<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:14pt"><div><span>Hi Doug,</span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>Elaborating on your idea.</span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>If you had digital pressure gauges you could have a system</span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>comparing the
voltage of the two, & when they were in a </span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>similar range they would activate or deactivate an electromagnet</span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>that pulled back a latch that was impeding the movement of the hatch</span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>release mechanism. (car door lock mechanism) You would</span></div><div style="color: rgb(0, 0,
0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>need a manual over-ride. Any electronics nerd could do this easily</span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>& the car lock mechanisms I've seen for round $20-</span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="background-color: transparent;">With the over-pressure valve set at a couple of psi you know</span><br></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family:
HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>that on the surface the most over pressure there could be is</span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>what your over-pressure valve is set at. Under-pressure is</span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>not such an issue as you won't be able to physically open the hatch </span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif;
background-color: transparent; font-style: normal;"><span>if the under pressure is too much, & hence you have to equalize.</span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>So I don't think it needs sophisticated monitoring. </span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>I'm not sure how much of an issue it would be if you opened your</span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>hatch with a couple of psi
over-pressure. Would the dome fly</span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>open at 90 miles an hour, or would pressure be released incrementally</span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>as the hatch dogs unlatched before fully releasing.</span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>Obviously G.L. thinks this is an issue.</span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px;
font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>Alan</span></div><div style="color: rgb(0, 0, 0); font-size: 18.88888931274414px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><br></div> <div style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 14pt;"> <div style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 12pt;"> <div dir="ltr"> <hr size="1"> <font size="2" face="Arial"> <b><span style="font-weight:bold;">From:</span></b> Douglas Suhr <spiritofcalypso@gmail.com><br> <b><span style="font-weight: bold;">To:</span></b> Personal Submersibles General Discussion <personal_submersibles@psubs.org> <br> <b><span style="font-weight:
bold;">Sent:</span></b> Thursday, December 12, 2013 8:06 AM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [PSUBS-MAILIST] G.L. summary Pressure Hull<br> </font> </div> <div class="y_msg_container"><br><div id="yiv5199466414"><div><div dir="ltr">I have to admit this one really befuddles me. What if you were to have two (independent) pressure sensors/gauges, one for cabin pressure and one for ambient pressure, but the gauges were linked at the needles with a one-way gate. This way, the gauges would both be free to move independently, but the gate would only open (and unlock the hatch lock-out via a switch) when both needles were lined up in tandem indicating equal pressure, be it at the surface or underwater. I think actually designing and building such a device would prove very difficult. <div>
<br clear="none"></div><div>Is this what they are talking about, or am I confused? </div><div><br clear="none"></div><div>Because if so, I'm not sure I would ever want to implement such a device on my vessel. If a malfunction of this system were to occur during an emergency egress, how much more time would it take to bypass the hatch lock-out? 3 seconds is a long time when you are dying! </div>
<div><br clear="none"></div><div>With pressure gauges alone I will have a pretty good idea of where I stand in terms of equalization. </div><div><br clear="none"></div><div><br clear="none"></div></div><div class="yiv5199466414gmail_extra"><br clear="none"><br clear="none"><div class="yiv5199466414yqt1339376741" id="yiv5199466414yqtfd29065"><div class="yiv5199466414gmail_quote">
