<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12px"><div><span>Steve,</span></div><div dir="ltr"><span>I have to admit it was getting </span>nervous watching my air supply gauge dropping, normally the sub lifts off with a couple of good squirts of air. I had 1,000 psi when I sank witch is lots normally, I dropped to 500 psi before anything happened. When I was ascending I could hear air coming out of the bottom of the MBT's so she was full power UP LOL.</div><div dir="ltr" id="yui_3_16_0_ym19_1_1466199293801_8115">Hank</div> <div class="qtdSeparateBR"><br><br></div><div class="yahoo_quoted" 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 size="2" face="Arial"> On Friday, June 17, 2016 5:04 PM, Stephen Fordyce via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<br></font></div> <br><br> <div class="y_msg_container"><div id="yiv3116615843"><div><div dir="ltr">Wow Hank, that sounds like one epic experience! At least you know the cause though and can do something about it.</div>
<div dir="ltr">Cheers,<br clear="none">
Steve</div>
<div class="yiv3116615843gmail_quote">On 18 Jun 2016 8:01 am, "Alan James via Personal_Submersibles" <<a rel="nofollow" shape="rect" ymailto="mailto:personal_submersibles@psubs.org" target="_blank" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br clear="none"><blockquote class="yiv3116615843gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div class="yiv3116615843yqt3095654434" id="yiv3116615843yqt26580"><div><div style="color:#000;background-color:#fff;font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"><div><span>Sounds exciting stuff Hank, can you repeat it so we can see it on video?</span></div><div><span>Looking at the segmented design of your saddle tanks, it would be hard</span></div><div dir="ltr"><span>to get trapped air to move out of the top of the center segment without having it's own</span></div><div dir="ltr"><span>venting valve (which I can't see). There might be up to 20 liters of air trapped in each of</span></div><div dir="ltr"><span>those center segments. That would contribute to making you 40kg light,</span></div><div dir="ltr"><span>but at a 100ft when the air compressed to 1/4, you would be 30kg heavy.</span></div><div dir="ltr"><span>You could check how much air we are talking about by blocking an end</span></div><div dir="ltr"><span>sections drain hole, pouring water in to it until it spills in to the next section</span></div><div dir="ltr"><span>then unplug & drain the water in to a bucket & measure how many liters you have.</span></div><div dir="ltr"><span>The water in liters would equate to air in liters that would be trapped up the top.</span></div><div dir="ltr"><span>Does that make sense?</span></div><div dir="ltr"><span>Alan</span></div><div><br clear="none"><br clear="none"></div><div style="display:block;"> <div style="font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"> <div style="font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"> <div dir="ltr"> <font face="Arial" size="2"> </font><hr size="1"> <b><span style="font-weight:bold;">From:</span></b> hank pronk via Personal_Submersibles <<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;">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;">Sent:</span></b> Saturday, June 18, 2016 8:40 AM<br clear="none"> <b><span style="font-weight:bold;">Subject:</span></b> [PSUBS-MAILIST] Listing solved<br clear="none"> </div> <div><br clear="none"><div><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">Today I dove Gamma to 80 feet and the cause of my list became clear. First off I extended my bottom vent tubes on the front MBT's and that fixed the list once surfaced. But the real problem was quite scary. It turns out that I am not evacuating all the air from my MBT's because there is not enough height difference between the vent valve and the tanks. I added about 200 lbs more weight than my calculations called for and that compensated for the trapped air. Now, I am no math wiz, so I chalked it up to a math error. When the sub is on an angle the air does not escape fully. I did my dive and vented till the sub was under and let her sink. I was not paying attention to the sink rate because I expected it to sink slowly thinking all the air was out of the MBT's. I was more concerned about the first time diving after all the modifications I have done. I have not done a deep test yet. Well I hit the bottom like a ton of bricks and Gamma went into the mud pretty deep I guess, because I had to use up 500 psi of air get it loose from the bottom. Once it was free, I was a rocket heading to the surface and the sub did about 4 full rotations on the way up and then It breached. Man that was freaky, so now I know the sub is too heavy because the air is trapped in the MBT's. </div><div dir="ltr"> There is an easy solution, I will mount manual vent valves to the tanks and rotate them with linkages from the main vent valve. I will leave the existing lines in place to get the air into the tanks but the extra valves will do the venting as well as the original vent valves.</div><div dir="ltr">Hank</div><div dir="ltr"><br clear="none"></div><div dir="ltr">Oh ya and my hip waders had another leak.</div><div dir="ltr"><br clear="none"></div></div></div></div><br clear="none">_______________________________________________<br clear="none">Personal_Submersibles mailing list<br clear="none"><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"><a rel="nofollow" shape="rect" target="_blank" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none"><br clear="none"><br clear="none"></div> </div> </div> </div></div></div></div><br clear="none">_______________________________________________<br clear="none">
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