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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b>…</b>> <b>On Behalf Of </b>Adrian Tymes via extropy-chat<br><b>Subject:</b> Re: [ExI] cool wind map graphic<o:p></o:p></p></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Tue, Jul 12, 2022 at 11:05 AM spike jones via extropy-chat <<a href="mailto:extropy-chat@lists.extropy.org">extropy-chat@lists.extropy.org</a>> wrote:<o:p></o:p></p></div><div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in'><p class=MsoNormal>Sea air is highly corrosive, so it makes for an interesting mechanical engineering puzzle to figure out how to make those rigs corrosion resistant.<o:p></o:p></p></blockquote><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>>…Why not just make it from copper, or something else that doesn't corrode? It's not like some homeless vagrant is going to roll up at sea and swipe it - or if they do, it'll be easy to identify when they try to fence it…<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Copper is way too expensive, and it does corrode if exposed to sulfur. There are sulfur ions in sea water, which is why brass aboard a ship needs to be polished regularly. Brass is more corrosion resistant than straight copper but it too will take on the classic greenish color if that top layer isn’t constantly removed.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Stainless steel does pretty well at sea, as does titanium, but cost is a huge factor. It might be the solution is the one navies have relied upon since steel came into fashion for ships: paint. Lotsa paint, over ordinary alloyed steel. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>It is easy enough to imagine some kind of surface-clinging robot which would crawl along, clean, paint, move along, perhaps operating 24/7, coming back to the hub for fresh paint, pausing operations if the wind gets too high or it is too wet that day. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>It would be a fun design exercise to imagine a crawler that could do its work on a spinning turbine of say 50 meter length, turning at 20rpm. Tip acceleration: I’m getting about 10.6 meters per second, so about 1 G, sounds manageable to me.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>On the other hand… the more I ponder it, the vertical axis designs sound ever more compelling.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><a href="https://www.youtube.com/watch?v=EM-gCvhQhPU">https://www.youtube.com/watch?v=EM-gCvhQhPU</a><o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Even if not practical, the young lady doing the presentation is most comely.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>As I write this, it occurred to me that all this already been studied 28 ways to Sunday. I need to spend some time getting up to speed on where we are with it.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>spike<o:p></o:p></p></div></div></div></div></body></html>