PLAN Type 035/039/091/092 Submarine Thread

[Schumacher]

Re: PLAN submarines Thread II

Sub techs & ASW are among the most complex & secretive. What we get from public sources & submariner friends are likely the tiny tip of the iceberg if not just plain wrong.
It's best to just look at what we know & deduce from there.
PLAN & USN have been for the last few months & right now in a very real & intense face off in the South & East China Sea. If you think it has been just the PLAN against the Filipinos & Japan, & their coast guard vessels, I think you're just plain ignorant.
Whenever PLAN is involved, we know their subs are playing a major role & we certainly know USN subs have been making very public appearances in Manila lately, not to mention USN carriers nearby, & what they have there is definitely more than what they publicly reveal.
And the outcome ? China has taken effective control of Scarborough Shoal from a major US ally right under its nose. Real wars have been started over something far less significant than the shoal.
With the Diaoyu islands, under Japan's effective control before, Chinese boats are now entering at will although the outcome is less clear cut yet as Scarborough Shoal.

So USN subs may indeed be more advanced overall than PLAN's & will likely enjoy an advantage out in the Pacific. When it comes to real face off in the South & East China Sea, not one on an internet debate, we see PLAN subs are more than a match for USN's.

 

[montyp165]

Re: PLAN submarines Thread II

I for one have never claimed that the PLAN subs were automatically equal or better than their western counterparts, but my feeling is that Tphuang is underrating Chinese sub tech far more than what actually is occurring. Based on my own readings of US, Russian and Chinese naval tech and developments, this is what my assessment of Chinese subs are comparable to atm:

Yuan --> Harushio class
Qing --> Oyashio/Soryuu

091 --> Skipjack class
093 --> Sturgeon class
095 --> 688i

Having access to top-level CNC machines can make bad design perform better, and good designs even better than otherwise, but I doubt seriously that the Chinese shipbuilding industry has issues with propeller designs compared to their western equivalents. Also, acoustic signal management isn't simply an issue of performance but also of reliability, which is why I feel the PLAN will match up faster than the skeptics are willing to admit.

 

[jackliu]

Re: PLAN submarines Thread II

I for one have never claimed that the PLAN subs were automatically equal or better than their western counterparts, but my feeling is that Tphuang is underrating Chinese sub tech far more than what actually is occurring. Based on my own readings of US, Russian and Chinese naval tech and developments, this is what my assessment of Chinese subs are comparable to atm:

Yuan --> Harushio class
Qing --> Oyashio/Soryuu

091 --> Skipjack class
093 --> Sturgeon class
095 --> 688i

Having access to top-level CNC machines can make bad design perform better, and good designs even better than otherwise, but I doubt seriously that the Chinese shipbuilding industry has issues with propeller designs compared to their western equivalents. Also, acoustic signal management isn't simply an issue of performance but also of reliability, which is why I feel the PLAN will match up faster than the skeptics are willing to admit.

Interesting assessment. So you are saying China's diesel submarine is already at world class level, however their nuclear sub is still in the 1980s level.

What is the difference between diesel submarine and nuclear sub besides the reactor and endurance difference?

Are nuclear sub always more quite than diesel submarine?

 

[no_name]

Re: PLAN submarines Thread II

I think diesel subs are quieter than nuclear subs when running on battery underwater. Nuclear subs have to keep their reactors on even when stationary and therefore will create some noise.

 

[luhai]

Re: PLAN submarines Thread II

Interesting assessment. So you are saying China's diesel submarine is already at world class level, however their nuclear sub is still in the 1980s level.

What is the difference between diesel submarine and nuclear sub besides the reactor and endurance difference?

Are nuclear sub always more quite than diesel submarine?

Nuke subs used to be quieter since diesel subs can't run battery very long and diesel engines are noisy. However, now diesel subs are quieter than nuke subs and most run below the ambient noise level. (however, a good sonar with with intel on the sub's period noise can still pick it up by running correlations)

Nuke subs on the other hand have to deal with the reactor noise, since it's circulating water all the time to keep the reactor cool. I think the main contributor for Chinese SSN's noise isn't really the sub hull or the propellers, but have a efficient and low noise sub nuclear power plant running. After all, Soviet Union and US has years of experience in the area and has gone though many generations to get things work right. China however is only on their 2nd gen. naval nuclear reactors, however, I expects things to improve fast since China nuclear technology overall in improving very fast.

On top of it, it's also all the operational experience and topography (specifically all the sea thermal layers and currents) knowledge that Soviets and US has accumulated, but China currently has very few.

