I heard a story of a fishing boat in the eastern US that was "fighting a fish" for miles but could never get any traction. When another fisherman looked at their chart, he noted that they were dragged miles in a straight line towards Europe, and said "You caught a sub". The submariners don't care, they probably find it funny.
Fishermen sometimes happen upon submarine accidents. This one dates from 2003:
On April 25, 2003 the crew of a Chinese fishing boat noticed a strange sight—a periscope drifting listlessly above the surface of the water. The fishermen notified the People's Liberation Army Navy (PLAN) which promptly dispatched two vessels to investigate.
> In a demonstration for some VIP civilian visitors, Greeneville performed an emergency ballast blow surfacing maneuver. As the submarine shot to the surface, she struck Ehime Maru. Within ten minutes of the collision, Ehime Maru sank. Nine of the thirty-five people aboard were killed: four high school students, two teachers, and three crew members.
Fascinating - I wonder what the procedure is for a jammed propeller on a sub. I’m used to airplanes, which have redundancies for everything, but a sub propeller is really a single point of failure. Potentially seaweed or rope could become entangled, right?
Would the sub typically have to surface to manually clear the propeller? Or, does it have enough torque to just (noisily) obliterate most entanglements?
The propellers on nuclear subs are powerful enough to ignore seaweed and almost anything else, it’s (edit: 100’s of thousands HP) rotating a multi story steel building with literally tons of momentum.
They do have divers which can get out without surfacing to deal with some problems, but Nuclear subs can move forward without the propeller.
Water is so dense those stubby wings you see on the side can when angled properly create forward thrust when the sub moves up or down which they can do repeatedly by adding and removing water from a ballast tank. Essentially acting like gliders who can swap gravity to keep going.
It probably isn’t millions of HP, 746MW is roughly equal to 1 million HP. Regardless, it’s still several hundred thousand horsepower driving the propeller, so your point still stands!
Underwater nets were a common defense against submarines during the second world war, protecting harbours and the like. I have no reason to think the case is otherwise now.
'Net' is a generic term. I have a 'computer', NOAA has a 'computer', but they aren't the same thing. I would be surprised if a fishing net was sufficient to stop a military sub.
Also, subs now are a lot more capable than they were then.
If a fishing net or line was strong enough to stop a sub, then no sane commercial fisherman would ever pay the extra $$$$$ for it, to get that that level of overkill. Plus, the "nuclear-strength" net or line would weigh a LOT more, and fishing involved plenty of hauling your stuff out of the water & other handling.
If silence is important, modern subs have divers and they can work on it w/o surfacing. In peacetime they'd probably want to surface and concentrate on not damaging anything.
I would guess they test props against real-world commercial fishing nets as part of some qualification process.
>I would guess they test props against real-world commercial fishing nets as part of some qualification process.
I assume enough nets have been run over by various vessels over the centuries that they can simply predict performance by looking at the design and plugging key parameters into a formula or table.
There are plenty of airplanes which have only a single propeller. You can find videos online from light aircraft where the propeller literally fell off in flight.
Sub propellers have a lot of torque. There's no way that one would really get entangled by seaweed. But thick ropes, cables, and heavy fishing tackle are a risk. Every military sub carries qualified divers who could manually cut it free as a last resort.
Those are usually different divers, sent as detachments to certain boats only for special missions. They are trained in using closed-circuit gear and perhaps in saturation operations, and aren't part of the submarine's standing crew.
The sub's standing crew would typically have a few qualified divers trained in just the basics. They would only use open-circuit gear on shallow bounce dives for inspections and light maintenance. Anything more complex would require bringing in a dedicated dive team.
My boat’s divers were definitely trained in more than just the basics, including closed-circuit. I don’t think it was regularly used, but they knew how to.
If you’re somewhere you aren’t supposed to be, and you have to dive to fix or inspect something, you don’t want to be sending bubbles up.
You’re on your own in the ocean, whether civilian or military, sub or surface. You have to be able to handle any and all potential issues.
Thanks for the clarification. The couple that I had talked to briefly weren't trained in closed-circuit but I suppose they were pretty junior and just recently qualified.
