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Underwater ears everywhere

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Re: Underwater ears everywhere

#121

Post by hef19898 »

KennyBlanken wrote: post #76
stuff800 wrote: post #62

> 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…

Also, SOSUS being secret until 1991, as per article, and being famously and prominently featured in the book Hunt for Red October 1984...

Re: Underwater ears everywhere

#122

Post by defrost »

wossab wrote: post #118
defrost wrote: post #96

Earlier quoted context omitted.

Australia has 'sunk' USS carriers in war games also - there are entire books written about how carriers are hard to defend in modern warfare - they're painful to lose but (shhh, don't tell anyone) relativey easy targets in all manner of ways. The wikipedia entry is about 1400+ ships that were mostly Dutch - from the days of the Dutch East Indies and Spice trades. It's of interest as that coast was one of the main dri…

While your post is informative, it's kind of disingenuous to claim a link between two phenomena when there is none, seemingly because you needed to say something bad about Dutch ships in some way. It's a shame really, because it detracts from the quality of your other links.

> it's kind of disingenuous to claim a link between two phenomena

Which two phenomena?

Dutch ships heading to the Dutch East Indies sinking and the need to accurately measure longitude?

These are very much linked.

> needed to say something bad about Dutch ships

I felt no such need.

It's a simple fact that a comment about Netherland naval ships faux sinking US carriers prompted a remark about the large numbers of Dutch ships famously sunk off our coast here in W.Australia.

It has little to do with the quality of the ships and everything to do with the then inability to accurately reckon longitude.

Of technical interest to anyone with an interest in the evolution of surveying, navigation, timekeeping, colonial expansion, shipwrecks, treasure, etc.

Re: Underwater ears everywhere

#124

Post by imwillofficial »

stuff800 wrote: post #62

> 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 are you talking about, pump jets?

Re: Underwater ears everywhere

#125

Post by wongarsu »

bee_rider wrote: post #113
dundarious wrote: post #63

Related 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?

You can also track the path of the boat, to figure out which port it came from and where it went afterwards. You can also correlate it with AIS, a mandatory tracking signal for ships (used for collision avoidance etc). Of course the ship could have turned it off, but if I owned a bunch of spy satellites I would pay very special attention to any ship that appears on satellite images but doesn't have a corresponding AIS beacon.

Of course unless you are tracking a submarine back to a submarine base all of this won't tell you exactly who it was. Any state actor can just rent a fishing ship and deploy a remote controlled submarine from it. That's where more traditional information gathering comes in.

Re: Underwater ears everywhere

#126

Post by MarkusWandel »

Ever 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?

Re: Underwater ears everywhere

#127

Post by batch12 »

shoo wrote: post #81
batch12 wrote: post #79

> This website is begrudgingly generated by the use of software. Letters to the editor are welcome via facsimile What does this mean? Is it a reference I'm missing, a vague disclaimer for generated text, or am I reading too much into the footer?

facsimile refers to communication by fax machine, an ancient method of written communication over telephone lines that was popular pre-email, and is still popular in remaining pre-email societies such as federal government departments and japan. > begrudgingly generated by the use of software read the top of https://computer.rip/

I know what a fax is, but I was missing the header context. Thank you.

Re: Underwater ears everywhere

#128

Post by Dah00n »

01100011 wrote: post #67
dundarious wrote: post #63

Related 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...

That area of the ocean is probably one of the most heavily surveilled areas in the world. Intelligence agencies absolutely know the ships involved. I still maintain it could have been anyone with about $300k. Work class ROVs capable of planting the explosives at that depth are commonplace in underwater construction and maintenance.

The German intelligence services has the ship involved and found explosive residue. As far as I remember it was linked to a Ukrainian business some time back but it could have been anyone of course.

https://www.reuters.com/world/europe/germany-tells-un-nord-s...

Edit: I didn't read the link posted above but I see it states the same as me. Nothing to see here.

Re: Underwater ears everywhere

#129

Post by andrewflnr »

hef19898 wrote: post #121
KennyBlanken wrote: post #76

Earlier quoted context omitted.

> . 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…

Also, SOSUS being secret until 1991, as per article, and being famously and prominently featured in the book Hunt for Red October 1984...

He said it was classified until 1991, but that it had been revealed accidentally multiple times before then. So that checks out.

Re: Underwater ears everywhere

#130

Post by runjake »

MarkusWandel wrote: post #126

Ever 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?

Yes, acoustics was explored[1] extensively.

1. https://www.google.com/search?q=MH370%20acoustic

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