Yuan Class AIP & Kilo Submarine Thread

[tphuang]

well that's actually a pretty interesting idea, a wireless charging infrastructure buried in the shallow littorals. wireless charging has already been proven to work through several meters of water.

if I were a PLAN sub designer, I'd design next gen "Type 043" subs as a littoral specialized sub that dominates the shallow water within the 1st island chain with the following characteristics and infrastructure:

Infrastructure:

1. fund offshore wind turbines at random places.

2. use cables connected to both offshore wind turbines and the on-shore grid to secret seabed recharge points located remotely

This is actually already discussed as a geopolitical concern. It's one thing to build offshore wind turbines in your own EEZ. Once you get to disputed areas, other countries are going to start complaining.

I think they are totally build underwater SOSUS type of networks and countries are not complaining. Once you start putting stuff above water and impeding fishing and resource exploration, you could get into big disputes.

Actual sub:

1.

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for both AIP and surface engine, no mechanical hydrocarbon engine at all. This eliminates 3 detection routes: 1. detection through exhaust gas samplers 2. detection through engine noise 3. detection through transmission noise

There are advantages to this. I would point out that running on battery alone would have the same advantages. The noise comes from propulsion system and auxiliary systems. I'd be curious whether a large fuel cell engine is more or less stealthy than a high torque electric motor when operating subs at low speed. Good thing for them to test out.

2. LFP batteries with wireless charging capabilities for fast sprinting, fast recharge and very high endurance in littorals.

How would they do this without a large charger around when operating in the oceans. I think recharging through Diesel engine is going to be the quickest way for a long time.

3. Littoral specialized equipment and nonacoustic sensing: LIDAR and refractive index (wake) sensors on photonic mast, fiber optics guided UUVs, mines and torpedos

All great ideas. I'd have no idea how well these sensors would work in water. I'd also imagine they get shorter range than a medium frequency bow sonar.

My assumption for littoral would be snorkeling possible very occasionally, but almost no snorkeling possible past Okinawa.

I mean, they have to snorkel every day or 2 for ventilation. There is just no getting around that. That's why China is not as afraid of Japanese subs now. If you can have MPAs flying around over the top, then you can pick up the snorkels from diesel subs. And you know how far they can go in 2 days at low to medium speed.

With the aircraft carrier cover + refueling, I would assume that China can operate MPAs or at least ASW helicopters well past Okinawa (like 1000 to 1500km off China's shore). Yuan absolutely need to be able to operate East of Ryukus. If Japanese P-3Cs and helicopters can't get close, then the occasional surfacing with radar reflecting sail would be hard to pick up. I really don't see why else they would need to have a redesigned sail unless they intend to do frequent recharging.

If PLAN is deploying a dedicated new class of littoral midget sub then I think that would be a better choice.

I'd expect them to be pumping out those 600t subs pretty soon and they will have good endurance through LIB. That would be a pretty big improvement in endurance compared to Song class operating in the same area.

 

[FairAndUnbiased]

This is actually already discussed as a geopolitical concern. It's one thing to build offshore wind turbines in your own EEZ. Once you get to disputed areas, other countries are going to start complaining.

I think they are totally build underwater SOSUS type of networks and countries are not complaining. Once you start putting stuff above water and impeding fishing and resource exploration, you could get into big disputes.

There are advantages to this. I would point out that running on battery alone would have the same advantages. The noise comes from propulsion system and auxiliary systems. I'd be curious whether a large fuel cell engine is more or less stealthy than a high torque electric motor when operating subs at low speed. Good thing for them to test out.

How would they do this without a large charger around when operating in the oceans. I think recharging through Diesel engine is going to be the quickest way for a long time.

All great ideas. I'd have no idea how well these sensors would work in water. I'd also imagine they get shorter range than a medium frequency bow sonar.

I mean, they have to snorkel every day or 2 for ventilation. There is just no getting around that. That's why China is not as afraid of Japanese subs now. If you can have MPAs flying around over the top, then you can pick up the snorkels from diesel subs. And you know how far they can go in 2 days at low to medium speed.

With the aircraft carrier cover + refueling, I would assume that China can operate MPAs or at least ASW helicopters well past Okinawa (like 1000 to 1500km off China's shore). Yuan absolutely need to be able to operate East of Ryukus. If Japanese P-3Cs and helicopters can't get close, then the occasional surfacing with radar reflecting sail would be hard to pick up. I really don't see why else they would need to have a redesigned sail unless they intend to do frequent recharging.

I'd expect them to be pumping out those 600t subs pretty soon and they will have good endurance through LIB. That would be a pretty big improvement in endurance compared to Song class operating in the same area.

The electric motor is the propulsive unit, not the engine. All conventional subs use some form of engine that drives a generator, a battery system to store energy and an electric motor as the actual propulsive unit. All conventional subs have electric transmission, not mechanical transmission, to a variable speed electric motor. SSNs have mechanical shaft and gear transmission. The mechanical transmission, plus the pumps, is why SSNs are so noisy. So far there has never been an IEP SSN built.

