Chinese submarines thread

[lilzz]

Re: Chinese sub thread

I think one thing for sure is littoral water is noiser than deep ocean water therefore easier to hide the diesel & nuke subs from subhunters like seawolf.
Now in real warefares if the PLAN subs stay in the littoral water and also masks by noisy commercial fishing boats, then there's good chance to evade the most sophisticated subhunters.

If China can make SSN cheap, then concentrate more on those. I Guess just being Nuke itself is somewhat a deterrent, because US need to think twice about blowing up a nuke sub and endanger the environment which lead to international condemnation.

I bet none of Japan, Taiwan would to see PLAN nuke subs blew up near their coast, therefore better not to touch them.

 

[Infra_Man99]

Re: Chinese sub thread

You are misunderstanding the entire point. The goal of having a diesel sub ambushing is to not take down Seawolf, but rather to hide from Seawolf and be at a striking distance from a more expensive surface ship like a carrier. They have different purpose. Seawolf's role is to hunt down these diesel subs. If the previous figures I read were correct, Seawolf is at least at the same order of quietness as the most advanced diesel subs in littoral environment.
And the other thing is that even seawolf is tracked, you still have to be close enough to it to have a chance of scoring a torpedo hit. Whereas for diesel subs, it simply can't escape from modern torpedoes.

That is NOT what the US navy says. The US navy has cut short the Seawolf class, because the US navy wanted a submarine that could perform in littoral warfare, but the Seawolf was not up to US naval standards for littoral warfare (too big and not quiet enough), thus the US navy quickly stopped the Seawolf class and made the Virginia class and continues to support the Virginia class. The Virginia class is a nuclear sub designed for littoral warfare and deep-sea warfare.

I still think China should use diesel subs for littoral warfare and nuclear subs for deep-sea warfare. This is assuming the obvious that China can make advanced subs of both types. Let me clarify, if all things are equal, diesel subs are better than nuclear subs for littoral warfare, but nuclear subs are better than diesel subs for deep-sea warfare. However, America is the most advanced and wealthiest nation right now, so America can make the most advanced nuclear subs that can challenge most or all diesel subs in quietness. Now imagine if America created the most advanced diesel subs. Think of how much more quiet this diesel can be than nuclear subs for littoral warfare.

If China can make a nuclear sub that can challenge diesel sub's small size and quietness, then China can use nuclear subs for both littoral warfare and deep-sea warfare. I wonder if pebble bed nuclear reactors will work for small, quiet nuclear subs. I know China is working on pebble bed nuclear reactors for civilian purposes.

 

[Pointblank]

Re: Chinese sub thread

That is NOT what the US navy says. The US navy has cut short the Seawolf class, because the US navy wanted a submarine that could perform in littoral warfare, but the Seawolf was not up to US naval standards for littoral warfare (too big and not quiet enough), thus the US navy quickly stopped the Seawolf class and made the Virginia class and continues to support the Virginia class. The Virginia class is a nuclear sub designed for littoral warfare and deep-sea warfare.

I still think China should use diesel subs for littoral warfare and nuclear subs for deep-sea warfare. This is assuming the obvious that China can make advanced subs of both types. Let me clarify, if all things are equal, diesel subs are better than nuclear subs for littoral warfare, but nuclear subs are better than diesel subs for deep-sea warfare. However, America is the most advanced and wealthiest nation right now, so America can make the most advanced nuclear subs that can challenge most or all diesel subs in quietness. Now imagine if America created the most advanced diesel subs. Think of how much more quiet this diesel can be than nuclear subs for littoral warfare.

If China can make a nuclear sub that can challenge diesel sub's small size and quietness, then China can use nuclear subs for both littoral warfare and deep-sea warfare. I wonder if pebble bed nuclear reactors will work for small, quiet nuclear subs. I know China is working on pebble bed nuclear reactors for civilian purposes.

Seawolf is reportly more quiet at speed than a LA boat while tied up at the dock. That's significantly more quiet than any current known Chinese nuclear submarines out there.

The Virginia class subs were born out of the extremely high costs of the Seawolfs.

 

[Infra_Man99]

Re: Chinese sub thread

Seawolf is reportly more quiet at speed than a LA boat while tied up at the dock. That's significantly more quiet than any current known Chinese nuclear submarines out there.

The Virginia class subs were born out of the extremely high costs of the Seawolfs.

Here is a US navy article about Seawolf subs, diesel subs, and littoral warfare. This article was written when the US navy was testing out 2 Seawolf subs.
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The Navy's ...From the Sea White Paper recognizes that the strategic landscape in the post-Cold war era has changed, and that the Navy will be increasingly involved in operations in the littoral or "near land" areas of the world, like the Persian Gulf. The littoral is characterized by a number of unique challenges: shallow, congested waterways, well-known to the adversary; mines; coastal missile and artillery batteries; sea-skimming cruise missiles; and tactical ballistic missiles. As ...From the Sea states, these littoral threats "tax the capabilities of our current systems and force structure. Mastery of the littoral should not be presumed. It does not derive directly from command of the seas."
---------------------

About the Virginia class, you are not entirely correct. Read the information at this link to find why the US navy quickly switched from Seawolf to Virginia:

Please, Log in or Register to view URLs content!

