<html><head></head><body><p dir="ltr">Hank, the acrylic will not carry any of the hull hoop stresses - it simply isn't strong enough to do so. You have to analyze the opening as if the acrylic isn't there, which means you need sufficient reinforcement around the opening to carry the stress that would otherwise have been carried by the steel that was removed. The stress in the reinforcement will be greater than the nominal shell stress because of the stress concentration resulting from the new geometry.</p>
<p dir="ltr">In short, you can determine the required acrylic window thickness, and design a window frame accordingly, but that alone does not determine how much steel needs to be in that frame. That is instead determined by the shell stresses that must necessarily be routed around - not through - the opening.</p>
<p dir="ltr">Sean<br>
</p>
<br><br><div class="gmail_quote">On July 3, 2017 5:32:36 PM PDT, hank pronk via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div style="color:#000; background-color:#fff; font-family:Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:13px"><div><span>Greg,</span></div><div><span>I am having trouble understanding why Ron says you need a hell of a lot more material that 100% rule for a window opening. </span></div><div id="yui_3_16_0_ym19_1_1499126880347_22380"><span id="yui_3_16_0_ym19_1_1499126880347_22379">My logic is as follows, if you remove a conical section out of a heavy wall sphere and the angle intersects the centre of the sphere, you can glue it back in and the hull has not lost strength in that area. Now if you replace that with an identical section of acrylic, it will not work. To my mind the reason it will not work is, the acrylic will compress and the mass is no longer sufficient to carry the load along the load path into the hull. Now, if the acrylic is thicker, it will handle the pressure without failing and it can compress and have enough
strength to carry the load to the frame . The window port frame need only transfer the force from the extra thickness into the load path. In short, to me, the port frame is only supporting the extra acrylic thickness and transferring the force into the hull. </span></div><div id="yui_3_16_0_ym19_1_1499126880347_22380"><span>Hank</span></div> <div class="qtdSeparateBR"><br /><br /></div><div class="yahoo_quoted" style="display: block;"> <div style="font-family: Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 13px;"> <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 Monday, June 26, 2017 6:58 PM, james cottrell via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<br /></font></div> <br /><br /> <div class="y_msg_container"><div id="yiv8670007850"><div><div
style="color:#000;background-color:#fff;font-family:verdana, helvetica, sans-serif;font-size:13px;"><div id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_3052"><span id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_3241">Here is a pic of Ron piloting the sub at 850 meters.</span></div><div dir="ltr" id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_3052"><span><a rel="nofollow" shape="rect" target="_blank" href="http://ocean-innovations.net/OceanInnovationsNEW/Global%20Ocean%20Design/ont_part3_god.pdf">http://ocean-innovations.net/OceanInnovationsNEW/Global%20Ocean%20Design/ont_part3_god.pdf</a><br clear="none" /></span></div><div id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_3052"><span><br clear="none" /></span></div><div dir="ltr" id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_3052"><span id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_4886">Ron told me that the rule about replacing the same amount of material removed from the viewport opening was wrong -"you need a hell of
a lot more" were his exact words. He also used a different steel for the hatch (300 M). He said that the best lube for the port was a "dry glide" spray from CRC. Contrary to popular thinking, vacuum or silcone grease stores up pressure and then releases it with a BANG! He really knows his stuff...</span></div><div dir="ltr" id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_3052"><span><br clear="none" /></span></div><div dir="ltr" id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_3052"><span id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_5175">There are a few good drawings of the DSC hull online and they might come in handy since you will be building something very similar.</span></div><div dir="ltr" id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_3052"><span><br clear="none" /></span></div><div dir="ltr" id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_3052"><span>Greg</span></div><div class="yiv8670007850qtdSeparateBR"
id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_3048"><br clear="none" /><br clear="none" /></div><div class="yiv8670007850yahoo_quoted" id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_4743" style="display:block;"> <div id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_4742" style="font-family:verdana, helvetica, sans-serif;font-size:13px;"> <div id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_4741" style="font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"> <div class="yiv8670007850yqt5197462937" id="yiv8670007850yqt66646"><div dir="ltr" id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_4748"> <font id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_4753" size="2" face="Arial"> </font><hr id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_4754" size="1" /> <b><span style="font-weight:bold;">From:</span></b> hank pronk via Personal_Submersibles <personal_submersibles@psubs.org><br clear="none" /> <b><span