Generally it’s just various design parameters. Until the newest (and not-yet-built) Columbia-class, boats are all steam propulsion, and you can hit various pressure limits for components without maxing the reactor out. That said, yes, with nominal conditions generally All Ahead Flank will have the reactor output at 100%. All Back Emergency usually hits some other limit first.
Columbia-class is electric drive, which is absolutely wild to me. Those are monstrous motors.
Source: I ran a reactor on a Virginia-class (not USS Virginia, the subject of the article, but in the same class).
My understanding is the electric motors have in general gotten scary-powerful. I know some cruise ships have switched over to them because it simplifies the overall mechanical architecture (fewer moving parts, fewer high-pressure fluid circuits). Some of the Royal Carribean fleet has "azipods" that can be angled 360 degrees to provide arbitrary thrust for simplifying docking and undocking.
From first principles I'd expect the functional limit not to be one of power generation but of energy transfer. The limit probably manifests as wiring and motors overheating in a full electric drive (I don't think any subs are...) or as sound, heat and fatigue in reduction gears and gear shafts.
Also if the propeller still ends up inoperable, the sub could in an emergency also use buoyancy control to both possibly tear free from entanglement but even to travel forward, by adjusting the dive planes, to make it also go forward instead of just up and down.
As a civilian I’m in no position to critique the CO’s decision making. However it doesn’t seem unreasonable to assume a SONAR contact classified as a fishing boat may have a net deployed posing a hazard within a certain radius.
I assume Aaron Aamick (Sub Brief) and H.I. Sutton will make a video about this incident in the coming days, and we’ll get a credible answer to whether there’s any fault here on the part of the sub crew.
> As a civilian I’m in no position to critique the CO’s decision making.
To nitpick, you absolutely are. The military reports to the civilians; that is who they are accountable to.
That said, I don't know anything about submarines. But it has nothing to do with being a civilian or military. It's the trick of management, oversight, responsibility - we need to oversee and make responsible decisions for things where we lack expertise. I need to hire a plumber even if I know nothing about plumbing. Other people need to hire IT professionals, and IME some of them know nothing about IT!
Not hard to notice the net on the sonar or passive listening devices surely. And they were in an area where encountering a fishing boat and its nets is an everyday occurrence. Someone onboard should be reprimanded.
Not “polite”. But, you know, professional. You are supposed to be the ultimate stealth ship. Act like it. A fish boat shouldn’t be able to detect you, especially if all it takes is a slight twist on the joystick.
It’s like a ninja being seen by a guy taking a piss in the three he’s hiding at. That’s a shitty ninja.
Yeah, I had to follow the link to another referenced article and read an image caption to find out that this seems to have just happened on November 11, I assume this year.
Usually a date and year are useful details to include in a story.
I heard a story of a fishing boat in the eastern US that was "fighting a fish" for miles but could never get any traction. When another fisherman looked at their chart, he noted that they were dragged miles in a straight line towards Europe, and said "You caught a sub". The submariners don't care, they probably find it funny.
Fishermen sometimes happen upon submarine accidents. This one dates from 2003:
On April 25, 2003 the crew of a Chinese fishing boat noticed a strange sight—a periscope drifting listlessly above the surface of the water. The fishermen notified the People's Liberation Army Navy (PLAN) which promptly dispatched two vessels to investigate.
https://www.chieftain.com/story/news/2018/06/07/in-2003-chin...
Every one of the submariners died.
There was another reported Chinese sub accident in 2023, but it's not clear how it was discovered (https://www.rfa.org/english/news/china/china-submarine-death...).
This kind of event be pretty nasty - 4 fishermen were killed by a Royal Navy submarine in 1990:
https://en.wikipedia.org/wiki/FV_Antares
A US submarine surfaced under a tourist boat near Hawaii; many died iirc. I think it was around the 2000s.
https://en.wikipedia.org/wiki/Ehime_Maru_and_USS_Greeneville...
> In a demonstration for some VIP civilian visitors, Greeneville performed an emergency ballast blow surfacing maneuver. As the submarine shot to the surface, she struck Ehime Maru. Within ten minutes of the collision, Ehime Maru sank. Nine of the thirty-five people aboard were killed: four high school students, two teachers, and three crew members.
Russian subs get caught as well: https://www.bbc.co.uk/news/uk-northern-ireland-32333336
I seem to remember this happening quite often (yearly, maybe?) during the Cold War in the North Sea and around Norway.
