[HN Gopher] In 2009, Two Nuclear Submarines Collided Under the S...
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In 2009, Two Nuclear Submarines Collided Under the Sea (2016)
Author : Rexxar
Score : 50 points
Date : 2021-08-30 13:35 UTC (9 hours ago)
(HTM) web link (nationalinterest.org)
(TXT) w3m dump (nationalinterest.org)
| codezero wrote:
| Submerged shipping containers seem like a fantastic platform for
| military remote sensing.
| uga4012 wrote:
| Are they really not detectable from space?
| TeMPOraL wrote:
| Let's hope not - that submarines carrying nuclear weapons are
| undetectable is the only thing that's keeping the major powers
| from going to war.
| jaywalk wrote:
| Why do you think they would be detectable from space? That
| doesn't make any sense.
| changoplatanero wrote:
| There is a technique for finding nuclear submarines from
| space by using satellites to look for the hot water exhaust
| from the nuclear reactors.
| hindsightbias wrote:
| Closed cycle steam generation plants aren't going to
| exhaust much. They can't filter seawater fast enough for
| use and you couldn't run seawater through those systems w/o
| messing them up.
|
| Wastewater is probably cooled before release.
| cryptonector wrote:
| Subs must necessarily produce heat. That heat has to go
| into the surrounding (usually very cold) water. This is
| unavoidable. Those nuclear reactors are cooled with that
| surrounding water, though obviously through heat
| exchangers.
| NovemberWhiskey wrote:
| Let me get this straight - there's a technique for
| detecting changes in the surface temperature of the water
| from a submarine that's probably hundreds of meters below
| the surface?
| willvarfar wrote:
| Yes.
|
| There are also magnetic anomaly detectors (MAD) and
| various wake detection approaches.
|
| Do these work all always? Probably not. But they work
| often enough to be researched and used.
|
| https://m.youtube.com/channel/UC9bMgCQyFNaMPsK9GtzM5dQ is
| a good starting point.
| NovemberWhiskey wrote:
| That's an entire YouTube channel. Where in this mess of
| videos can I find a reference to thermal detection of
| submerged submarines, please?
| cryptonector wrote:
| These subs are large, metallic, full of electric equipment,
| and _heavy_. They have magnetic and gravitational effects on
| their surroundings. They also have electromagnets to help
| hide their magnetic signatures. A network of very sensitive
| satelites with very precise clocks could be used to detect
| gravitational anomalies -- maybe, I 'm not sure what kind of
| precision would be needed, or if that is achievable.
| chinathrow wrote:
| Why do you think that no nation states and their 3 letter
| agiens might have developed such technology by now?
|
| We basically know nothing about what current NRO spy sats
| carry, or do we?
| SonicScrub wrote:
| Any detection from space would have to use an optics system to
| detect light bouncing off the submarine. This light could be
| either the naturally occurring visible light, or some form of
| active system (probably emitting radar waves). Unfortunately
| light can't penetrate very far into water, so this idea is a
| non-starter. Light can barely make it 200m into the ocean
| (meaning 100m depth for light to make a round-trip and back for
| detection), and subs can go as deep as 300m.
|
| Any satellite-based detection system would have to rely on
| catching the sub while on the surface. I'm positive this is
| being attempted constantly, but catching a sub at depth is an
| entirely different manner.
| jazzyjackson wrote:
| next time you're out on the open ocean check how far down into
| the water you can see, and then check out this graph [0] of
| electromagnetic radiation absorption of water: visible light is
| the best case scenario.
|
| there's a reason sonar is acoustic and not light based
|
| [0] http://hyperphysics.phy-
| astr.gsu.edu/hbase/Chemical/watabs.h...
| detritus wrote:
| Using what technology? I can imagine in some future there being
| the means, but I find it hard to believe we have that level of
| tech available to the sort of packages we can aloft into orbit
| now.
| dmos62 wrote:
| They're hardly detectable from Earth.
| skinkestek wrote:
| I won't say modern submarines can or cannot be detected from
| space, but this should give you some ideas about what is
| publicly known:
| https://duckduckgo.com/?q=spotting%20submarines%20using%20ma...
|
| This is fairly open secrets to the degree that it is secret at
| all so it probably also is no big secret that passive and
| active countermeasures are used to prevent these techniques.
| cryptonector wrote:
| That's not a bad question.
|
| Subs would be detectable using magnetometers, except that they
| have electromagnets in them to hide their magnetometer
| footprint. Still, this is not perfect.
