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.
During world war two, German U-boats used to have issues with chlorine gas being produced from the batteries and it would flood the boat and kill everyone onboard.
My grandfather was in a US Navy salvage group in WWII. At the time, to verify an enemy vessel (especially subs) had been sunk, they would send down divers in the old fashioned "heavy gear" suits to identify the vessels.
They would also bring up proof, usually something that could be tied to the vessel, which could be a piece of military-grade equipment or even silverware engraved with the names of the ship or the enemy seal.
My grandfather was a submariner in the Pacific during the war, they were even inside Tokyo bay during wartime. He had many stories, one of them was that the batteries always got the priority in regards to water. Especially on patrol and missions, they would often go days between wiping themselves down with hand towels from a basin of shared water, all to preserve the fresh water for the batteries.
Lead acid batteries, especially very old ones, actually consume water. The electrolyte is sulphuric acid diluted in pure water. When the battery is charging, some of the water is electrolyzed into hydrogen and oxygen gas. Modern lead acid designs still have this flaw, but it's much reduced and you typically don't need to refill them. Look at the warning stickers on your car battery, it's talking about hydrogen gas.
To be more specific, that is why the battery needs to be in a place that can vent.
When I replaced the AGM battery on my German car, I learned that, even though they don't vent under normal conditions, still have a vent hole. But that's paired with a pressure regulator and not for normal conditions.
Which makes me wonder: did BMW start to use AGM so they can move the heavy battery to the trunk, which helps with weight balance? Or was it an emissions thing that enabled them to move it to the trunk.
> They would also bring up proof, usually something that could be tied to the vessel, which could be a piece of military-grade equipment or even silverware engraved with the names of the ship or the enemy seal.
I believe traditionally, a diver will bring up a ship's bell for this purpose, if they are able. But maybe I'm off base about about, particularly when it comes to an enemy ship.
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.
> 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.
Yes it's called a sonar. And would they even need to fire the sonar for that? Even using passive sonar they should be able to hear there's a boat above them considering how sensitive their sonars are. But operational mistakes can happen no matter how many sensors you have.
If you are thinking about the USS Greeneville colliding with the Ehime Maru 10 miles (16 km) off the coast of Oahu, then that ship was a training ship not a tourist boat.
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.
Everything I think about them. As you state, just the fuel pumps (that pump fuel at cryo temperatures) are hundreds if thousands of horsepower and are amazing fears of engineering on their own. Each piece of that engine is like that.
I had the immense privilege of seeing a few F1s in person recently in DC and I was not let down.
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!
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.
One of my professors when I was an anesthesiology resident was ex-Navy. He had been in the submarine service, and not as just a general medical officer. As an anesthesiologist. You can imagine the kind of missions a submarine with an anesthesiologist on board might be sent on. There might even be a surgeon on board...
Anyway, he was dive-rated. Closed-circuit breathing is the basis of anesthesia machines and has been for ages (at least 60 years). So for us, a closed-circuit system isn't new - it's something we do every day at work. You just have to account for depth. I'd be shocked if he hadn't done it.
That is cool as hell. And yes, one can imagine. The list of boats he was probably on is extremely short: Seawolf (the 2nd one), Halibut, Parche, and Jimmy Carter.
Incidentally, I would add that while he never specified, he very likely may have shipped out as a “general medical officer” with the crew not necessarily knowing he had a deeper skill set. They wouldn’t necessarily twig to it on early deployment. Only when they take on a SEAL team and a surgeon would it become obvious (or he goes on another boat with a surgeon as the GMO). The only obvious clue would have been his being slightly older than a typical GMO.
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.
Totally, and the controls for the motors have to be crazy now. Imagine trying to reliably switch and vary that amount of power to turn on and off, and control speed at that level of power
Electric drives are nothing new on submarines in general; the _Gato_ class were diesel-electric, and the French and Chinese apparently prefer nuclear-electric. But I think this is the US Navy's first nuclear-electric ship
Nah, we’ve had two nuclear-electric boats before: Tullibee and Glenard P. Lipscomb. They just weren’t successful (Tullibee was to some extent, but she was also quite small).