And possibly https://en.wikipedia.org/wiki/Bugaled_Breizh as well.
Fascinating - I wonder what the procedure is for a jammed propeller on a sub. I’m used to airplanes, which have redundancies for everything, but a sub propeller is really a single point of failure. Potentially seaweed or rope could become entangled, right?
Would the sub typically have to surface to manually clear the propeller? Or, does it have enough torque to just (noisily) obliterate most entanglements?
The propellers on nuclear subs are powerful enough to ignore seaweed and almost anything else, it’s (edit: 100’s of thousands HP) rotating a multi story steel building with literally tons of momentum.
They do have divers which can get out without surfacing to deal with some problems, but Nuclear subs can move forward without the propeller.
Water is so dense those stubby wings you see on the side can when angled properly create forward thrust when the sub moves up or down which they can do repeatedly by adding and removing water from a ballast tank. Essentially acting like gliders who can swap gravity to keep going.
According to Wikipedia, the reactor on a Virginia-class sub has 280,000 hp (thermal, I guess) and 2x40,000 shp steam turbines.
So a little less oomph than 2 out of the 5 fuel pumps on a Saturn V, just for an irrelevant comparison ;)
I did not know that subs can do that reversible gliding trick. That is pretty neat.
It probably isn’t millions of HP, 746MW is roughly equal to 1 million HP. Regardless, it’s still several hundred thousand horsepower driving the propeller, so your point still stands!
Good catch, I remember someone referring to a sub that way and never double checked the numbers.
right, horsepower not hit points I see now.
If fishing nets / lines can stop a sub, it would save money on mines.
Underwater nets were a common defense against submarines during the second world war, protecting harbours and the like. I have no reason to think the case is otherwise now.
'Net' is a generic term. I have a 'computer', NOAA has a 'computer', but they aren't the same thing. I would be surprised if a fishing net was sufficient to stop a military sub.
Also, subs now are a lot more capable than they were then.
If a fishing net or line was strong enough to stop a sub, then no sane commercial fisherman would ever pay the extra $$$$$ for it, to get that that level of overkill. Plus, the "nuclear-strength" net or line would weigh a LOT more, and fishing involved plenty of hauling your stuff out of the water & other handling.
If silence is important, modern subs have divers and they can work on it w/o surfacing. In peacetime they'd probably want to surface and concentrate on not damaging anything.
I would guess they test props against real-world commercial fishing nets as part of some qualification process.
>I would guess they test props against real-world commercial fishing nets as part of some qualification process.
I assume enough nets have been run over by various vessels over the centuries that they can simply predict performance by looking at the design and plugging key parameters into a formula or table.
There are plenty of airplanes which have only a single propeller. You can find videos online from light aircraft where the propeller literally fell off in flight.
Sub propellers have a lot of torque. There's no way that one would really get entangled by seaweed. But thick ropes, cables, and heavy fishing tackle are a risk. Every military sub carries qualified divers who could manually cut it free as a last resort.
> Every military sub carries qualified divers
The same divers who occasionally "inspect" undersea cables. :)
They've even been alleged to "maintain" pipelines.
Those are usually different divers, sent as detachments to certain boats only for special missions. They are trained in using closed-circuit gear and perhaps in saturation operations, and aren't part of the submarine's standing crew.
The sub's standing crew would typically have a few qualified divers trained in just the basics. They would only use open-circuit gear on shallow bounce dives for inspections and light maintenance. Anything more complex would require bringing in a dedicated dive team.
My boat’s divers were definitely trained in more than just the basics, including closed-circuit. I don’t think it was regularly used, but they knew how to.
If you’re somewhere you aren’t supposed to be, and you have to dive to fix or inspect something, you don’t want to be sending bubbles up.
You’re on your own in the ocean, whether civilian or military, sub or surface. You have to be able to handle any and all potential issues.
Thanks for the clarification. The couple that I had talked to briefly weren't trained in closed-circuit but I suppose they were pretty junior and just recently qualified.
Is max torque on an typical nuclear submarine limited by the max reactor output, or can they rely on batteries to exceed this temporarily?
