US Navy finds damaged nuclear sub hit underwater mountain

[Klaralven]

A US Navy nuclear submarine that was severely damaged in an accident while submerged in the disputed South China Sea last month struck an uncharted underwater mountain, the Navy said Monday.

The US Navy regularly conducts operations in the South China Sea to challenge China's disputed territorial claims on small islands, reefs and outcrops, to the irritation of Beijing.

The 7th Fleet, which operates in the western Pacific, said an investigation had concluded that the USS Connecticut smashed into a geological formation and not another vessel on October 2.

"The investigation determined USS Connecticut grounded on an uncharted seamount while operating in international waters in the Indo-Pacific region," a 7th Fleet spokesperson said in an emailed statement.

https://www.france24.com/en/live-news/20211102-us-navy-finds-damaged-nuclear-sub-hit-underwater-mountain

[marble falls]

1. Who had the sonar watch?

[MineralMan]

2. Yah, well, if it's running in silent mode, it's not using sonar to look ahead.

Sonar gives away the presence of any submarine to anyone listening.

So, there's that.

[marble falls]

4. In that they were making a flag show cruise in a disputed area, I don't know why they'd rig silent.

[MineralMan]

5. I doubt they were doing that, actually.

The Navy tends to use surface vessels for such purposes. It's not typical for submarines to be used to openly dispute disputed areas, i think.

If you want to be seen to be challenging a disputed area, then you need to be seen. The whole point of submarines is NOT to be seen.

However, since I'm not in any way involved in naval operations, I can't be more definitive than that.

[hack89]

9. They use this class of submarines for spying

they are super quiet. They would do their best to not be detected while they are in the region - wouldn't want to tip off the Chinese as to what they were interested in.

Let the carriers and other surface ships put on a noisy show while the submarines sit quietly monitoring exactly how the Chinese respond.

[Towlie]

24. Active sonar is sort of like using a lantern to see while avoiding enemies in the dark.

 
←

Mountains don't make noise, so the only way sonar could help would be in "active" mode, sending out pings and listening for echoes. If a submarine did that then they might as well not even be submerged.

[underpants]

3. Are they SURE it wasn't The Kracken?

[bluewater]

13. Definitely the Kraken

[madinmaryland]

34. And who released it?

[lagomorph777]

6. How can there be an uncharted seamount?

Haven't we pretty thoroughly mapped the whole seafloor by now?

[sarisataka]

8. Nope

NOAA says we have yet to explore over 80%. There are many things to be discovered, sometimes found by running into them

[lagomorph777]

10. I guess the maps are lower resolution than they appear?

Or painted in by hand; they've just stopped putting in "Here be dragons" in the blank bits...

[sarisataka]

14. They do have macro maps

But that only gives an overall picture, not every rock sticking up among its companions.

It would be like saying we will meet at the 7-11 outside of Newark. Here's the map ro get there-

[lagomorph777]

15. Hmm, not a sailor, so I wasn't up on the latest.

We should have policies about navigating uncharted waters. Restrictions on depth if you're cruising silently, for example...?

[sarisataka]

18. Typically they do

If they know 99% of an area is 2000 ft deep with a some projections going up to 1500 ft there will be a max depth restriction of 1000ft. (I'm making these numbers up as an example. Actual guidelines are classified)

However if a mission requires extra stealth there may be an exception allowing the sub to go to 1300 ft. Still all well and good until it finds the one projection that no one noticed goes up to 1280 ft.

Ot isn't just the US that has this issue. Submarines are like airplanes that always fly on instruments. You need accurate maps and navigational data. It isn't out of the question that the sub was there trying to improve our maps. You can understand why China wouldn't necessarily share their best maps with us.

[DFW]

31. Oh, yeah, THAT 7-11

I've been there many times, myself........

[hack89]

11. Not to the resolution required to detect all navigation hazards.

we know more about Mars than we do about the bottom of the oceans. There are vast stretches of remote areas where the sea bottom is a complete mystery.

[Ilsa]

25. Is it also possible there could be geologic reformations

that lift underwater structures some, enough to now be high enough to hit? I wonder about these things.

[cloudbase]

7. Not a career enhancing event for the commanding officer.

That kind of stuff will ruin your morning.

[hack89]

12. It depends how well trained his navigation team is

if they are all qualified, their charts are up to date and they cut no corners regard navigation procedures, he should be ok.

[hunter]

16. Passive sonar may not have been up to the task.

Open your wallet. Time for an upgrade.

I'm not complaining.

Unlike many military projects, submarines are not all vanity and pork.

[hack89]

19. Passive sonar will never detect a sea mount

and a submarine will never use active sonar for navigation unless in a true emergency.

[hunter]

21. Blind people learn to image their environment using ambient sound.

Aquatic animals do this too.

Active sonar is easier to process, and may offer more detail, but the technology is advancing as computing power increases.

https://nfb.org//sites/default/files/images/nfb/publications/fr/fr30/1/fr300107.htm

[hack89]

23. Littoral waters like the South China Sea are a sonic nightmare

High ambient noise, high shipping density, bottom reverberation, etc.

It will be a very long time before passive sonar can be used in that sort of environment.

[hunter]

27. It makes one feel sorry for the animals who have to suffer that.

I look forward to the return of sailing ships.

Technically, more ambient noise is roughly equivalent to more ambient light. Processing that information is the difficult part, a problem made more difficult by variations in water temperature which change the speed of sound in water. Nevertheless it's not entirely a house of mirrors.

Above the water there's a lot of similar research using ambient radio illumination for imaging.

[hack89]

32. The biggest technical issue is getting meaningful tactical ranges

the volume of area of interest grows enormously as desired detection ranges increase. There are so many possible interactions to model.

[hunter]

33. We started talking about underwater mountains...

... and how to avoid the uncharted ones without using active sonar.

I'm having a good time thinking about this.

[cloudbase]

17. I'm not so certain.

Look at how they bent over Capt. Crozier on the Roosevelt.

[hack89]

20. Different situation

he was punished for making his chain of command look bad.

[pecosbob]

22. The basic math is that if the captain ran aground or hit another vessel, he's toast.

Photos from Guam show that the submarine's nose is gone and the sonar array is exposed.

[Brother Buzz]

26. It hasn't arrived in Guam yet

The photos from Guam showing a submarine's nose damage is the USS San Francisco sitting in the Guam dry dock in 2005. The dry dock is no longer even there.

[pecosbob]

28. Here's a video showing the photos

All open-source information.

You are correct in that the floating drydock was removed from Guam, in 2016 I believe. These photos are taken with the submarine tied up at the pier.

[Brother Buzz]

29. Cool, it made it to Guam, but according to the second video....

it looks like they have to move it again for a proper inspection and repairs

[pecosbob]

30. Yeah...they're liable to take it back to it's original boatyard as the damage is major