|
| Large subs have somewhat detectable gravitometric footprints
| that could be observed from space, indeed.
| nradov wrote:
| The US Navy has researched the possibility of detecting shallow
| submarines from space since at least the 1990s by looking for
| subtle wake turbulence on the surface. The results are
| classified so we don't know if they were ever successful. It's
| not completely _impossible_ , but the signal to noise ratio
| would be extremely low.
| sca4 wrote:
| Lot of dismissive reactions to these questions, but there
| actually are non sound related signals we use to detect
| submarines and there is absolutely research on how to do that
| from space. This article is great, but just read the "Signal
| Processing" section if you're interested in space.
| https://www.aspistrategist.org.au/prospects-for-game-changer...
| bambax wrote:
| Interesting article. Also, we are now able to reconstruct a
| conversation by analyzing the movement of the glass on a
| window to the room where people are talking. It doesn't seem
| absolutely out of reach that we could some day detect huge
| underwater vessels from analyzing surface perturbations.
| lnwlebjel wrote:
| Not sure if they are, but I do know that the US Navy funded a
| lot of oceanographic research into predicting and understanding
| bioluminescence of marine organisms for this very reason. The
| surface waters of the North Atlantic have massive spring blooms
| of phytoplankton, which are sometimes bioluminescent, and could
| certainly give away the presence of a large subsurface vessel.
| dotancohen wrote:
| Even more amazing, only a month later (or before) two satellites
| collided in LEO. Literally astronomical odds, and the two
| incidents happened so soon after one another as well.
| clipradiowallet wrote:
| Pie in the sky ideas here... but how far is active sonar
| effective for? Can you launch a probe that enables active sonar
| some 50-100 miles away, and radios the results back? Or would the
| depth prevent any type of radio communication...or is active
| sonar not that long-range?
|
| This whole field is really fascinating to think about.
| nradov wrote:
| The effective range of active sonar varies tremendously based
| on many factors: power output, microphone sensitivity, signal
| processing, bottom contour, water temperature, ambient noise,
| etc. There is no typical range. Aircraft can drop active
| sonobuoys but they're very expensive and in limited supply. Use
| of active sonar is restricted in many areas due to impact on
| marine life.
|
| Water blocks all radio traffic except for extremely low
| frequency. The bandwidth on that is too low to use as an
| effective navigation aid, and transmissions can only be sent
| from large facilities on land. Some submarines can also send up
| floating antennas on towed buoys but they prefer not to do so
| due to the risks of detection and entanglement.
| baobabKoodaa wrote:
| So the submarines can't use active sonar, because their number
| one priority is to avoid detection... but then these subs are all
| parked in the same "parking spots" in the ocean. If the favored
| parking spots for submarines are so rare and small that
| collisions happen more than once, surely that undermines their
| stated number one priority of remaining hidden? If someone wanted
| to locate enemy submarines, surely they could just send a bunch
| of underwater drones to swim through these parking spots?
| trhway wrote:
| USSR concept of naval bastions
|
| https://en.wikipedia.org/wiki/Bastion_(naval)
|
| >If someone wanted to locate enemy submarines, surely they
| could just send a bunch of underwater drones to swim through
| these parking spots?
|
| back then it were US attack submarines which USSR tried to
| actively track and push out of the bastions.
| nradov wrote:
| There are no parking spots. Ballistic missile submarines
| conducting deterrence patrols are assigned to large areas
| covering hundreds of square nautical miles. The sub then
| maneuvers inside that patrol area to remain as hidden as
| possible. They almost never stop as it's easier to maintain
| depth control with at least a few knots of steerageway. So a
| collision in open ocean is theoretically possible but highly
| unlikely.
|
| The real risk of collisions comes with transiting through
| constricted navigational channels, typically when leaving or
| entering port. Those channels force a lot of vessels into a
| small area. There have also been a few incidents where
| submarines failed to do a thorough surface search before
| surfacing and collided with smaller boats.
|
| During the Cold War there were supposedly a few incidents where
| NATO attack submarines were following Soviet submarines too
| closely and ended up colliding.
| baobabKoodaa wrote:
| > There are no parking spots. Ballistic missile submarines
| conducting deterrence patrols are assigned to large areas
| covering hundreds of square nautical miles ... So a collision
| in open ocean is theoretically possible but highly unlikely.
