<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>Marc,</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>>></span><span style="font-size: 15.555556297302246px;">Right now I feel like I'm one of a tiny deviant cult</span><span style="font-size: 15.555556297302246px;"> .......</span></div><div style="color: rgb(0, 0, 0); font-size: 15.555556297302246px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 15.555556297302246px;">   Well you are an American of French heritage hiding away on an obscure</span></div><div
 style="color: rgb(0, 0, 0); font-size: 15.555556297302246px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 15.555556297302246px;">seldom visited South East Asian Island populated by man hungry women</span></div><div style="color: rgb(0, 0, 0); font-size: 15.555556297302246px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 15.555556297302246px;">& Moslem rebels.</span></div><div style="color: rgb(0, 0, 0); font-size: 15.555556297302246px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span style="font-size: 15.555556297302246px;">Alan</span></div><div><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> Marc de Piolenc <piolenc@archivale.com><br> <b><span style="font-weight: bold;">To:</span></b> personal_submersibles@psubs.org <br> <b><span style="font-weight: bold;">Sent:</span></b> Saturday, April 12, 2014 1:42 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [PSUBS-MAILIST] concrete<br> </font> </div> <div class="y_msg_container"><br>I think I will post those reports to Dropbox.<br clear="none"><br clear="none">Right now I feel like I'm one of a tiny deviant cult of Portland cement <br clear="none">cultists within the psubs community. Maybe the reports will help me <br clear="none">proselytize new adherents...<br
 clear="none"><br clear="none">Marc<br clear="none"><br clear="none">On 4/12/2014 9:03 AM, hank pronk wrote:<br clear="none">> Marc,<br clear="none">> Not only is it dirt cheap, concrete is so easy to form. The material cost for a 6 foot sphere is in the hundreds, not thousands. Hank<br clear="none">> --------------------------------------------<br clear="none">> On Fri, 4/11/14, Marc de Piolenc <<a shape="rect" ymailto="mailto:piolenc@archivale.com" href="mailto:piolenc@archivale.com">piolenc@archivale.com</a>> wrote:<br clear="none">><br clear="none">>   Subject: Re: [PSUBS-MAILIST] concrete<br clear="none">>   To: "Personal Submersibles General Discussion" <<a shape="rect" ymailto="mailto:personal_submersibles@psubs.org" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br clear="none">>   Received: Friday, April 11, 2014, 8:26 PM<br clear="none">><br
 clear="none">>   I don't have hard numbers, but<br clear="none">>   remember that resistance to mostly<br clear="none">>   compressive loading is a structural STABILITY problem. Most<br clear="none">>   practical<br clear="none">>   steel structures buckle under compression long before<br clear="none">>   reaching their<br clear="none">>   actual compression limit. Concrete has an advantage there<br clear="none">>   due to its<br clear="none">>   stiffness - the NCEL tests suggest that it comes much closer<br clear="none">>   to using<br clear="none">>   its full compressive strength.<br clear="none">><br clear="none">>   That said, my primary interest in concrete is due to its<br clear="none">>   cost and ease<br clear="none">>   of maintenance.<br clear="none">><br clear="none">>   Marc<br clear="none">><br
 clear="none">>   PS. If anybody is interested, I will add the relevant<br clear="none">>   reports that I<br clear="none">>   have to my public Dropbox folder and post the link.<br clear="none">><br clear="none">>   On 4/12/2014 3:15 AM, hank pronk wrote:<br clear="none">>   > A six foot od sphere built in 1.25in thick steel would<br clear="none">>   be equal in weight to 4in thick concrete.  I would not<br clear="none">>   ever expect 4in concrete to compare to 1.25 steel.<br clear="none">>   But, it would be interesting to know where the concrete<br clear="none">>   stands in comparison.<br clear="none">>   > Hank<br clear="none">>   > --------------------------------------------<br clear="none">>   > On Fri, 4/11/14, Marc de Piolenc <<a shape="rect" ymailto="mailto:piolenc@archivale.com"
 href="mailto:piolenc@archivale.com">piolenc@archivale.com</a>><br clear="none">>   wrote:<br clear="none">>   ><br clear="none">>   >   Subject: Re: [PSUBS-MAILIST] concrete<br clear="none">>   >   To: "Personal Submersibles General<br clear="none">>   Discussion" <<a shape="rect" ymailto="mailto:personal_submersibles@psubs.org" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>><br clear="none">>   >   Received: Friday, April 11, 2014, 9:59<br clear="none">>   AM<br clear="none">>   ><br clear="none">>   >   A huge amount of work was done on<br clear="none">>   >   concrete for pressure-resisting<br clear="none">>   structures, including long<br clear="none">>   >   term, deep exposure tests, by the US<br clear="none">>   Naval Civil Engineering<br
 clear="none">>   >   Laboratory. Most of the reports are<br clear="none">>   available for<br clear="none">>   >   downloading free of charge from DTIC.<br clear="none">>   ><br clear="none">>   >   Excellent results were achieved with<br clear="none">>   concrete having NO<br clear="none">>   >   reinforcement. There has been limited<br clear="none">>   work done with<br clear="none">>   >   prestressed concrete and even less<br clear="none">>   done with reinforced<br clear="none">>   >   concrete and ferrocement, which can<br clear="none">>   reasonably be expected<br clear="none">>   >   to give much more efficient and<br clear="none">>   distortion-tolerant<br clear="none">>   >   structures.<br clear="none">>   ><br clear="none">>   >  
 Marc<br clear="none">>   ><br clear="none">>   >   On 4/11/2014 8:25 PM, hank pronk<br clear="none">>   wrote:<br clear="none">>   >   > A cheap alternative to a super<br clear="none">>   strong sphere hull is<br clear="none">>   >   re-enforced concrete. I feel like<br clear="none">>   hiding under a blanket<br clear="none">>   >   while I say this,lol.  I know it<br clear="none">>   is way out there, but<br clear="none">>   >   concrete is super strong under<br clear="none">>   compression.  It is not<br clear="none">>   >   so good for impact resistance.<br clear="none">>   Concrete is a very easy<br clear="none">>   >   material to work with and form into a<br clear="none">>   sphere shape.  I<br clear="none">>   >   have no idea what
 thickness would be<br clear="none">>   needed.  Properly<br clear="none">>   >   engineered I would trust it.<br clear="none">>   >   > Hank<br clear="none">>   >   ><br clear="none">>   >   ><br clear="none">>   _______________________________________________<br clear="none">>   >   > Personal_Submersibles mailing<br clear="none">>   list<br clear="none">>   >   > <a shape="rect" ymailto="mailto:Personal_Submersibles@psubs.org" href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br clear="none">>   >   > <a shape="rect" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none">>   >   ><br clear="none">>   ><br
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