# Japan: Submarine crew phone for help after crash



## Blackadder1916 (9 Feb 2021)

Japan: Submarine crew phone for help after crash​








						Japan: Submarine crew phone for help after crash
					

The submarine collided with a commercial ship as it attempted to surface off Japan's Pacific coast.



					www.bbc.com
				





> *A Japanese submarine has collided with a commercial ship as it attempted to surface off the country's Pacific coast.*
> 
> Three of the submarine's crew sustained minor injuries in the crash which occurred on Monday, government officials said.
> 
> ...



Good photos of the damage at link.


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## CBH99 (9 Feb 2021)

Glad nobody was seriously hurt or killed.

Curious...over the years, there has been a few incidents of submarines colliding with fishing vessels, commercial ships, etc etc while they surface.  Why is that?

These are ships that can somehow maneuver along the ocean floor, through under-ocean geographic features like canyons and such - and have extremely sophisticated active & passive detection systems.  

What is it about surfacing that seems to leave submarines somewhat blind to what is directly above them?  I'm sure there is a scientific or technical explanation, but I've googled a bit & haven't found anything concrete.


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## SeaKingTacco (9 Feb 2021)

Blackadder1916 said:


> Japan: Submarine crew phone for help after crash​
> 
> 
> 
> ...


That will buff right out...


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## CBH99 (9 Feb 2021)

SeaKingTacco said:


> That will buff right out...


Absolutely.  Nothing a little grease can't fix   

Or if that fails, it can take the lead for one of the most expensive, and least effective surface combatants in the world today!


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## brihard (9 Feb 2021)

SeaKingTacco said:


> That will buff right out...


I wouldn’t get bent out of shape over it.


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## Pelorus (9 Feb 2021)

CBH99 said:


> Curious...over the years, there has been a few incidents of submarines colliding with fishing vessels, commercial ships, etc etc while they surface.  Why is that?
> 
> These are ships that can somehow maneuver along the ocean floor, through under-ocean geographic features like canyons and such - and have extremely sophisticated active & passive detection systems.
> 
> What is it about surfacing that seems to leave submarines somewhat blind to what is directly above them?  I'm sure there is a scientific or technical explanation, but I've googled a bit & haven't found anything concrete.



Caveat: I am not a submariner, so take the following with a grain of salt.

Probably easier to answer your question using an analogy (maybe not, we'll see by the end).

Imagine yourself blindfolded, trying to get from one end of a cornfield maze to the other. Normally, it would be difficult to avoid bumping into the corn as you progress. If, however, you had a perfect map of the maze seared into your brain, knew your exact position relative to the maze prior to entering it, your body had a near-perfect sense of proprioception (i.e. you could tell exactly how far you travelled with each step and how much of an angle you rotated when you turned), and you had the brainpower to plot all your movements in your mental map of the maze in real time, you could probably get to the end without touching the corn.

In this analogy, the map of the corn maze is accurate undersea charting, your known position before entering the maze is a GPS fix from the surface, your ability to accurately measure self-movement is the submarine's Inertial Navigation System, and your brain is the sub's navigation processor (and its human operators).

In a second scenario, you again are blindfolded and walking towards a busy 4 way intersection with the intent to cross it without getting hit. It's very foggy out so you have to assume that no car is going to see you in time as you're crossing to avoid hitting you. Now, fortunately you were blessed with very accurate ears that can a) make distinctions between different car noises so that you can get a sense of how many cars are at risk of hitting you, and b) tell in a general sense from the doppler shift being generated by those cars whether those cars are moving towards or away from you. You again have near-perfect proprioception, and your brain is able to process multiple noise sources at once and compare them with your own movement to try to figure out their true movement (e.g. moving in the N-S lane, the E-W lane, turning, etc.). Unfortunately though, these calculations take time, are being made using the imperfect information of the sound the cars make, and are made much more difficult by any erratic movements the cars in the intersection make.

