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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 spo

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?

wil421 5y ago
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 5y ago
  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 5y ago
    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 5y ago
      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.2017.00295/full https://www.frontiersin.org/articles/10.3389/fmars.2017.0029...
      - wil421 5y ago
        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.
        nradov 5y ago
        You're really missing the point. No navy would ever assign one of their limited number of surface warships to that mission. There aren't enough to go around. And if a ship detects a massive blob passing underneath it's already too late. 1,100 feet isn't nearly enough range for collision avoidance; a ballistic missile submarine can't turn on a dime and a collision risk can come from any direction including astern. None of your suggestions are even remotely practical in the real world. When submarines actually need to be sure of avoiding collisions they just run on the surface and follow the same rules of the road as any other vessel.
        bell-cot 5y ago
        I suspect that wil421's idea is that the "near-harbor escort" job does not need anything near so grand as a surface warship. A low-end tugboat or similar would more than suffice.
yborg 5y ago
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 5y ago
  > 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 5y ago
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 5y ago
  Because it could be active?
  - earthbee 5y ago
    Then you could hear them coming and avoid them
    - omni 5y ago
      If you can hear them, they've already found you
      - gpm 5y ago
        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 5y ago
        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
hinkley 5y ago
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.
- richwater 5y ago
  That's why we've implemented SLOP https://en.wikipedia.org/wiki/Strategic_lateral_offset_procedure https://en.wikipedia.org/wiki/Strategic_lateral_offset_proce...
  - pjerem 5y ago
    Thank you, pretty interesting
- yummypaint 5y ago
  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-navigation-surveillance-cns/tcas/ https://nbaa.org/aircraft-operations/communications-navigati... My understanding is these automated instructions override those from ATC
  - etimberg 5y ago
    I believe TCAS is built off of ADS-B which is terribly insecure https://youtu.be/CXv1j3GbgLk https://youtu.be/CXv1j3GbgLk
    - 5y ago
nradov 5y ago
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 5y ago
  > 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 5y ago
    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.
    - baobabKoodaa 5y ago
      > You missed the point. The collision covered in this article occurred relatively close to port, not during an open ocean patrol. So you're saying the collision _didn't_ occur at a time when the sub was trying to stay hidden, you're saying that the operators could have / should have used active sonar? Is that it? Look, either the sub was trying to stay hidden at the time it accidentally collided with another submarine, or it wasn't trying to stay hidden. In either case it didn't do a good job. If it wasn't trying to stay hidden, then it shouldn't have collided. If it was trying to stay hidden, then its location was not as unpredictable as it should have been.
trhway 5y ago
USSR concept of naval bastions https://en.wikipedia.org/wiki/Bastion_(naval) 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.
- NickNameNick 5y ago
  Clearly with limited success - That article links to https://en.wikipedia.org/wiki/Submarine_incident_off_Kola_Peninsula https://en.wikipedia.org/wiki/Submarine_incident_off_Kola_Pe... Which in turn links to https://en.wikipedia.org/wiki/Submarine_incident_off_Kildin_Island https://en.wikipedia.org/wiki/Submarine_incident_off_Kildin_... So there have been at least two other submarine collisions.

wil421 5y ago

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 5y ago
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 5y ago
  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 5y ago
    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.2017.00295/full https://www.frontiersin.org/articles/10.3389/fmars.2017.0029...
    - wil421 5y ago
      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.
      - nradov 5y ago
        You're really missing the point. No navy would ever assign one of their limited number of surface warships to that mission. There aren't enough to go around. And if a ship detects a massive blob passing underneath it's already too late. 1,100 feet isn't nearly enough range for collision avoidance; a ballistic missile submarine can't turn on a dime and a collision risk can come from any direction including astern. None of your suggestions are even remotely practical in the real world. When submarines actually need to be sure of avoiding collisions they just run on the surface and follow the same rules of the road as any other vessel.
        bell-cot 5y ago
        I suspect that wil421's idea is that the "near-harbor escort" job does not need anything near so grand as a surface warship. A low-end tugboat or similar would more than suffice.

yborg 5y ago

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 5y ago
> 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 5y ago

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 5y ago
Because it could be active?
- earthbee 5y ago
  Then you could hear them coming and avoid them
  - omni 5y ago
    If you can hear them, they've already found you
    - gpm 5y ago
      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 5y ago
        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

hinkley 5y ago

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.

richwater 5y ago
That's why we've implemented SLOP https://en.wikipedia.org/wiki/Strategic_lateral_offset_procedure https://en.wikipedia.org/wiki/Strategic_lateral_offset_proce...
- pjerem 5y ago
  Thank you, pretty interesting
yummypaint 5y ago
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-navigation-surveillance-cns/tcas/ https://nbaa.org/aircraft-operations/communications-navigati... My understanding is these automated instructions override those from ATC
- etimberg 5y ago
  I believe TCAS is built off of ADS-B which is terribly insecure https://youtu.be/CXv1j3GbgLk https://youtu.be/CXv1j3GbgLk
  - 5y ago

nradov 5y ago

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 5y ago
> 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 5y ago
  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.
  - baobabKoodaa 5y ago
    > You missed the point. The collision covered in this article occurred relatively close to port, not during an open ocean patrol. So you're saying the collision _didn't_ occur at a time when the sub was trying to stay hidden, you're saying that the operators could have / should have used active sonar? Is that it? Look, either the sub was trying to stay hidden at the time it accidentally collided with another submarine, or it wasn't trying to stay hidden. In either case it didn't do a good job. If it wasn't trying to stay hidden, then it shouldn't have collided. If it was trying to stay hidden, then its location was not as unpredictable as it should have been.

trhway 5y ago

USSR concept of naval bastions https://en.wikipedia.org/wiki/Bastion_(naval) 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.

NickNameNick 5y ago
Clearly with limited success - That article links to https://en.wikipedia.org/wiki/Submarine_incident_off_Kola_Peninsula https://en.wikipedia.org/wiki/Submarine_incident_off_Kola_Pe... Which in turn links to https://en.wikipedia.org/wiki/Submarine_incident_off_Kildin_Island https://en.wikipedia.org/wiki/Submarine_incident_off_Kildin_... So there have been at least two other submarine collisions.