Between conventional subs it's only the power supply that charges the batteries which differs (diesel engine, Stirling engine, fuel cell). So the electric motor is completely independent of what particular power supply is used. There is no conflict between a high torque electric motor and a fuel cell. You can use both.

In the littorals and other complex environments, sonar alone is insufficient because of multiple reflection effects, high background noise, complex environments, etc. in particular, for finding enemy subs. Russian SSNs have chemical samplers and refractive index wake sensors specifically for finding enemy SSNs in complex environments like the Arctic and Siberian Pacific. East China Sea, Yellow Sea and South China Sea are just as complex.

In the littoral, you also get random bullshit like fishing nets, underwater sand dunes, sunken cargo containers, etc. Passive sonar also cannot detect enemy contact mines. Optical and chemical sensors greatly increase capability for detection of silent enemy assets and obstacles.

And finally for underwater charging points, you don't need the wind turbine right there. You can build turbines in your EEZ then run an underwater power line to a charging point. Or just run one from shore. Underwater cables can be very long.

 

[tphuang]

The electric motor is the propulsive unit, not the engine. All conventional subs use some form of engine that drives a generator, a battery system to store energy and an electric motor as the actual propulsive unit. All conventional subs have electric transmission, not mechanical transmission, to a variable speed electric motor. SSNs have mechanical shaft and gear transmission. The mechanical transmission, plus the pumps, is why SSNs are so noisy. So far there has never been an IEP SSN built.

There are a lot more parts to a nuclear reactor that's noisy. Let's not simplify things and just say it's a couple of things.

Yes, I do realize electric motor is the propulsion unit.

Between conventional subs it's only the power supply that charges the batteries which differs (diesel engine, Stirling engine, fuel cell). So the electric motor is completely independent of what particular power supply is used. There is no conflict between a high torque electric motor and a fuel cell. You can use both.

Stirling engine does not charge batteries. It's used to operate the boat.

I see no reason why batteries are still needed if you have fuel cell. It seems like you just need H2 and Cryogenic Oxygen tank on board to keep it going.

In the littorals and other complex environments, sonar alone is insufficient because of multiple reflection effects, high background noise, complex environments, etc. in particular, for finding enemy subs. Russian SSNs have chemical samplers and refractive index wake sensors specifically for finding enemy SSNs in complex environments like the Arctic and Siberian Pacific. East China Sea, Yellow Sea and South China Sea are just as complex.

That's why they have so many sensors in the South China Sea and building a library of data that AI can take advantage of.

In the littoral, you also get random bullshit like fishing nets, underwater sand dunes, sunken cargo containers, etc. Passive sonar also cannot detect enemy contact mines. Optical and chemical sensors greatly increase capability for detection of silent enemy assets and obstacles.

Yes, that's why you use active and passive sonar from many assets. You use MAD. There are a lot of things at disposal.

Not against Lidar or anything like that. But the range on those things on land is not great right now.

And finally for underwater charging points, you don't need the wind turbine right there. You can build turbines in your EEZ then run an underwater power line to a charging point. Or just run one from shore. Underwater cables can be very long.

This seems more trouble than it's worth. It would take many hours, maybe days to wireless charge a submarine from underwater. There is no need to over think this. China has to establish air superiority in the region it's operating.

 

[FairAndUnbiased]

There are a lot more parts to a nuclear reactor that's noisy. Let's not simplify things and just say it's a couple of things.

Yes, I do realize electric motor is the propulsion unit.

Stirling engine does not charge batteries. It's used to operate the boat.

I see no reason why batteries are still needed if you have fuel cell. It seems like you just need H2 and Cryogenic Oxygen tank on board to keep it going.

That's why they have so many sensors in the South China Sea and building a library of data that AI can take advantage of.


Yes, that's why you use active and passive sonar from many assets. You use MAD. There are a lot of things at disposal.

Not against Lidar or anything like that. But the range on those things on land is not great right now.


This seems more trouble than it's worth. It would take many hours, maybe days to wireless charge a submarine from underwater. There is no need to over think this. China has to establish air superiority in the region it's operating.

Subs can't use magnetic anomaly detectors usefully (unless they have titanium hull) due to interference from own hull. A towed MAD doesn't work in littorals. A MAD on a UUV connected by fiber optics could work. They're not super long ranged though, ~1000 m at best. LIDAR is not long range either, maybe ~100m but can see the other hazards of littoral regions such as obstacles and mines.

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Stirling engine being used for mechanical drive is something I am not sure on. Why wouldn't they use it for generator charging so you don't need a redundant transmission? If this isn't already done, then this is an obvious improvement.

fuel cell subs like Type 212 have battery as well to buffer and manage power supply and demand. This allows the fuel cell to run continuously at the highest possible efficiency while the battery can charge and discharge as demand requires. The alternative is throttling the fuel cell and at minimum affecting the efficiency and at maximum risking an engine shutoff. Using batteries as a power management buffer is a widely accepted practice.

