<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 id="yui_3_16_0_ym18_1_1458735765706_3953"><span>John,</span></div><div id="yui_3_16_0_ym18_1_1458735765706_3952" dir="ltr"><span id="yui_3_16_0_ym18_1_1458735765706_3951">My hatch dome is 1 inch thick with a 2 inch thick conical ring 2 inches wide. The weight is 130 lbs at 18 inches dia. I have incorporated one torsion spring but not sure if I will use it. It is </span>easy enough to lift open. You will need a heavier set of springs is all. Do you have clearance for thicker springs. I am using one spring only and it works well. My spring is from a trailer door or trailer ramp. Two of those would lift your hatch.</div><div id="yui_3_16_0_ym18_1_1458735765706_3952" dir="ltr">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 Tuesday, March 22, 2016 7:24 PM, John Kammerer via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<br></font></div> <br><br> <div class="y_msg_container">Hank:<br> <br>You mentioned in a earlier post that your hatch was 2' thick. What is <br>the diameter and how much does it weigh? How do you open it? Do you have <br>a torsion spring or is it hydraulically operated.<br> <br>I have two 26' diameter 1' thick access hatches each weighing in at 200 <br>lbs. each I had a torsion spring made, rated at 2100 inch lbs. to <br>provide a lift assist of about 160 lbs. its not enough.<br> <br>Any suggestions anyone.<br> <br>John K.<br>(203) 414-1000<br><br>_______________________________________________<br>Personal_Submersibles mailing list<br><a ymailto="mailto:Personal_Submersibles@psubs.org" href="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>