<DIV style="font-family:Arial, sans-serif; font-size:10pt;"><DIV>Hank, I was just referring to the issue of the hatch wanting to leak right at the surface before there is any pressure on it. The Dogs should take care of that, unless there is some play there.</DIV><DIV> </DIV><DIV>Brian<BR><BR>--- personal_submersibles@psubs.org wrote:<BR><BR>From: hank pronk via Personal_Submersibles <personal_submersibles@psubs.org><BR>To: Personal Submersibles General Discussion <personal_submersibles@psubs.org><BR>Subject: Re: [PSUBS-MAILIST] hatch pin<BR>Date: Wed, 23 Mar 2016 17:37:51 +0000 (UTC)<BR><BR></DIV><DIV style="color: rgb(0, 0, 0); font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12px; background-color: rgb(255, 255, 255);"><DIV dir="ltr"><SPAN>I can tighten the hatch with my dogs-same as Gamma. It is very simple, the dogs are flat pieces ground to a taper and they simply slide under the land ring. The more they </SPAN>slide the tighter the hatch is. I can not cinch it metal to metal though from inside. I can pull a harder vacuum to test the alignment, I was just worried about some equipment inside being damaged from vacuum. </DIV><DIV dir="ltr">The way it reads to me is that it does not need to be cinched from inside. It says "hatches are to be designed to seat with pressure" not by mechanical means. In the case of a sub with a dome sitting on a Aul ring acting as a hatch-the localized force of a hatch dog could bend the Aul ring if you were to try to cinch it down.</DIV><DIV dir="ltr">Hank</DIV> <DIV><BR><BR></DIV><DIV style="display: block;"> <DIV style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12px;"> <DIV style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <DIV dir="ltr"><FONT face="Arial" size="2"> On Wednesday, March 23, 2016 10:35 AM, Brian Cox via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<BR></FONT></DIV> <BR><BR> <DIV><DIV><DIV style="font-family: Arial, sans-serif; font-size: 10pt;"><DIV>I seem to remember in some of those old WWII movies ( run silent, run deep) where the are diving ( dive, dive) and they have a line on the inside of the hatch that one guy is hanging on, to hold it down,, presumably until pressure builds up on the outside so it is secured by the pressure alone. Then maybe they worry about securing the hatch dogs . Of course they were in a bit of a panic in those situations .</DIV><DIV> </DIV><DIV>Brian <BR><BR>--- personal_submersibles@psubs.org wrote:<BR><BR>From: "Sean T. Stevenson via Personal_Submersibles" <personal_submersibles@psubs.org><BR>To: Personal Submersibles General Discussion <personal_submersibles@psubs.org><BR>Subject: Re: [PSUBS-MAILIST] hatch pin<BR>Date: Tue, 22 Mar 2016 22:49:59 -0600<BR><BR>
</DIV><DIV>I know that this particular rule is
often voluntarily disregarded by hobbyists, but just FYI:<BR>
<BR>
ABS Rules for Building and Classing Underwater Vehicles, Systems
and Hyperbaric Facilities (2016)<BR>
Section 11 (Submersibles)<BR>
Subsection 5 (Access Hatches)<BR>
<BR>
5.3 (Operation):<BR>
<BR>
"All hatches are to be operable from both internal and external
sides. Hatches should be designed to seat with pressure. Hatches
that unseat with pressure will be considered based on the
application of the unit. The means for opening and closing of
hatches should permit operation by a single person under all
anticipated operating and emergency conditions. Hatches are to
have means for securing in the open and closed positions. Means
are to be available to ensure that hatches are clear of water
before opening. All hatches are to be considered when evaluating
the surface stability of the submersible. See subsection 11/31."<BR>
<BR>
5.5 (Pressure Equalization):<BR>
<BR>
"Means are to be provided for equalizing pressure on each side of
a hatch prior to hatch opening. As an alternative, an absolute
pressure indicator with means of adjusting the internal pressure
on either side may be provided."<BR>
<BR>
<BR>
Technically, to be in compliance you need to be able to cinch it
down from the outside too. Gets to be a complicated mechanism
though.<BR>
<BR>
Sean<BR>
<BR>
<BR>
On 2016-03-22 22:07, Brian Cox via Personal_Submersibles wrote:<BR>
</DIV>
<BLOCKQUOTE>
<DIV style="font-family: Arial, sans-serif; font-size: 10pt;">
<DIV>Hank, can you cinch it down from the inside , obviously
you would have to be inside at the time, but you might be able
to determine if it is where you want it.</DIV>
<DIV> </DIV>
<DIV>Brian<BR>
</DIV>
</DIV>
</BLOCKQUOTE>
<BR>
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