<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-size: 13px;color: rgb(0, 0, 0);font-family: arial, sans-serif;"><div><br></div>I believe the standard K250/K350 dog latch could be relatively easily modified to meet these requirements.<div><br></div><div>Something like:<br><div>Instead of straight folks, where the dog can slide right off it as soon as it's loose, a small bend downwards could be introduced. This would mean that to open the hatch the dogs would need to be loosened slightly further, this will also give the hatch enough room to "burp" equalizing the pressure, before it's possible to fulling remove the dog and open the hatch.</div><div><br></div><div>It could be possible to do this to only one folk, but operating procedure would need to make that the last one to open (clearly labelled/numbered).</div><div><br></div><div>While it would be more full proof to bend all 3 folks, I'm a little reluctant to make my sub too hard to exit.</div><div><br></div><div>Cheers,</div><div> Ian.<br><blockquote style="padding-left: 5px; margin-left: 0px; border-left: #0000ff 2px solid; font-weight: normal; font-style: normal; text-decoration: none; font-size: 10pt; font-family: arial,sans-serif; color: black;">-----Original Message-----
<br>From: Alan via Personal_Submersibles <personal_submersibles@psubs.org>
<br>Sent: Dec 30, 2017 12:50 PM
<br>To: Personal Submersibles General Discussion <personal_submersibles@psubs.org>
<br>Subject: Re: [PSUBS-MAILIST] Hatch Closure Mechanism
<br><br><zzzhtml><zzzhead><zzzmeta http-equiv="content-type" content="text/html; charset=utf-8"></zzzmeta></zzzhead><zzzbody 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 target="_blank" 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>
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On Friday, December 29, 2017, 11:09:03 PM MST, Alan via Personal_Submersibles <<a target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:
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<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 target="_blank" ymailto="mailto:Personal_Submersibles@psubs.org" href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br></div><div dir="ltr"><a target="_blank" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br></div></div>
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