On Wed, Dec 11, 2013 at 9:53 AM, Joe Perkel <span dir="ltr"><<a rel="nofollow" shape="rect" ymailto="mailto:josephperkel@yahoo.com" target="_blank" href="mailto:josephperkel@yahoo.com">josephperkel@yahoo.com</a>></span> wrote:<br clear="none"><blockquote class="yiv5199466414gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<table cellspacing="0" cellpadding="0" border="0"><tbody><tr><td colspan="1" rowspan="1" valign="top">Alan<br clear="none"><br clear="none">No definitive answer but we can postulate that both sensing and actuation are involved. <br clear="none"><br clear="none">On sensing, differential pressure on either side of the hatch is translated to a impulse to actuation.<br clear="none">
<br clear="none">On actuation, a method of locking out the operator from physically un-dogging the hatch, is the only way to meet the standard as per your O.P.<br clear="none"><br clear="none">Joe<a rel="nofollow" shape="rect" target="_blank" href="http://overview.mail.yahoo.com/?.src=iOS"><br clear="none">
<br clear="none">Sent from Yahoo Mail for iPad</a></td></tr></tbody></table> <div>
<div>
<br clear="none"><div class="yiv5199466414hm yiv5199466414HOEnZb">
</div><div><div class="yiv5199466414hm yiv5199466414HOEnZb">
<div style="font-size:0.9em;">
<hr size="1">
<b>
<span style="font-weight:bold;">From:</span>
</b>
hank pronk <<a rel="nofollow" shape="rect" ymailto="mailto:hanker_20032000@yahoo.ca" target="_blank" href="mailto:hanker_20032000@yahoo.ca">hanker_20032000@yahoo.ca</a>>; <br clear="none">
<b>
<span style="font-weight:bold;">To:</span>
</b>
Personal Submersibles General Discussion <<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>>; <br clear="none">
<b>
<span style="font-weight:bold;">Subject:</span>
</b>
Re: [PSUBS-MAILIST] G.L. summary Pressure Hull <br clear="none">
<b>
<span style="font-weight:bold;">Sent:</span>
</b>
Wed, Dec 11, 2013 2:36:26 PM <br clear="none">
</div></div><div><div class="yiv5199466414h5">
<br clear="none">
<table cellspacing="0" cellpadding="0" border="0"><tbody><tr><td colspan="1" rowspan="1" valign="top"><div style="font-size: 12pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif;"><div><span>Alan,</span></div><div><span>Is this equalization from overpressure inside the hull? or external pressure. </span></div>
<div><span>Hank </span></div><div style="display:block;"> <br clear="none"> <br clear="none"> <div style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 12pt;"> <div style="font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 12pt;">
<div><div dir="ltr"> <font face="Arial"> On Wednesday, December 11, 2013 1:23:21 AM, Alan <<a rel="nofollow" shape="rect" ymailto="mailto:alanlindsayjames@yahoo.com" target="_blank" href="mailto:alanlindsayjames@yahoo.com">alanlindsayjames@yahoo.com</a>> wrote:<br clear="none"> </font> </div>
<div><div><div><div>Can
anyone enlighten me on what sought of mechanism</div><div>is used that renders the opening of the
hatch possible only after</div><div>equalisation, as per G.L. Requirements?</div><div>Thanks</div><div>Alan<br clear="none"><br clear="none">Sent from my iPad</div><div><div><br clear="none">On 11/12/2013, at 3:01 PM, Alan James <<a rel="nofollow" shape="rect" href="">alanlindsayjames@yahoo.com</a>> wrote:<br clear="none">
<br clear="none"></div><blockquote type="cite"><div><div style="font-size: 14pt; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif;"><div>Hi,</div><div>I'm not covering much in this section because if I started on construction</div>
<div>regulations, I would just be duplicating what was printed.</div><div>G.L. wants you to have manufacturer certificates for every non structural
screw.</div><div>Any company you contract to do your welding has to have their facilities, personal</div><div>& supervision approved by G.L..</div><div>Some points of interest are.... hatches need to be opened from both sides, they need</div>
<div>to be able to be secured open, they need to be designed in a way that opening of the</div><div>hatch is only possible after equalization. Two measures are required to guarantee that</div><div>the hatches are closed & secured before diving; one measure is to be visibly noticeable.</div>
<div>Mechanical
measures for stopping a banging of the hatch is required.</div><div>Any external through hulls are to be protected against damage by appendages or covers.</div><div>If you are doing calculations on a computer you have to prove that the program is suitable.</div>
<div>Alan</div></div></div></blockquote></div><blockquote type="cite"><div><span>_______________________________________________</span><br clear="none"><span>Personal_Submersibles mailing list</span><br clear="none"><span><a rel="nofollow" shape="rect" href="">Personal_Submersibles@psubs.org</a></span><br clear="none">
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