|
| It's misleading to describe collisions as "theoretically
| possible" when we have evidence that these collisions have
| occurred. The fact that collisions have occurred makes me
| think that these submarines are not randomly located in a
| large area where it would be difficult to locate them.
| nradov wrote:
| You missed the point. The collision covered in this article
| occurred relatively close to port, not during an open ocean
| patrol.
|
| A ballistic missile submarine's position isn't completely
| random, but they do move around somewhat randomly to reduce
| the risk of detection. They intentionally avoid repeating
| movement patterns or lingering in the same spot. And this
| also reduces the risk from spies on land. If a spy sees the
| patrol orders he'll only know a large general area but
| won't precisely know the submarine's position at any time.
| dragonwriter wrote:
| > large areas covering hundreds of square nautical miles.
|
| That's...not very large.
|
| > The sub then maneuvers inside that patrol area to remain as
| hidden as possible.
|
| Given that the same concerns will drive "as hidden as
| possible" concerns in any sub, that further narrows the
| space. And unless the decisions made within that space are
| made in a truly random manner which approaches all equally
| good options equally (and tolerates a loose enough sense of
| "equally good" not to excessively narrow the space to start
| with), common cognitive biases, etc., will result in common
| decisions.
| hinkley wrote:
| Sounds like the FAA altitude problem all over again.
|
| As altimeters got more accurate, the odds that you were flying
| at exactly 28000 feet went up. If an air traffic controller
| fucks up and puts two planes at 28000ft, they can now collide
| because they're +-10ft instead of +-200ft. That was the RCA of
| that mid-air collision over Brazil a while back.
|
| The more you try to control a thing the more problems you can
| have. A parking lot for stealth ships is... I don't want to say
| dumb but confusing for sure.
| bambax wrote:
| > _That was the RCA of that mid-air collision over Brazil a
| while back._
|
| Yeah the article made me think about that incident too,
| described here in detail:
|
| https://www.vanityfair.com/culture/2009/01/air_crash200901
|
| It's a great read.
| tablespoon wrote:
| > The more you try to control a thing the more problems you
| can have. A parking lot for stealth ships is... I don't want
| to say dumb but confusing for sure.
|
| https://en.wikipedia.org/wiki/Navigation_paradox
| yummypaint wrote:
| These days there are special collision avoidance systems on
| big commercial planes:
|
| _TCAS II provides the pilot with specific instructions on
| how to avoid the conflict with traffic. These instructions
| are known as a "Resolution Advisory" (RA) and may instruct
| the pilot to descend, climb, or adjust vertical speed. TCAS
| II systems are also able to communicate with each other to
| ensure that the RA provided to each aircraft maximizes
| separation._
|
| From https://nbaa.org/aircraft-operations/communications-
| navigati...
|
| My understanding is these automated instructions override
| those from ATC
| etimberg wrote:
| I believe TCAS is built off of ADS-B which is terribly
| insecure https://youtu.be/CXv1j3GbgLk
| aaronmdjones wrote:
| TCAS does not work if your transponder (or theirs) is off,
| which is how that collision in Brazil happened.
|
| https://en.wikipedia.org/wiki/Gol_Transportes_A%C3%A9reos_F
| l...
|
| The Legacy's pilot footrest places the end of your shoes
| dangerously close to the transponder standby button.
|
| https://www.bangaloreaviation.com/wp-
| content/uploads/2014/04...
|
| The footrest is below the white screen with the
| navigational chart on it. The radio and transponder panel
| is the black screen to the right of that, with the yellow
| and green text on it. The 0512 is your transponder code
| (squawk); the button to the left of that and down one row
| turns it off.
|
| This resulted in the Legacy losing its TCAS ability, and
| the 737 it collided with being unable to see the Legacy.
| richwater wrote:
| That's why we've implemented SLOP https://en.wikipedia.org/wi
| ki/Strategic_lateral_offset_proce...
| pjerem wrote:
| Thank you, pretty interesting
| wil421 wrote:
| You don't need drones. Planes and helicopters already drop
| sonar buoys for the exact reason you stated.
|
| A better solution would be for an escort when they get into
| crowded lanes. Surface ships can use active sonar to scan for
| other subs while being some what close to their sub. The only
| problem is other listeners can pick up on what is reflecting
| off your active sonar as well. Also the subs try to avoid ever
| being detected because they can save your signature for
| comparison later.
