<table cellspacing="0" cellpadding="0" border="0"><tr><td valign="top">Jon,<br/><br/>I like it, I'll look it over closer when I get home.<br/><br/>There's a bit of trepidation for an amateur to tread new design territory, but you're correct we have tools available to maintain a safe conservative approach.<br/><br/>Thanks!<br/><br/>Joe<a href="http://overview.mail.yahoo.com?.src=iOS"><br/><br/>Sent from Yahoo Mail for iPad</a></td></tr></table> <div id="_origMsg_">
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<span style="font-weight:bold">From:</span>
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Jon Wallace <jonw@psubs.org>; <br>
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<span style="font-weight:bold">To:</span>
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PSUBS Member Discussion Group <member-forum@psubs.org>; <br>
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<span style="font-weight:bold">Subject:</span>
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Re: [Member-Forum] Moment of Inertia <br>
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<span style="font-weight:bold">Sent:</span>
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Fri, Mar 28, 2014 1:07:49 PM <br>
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Hi Joe,<br clear="none">
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I don't recall ever seeing a rule of thumb for t-ribs. The hull
calculator worksheet on the website will let you see how rib
dimensions affect the strength of the hull. Sean Stevenson once
gave a good explanation of the relationship between the hull and
ribs but I can't find that email at the moment. In general, and
this is REALLY just a general statement, my experience with the
hull calculator has shown that ribs of the same thickness as the
hull, 4 times thickness for the web, and 6 times thickness for the
flange, are appropriate. That may not produce ideal results in
every instance, but for conceptual rule-of-thumb it should be
adequate.<br clear="none">
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Jon<br clear="none">
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On 3/25/2014 10:10 AM, Joe Perkel wrote:<br clear="none">
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<table cellpadding="0" cellspacing="0" border="0"><tbody><tr><td colspan="1" rowspan="1" valign="top">Hi Paul,<br clear="none">
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The question is anecdotal based on an off the cuff thought
of upsizing the shell O.D. to 42" from 36". I am very
hesitant to do this do to weight and handling issues
however, several members have made a compelling rationale
r/t simple comfort. At 53 I'm 6' 190 lbs and should expect
that L to W ratio to change by build time! <br clear="none">
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I have to think a bit about the shell thickness r/t
welding and corrosion issues, but Depth no more than 350'.
I seem to remember a cross section drawing of a T section
somewhere with a simple L/W/H relationship to shell T, but
can't find it again. <br clear="none">
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I'll take that pdf if you don't mind. I'm not at home and
won't be until later this week to do some number
crunching.<br clear="none">
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Thanks Paul!<br clear="none">
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Joe<a rel="nofollow" shape="rect" target="_blank" href="http://overview.mail.yahoo.com?.src=iOS"><br clear="none">
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Sent from Yahoo Mail for iPad</a></td></tr></tbody></table>
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