I made this point several times on social media during the Titan incident but it fell on deaf ears; it seemed crazy to me that people were accusing the US Navy of some nefarious cover-up regarding possible acoustic detection of implosion.

Anyone who’s ever worked with any type of signal analysis would be aware of the huge uncertainty involved; the idea that we could positively identify the specific destruction of the Titan remotely was ludicrous on its face.

That aside, even if the Navy was 100% certain, would you want the search for your loved ones called off because someone heard a noise? Of course not. You search for people missing at sea until you find them or until the point where any reasonable hope of finding them is gone. That applies to billionaires as well as anyone else.

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

https://www.wired.com/1996/12/ffglass/

"Mother Earth, Mother Board" (stories about laying undersea cable and the history of wiring the Earth up"

(or unpaywalled: https://archive.is/ICkHe)

> 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. I don't know if this is true today, but at least years ago the low-noise design of the screw on modern US submarines was classified, and so the screw was covered by a sheath whenever a submarine was out of the water.

I wander if they are Toroidal or "tipless" propellers? They create less turbulence and cavitation.

https://en.m.wikipedia.org/wiki/Toroidal_propeller

Previous posts on HN:

> Toroidal propellers turn your drones and boats into noiseless machines

https://news.ycombinator.com/item?id=34571282

> Sharrow MX-1: Tipless propeller

https://news.ycombinator.com/item?id=33949895

Do the British know ?

eg: https://en.wikipedia.org/wiki/Sonar_2087

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 design of the screw on modern US submarines was classified, and so the screw was covered by a sheath whenever a submarine was out of the water.

Many US fast attack (Virginia, Seawolf) and the upcoming Columbia SSBN use some sort of external pump jet. I'm not sure if they cover those up out of water like they did with more 'traditional' screws.

> The Navy did not withhold information on the detection for four days out of some concern for secrecy.

I think it's more likely than not that the statement is correct, but what gives the author the authority to make the claim so definitively? The author's bio indicates he's a consultant and there is no indication of direct involvement in this or any other SAR effort.

While the workings of the SOSUS and IUSS systems may be declassified, the deployments and capabilities (mostly range and computation related) of such systems most likely are not. And there is always the possibility that there is yet another system the author simply isn't aware of.

IMO, it isn't negligence to value the secrecy of systems used for defense above some number of lives, in some situations.

The cover-story to build the Glomar Explorer to recover K-129 was that Howard Hughes thought that it was economically feasible to mine manganese nodules from the deep sea. A lot of engineering research started that year (1974) that now, 2023, bears fruit in several large companies trying to mine the ocean floor with approvals to start probably happening this year: https://www.nature.com/articles/d41586-023-02290-5

Without the cover-story and Howard Hughes I wonder how many researchers would have ever looked at deep sea mining.

Experts in marine biology. Reminds me of the night vision camera the british military were showing off on BBC Countryfile program. Who would have thought the military are experts in biology, but probably explains why the brits took off sunglasses in Iraq when talking to people, but the US didnt. You should see the british scarecrows as well!

> 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.

https://en.wikipedia.org/wiki/Toroidal_propeller Difference in cavitation. https://youtu.be/k0yzBTTqfzs?t=436

Dont know if these toroidal propellers scale up to submarine sizes, they keep them hidden under an large oily rag along with the front of the subs.

> did the Navy withhold information on the detection from searchers out of concern for secrecy

Location of sensors maybe, after all something like the titanic will attract treasure hunters, why wouldnt interested govt's deploy remote sensors to detect who is in the area? Submarines make it easy for crew to be kept in the dark on missions as not many can use the periscope or other sensors.

I read somewhere once that a sensor, sonar or hydrophone, in UK waters could detect the sounds come from a New York harbour, which gives an insight into the distance sounds can travel underwater, but considering all the noises that can be detected, having sound processing abilities, a little bit better than something like Dolby Noise Reduction, is the key part of the underwater arms race.

https://www.theguardian.com/environment/2023/may/15/listen-t...

https://news.sky.com/story/titanic-sub-search-what-are-the-s...

I would love to learn more about the technology — are these wireless transmitters? Undersea cables all around the oceans of the world?

I just finished reading Thunderstruck (Erik Larson, author of Devil in the White City), which I don't recommend. It ineffectively juxtaposes the story of Marconi with Hawley Crippen, a murderer in London whose case became famous around 1910. (I say "ineffectively" because their stories really don't intersect, IMHO) The book goes on and on about all the demos and tests he ran for years and years, to the point of being eye-glazingly boring. All that aside...

Anyhow: at the very end, the author tells us that Marconi discovered near the end of his life that higher frequencies obviate the need for the gigantic transmitters and receivers he'd been using. Yet he never tells us what frequencies Marconi was using! Does anyone know?

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?

"James H. ROGERS Underground & Underwater Radio ( Static-free Reception & Transmission Underwater & Underground )" http://rexresearch.com/rogers/1rogers.htm

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

I've bookmarked the page and will definitely return.

It would be interesting to know what the compute power was there back when, let alone what kind of people worked there.

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.

They're ducted propulsors, a direct evolution of the classic submarine prop that integrates a pressure-increasing shroud and stator vane assembly. A "pump jet" classically involves some sort of centrifugal pump element or at least a vectoring mechanism.

You typically wouldn't call a ducted fan (ex, on the X-22 [1]) a jet, but I guess in the water we do.

[1]: https://en.wikipedia.org/wiki/Bell_X-22

Which is why old timey diesel electric submarines still sometimes have the edge over modern subs. No plant noises at all if they are running silent.

This leads to some hilarity in joint naval exercises every now and then. e.g. when HNLMS Walrus managed to "sink" among others the USS Theodore Roosevelt before getting away, to great consternation of the Americans.