 

[tphuang]

Re: Chinese sub thread

That is NOT what the US navy says. The US navy has cut short the Seawolf class, because the US navy wanted a submarine that could perform in littoral warfare, but the Seawolf was not up to US naval standards for littoral warfare (too big and not quiet enough), thus the US navy quickly stopped the Seawolf class and made the Virginia class and continues to support the Virginia class. The Virginia class is a nuclear sub designed for littoral warfare and deep-sea warfare.

That seawolf being too big and not quiet enough is simply not true. They stopped at 3, because it was simply too expensive to keep on building seawolf. Think of Seawolf and Virginia more as F-22 and F-35 combination. Nothing in plan right now can come close to matching the quietness of Seawolf. I remember Gary on DT said before that Seawolf is a magnitude quieter than Amur.

I still think China should use diesel subs for littoral warfare and nuclear subs for deep-sea warfare. This is assuming the obvious that China can make advanced subs of both types. Let me clarify, if all things are equal, diesel subs are better than nuclear subs for littoral warfare, but nuclear subs are better than diesel subs for deep-sea warfare. However, America is the most advanced and wealthiest nation right now, so America can make the most advanced nuclear subs that can challenge most or all diesel subs in quietness. Now imagine if America created the most advanced diesel subs. Think of how much more quiet this diesel can be than nuclear subs for littoral warfare.

If China can make a nuclear sub that can challenge diesel sub's small size and quietness, then China can use nuclear subs for both littoral warfare and deep-sea warfare. I wonder if pebble bed nuclear reactors will work for small, quiet nuclear subs. I know China is working on pebble bed nuclear reactors for civilian purposes.

As I said, it's not about which one is better in littoral warfare. Diesel sub can pretty much just sit there and wait for much faster ships/nuclear subs coming around it. You build diesel subs because they are cheaper and faster to build and they can do the role of ambushing carrier group better than an equivalent generation nuclear sub. But if you try to match up one against another in littoral, diesel sub would never be able to outrun a torpedo. It would never be able to catch up to a nuclear sub. It would never have the detecting capability of a nuclear sub.

 

[Norfolk]

Re: Chinese sub thread

Here is a US navy article about Seawolf subs, diesel subs, and littoral warfare. This article was written when the US navy was testing out 2 Seawolf subs.
---------------------
The Navy's ...From the Sea White Paper recognizes that the strategic landscape in the post-Cold war era has changed, and that the Navy will be increasingly involved in operations in the littoral or "near land" areas of the world, like the Persian Gulf. The littoral is characterized by a number of unique challenges: shallow, congested waterways, well-known to the adversary; mines; coastal missile and artillery batteries; sea-skimming cruise missiles; and tactical ballistic missiles. As ...From the Sea states, these littoral threats "tax the capabilities of our current systems and force structure. Mastery of the littoral should not be presumed. It does not derive directly from command of the seas."
---------------------

About the Virginia class, you are not entirely correct. Read the information at this link to find why the US navy quickly switched from Seawolf to Virginia:

Please, Log in or Register to view URLs content!

Pointblank is correct in that the principle reason that the Seawolf-Class was cancelled after only 3 boats and the Virginia-Class was developed and ordered in its stead was the sheer cost. 15 years ago the Administration and Congress balked at the cost of buying around 30 of these monsters and insisted that the Navy come up with something affordable to replace the LA-Class (while the 37 earlier Sturgeon-Class subs were simply yanked out of service without replacement). It was all about the bucks.

The Navy turned around and made a virtue of necessity, and optimized the new Virginia-Class for coastal operations; back in the 90's anything that smacked of "Cold War" strategy was smacked-down, hard. Now we're discovering that a lot of that "Cold War" thinking is better than the "4GW" or "RMA" thinking. Peacetime doctrine.

 

[crobato]

Well despite the quietness of the Seawolf, the USN is still leasing foreign subs like the Gotland (which they had a hard time finding during execises) and doing exercises with countries that have SSKs, like Canada, Chile, Peru, Australia, Japan, Germany, Greece, Norway, Israel, Netherlands and even South Africa. And for all the hoopla, the diesel subs seems to be doing their part. I always feel that actions speak louder than words. So there is still something there that is accounting for all these.

Maneuverbility is still a factor in the littoral environment. In any 3D environment, whether its air or water, there is going to be the "dogfight". Smaller subs still have this advantage because they can turn and point around faster, hence why SSBNs can be particularly vulnerable if they are ambushed by a smaller sub.

