sunday Posted November 11, 2021 Share Posted November 11, 2021 (edited) 12 hours ago, Ssnake said: My friend at TKMS naval engineering has a much less favorable view on the implications, R011. This may very well lead to extensive yard time for some boats. No wonder, if they need to retest all the affected steel. I think usually you have to cut out a test specimen to do one of those tests, but I am no expert on the matter. A possible procedure is explained here: http://www.navweaps.com/index_tech/tech-037.php Edited November 11, 2021 by sunday Link to comment Share on other sites More sharing options...
shep854 Posted November 11, 2021 Share Posted November 11, 2021 I wonder if her tune would change if she rode a sub to test depth, watched the string sag and listened to the ship groaning? Link to comment Share on other sites More sharing options...
DB Posted November 11, 2021 Share Posted November 11, 2021 2 hours ago, shep854 said: I wonder if her tune would change if she rode a sub to test depth, watched the string sag and listened to the ship groaning? I think that one needs to be able to imagine the risk to others that arise as a consequence of your actions. It should be clear to anyone who has observed people at all for a few years that analysis of potential consequences does not often factor into peoples' thinking. Just look at how many people can't live within their means when they earn enough to do so, and the appalling risks taken by people to save a few seconds in traffic. Link to comment Share on other sites More sharing options...
R011 Posted November 11, 2021 Share Posted November 11, 2021 7 hours ago, RETAC21 said: I would say the steel hasn't been tested in real life to the conditions of the test, but these are not outlandish, -100 F comes to -38C which is a temperature that is not uncommon in the Arctic. A collision or an impact may have significant consequences for those inside the people tank, and subsafe was written in blood, those of the crewmen of the Thresher and Scorpion. Minus 100 F is Minus 73 C. You're thinking of Plus 100 F. The Arctic Ocean, the coldest place a sub can operate, doesn't get that cold. The air temperature rarely gets below Minus 40 C/Minus 40 F while the water temp is above zero/Plus 32 F - or it would be ice. Link to comment Share on other sites More sharing options...
RETAC21 Posted November 11, 2021 Share Posted November 11, 2021 3 minutes ago, R011 said: Minus 100 F is Minus 73 C. You're thinking of Plus 100 F. The Arctic Ocean, the coldest place a sub can operate, doesn't get that cold. The air temperature rarely gets below Minus 40 C/Minus 40 F while the water temp is above zero/Plus 32 F - or it would be ice. You are absolutely right indeed. Link to comment Share on other sites More sharing options...
RETAC21 Posted November 11, 2021 Share Posted November 11, 2021 1 hour ago, DB said: I think that one needs to be able to imagine the risk to others that arise as a consequence of your actions. It should be clear to anyone who has observed people at all for a few years that analysis of potential consequences does not often factor into peoples' thinking. Just look at how many people can't live within their means when they earn enough to do so, and the appalling risks taken by people to save a few seconds in traffic. Always remember the Military Intelligence motto: We bet your life. Link to comment Share on other sites More sharing options...
R011 Posted November 11, 2021 Share Posted November 11, 2021 5 minutes ago, RETAC21 said: You are absolutely right indeed. Mind you, it is nice to know there is a big margin of safety. I'm sure they didn't decide on this temperature randomly, and there is a reason the company got fined and the tester faces jail. Link to comment Share on other sites More sharing options...
bojan Posted November 11, 2021 Share Posted November 11, 2021 Mr.Nitpicker - -2 - -3 deg C is actually freezing point for sea water, not zero. Link to comment Share on other sites More sharing options...
DB Posted November 11, 2021 Share Posted November 11, 2021 (edited) MIL-STD-810G goes into some (!) detail when describing environmental conditions, everything from temperature to pressure to vibration and such. Here is what it says as a summary cold environmental conditions: Quote Cold and Severe Cold Climatic Categories. These areas include northern North America, Greenland, northern Asia, and Tibet. In the Cold Climatic Category, the temperature during the coldest month in a normal year may be colder than the Basic Climatic Category cold extreme of -32°C (-25°F). In the Severe Cold areas, the temperature during the coldest month in a normal year may be colder than the Cold Climatic Category extreme of -46°C (-50°F). Temperatures colder than -51°C (-60°F) occur no more than 20 percent of the hours in the coldest month of the coldest part of the area (northern Siberia) where temperatures as low as -68°C (-90°F) have been recorded. Because extremely low temperatures are not controlled by a daily solar cycle, they persist for a long enough period of time to cause materiel to reach equilibrium at extremely low temperatures. You will note that the lowest temperature cited is for North Siberia at -68C. This is an extreme limit, and would not be likely to that experienced at sea because the sea moderates temperature extremes. It wouldn't be entirely impossible to approach that over icepack, I suppose. Anyway, this MIL-STD doesn't explicitly define the limits required for US nuclear submarines because it acknowledges that certain environments warrant special handling. Nevertheless, I think it shows that the military does not think that the low temperature limit is outlandish. Air temperatures for high altitude flight are frequently down below -50, and the coldest temperatures tend to be at the equator (once one gets high enough). Edited November 11, 2021 by DB Link to comment Share on other sites More sharing options...
KV7 Posted November 11, 2021 Share Posted November 11, 2021 (edited) The test temperature and the expected extreme operating conditions do not need to align. For example one could include tests at extreme temperatures in order to better determine the temperate toughness curve, even if you are mostly concerned with toughness at more moderate temperatures. Or it could be there as a safety margin given variations in composition etc. Edited November 11, 2021 by KV7 Link to comment Share on other sites More sharing options...
sunday Posted November 11, 2021 Share Posted November 11, 2021 1 hour ago, KV7 said: The test temperate and the expected extreme operating conditions do not need to align. For example one could include tests at extreme temperatures in order to better determine the temperate toughness curve, even if you are mostly concerned with toughness at more moderate temperatures. Or it could be there as a safety margin given variations in composition etc. Exactly. Link to comment Share on other sites More sharing options...
EchoFiveMike Posted November 11, 2021 Share Posted November 11, 2021 Single point of failure bottleneck. Stupid. Hired a woman for a critical role in an absolutely non-negotiably objective field, also stupid. S/F...Ken M Link to comment Share on other sites More sharing options...
rmgill Posted November 13, 2021 Share Posted November 13, 2021 Makes me think of the engineer in Memphis that was supposedly checking the Bridge over the Mississippi. The SINGLE engineer, who more or less started phoning it in a few years ago and missed that big crack in the bridge structure. Link to comment Share on other sites More sharing options...
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