Generally it’s just various design parameters. Until the newest (and not-yet-built) Columbia-class, boats are all steam propulsion, and you can hit various pressure limits for components without maxing the reactor out. That said, yes, with nominal conditions generally All Ahead Flank will have the reactor output at 100%. All Back Emergency usually hits some other limit first.
Columbia-class is electric drive, which is absolutely wild to me. Those are monstrous motors.
Source: I ran a reactor on a Virginia-class (not USS Virginia, the subject of the article, but in the same class).
Thanks for the detailed answer!
My understanding is the electric motors have in general gotten scary-powerful. I know some cruise ships have switched over to them because it simplifies the overall mechanical architecture (fewer moving parts, fewer high-pressure fluid circuits). Some of the Royal Carribean fleet has "azipods" that can be angled 360 degrees to provide arbitrary thrust for simplifying docking and undocking.
From first principles I'd expect the functional limit not to be one of power generation but of energy transfer. The limit probably manifests as wiring and motors overheating in a full electric drive (I don't think any subs are...) or as sound, heat and fatigue in reduction gears and gear shafts.
Sorry, I was referring to Part 121 operations and missed it in an edit.
I think divers can be dispatched from the sub.
Also if the propeller still ends up inoperable, the sub could in an emergency also use buoyancy control to both possibly tear free from entanglement but even to travel forward, by adjusting the dive planes, to make it also go forward instead of just up and down.
I understand how this works, but for some reason, when I read your comment, I thought of Flappy Bird.
https://www.nrk.no/tromsogfinnmark/harald-fra-sommaroya-fikk... original article here.
> "No use getting riled up about it" says young fisherman after sub ruined fishing gear worth 50.000 NOK (4.500 USD)
I’m surprised Virginia didn’t hear the ship’s motor from miles away and kept its distance. I wonder if there will be any disciplinary actions.
They for sure heard the motor, a lot harder to hear the net though.
As for keeping their distance... well, they are a nuclear submarine, why should they be polite?
As a civilian I’m in no position to critique the CO’s decision making. However it doesn’t seem unreasonable to assume a SONAR contact classified as a fishing boat may have a net deployed posing a hazard within a certain radius.
I assume Aaron Aamick (Sub Brief) and H.I. Sutton will make a video about this incident in the coming days, and we’ll get a credible answer to whether there’s any fault here on the part of the sub crew.
> As a civilian I’m in no position to critique the CO’s decision making.
To nitpick, you absolutely are. The military reports to the civilians; that is who they are accountable to.
That said, I don't know anything about submarines. But it has nothing to do with being a civilian or military. It's the trick of management, oversight, responsibility - we need to oversee and make responsible decisions for things where we lack expertise. I need to hire a plumber even if I know nothing about plumbing. Other people need to hire IT professionals, and IME some of them know nothing about IT!
>well, they are a nuclear submarine, why should they be polite?
Because you'll fight like you train. Accidentally snagging a trawler in unfriendly waters after having just tapped a seabed cable would be a problem.
That said, there's a fine line between maintaining good standard procedure and getting absurd with it.
Dodging a trawler in the middle of nowhere, fine. Dodging a trawler in a crowded channel, probably not worth it.
To not inconvenience the natives? Seems obvious.
Not hard to notice the net on the sonar or passive listening devices surely. And they were in an area where encountering a fishing boat and its nets is an everyday occurrence. Someone onboard should be reprimanded.
They maybe would not like to kill civilians, nor would they like to be detected so easily.
Not “polite”. But, you know, professional. You are supposed to be the ultimate stealth ship. Act like it. A fish boat shouldn’t be able to detect you, especially if all it takes is a slight twist on the joystick.
It’s like a ninja being seen by a guy taking a piss in the three he’s hiding at. That’s a shitty ninja.
Funny story, but unfortunately the article is light on details.
Yeah, I had to follow the link to another referenced article and read an image caption to find out that this seems to have just happened on November 11, I assume this year.
Usually a date and year are useful details to include in a story.
Better throw it back then; they aren't in season right now.
But it was not this nuclear sub - https://en.wikipedia.org/wiki/USS_Halibut_(SSGN-587) - which would have been a far more interesting tail.
Man this makes me wish it had been this sub haha
"Guess we have a sub now! It's the law of the sea."