Numbers do matter. No matter how passively quiet a sub is, its detectable by active sonar. A sub is not like an F-22 that it can deflect radar (in the case of sub, sound) from another direction to the emitting source. A two sub team working in tandem has a serious chance of taking out a single sub, even if that single sub is more technologically advanced. One sub can actively ping while the other sub remains passive, and if there is underwater communications, the tactical synergy of the two or four pack will be more than the sum of its elements. The other partner does not have to be another sub, it can be a surface ship too. Its all going to boil down to the tactical.

The nuclear sub however, can dash in and out. It still has the supreme advantage of speed and endurance. Its sheer electrical power also means the capacity for more powerful sonars and sensors, and keep them running longer, as well in control and command systems. It is free from the limitations of running out of battery power. Even against a quieter diesel sub, a noisier nuclear sub holds critical advantages. Remember, its still faster. Once the sub starts actively pinging, it becomes the equalizer, and its only a matter of time the diesel sub will be detected, and the nuclear sub has the electrical endurance to keep doing that all day long.

BTW, the Virginia class holds one important advantage over the Seawolf, is that the Seawolf, for all its price, does not have VLS tubes.

 

[elinge]

I think that a "Seawolf" is a SSN thinked to operate as a "hunter-killer" in "blue waters" against. I also think that in littoral waters that advantages lose relevance. For that reason, USA design the "Virginia" class and are planning other nuke small SSN (Tango Bravo Project).

 

[crobato]

There are always inherent advantages in a diesel-electric boat. When running underwater for example, the only moving thing is the electric motor, which can be directly shafted to the propeller without a reduction box, the latter can add their own noise. Electric motors can generate much torque on their own. On a nuclear sub, you have the reactor which has the coolant running and flowing through tubes, heating up steam which has to run on its tubes, then blow at steam turbines, which has to turn more rapidly than electric motors, and then the output of the steam turbines have to go to a reduction gear, which has to reduce the revolutions and increase the torque. On the other hand, the large boat has much better sound distribution qualities, and lower flow noise (water flowing along the side of the vessel). They have less drag per displacement. Big boats mean a lot of room and places where you can tile and coat insulation.

One thing to be careful about sub to sub noise comparison is whether these comparisons are done in speed and whatever speed. At speed, a diesel submarine can actually end up being noisy and noisier than a nuclear submarine.

But all of that has nothing to say when a sub shuts down. A diesel sub has something going for when its completely shut down. Literally shut down, no motors running with barely any electricity on. A nuclear sub cannot completely shut down, the reactor has to keep running, heating and cooling. This is where you have to depend that your nuclear reactor system is one that is quiet, e.g. uses natural circulation as much as possible, and the compartment is heavily insulated. And remember, big helps here, the bigger the sub, the more it can absorb and distribute the reactor noise and the more places where you can insulate the reactor from the ocean.

But then the bigger the sub, the less maneuverable it becomes which challenges it more to a littoral environment. Hence it is the big technical challenge to make a nuclear sub that is small and yet quiet.

IMO, JMSDF diesel-electric subs like the Oyahsio class may potentially offer even greater challenges to the PLAN fleet.

As to the future direction of PLAN diesel-electric sub vs. nuclear sub, as the PLAN turns more blue than brown, it will increasingly tilt more to building more nuclear subs than diesel subs. Budget increases going to help on that as well as more global issues China has to face. Sometimes I really wonder how many Yuans they will eventually make. With AIP, its probably a bit more expensive than the Song, and AIP subs have less of an attraction when you are already on nuclear power.

Also in irony, China's own technological development is so uneven, it can make its own nuclear reactors and steam turbines, but has to license diesel engines. If the trend is going to larger diesel submarines for more ocean persistence capability, your are going to need more powerful diesel engines, necessary to drive the sub on surface while charging the batteries.

Latest pics from the CDF show the Varyag appearing to have depth charges installed. I mention this because how serious is the PLAN in having a carrier will affect its future sub choices. Given that PLAN ships are not that good in surface ASW, a PLAN CSG will need fleet submarines to protect the carrier from the bottom, and the only things that will keep up are nuclear subs.

 

[Pointblank]

Latest pics from the CDF show the Varyag appearing to have depth charges installed. I mention this because how serious is the PLAN in having a carrier will affect its future sub choices. Given that PLAN ships are not that good in surface ASW, a PLAN CSG will need fleet submarines to protect the carrier from the bottom, and the only things that will keep up are nuclear subs.

Why on earth are the Chinese fitting depth charge launchers on a ship that large? Its an exercise in futility and sheer stupidity in ASW warfare. You can't properly depth charge a enemy submarine using a 55,000 ton aircraft carrier; its not maneuverable enough. And even if it does get close enough, its a easy torpedo target, so your in reality sending a ship to its own demise by doing that.