style="font-weight:bold;">To:</span></b> Personal Submersibles General Discussion <personal_submersibles@psubs.org> <br clear="none" /> <b><span style="font-weight:bold;">Sent:</span></b> Monday, June 26, 2017 8:28 PM<br clear="none" /> <b><span style="font-weight:bold;">Subject:</span></b> Re: [PSUBS-MAILIST] Pressure Test<br clear="none" /> </div> <div class="yiv8670007850y_msg_container" id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_4740"><br clear="none" /><div id="yiv8670007850"><div id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_4739"><div id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_4738" style="color:#000;background-color:#fff;font-family:Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:13px;"><div id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_4747"><span>Greg,</span></div><div id="yiv8670007850yui_3_16_0_1_1498522847649_3451"><span id="yiv8670007850yui_3_16_0_1_1498522847649_3450">Being a non engineer, I am a copy cat, that is how I
built Elementary 3000, I listened to what Sean had to say, I studied Scotts P6 and even duplicated Scott's P6 port and frame. You could take my port and fit it in Scotts sub. I stole the port in the Hatch Idea. The only idea I have had is to glue and bolt the whole thing together. Trieste has a second sphere from new and it is made from 3 perfectly machined sections.</span></div><div id="yiv8670007850yui_3_16_0_1_1498522847649_3451">Hank</div> <div class="yiv8670007850qtdSeparateBR" id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_5387"><br clear="none" /><br clear="none" /></div><div class="yiv8670007850yahoo_quoted" id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_4737" style="display:block;"> <div id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_4736" style="font-family:Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:13px;"> <div id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_4735" style="font-family:HelveticaNeue, Helvetica
Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"> <div class="yiv8670007850yqt2433550747" id="yiv8670007850yqt48227"><div dir="ltr" id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_5389"><font id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_5388" size="2" face="Arial"> On Monday, June 26, 2017 5:56 PM, james cottrell via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<br clear="none" /></font></div> <br clear="none" /><br clear="none" /> <div class="yiv8670007850y_msg_container" id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_4734"><div id="yiv8670007850"><div id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_4733"><div id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_4732" style="color:#000;background-color:#fff;font-family:verdana, helvetica, sans-serif;font-size:13px;"><div dir="ltr" id="yiv8670007850yui_3_16_0_ym19_1_1498520104705_4414"><span id="yiv8670007850yui_3_16_0_ym19_1_1498520104705_4413">I had the pleasure of meeting him at Nat
Geo when Jim C was there with the sub and gave a talk. Ron is THE MAN! Probably the most knowledgeable DEEP sub builder today. If you're serious about Titanic, find out EVERYTHING you can about the way he put that sub together.</span></div><div dir="ltr" id="yiv8670007850yui_3_16_0_ym19_1_1498520104705_4414"><span id="yiv8670007850yui_3_16_0_ym19_1_1498520104705_5353">One thing he told me was never used silicone grease on a viewport and added that "it is the worst". Through testing, Ron discovered that a lot of accepted standards and practices about deep sub construction are actually not correct.</span></div><div dir="ltr" id="yiv8670007850yui_3_16_0_ym19_1_1498520104705_4414"><span><br clear="none" /></span></div><div dir="ltr" id="yiv8670007850yui_3_16_0_ym19_1_1498520104705_4414"><span>Greg</span></div><div class="yiv8670007850qtdSeparateBR" id="yiv8670007850yui_3_16_0_ym19_1_1498520104705_4278"><br clear="none" /><br clear="none" /></div><div
class="yiv8670007850yahoo_quoted" id="yiv8670007850yui_3_16_0_ym19_1_1498520104705_4992" style="display:block;"> <div id="yiv8670007850yui_3_16_0_ym19_1_1498520104705_4991" style="font-family:verdana, helvetica, sans-serif;font-size:13px;"> <div id="yiv8670007850yui_3_16_0_ym19_1_1498520104705_4990" style="font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"> <div class="yiv8670007850yqt3796256681" id="yiv8670007850yqt16715"><div dir="ltr" id="yiv8670007850yui_3_16_0_ym19_1_1498520104705_4989"> <font id="yiv8670007850yui_3_16_0_ym19_1_1498520104705_4988" size="2" face="Arial"> </font><hr id="yiv8670007850yui_3_16_0_ym19_1_1498520104705_4987" size="1" /> <b id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_5512"><span id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_5511" style="font-weight:bold;">From:</span></b> hank pronk via Personal_Submersibles <personal_submersibles@psubs.org><br clear="none" /> <b
id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_5514"><span id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_5513" style="font-weight:bold;">To:</span></b> Personal Submersibles General Discussion <personal_submersibles@psubs.org> <br clear="none" /> <b id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_5516"><span id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_5515" style="font-weight:bold;">Sent:</span></b> Monday, June 26, 2017 7:32 PM<br clear="none" /> <b id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_5518"><span id="yiv8670007850yui_3_16_0_ym19_1_1498523979012_5517" style="font-weight:bold;">Subject:</span></b> Re: [PSUBS-MAILIST] Pressure Test<br clear="none" /> </div> <div class="yiv8670007850y_msg_container" id="yiv8670007850yui_3_16_0_ym19_1_1498520104705_5800"><br clear="non"
/></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div></blockquote></div></body></html>