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.
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.
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.
They are in actively using, where convenient to block large water area. As even in war ports, usually active traffic.
Second reason why now limited usage, WWII submarines was very limited power, many experts consider them as just high-speed boats with extremely limited underwater capabilities, but modern submarines are really powerful, especially nuclear.
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.
Here's a modern commercial fishing net: [1] The net itself isn't that heavy per unit area; it's just big.
The top support line of the net is a string of floats, like pool lane markers, but larger.
They're fishing for herring, not the Great White Whale.
Anti-submarine nets are far, far heavier.[2]
MESH ROPES: - flexible steel galvanized wire rope
This is a single strand, flexible steel galvanized wire rope consisting of 70 wires and 21 hemp yarns. It is one-inch in diameter, has a breaking strength of 98,280 pounds and is internally lubricated and protected against the action of salt water by saturating the fiber cores with a preservative composition. It weighs 1.8 pounds per running foot and is supplied on reels carrying 3,000 feet of wire and weighing 5,000 pounds packed for shipment.
The top support line of a submarine net looks like a bridge cable. The floats are the size of cars or larger.
For safety, you do not want it to stop the sub. You want the sub to tear right through it or else the sub is going to take your boat with it, and what if the sub decides to dive?
Sorta kinda. The sub could be stopped, in the sense of "badly tangled in our equipment, and will need to stop and get untangled", without actually hauling the fishing boat along after it. Maybe the equipment wasn't well secured to the boat. Maybe your savvy crew realized the problem and cut loose. Either way, you're out some expensive equipment.
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!
Yes, they do, but we don't want the civilian leadership criticizing captains for their operational decisions. Strategic, yes, absolutely. "Do we do this mission or not?" is absolutely up to civilians (Secretary of the Navy, Secretary of Defense, President) to decide. A captain making in-the-moment decisions about the running of the boat or ship can be handled by the military - up to and including loss of command or even court martial. If they are operating within their orders and official regulations, civilians should stay out of it or risk having a military that doesn't work when we need it.
In any organization, military or otherwise, there is a hierarchy of authority. The paint operator reports to their forperson who reports to shop floor manager who reports to the ... etc. who reports to the CEO who reports to the board of directors.
It's generally not a good idea for the CEO or board member to directly manage the painter, because there is so much they don't know about the person, situation, paint, etc; that's why they delegate. Also it undermines all the managers in the chain. On the other hand, sometimes those costs are worth it, and it's better than the alternative - sometimes the bureaucratic rules get in the way, or the structure is malfunctioning, and you need to get things moving.
But none of that is not special to militaries.
> civilians should stay out of it
While it may be true practically in many cases, I think that phrase is antithetical to democracies and freedom. A big threat to democracy is a military that is above civilians in status, power, etc. And one big advantage of a democracy is an open society, where citizens can see and respond to issues; sunlight disinfects corruption.
You left out my leading phrase: if they are operating within their orders and military regulation. And civilians are quite entitled to question those. If the captain is within both of them and still commits a war crime somehow, you don't hang the captain, you hang the admiral.
It might seem like a technicality, but my point is that civilians are entitled to question anything they want about the military - that's necessary for democracy. I would agree that it's usually not wise.
> If the captain is within both of them and still commits a war crime somehow, you don't hang the captain, you hang the admiral.
You hang both. Captains are officers, not automatons; they are responsible for their actions. But I agree that the admiral is the biggest issue, or maybe the secretary / minister of defense.
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.
I'm simply assuming that fancy submarines are well equipped to detect things that are trying to be quiet so detecting something like an active fishing boat and its trawl should surely not be difficult; especially when you already know that it is likely to be in the area.
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.
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...).