I think the question on everyone's mind is probably how to produce a signal from inside the hull of a single-hulled cargo vessel in the North Atlantic that will allow one to relay messages in morse code to the US Navy.
Underwater ears everywhere
141–150 of 179 posts
Re: Underwater ears everywhere
#142Ever since that MH370 plane disappeared, I've been wondering. Would it going into the water make a splash that is audibly significant (compared to other surface noise i.e. waves) and would there be hydrophones in that area of the ocean, and would enough signal processing perhaps be able to locate the splash? And has all this perhaps already been done, but the people who have, can't talk about it?
It took them many days to find the Titan despite exact knowledge of where the Titanic is.
MH370 could be in a significantly wider area of the ocean so it's going to be much harder to find it. Although prices of it have already been found [1] and used to determine a crash location (35.6°S 92.8°E).
[1]: https://en.wikipedia.org/wiki/Malaysia_Airlines_Flight_370#M...
Re: Underwater ears everywhere
#143Earlier quoted context omitted.
reactor plant noises? Would like to hear more about this! Assuming the reaction itself is silent (?) what kinds of sounds is the reactor making and what are the challenges in quieting them?
In order to generate electricity from heat, one generally must transform the heat into mechanical energy first. This is most often done creating steam and using it to spin a turbine. I assume that this is the process that is noisy.
Plus all sorts of pumps and cooling loops.
Re: Underwater ears everywhere
#144> Instead, the battle of submarine silence has mostly revolved around obscure technical problems of fluid dynamics, since one of the loudest noises made by submarines is the cavitation around the screw. Cavitation is loud, but usually only happens if they're running full out. What they're really listening for now are reactor plant noises. > I don't know if this is true today, but at least years ago the low-noise desi…
reactor plant noises? Would like to hear more about this! Assuming the reaction itself is silent (?) what kinds of sounds is the reactor making and what are the challenges in quieting them?
lol not today FBI! ;)
Re: Underwater ears everywhere
#145Earlier quoted context omitted.
How does this interact with the norm of commercial vessels responding to distress calls at sea? I know distress calls aren't at all the same as search and rescue, but in some incidents both phases must occur.
There’s a bit of a difference between a ship already at sea altering it’s course to get near and assist a vessel in distress (where they might be first on he scene), vs ship going to sea especially for an event I guess? You don’t want the area too crowded with “good Samaritans” who’ve all gone to sea just to assist. I recall some comments saying that operators of a submersible that could hypothetically rescue a sub s…
I would say its more of a function of not trying to have to rescue two submarines.
The depths at work, and the ambiguity of where the lost sub was would result in the coast guard being careful in deploying resources until more concrete info was nailed down.
Re: Underwater ears everywhere
#146Related but off topic (so I could understand being flagged, etc.), but in all likelihood, these capabilities could say a lot about what happened surrounding the Nord Stream pipeline explosions. I think it's a reasonable assumption that the US has these detectors beyond the borders of the US -- I've seen others claim as much: https://www.thenation.com/article/world/nord-stream-pipeline...
Sonar would tell you that there was a boat down there, but not necessarily who was driving it, right?
> A major concern in naval intelligence is the collection of up-to-date acoustic signatures for contemporary vessels so that IUSS can correctly identify them.
Doesn’t identify the occupants but could perhaps identify the vessel, depending on how extensive these databases are. Of course that’s a massive open question and I don’t want to claim it extends to small rental vessels, but I also don’t want to claim it doesn’t!
The main thing to note is that OSINT types are working with poor quality manipulable data compared to what’s available to US/NATO, even if we focus only on larger vessels with AIS. Which is not to say US/NATO should be trusted in their public statements.
Re: Underwater ears everywhere
#147> Instead, the battle of submarine silence has mostly revolved around obscure technical problems of fluid dynamics, since one of the loudest noises made by submarines is the cavitation around the screw. Cavitation is loud, but usually only happens if they're running full out. What they're really listening for now are reactor plant noises. > I don't know if this is true today, but at least years ago the low-noise desi…
> . What they're really listening for now are reactor plant noises. Yep; a fanatical obsession with reducing plant noise is why US subs were so quiet compared to everyone else. The author knows fuck-all about what he's talking about going on about cavitation. It's also why diesel hybrid subs from Sweden are nearly undetectable. There's virtually no plant noise - probably just a coolant pump or two - while running on…
> The bit about it being unrecognizable as an implosion because of its unique construction is complete supposition.
the theory that it would have been correctly classified by the trained system seems an even less likely complete supposition - the only arguments I've seen in favor of it are argument ad incredulity fallacies
Re: Underwater ears everywhere
#148Reminded me of this story: https://en.wikipedia.org/wiki/Toshiba%E2%80%93Kongsberg_scan... Toshiba wasn't allowed to export a 9-axis (C)NC-machine to the Soviet union, because it could (and would) be used to create ultra-silent submarine props, in the 80s. Asianometry video about it: https://www.youtube.com/watch?v=uaRyqAVIkwI
When the company I work for was buying a brand new swiss grinding machine (which enables the manufacturing of some extremely precise parts), I had to fill and sign a very strange statement about: - the exact kind of goods that we will use the machine for - certify that we will not use it in any nuclear explosive activity, or unsafeguarded nuclear fuel-cycle activity, or the use of nuclear, chemical or biological weap…
Now I'm very curious what makes a precision grinding machine particularly useful for nuclear applications.
Re: Underwater ears everywhere
#149Ever since that MH370 plane disappeared, I've been wondering. Would it going into the water make a splash that is audibly significant (compared to other surface noise i.e. waves) and would there be hydrophones in that area of the ocean, and would enough signal processing perhaps be able to locate the splash? And has all this perhaps already been done, but the people who have, can't talk about it?
There was a bit in the Lemmino video about exactly this. In it he states that there were 4 hydrophonic stations that heard "something" and follows up with the recordings for you to hear.
Re: Underwater ears everywhere
#150> This system, called SOSUS for Sound Surveillance System, remained secret until 1991. The secrecy of SOSUS is no great surprise, as it was one of the most important military intelligence systems of the Cold War.
I grew up in West Wales in the 80s, ‘everyone’ knew that the US Navy staff at RAF Brawdy were monitoring the cables that listened for submarines in the Atlantic