| nradov wrote:
| It's not like any navy has spare surface warships with active
| sonar available to escort submarines through constricted
| navigational channels. There are also environmental concerns
| with active sonar due to impacts on marine life, especially
| cetaceans. During peacetime it's usually only allowed in
| designated exercise areas.
| wil421 wrote:
| I have sonar on my kayak. You can certainly use a power
| that is not going to hurt sea creatures. A lot of Navy
| ships including submarines have off the shelf sonar as well
| as military sonar. I've seen a pic of a sub with Raymarine
| radar they use when surfaced in channels. The subs don't
| want to use their own military grade stuff because then the
| enemies have the frequency signature so they use off the
| shelf for navigating in public areas.
| nradov wrote:
| That's simply not how it works. The active sonar on your
| kayak has nowhere near enough power or resolution to
| detect a military submarine at sufficient range for
| reliable collision avoidance. Due to the inverse square
| law, active sonars have to put out a huge amount of power
| to detect submarines at any useful range. This is a
| proven risk to marine life.
|
| https://www.frontiersin.org/articles/10.3389/fmars.2017.0
| 029...
| wil421 wrote:
| The escort ships would know exactly where the sub they
| are escorting is. They could easy see the bottom or a
| massive blob passing underneath (an unknown sub) or even
| an undersea mountain. You don't need enough resolution to
| tell if it's a sub or even a whale you just need enough
| to say watch out.
|
| My middle of the road Garmin can see 1,100 feet deep in
| salt and side scan 500 feet in either direction. You can
| see bottom features and schooling fish. The higher end
| stuff is so much better.
| yborg wrote:
| How are the drones going to detect them apart from randomly
| running into them? Simpler approach is for an adversary to just
| cruise attack boats through these areas, which you would want
| to do anyway since once you detect them you want to sink them
| in wartime.
| feral wrote:
| > How are the drones going to detect them apart from randomly
| running into them?
|
| In this context the idea would be that drones can use active
| sonar, because they are relatively expendable.
| earthbee wrote:
| If the passive sonar filling the entire nose of a huge
| submarine can't hear another submarine, why would a much
| smaller sonar in the nose of a drone be able to detect a
| submarine?
| feral wrote:
| Because it could be active?
| earthbee wrote:
| Then you could hear them coming and avoid them
| omni wrote:
| If you can hear them, they've already found you
| gpm wrote:
| Surely not.
|
| The submarine with the larger more sensitive instruments
| in a quieter environment ought to be able to detect sound
| levels below that which their active opposition can.
|
| If X amount of noise-energy hits the submarine, it only
| reflects Y<X of that energy, and only Z<Y of that
| reflection goes in the right direction to be detected by
| the opposition. The noise should be louder at the
| submarine, than at the thing detecting the submarine.
|
| Both of these weigh in favor of the submarine detecting
| the searcher before the searcher detects the submarine.
| omni wrote:
| I'm fully willing to admit I'm talking out my ass here,
| but does it not make sense to assume that both a) the
| active drones are going to be much faster than a
| submarine trying to maintain silence, and b) there are
| likely to be many drones converging from different
| directions if they're searching a known submarine parking
| spot? Still seems like advantage drones to me
| gpm wrote:
| I'm not more of an expert of submarine tactics than you
| are, I was just taking issue with the physical claim that
| they already know where you are by the time you hear
| them.
| addingnumbers wrote:
| ... so the sub discovers the active buoy 0.66 seconds
| sooner for every kilometer of distance between them.
|
| I don't imagine that knowing you'll be detected 40
| seconds before they know you've been detected changes the
| tactical situation a whole lot.
| gpm wrote:
| No, nothing I was talking about was related to the speed
| of sound in water (which is where I assume you're getting
| 0.66 seconds/km, since it's about right). I agree the
| speed of signal propagation seems unlikely to matter much
| in most situations.
| addingnumbers wrote:
| My point is in this scenario there's no appreciable
| difference between "if you can hear them, they've already
| found you" and "if you can hear them, they'll find you in
| 40 seconds"
|
| The observation that they are "detecting the searcher
| before the searcher detects the submarine" is academic
| and inconsequential when we're talking about such a
| negligible amount of time between detections.
| gpm wrote:
| But there is an appreciable difference between "if you
| can hear them, they've already found you", and "if you
| can hear them, they might never find you because you can
| see them looking from farther away than they can see, and
| they might just be outright searching the wrong area".
|
| All my arguments went to the latter kind of problem, not
| the former. Your 40 seconds number seems to be based on
| the speed of signal propagation, not the range at which
| things can be detected.