The sub CO's job during surfacing is to process all of this information as well as he or she can to determine the position and movement of relevant surface vessels to make sure that the sub can safely surface without something like what's in the article happening. Unfortunately from time to time this does not go according to plan, and the investigators will need to determine if the accident occurred due to some likely combination of human error, incomplete information, inadequate training, inadequate policy, etc.


*TL; DR:* Modern submarine Inertial Navigation Systems and submarine charts are both very accurate, so dived navigation typically has less sources of error or confusion than trying to rely on passive acoustics and Target Motion Analysis to determine a busy surface picture prior to surfacing. Sound propagation in bodies of water is dynamic and accurately measuring this is a tough nut to crack for even the most sophisticated sensors and processors.

*Edit:* To add, this is a contact detection and tracking issue, not specifically a surfacing issue. There are known instances in the past of submarines bumping into each other while submerged. You just rarely hear about it as it's much lower probability than dealing with surface traffic due to the number of vessels which could be involved.


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## Blackadder1916 (9 Feb 2021)

CBH99 said:


> Glad nobody was seriously hurt or killed.
> 
> Curious...over the years, there has been a few incidents of submarines colliding with fishing vessels, commercial ships, etc etc while they surface.  . . .



And speaking of such, it is the twentieth anniversary (9 Feb 2001) of the collision of the USS _Greenville_ (SSN 772) with the Japanese fishery high school training ship _Ehime Maru_ off Oahu that resulted in the sinking of the Japanese vessel with the loss of nine lives.


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## Ping Monkey (9 Feb 2021)

CBH99 said:


> What is it about surfacing that seems to leave submarines somewhat blind to what is directly above them?  I'm sure there is a scientific or technical explanation, but I've googled a bit & haven't found anything concrete.


Some details on the challenges of surfacing, navigating sea lanes at periscope depth, and speculation on potential causes of the collision here: 








						Veteran Submariners Explain What Might Have Caused Japanese Submarine Collision
					

Despite all the technology at their disposal, for a submarine crew, the simple act of surfacing can sometimes be fraught with danger.




					www.thedrive.com
				




Very glad nobody was seriously hurt, and the Soryu appears repairable.


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## Journeyman (11 Feb 2021)

Maybe it wasn't a problem with sensors and situational awareness, so much as grammar.  The submarine collided "with a commercial ship as it attempted to surface."  Why would a commercial ship not already be on the surface?


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## CBH99 (12 Feb 2021)

boot12 said:


> Caveat: I am not a submariner, so take the following with a grain of salt.
> 
> Probably easier to answer your question using an analogy (maybe not, we'll see by the end).
> 
> ...


As I've gotten older, I've developed certain...'things'...about flying, submarine service, etc etc.  I wouldn't call them phobias, but as you get older you start to realize all the things that could go wrong, that I was blissfully unaware of as a child.

I don't think I'd be cut out for submarine service.  I did chat with an American guy a few years back, and he did 8 years in submarines, had great things to say.  I just don't think I'd be cut out for it.  And after watching that miniseries a while back (Sub School, apparently narrated by Stewie Griffin) I also realize I don't have the brains anyway.



Ping, thanks for that article.  The video was very helpful!


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## tomahawk6 (15 Feb 2021)

A poorly trained sonar operator ?


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## daftandbarmy (15 Feb 2021)

CBH99 said:


> As I've gotten older, I've developed certain...'things'...about flying, submarine service, etc etc.  I wouldn't call them phobias, but as you get older you start to realize all the things that could go wrong, that I was blissfully unaware of as a child.



Same goes for marriage, right?


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## CBH99 (15 Feb 2021)

The older I get, the more distant that seems too


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## Ping Monkey (18 Feb 2021)

Additional details.  Lesson learned, kids:  Always clear your baffles.



			MSDF sub crew’s failure to check blind spot probed as collision cause | The Asahi Shimbun: Breaking News, Japan News and Analysis


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