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 battery. They are sometimes 'hired' by other navies for exercises because they're so incredibly quiet.

He's spouting pure bullshit about the Navy retroactively going back over their 'tapes'. He first explains that for decades the Navy has run computerized classification systems, but then we're supposed to believe that a highly sensitive listening array did not detect the extremely energetic implosion that would sound like nothing else?

Cameron said that buddies in the navy told him very quickly that they'd heard the implosion, but they were confirming what he already knew when he heard that telemetry was lost at the same time as comms; telemetry came from a completely separate external pressure vessel. It going silent means it was destroyed, and the only way that could have happened was the sub imploding.

The bit about it being unrecognizable as an implosion because of its unique construction is complete supposition.

This is what happens when you have an article about submarines written by a guy who checks is a github engineer who likes 80's and 90's phone technology.

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?

Many aspects of IUSS are still classified, and for example we can assume that the actual data will never be released because of sensitivity of the collection system. But the news that the Navy detected the implosion is nothing new, it would probably be more surprising if the Navy didn't (I don't know that the sound levels associated with a vessel of this type imploding are well known, maybe it could be explained away as the implosion having somehow produced almost no acoustic signature). We know that in the '60s the Navy detected submarine implosions (admittedly of larger submarines) further afield, and we also know that IUSS has seen major upgrades including new sensor arrays since then.

But they confirmed it 4 days later - which would be admitting to its capabilities. The entire talk track of: "they kept it secret because of conspiracy theory X" makes no sense when they didn't actually keep it secret, they simply didn't make it public until AFTER the team was there to search - for the fairly obvious reasons the author stated. Mainly it creates unnecessary publicity that is hurtful to the relatives of the folks that are at the bottom of the ocean, and political pressure to "not spend money on the search" which was already coming from some circles even without the Navy's information.

What could also be possible is that US has improved its sensory technology, and while its known that the US is capable of listening to the sea, they may have some new edge they want to keep obscured from the likes of russia.

I’m just some guy, but it struck me as a possible way for the US to flex on the russians, especially right now when Putin is threatening to use nukes, and the US, by the book wouldnt want to because the US may not know where all of russias nuclear subs are supposed to be. It was a great opportunity for the US military apparatus to turn on a sort of fog of war machine… for all we know intelligence may have told the likes of James Cameron and Rob Ballard to say they got early news from their navy friends.

There's a more interesting answer if you want one, although this is decidedly a conspiracy theory with, I would say, "medium" credibility within the realm of conspiracy theories. Some believe that both K-129 and Scorpion were sunk by enemy action, K-129 having been sunk by an accidental collision with the Swordfish and Scorpion having then been torpedoed in retaliation. The story goes that the admiralty of both countries, agreeing this situation could rapidly escalate into an undesirable war, agreed to suppress information on the cause of both incidents. The Soviet search for K-129 and American search for Scorpion could both have been cover operations.

Yeah, it doesn't make total sense, and the evidence supporting this theory is a combination of circumstantial and recollections of people in their 80s. Besides, in the later sinking of the Kursk, Russian leadership immediately blamed a collision with a US submarine. But obviously the Russian political climate of 2000 was very different from 1968. It's a fun conspiracy theory.

A more interesting conspiracy theory is that K-129 was on a rogue mission to launch nuclear weapons on the US and was torpedoed by the US (once again perhaps by Swordfish, it was in the right place at the time) to prevent this after being tipped off by by the USSR. If that sounds a bit like the plot of The Hunt for Red October, well, it does. The evidence for this story is not nonexistent but it's pretty limited, and no one takes it very seriously.

Still, it gets at one of the oddities of K-129: the Soviet Union searched for it in its assigned patrol area, but the wreck was ultimately found far away from its assigned patrol area. I don't think anyone has a really good explanation for this. It was not at all typical for Soviet submarines to go off on their own, Moscow kept very tight control of them. So it seems that either Moscow didn't know where K-129 was (perhaps suggesting some kind of plot, whether of defection or rogue attack who knows), or they knew where it was and searched elsewhere to avoid showing their hand (suggesting K-129 was on some sort of very secret mission). I tend to suspect the latter is more likely, K-129 may have been ordered to leave its patrol area and approach the US as a show of force (this happened at other points in the Cold War) and when it was lost the search was conducted in the normal patrol area to avoid revealing that had happened. All indications are that SOSUS was successfully kept secret from the USSR for quite some time, although certainly not all the way until 1991.

Tom Clancy seems to have based The Hunt for Red October at least in part on rumors about K-129. Yeah, I watched too many submarine movies and read too many submarine books as a kid. What can I say, I had a middle-aged father.

I didn't really get into this in the article but there's a phenomenon called SOFAR (I think this does stand for something but the acronym is sort of a joke). It's basically a specific static water pressure (and thus depth) in which sound "ducts" sort of like how HF radio can duct in the ionosphere. As I understand it, it's not at all unreasonable for a sound in the SOFAR channel to go clear around the world. I know there are cases where hydrophones have recorded a particularly loud sound multiple times because of it coming "the long way around" as well as echo effects. Some of these sounds have been things like "perhaps the loudest sound ever produced" and are attributed to seismic phenomenon, but there are a lot of strange things going on in the ocean and hydrophones continue to provide plenty of questions for marine researchers to answer. And, of course, at least some of the IUSS sensors are very intentionally placed within the SOFAR channel to capitalize on this effect.

In a typical attack sumbarine, a substantial amount of the ship's volume is dedicated to acoustic sensors: https://media.defenceindustrydaily.com/images/SHIP_SSN_Virgi...

This arms race is very old, and the state of the art even 20 years ago is pretty impressive.