 

[tphuang]

Subs can't use magnetic anomaly detectors usefully (unless they have titanium hull) due to interference from own hull. A towed MAD doesn't work in littorals. A MAD on a UUV connected by fiber optics could work. They're not super long ranged though, ~1000 m at best. LIDAR is not long range either, maybe ~100m but can see the other hazards of littoral regions such as obstacles and mines.

sorry, I was not referring to subs. I'm talking about MPAs. MAD don't have long range, but if they get cued, your aircraft can fly through a relatively large area quickly. The many sonars you have in the Ocean along with experienced ASW operator and AI can identify possible intruders. MPAs will allow you to scan through the area with MAD and drop sonobuoys and detect whether or not there is a sub there. Fyi, MAD these days could achieve longer range than 1000m.

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Stirling engine being used for mechanical drive is something I am not sure on. Why wouldn't they use it for generator charging so you don't need a redundant transmission? If this isn't already done, then this is an obvious improvement.

300 kw isn't enough to charge batteries when 4 knots probably requires 200 to 250 kw of power.

fuel cell subs like Type 212 have battery as well to buffer and manage power supply and demand. This allows the fuel cell to run continuously at the highest possible efficiency while the battery can charge and discharge as demand requires. The alternative is throttling the fuel cell and at minimum affecting the efficiency and at maximum risking an engine shutoff. Using batteries as a power management buffer is a widely accepted practice.

I guess it doesn't hurt to have a 10 MWh LIB. It won't take up much space.

There is a lot of good idea here. I would guess with the advancement in fuel cell and LIB technology, PLAN have decided that mini-nuke is not needed. Even if Stirling/mini-nuke is mostly quiet with rafting, it's still not really necessary if they have technology that can achieve the same endurance with technology that produces no noise outside of the drive train and onboard machines.

The biggest change in the stealth of 039C and the new littoral subs might be the much improved electric motor technology that is now available.

I just listened to Shilao's podcast and they actually talked about Lada. So back in 2013, report came out that Russia was looking to work with China on Lada. At the time, it sounded like interesting news. Kilo had really improved China's underwater capabilities. One would've expected Lada to be a generation better. As it turned out, Russia wanted China's Stirling AIP technology and wanted China to pay money to have it installed on Lada. Needless to say, that did not work out. Lada itself has also turned out to be a failure so far. Russia continues to build the much larger Kilo. Kilo is a little quieter (due to its larger size) despite being 30 years older than Lada.

 

[FairAndUnbiased]

sorry, I was not referring to subs. I'm talking about MPAs. MAD don't have long range, but if they get cued, your aircraft can fly through a relatively large area quickly. The many sonars you have in the Ocean along with experienced ASW operator and AI can identify possible intruders. MPAs will allow you to scan through the area with MAD and drop sonobuoys and detect whether or not there is a sub there. Fyi, MAD these days could achieve longer range than 1000m.

300 kw isn't enough to charge batteries when 4 knots probably requires 200 to 250 kw of power.


I guess it doesn't hurt to have a 10 MWh LIB. It won't take up much space.

There is a lot of good idea here. I would guess with the advancement in fuel cell and LIB technology, PLAN have decided that mini-nuke is not needed. Even if Stirling/mini-nuke is mostly quiet with rafting, it's still not really necessary if they have technology that can achieve the same endurance with technology that produces no noise outside of the drive train and onboard machines.

The biggest change in the stealth of 039C and the new littoral subs might be the much improved electric motor technology that is now available.

I just listened to Shilao's podcast and they actually talked about Lada. So back in 2013, report came out that Russia was looking to work with China on Lada. At the time, it sounded like interesting news. Kilo had really improved China's underwater capabilities. One would've expected Lada to be a generation better. As it turned out, Russia wanted China's Stirling AIP technology and wanted China to pay money to have it installed on Lada. Needless to say, that did not work out. Lada itself has also turned out to be a failure so far. Russia continues to build the much larger Kilo. Kilo is a little quieter (due to its larger size) despite being 30 years older than Lada.

Russian SSK has little to offer now. SSK doctrines are highly local. In addition the key tech like battery and fuel cell is already too far behind China. They still have some useful foundational tech and SSN tech like titanium hull construction, reactor quieting and munitions, but even their trump card of non sonar sensors is something that China can likely do better.

 

[ChongqingHotPot92]

 

[ChongqingHotPot92]

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Also, the PLAN officers' cafeteria shown above appear to be super luxurious. Not sure what sailors' mess at a typical base look like.

 

[Tam]

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It is interesting to see what they have on the wall there and no one has mentioned it.

 

[by78]

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Could you at least provide a description or comment on the image? Don't just throw it out there and let the rest of the forum guess what it implies, especially when the subject isn't immediately obvious to our less experienced members.