
colder is better for the pressure resistant of the windows
(acryl). <br>
<br>
vbr Carsten<br>
</font>
<br>
<br>
"hank pronk" <<a href="mailto:hanker_20032000@yahoo.ca">hanker_20032000@yahoo.ca</a>> schrieb:
<blockquote style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; PADDING-RIGHT: 0px; MARGIN-RIGHT: 0px">
<div style="FONT-SIZE: 12pt; FONT-FAMILY: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; COLOR: #000; BACKGROUND-COLOR: #fff">
<div>Is there an adverse effect from cold temperatures on ports.
I hear about cold weather dives in the North Sea etc.</div>
<div>When is
it to cold for ports if ever?</div>
<div>Hank</div>
</div>
</blockquote>
<font face="Courier New" size="2"> </font>
<div style="margin-top: 2.5em; margin-bottom: 1em; border-bottom: 1px solid #000"></div>
<pre class="k9mail"><hr><br>
Personal_Submersibles mailing list<br>
<a href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br>
<a target="_blank" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br>
</pre></blockquote></div>
</div>
</div>
<div id="AOLMsgPart_3_07d6f7c8-ab77-4e30-a815-98ac68767712" style="margin: 0px;font-family: Tahoma, Verdana, Arial, Sans-Serif;font-size: 12px;color: #000;background-color: #fff;">
<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_07d6f7c8-ab77-4e30-a815-98ac68767712 -->
</div>
</div>
</font>