<html><head></head><body><div style="color:#000; background-color:#fff; font-family:verdana, helvetica, sans-serif;font-size:13px"><div id="yui_3_16_0_ym19_1_1502486076526_4971"><span>Hank,</span></div><div id="yui_3_16_0_ym19_1_1502486076526_4971"><span><br></span></div><div id="yui_3_16_0_ym19_1_1502486076526_4971" dir="ltr">Too bad we don't have the captain around to answer questions anymore- he did it all. George was an expert at building simple things that worked really well.</div><div id="yui_3_16_0_ym19_1_1502486076526_4971" dir="ltr"><br></div><div id="yui_3_16_0_ym19_1_1502486076526_4971" dir="ltr">Don't worry about 6 hp being too small- it will be plenty. George was working on another diesel boat for himself before he passed. I think that the engine was 7 hp. The hull is now on display in South Thomaston ME. as a memorial to him.</div><div id="yui_3_16_0_ym19_1_1502486076526_4971" dir="ltr"><br></div><div id="yui_3_16_0_ym19_1_1502486076526_4971" dir="ltr">Ideally, a high thrust motor needs to be pushing at the metacentric point (average between center of buoyancy and center of gravity) This point is usually very low on a shallow diving sub. There are a couple of guys around that mounted high thrust engines at the mid point on the stern and found that the subs would nose dive at full power. You can get away with a center mounted prop when the thrust is low.</div><div id="yui_3_16_0_ym19_1_1502486076526_4971" dir="ltr"><br></div><div id="yui_3_16_0_ym19_1_1502486076526_4971" dir="ltr">George also ran the engine with the intake open to the inside of the hull and the hatch open for simplicity. He used flexible stainless exhaust hose through a ball valve at the bottom of the hull. The "skeg" was a thick piece of steel angle welded to the bottom (pointing down and back) ahead of the exhaust outlet with the "V" pointing forward.</div><div id="yui_3_16_0_ym19_1_1502486076526_4971" dir="ltr"><br></div><div id="yui_3_16_0_ym19_1_1502486076526_4971" dir="ltr">Greg C.</div><div class="qtdSeparateBR" id="yui_3_16_0_ym19_1_1502486076526_5170"><br><br></div><div class="yahoo_quoted" id="yui_3_16_0_ym19_1_1502486076526_5191" style="display: block;"> <div style="font-family: verdana, helvetica, sans-serif; font-size: 13px;" id="yui_3_16_0_ym19_1_1502486076526_5190"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;" id="yui_3_16_0_ym19_1_1502486076526_5189"> <div dir="ltr" id="yui_3_16_0_ym19_1_1502486076526_5188"> <font size="2" face="Arial" id="yui_3_16_0_ym19_1_1502486076526_5193"> <hr size="1" id="yui_3_16_0_ym19_1_1502486076526_5192"> <b><span style="font-weight:bold;">From:</span></b> hank pronk via Personal_Submersibles <personal_submersibles@psubs.org><br> <b><span style="font-weight: bold;">To:</span></b> Personal Submersibles General Discussion <personal_submersibles@psubs.org> <br> <b><span style="font-weight: bold;">Sent:</span></b> Friday, August 11, 2017 5:14 PM<br> <b id="yui_3_16_0_ym19_1_1502486076526_5761"><span style="font-weight: bold;" id="yui_3_16_0_ym19_1_1502486076526_5760">Subject:</span></b> Re: [PSUBS-MAILIST] Gamma's diesel engine<br> </font> </div> <div class="y_msg_container" id="yui_3_16_0_ym19_1_1502486076526_5759"><br><div id="yiv8577125303"><div id="yui_3_16_0_ym19_1_1502486076526_5877"><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;" id="yui_3_16_0_ym19_1_1502486076526_5876"><div id="yui_3_16_0_ym19_1_1502486076526_5875"><div id="yui_3_16_0_ym19_1_1502486076526_5874">Hi Greg,</div></div><div id="yui_3_16_0_ym19_1_1502486076526_5878">Thank you for the input. That is good to know that the captain liked the diesel model. I have been torn over the idea, but since I have an actual engine room with insulated door, it should be fine. My 6 hp motor sounds small now, I can get a bigger one. My problem is it has to fit through a 18 in dia opening with ease so the escape pod can still be an escape pod. Gamma had a 2 hp electric originally with the prop in the centre of the height. I figure the 6 hp diesel should be double that and spin the prop twice the speed. I will take the transmission advice, I have one so no problem there.</div><div id="yui_3_16_0_ym19_1_1502486076526_5879">Hank</div><div id="yui_3_16_0_ym19_1_1502486076526_5880"><br clear="none"></div><div><br clear="none"></div><div class="yiv8577125303yqt8302741324" id="yiv8577125303yqt71017"><div class="yiv8577125303yahoo_quoted" id="yiv8577125303yahoo_quoted_3153971171" style="display: block;"><div style="font-family:'Helvetica Neue', Helvetica, Arial, sans-serif;font-size:13px;color:#26282a;" id="yui_3_16_0_ym19_1_1502486076526_5882"><div id="yui_3_16_0_ym19_1_1502486076526_5881">On Friday, August 11, 2017, 6:31:48 AM MDT, james cottrell via Personal_Submersibles <personal_submersibles@psubs.org> wrote:</div><div><br clear="none"></div><div id="yui_3_16_0_ym19_1_1502486076526_5893"><br clear="none"></div><div><div id="yiv8577125303"></div></div></div></div></div></div></div><div class="yiv8577125303yqt8302741324" id="yiv8577125303yqt73438"><div id="yui_3_16_0_ym19_1_1502486076526_5885"><div id="yui_3_16_0_ym19_1_1502486076526_5884"><div style="color:#000;background-color:#fff;font-family:verdana, helvetica, sans-serif;font-size:13px;" id="yui_3_16_0_ym19_1_1502486076526_5883"><div