<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_ym19_1_1466198704593_4647"><span id="yui_3_16_0_ym19_1_1466198704593_4646">Sounds exciting stuff Hank, can you repeat it so we can see it on video?</span></div><div id="yui_3_16_0_ym19_1_1466198704593_4559"><span id="yui_3_16_0_ym19_1_1466198704593_4558">Looking at the segmented design of your saddle tanks, it would be hard</span></div><div id="yui_3_16_0_ym19_1_1466198704593_4482" dir="ltr"><span id="yui_3_16_0_ym19_1_1466198704593_4481">to get trapped air to move out of the top of the center segment without having it's own</span></div><div id="yui_3_16_0_ym19_1_1466198704593_4488" dir="ltr"><span id="yui_3_16_0_ym19_1_1466198704593_4487">venting valve (which I can't see). There might be up to 20 liters of air trapped in each of</span></div><div id="yui_3_16_0_ym19_1_1466198704593_4479" dir="ltr"><span id="yui_3_16_0_ym19_1_1466198704593_4478">those center segments. That would contribute to making you 40kg light,</span></div><div id="yui_3_16_0_ym19_1_1466198704593_4513" dir="ltr"><span id="yui_3_16_0_ym19_1_1466198704593_4534">but at a 100ft when the air compressed to 1/4, you would be 30kg heavy.</span></div><div id="yui_3_16_0_ym19_1_1466198704593_4560" dir="ltr"><span id="yui_3_16_0_ym19_1_1466198704593_4611">You could check how much air we are talking about by blocking an end</span></div><div id="yui_3_16_0_ym19_1_1466198704593_4609" dir="ltr"><span id="yui_3_16_0_ym19_1_1466198704593_4608">sections drain hole, pouring water in to it until it spills in to the next section</span></div><div id="yui_3_16_0_ym19_1_1466198704593_4622" dir="ltr"><span id="yui_3_16_0_ym19_1_1466198704593_4621">then unplug & drain the water in to a bucket & measure how many liters you have.</span></div><div id="yui_3_16_0_ym19_1_1466198704593_4637" dir="ltr"><span id="yui_3_16_0_ym19_1_1466198704593_4638">The water in liters would equate to air in liters that would be trapped up the top.</span></div><div id="yui_3_16_0_ym19_1_1466198704593_4645" dir="ltr"><span id="yui_3_16_0_ym19_1_1466198704593_4661">Does that make sense?</span></div><div id="yui_3_16_0_ym19_1_1466198704593_4610" dir="ltr"><span>Alan</span></div><div class="qtdSeparateBR" id="yui_3_16_0_ym19_1_1466198704593_4489"><br><br></div><div class="yahoo_quoted" id="yui_3_16_0_ym19_1_1466198704593_4475" style="display: block;"> <div id="yui_3_16_0_ym19_1_1466198704593_4474" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_ym19_1_1466198704593_4473" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_ym19_1_1466198704593_4476" dir="ltr"> <font id="yui_3_16_0_ym19_1_1466198704593_4477" face="Arial" size="2"> <hr size="1" id="yui_3_16_0_ym19_1_1466198704593_4514"> <b><span style="font-weight: bold;">From:</span></b> hank pronk via Personal_Submersibles <personal_submersibles@psubs.org><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> Saturday, June 18, 2016 8:40 AM<br> <b><span style="font-weight: bold;">Subject:</span></b> [PSUBS-MAILIST] Listing solved<br> </font> </div> <div class="y_msg_container" id="yui_3_16_0_ym19_1_1466198704593_4472"><br><div id="yiv4220740833"><div id="yui_3_16_0_ym19_1_1466198704593_4471"><div id="yui_3_16_0_ym19_1_1466198704593_4470" 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 id="yiv4220740833yui_3_16_0_ym19_1_1466195068419_2645" 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 id="yiv4220740833yui_3_16_0_ym19_1_1466195068419_2645" 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 id="yiv4220740833yui_3_16_0_ym19_1_1466195068419_2645" dir="ltr">Hank</div><div id="yiv4220740833yui_3_16_0_ym19_1_1466195068419_2645" dir="ltr"><br></div><div id="yiv4220740833yui_3_16_0_ym19_1_1466195068419_2645" dir="ltr">Oh ya and my hip waders had another leak.</div><div id="yiv4220740833yui_3_16_0_ym19_1_1466195068419_2645" dir="ltr"><br></div></div></div></div><br>_______________________________________________<br>Personal_Submersibles mailing list<br><a href="mailto:Personal_Submersibles@psubs.org" ymailto="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br><br><br></div> </div> </div> </div></div></body></html>