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<body link="#000000" vlink="#000000" alink="#000080" topmargin=0 leftmargin=0 marginwidth="0" marginheight="0"><font face="Courier New" size=2>Hi Alan, <BR><BR>additional the sub can dynamic
unstable during surfacing.<BR> <BR>There is a lot of water in the free
flooding open sail.<BR>If you surface fast and with to small opening in the
<BR>bottom of the free flooding sail the extra weight can <BR>move
the CG so high that the sub tends to get heavy <BR>side angles during
surfacing until the water rush out. <BR><BR>The picture 8382a shows the
higher waterlevel during surfacing <BR>in the sail and the MBT sadlle tanks
still under water <BR>but for this sub the extra weight was not
critical.<BR><BR>But on a military one with there tons of <BR>water in the sail
during a fast emergency surfacing <BR>it can be a problem. <BR><BR>By the way
Euronaut has no Kingston valve without any problem<BR>and a positve GB alltimes
greater than 2". <BR>On dive station or surfaced. <BR>And great openings in the
bottom of the sail. <BR><BR>Boats without Kingston valve tends to lost some
<BR>bouancy during rough sea. The tanks and the seastage<BR>work like a air pump
and some water enter the tanks.<BR><BR>On the otherside a boat with Kingston and
a <BR>compressed air blow out system can blow away the <BR>tanks very fast if
you forget to open the Kingstons <BR>during blowing the tanks or have a air leak
<BR>in the in the pipe to the tanks.<BR><BR>vbr Carsten <BR> </font>
<BR>
<BR>"Alan James" <alanlindsayjames@yahoo.com> schrieb:
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><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554">Hi everyone,</div><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554">While reading through some background info for the G.L.</div><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554">certification document, I came across this link with a good</div><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554">explanation of stability & buoyancy</div><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554"><a
href="http://maritime.org/doc/fleetsub/chap5.htm">http://maritime.org/doc/fleetsub/chap5.htm</a><br></div><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554">There is a phenomena described, where submarines can be </div><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554">unstable to the point of turning over during the transition from</div><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554">surface to diving & vice versa.</div><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554">This has to do with the centre of buoyancy moving upward past</div><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554">the centre of gravity. As it approaches the centre of gravity the</div><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554">submarine is at it's most vulnerable point.</div><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554">This would be different for individual designs & a worry if</div><div
id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554">you dropped your emergency drop weight.</div><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554">I had been told by a pilot that he never stuffed around while</div><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554">descending & liked to drop as quick as he could.</div><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554">I didn't have a full understanding of this & thought there may</div><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554">be others in the same boat.</div><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554">Regards Alan</div><div id="yiv3971601525yui_3_13_0_ym1_1_1385768974238_2554"><br></div></div></div></div><span></span><div></div></div>
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<font face="Courier New" size=2> </font><font face="Courier New" size=2><br><br>-- <br><BR>Carsten Standfuß<BR>Dipl.Ing.Schiffbau @ Meerestechnik<BR>Heinrich Reck Str.12A<BR>18211 Admannshagen<BR><BR>0172 8464 420<BR>WWW.Euronaut.org<BR>Carsten@euronaut.org</font></body>
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