id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_11809"><span id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_11911">Hank,</span></div><div id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_11809"><span><br clear="none"></span></div><div id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_11809"><span id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_11913">Captain Kittredge built three diesel subs and liked them very much. He used 7-8 hp yanmar diesels with a transmission. He highly recommended using a transmission and considered reverse a necessity. Exhaust existed at the bottom of the hull just behind a makeshift "skeg" that created cavitation (vacuum to reduce back pressure). </span></div><div id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_11809"><span><br clear="none"></span></div><div id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_11809">The prop should be below center on a sub due to the low center of gravity. If you place a powerful prop as high up as the middle it will lift the stern.<br clear="none"></div><div id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_11809"><span><br clear="none"></span></div><div id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_11809"><span id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_12062">Greg C</span></div><div class="yiv8577125303qtdSeparateBR" id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_11840"><br clear="none"><br clear="none"></div><div class="yiv8577125303yahoo_quoted" id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_11934" style="display:block;"> <div id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_11933" style="font-family:verdana, helvetica, sans-serif;font-size:13px;"> <div id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_11932" style="font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px;"> <div class="yiv8577125303yqt1107302114" id="yiv8577125303yqt82674"><div dir="ltr" id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_11931"> <font id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_12180" size="2" face="Arial"> </font><hr id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_12179" size="1"> <b id="yui_3_16_0_ym19_1_1502486076526_6023"><span style="font-weight:bold;" id="yui_3_16_0_ym19_1_1502486076526_6022">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> Thursday, August 10, 2017 5:14 PM<br clear="none"> <b><span style="font-weight:bold;">Subject:</span></b> [PSUBS-MAILIST] Gamma's diesel engine<br clear="none"> </div> <div class="yiv8577125303y_msg_container" id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_12159"><br clear="none"><div id="yiv8577125303"><div id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_12158"><div id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_12157" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:small;"><div id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_12156">Hi All,</div><div id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_12173">I have just purchased a 6 hp diesel for Gamma. The plan is to use the original prop assembly that can jettison. The only thing I am not sure of is will I have cavitation problems. The prop will be about 12 inches from the occupant sphere, mounted in the centre of the sphere (equator) </div><div id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_12175">Will I have to put a spacer between the sphere and prop assembly to move it further away?</div><div id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_12161">Hank</div><div id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_12177"><br clear="none"></div><div id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_12171"><br clear="none"></div></div></div></div>_______________________________________________<br clear="none">Personal_Submersibles mailing list<br clear="none"><a rel="nofollow" shape="rect" ymailto="mailto:Personal_Submersibles@psubs.org" target="_blank" href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br clear="none"><a rel="nofollow" shape="rect" id="yiv8577125303yui_3_16_0_ym19_1_1502453497437_12164" target="_blank" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none"><br clear="none"><br clear="none"></div></div> </div> </div> </div></div></div></div></div><div><div class="yiv8577125303yqt1107302114" id="yiv8577125303yqt09366"></div></div><div>_______________________________________________<br clear="none">Personal_Submersibles mailing list<br clear="none"><a rel="nofollow" shape="rect" ymailto="mailto:Personal_Submersibles@psubs.org" target="_blank" href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br clear="none"><a rel="nofollow" shape="rect" target="_blank" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none"></div></div><div class="yqt8302741324" id="yqt22662">_______________________________________________<br clear="none">Personal_Submersibles mailing 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"></div><br><br></div> </div> </div> </div></div><div id="DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2"><br>
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