|
| Even in the event where they do find you, the arguments I
| gave would suggest that it would take vastly longer than
| the speed of signal propogation to do so, because they
| would have to move closer to you. Giving you
| substantially more notice than 40 seconds.
| addingnumbers wrote:
| I see where you're coming from. Good points.
|
| I was taking it for granted that knowing the location of
| an unmanned, expendable sonar buoy or probe before you're
| discovered is not tactically important.
|
| Now that you have me thinking, it would clearly allow you
| to stay out of detection range if you had the good
| fortune for their pings to initiate within your detection
| range but outside theirs.
| zoomablemind wrote:
| Surprisingly, no side was assigned the blame for the collision.
| Unlike air traffic or surface navy accident.
|
| One had a conning tower damage, the other had a bow damage; both
| were supposedly slow-moving at the moment. Is there such thing as
| right of way for subs?
| juanani wrote:
| Both are western power countries. Blame gets assigned when the
| others are a part of it. The headline also would've read:
| Disaster averted as our forces save the day..
| tjohns wrote:
| How do you exercise right of way over another submarine that
| you don't know the position of?
|
| The whole point of submarines is that they're stealthy. Active
| sonor would give away their position. They're basically
| swimming blind. The only way this all works is the ocean is big
| enough that random collisions are statistically rare - but
| there's not much actually preventing them.
| zoomablemind wrote:
| > ...They're basically swimming blind.
|
| It did appear just like that. Shouldn't there be some
| proximity sensors to avert collisions with massive bodies?
| After all in the aftermath both subs were rendered mission
| incapable.
| idoh wrote:
| How would the proximity sensors work? The can't go active
| sonar...
| zoomablemind wrote:
| Low power high freq radio waves? These should rapidly
| attenuate underwater, so not much of giveaway, but could
| be enough for proximity scans around the sub.
|
| Is there some spectrum of emissions from an even stealthy
| sub, some kind of "local presence"? The immediate massive
| obstacles would result in distortions to such a self-
| presence profile. So the sensors could be trained to
| detect such local distortions, almost like some fish have
| a lateral line of nerves supposedly helping detect
| current flows etc. [1].
|
| [1]:https://en.m.wikipedia.org/wiki/Lateral_line
| zoomablemind wrote:
| >...So the sensors could be trained to detect such local
| distortions, almost like some fish have a lateral line
| ...
|
| Turns out, this has been modeled already (2007):
|
| [1]:https://www.photonics.com/Articles/Fish_Navigation_Sy
| stem_Re...
| dotancohen wrote:
| Optical, perhaps? How much light is at these depths? How
| do the subs avoid terrain?
| nradov wrote:
| Subs avoid terrain using charts and dead reckoning,
| including inertial navigation systems. They typically
| come to periscope depth occasionally to get a
| navigational fix. In 2005 a US submarine allided with an
| underwater mountain due to a navigational error.
|
| https://www.cbsnews.com/news/whos-to-blame-for-sub-
| accident/
|
| There is little or no light at typical operating depths.
| Lidar can work to a limited extent in some water
| conditions but it's not something to rely upon for
| collision avoidance.
| sbierwagen wrote:
| >Lidar can work to a limited extent in some water
| conditions but it's not something to rely upon
|
| And, of course, it's an active sensor. An adversary could
| detect the emitted light.
| jvzr wrote:
| I remember (barely) from a diver friend that colors
| disappear below 20 meters (everything appears blue,
| unless a bright light is shone), and sun light disappears
| completely below 70 meters. You'd assume that an optical
| system with flood lights could theoretically work, but
| then it would be pretty simple to monitor for light at
| these depths (for counter-intelligence/retaliatory
| purposes)
| daveslash wrote:
| _Re >> "the French Ministry of Defense reported that the
| submarine had suffered a collision with an "an immersed object
| (probably a container).""_
|
| and
|
| _Re >> "At some point, the two navies compared notes"_
|
| I get that ballistic submarines want to stay secret and use
| passive sonar, instead of active sonar. But I also would have
| thought - if a submarine mysteriously _ran into_ something under
| water that they _did not expect to be there_ , that they'd start
| taking a more "active" approach to figuring out what was going
| on. It'd be like if I tried to walk blindfolded through a large &
| empty conference room: if I bumped into a whole wall after
| walking only 3 or 4 steps, I'd be _very_ confused!
| FridayoLeary wrote:
| And they didn't even realise...
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