<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>Thanks Hank,</div><div id="AppleMailSignature">will have to think on this one. I want to let a novice dive my sub, so</div><div id="AppleMailSignature">the system needs to be bullet proof.</div><div id="AppleMailSignature">If I have some sort of lock mechanism I would need to be able to bypass</div><div id="AppleMailSignature">it if I needed to escape at depth. The pressure at depth would be apposing </div><div id="AppleMailSignature">the manual operation of the overpressure valve. You could flood the sub first</div><div id="AppleMailSignature">but normally the hatch is un-dogged prior to the hull equalizing.</div><div id="AppleMailSignature">Cheers Alan</div><div id="AppleMailSignature"><br></div><div id="AppleMailSignature"><br><br>Sent from my iPad</div><div><br>On 31/12/2017, at 1:49 AM, hank pronk via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br><br></div><blockquote type="cite"><div><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div></div>
<div>Alan,</div><div>You could have a lock that prevents the hatch mechanism from opening that is activated by turning the hatch vent. I always vent before I one the hatch anyways.</div><div>Hank</div><div><br></div>
<div id="yahoo_quoted_4704983245" class="yahoo_quoted">
<div style="font-family:'Helvetica Neue', Helvetica, Arial, sans-serif;font-size:13px;color:#26282a;">
<div>
On Friday, December 29, 2017, 11:09:03 PM MST, Alan via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:
</div>
<div><br></div>
<div><br></div>
<div><div dir="ltr">Just doing some evening reading of the GL rules & noticed this rule about hatches....<br></div><div dir="ltr">"the closing mechanism is to be designed in such a way that opening of<br></div><div dir="ltr">the hatch is only possible after pressure equalisation" <br></div><div dir="ltr">I am wondering what options there are for achieving this.<br></div><div dir="ltr">Has anyone had experience of the hatch opening with explosive force due<br></div><div dir="ltr">to internal over-pressure not being equalised.<br></div><div dir="ltr">Alan <br></div><div dir="ltr"><br></div><div dir="ltr">Sent from my iPad<br></div><div dir="ltr"><br></div><div dir="ltr">_______________________________________________<br></div><div dir="ltr">Personal_Submersibles mailing list<br></div><div dir="ltr"><a ymailto="mailto:Personal_Submersibles@psubs.org" href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br></div><div dir="ltr"><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br></div></div>
</div>
</div></div></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">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a></span><br></div></blockquote></body></html>