 

[tphuang]

Re: PLAN submarines Thread II

It's not that I disagree with what you're saying per se, but if we're attributing a submarine's acoustics as significantly factored by the hull shape...
Well virginia doesn't look "that" different from 688i -- even though virginia is supposedly quieter underway than 688 is sitting at the pier(!)

And 093 doesn't look "that" different from vanilla 688, yet some people are saying it's an entire generation behind.

Sure, astute looks very different to virginia or seawolf, but we dont' really know which is really quieter.

So I think the external hull shape is a less significant indicator than the internal signature management, powerplant/reactor, and the propeller.

hmm, there are some quite real differences which make big differences to noise level. I mean you can just start by looking at the shape, size, positioning of the sail. And then there are also other factors obviously. I'm clearly not an expert on this area, but it's quite clear to me that submarine designers can assess noise level based on pictures of the shaping.

Sure there are a few commonalities that the world's supposedly most quiet submarines have; pump jet propulsion, retractable diving planes etc, but the hull shapes vary quite significantly for vessels in the supposed same ballpark (virginia vs astute), yet submarines of completely different generations can look nearly indistinguishable (virginia vs 688i. hell even 091 vs 093 or 092 vs 094!). So the other, more significant factors which we cannot use eyeballs to judge we unfortunately have to rely on anecdote, rumour and our own logic even if sometimes they are at odds with each other.

a lot of development work is required to figure out what kind of shaping can arrive at the best sig management. You can go down a certain path and make detail to us that seem insignificant may yield huge noise reduction. But you can go in two different path (collins class vs U-212 for example) that look quite different and do the work to find the most noise reduction.

I mean if 095 came out tomorrow and looked like virginia or seawolf I don't think many people would assume it was in that ballpark... even though 095 would have been designed some twenty years later than seawolf using the relevant, current shipbuilding techniques compared to the US of two decades ago and we can make some guesstimates as to how much the chinese have come along with signature management since the mid 90s when 093 would've been designed.


This entire SSN debacle reminds me of when everyone in the western community, including experts, believed it would take the chinese years and years to develop a fighter with the stealth shaping to compete with top end F-22/35, arguing they didn't have the experience, etc.
Now I'm not saying 095 will prove this prediction wrong the same way J-20 did, but keep an open mind aye.

Also, considering how the large SSK that came out a few years ago supposedly has the most impressive sig management features we've seen aboard a chinese SSK -- all evidence points that it's an SSB testbed to replace the golf. So would it be logical for them to use supposed top end sig reduction principles on something meant to be a test boat?

Actually, 095 is coming out later than I expected. I stated back when 093 was unveiled that I thought 095 will be commissioned by 2015. And it needs to, because this is the one area where China really needs to continue putting money into to catch up.

As for the thing that supposes to replace No. 200, I originally thought it was going to be its own class, because of the leap that I thought it had made vs Yuan class. But now according to a bunch of people on Chinese bbs, it's just going to be a one shot deal replacing No. 200, so I will accept that until evidence to the contrary. But, it certainly also makes sense for them to test out some concepts on this before they start building a new class of diesel submarines.

I for one have never claimed that the PLAN subs were automatically equal or better than their western counterparts, but my feeling is that Tphuang is underrating Chinese sub tech far more than what actually is occurring. Based on my own readings of US, Russian and Chinese naval tech and developments, this is what my assessment of Chinese subs are comparable to atm:

Yuan --> Harushio class
Qing --> Oyashio/Soryuu

091 --> Skipjack class
093 --> Sturgeon class
095 --> 688i

Well, that's somewhat close to my assessment too. I think I'm probably optimistic, because ONI thinks 095 will still be louder than Akula I and LA class. I find that a little hard to believe their chart.

And as for this "Qing" class, it sounds like it's just one boat replacing No. 200. Let's wait and see their next mass produced one.

I would guess the latest improved Yuan are probably comparable to Kilo in terms of stealth technology.

Having access to top-level CNC machines can make bad design perform better, and good designs even better than otherwise, but I doubt seriously that the Chinese shipbuilding industry has issues with propeller designs compared to their western equivalents. Also, acoustic signal management isn't simply an issue of performance but also of reliability, which is why I feel the PLAN will match up faster than the skeptics are willing to admit.

it's just a lot of RnD they need to put in to refine the entire submarine development progress. The western countries have been doing this for a long time and may even share their sig management data with each other. That's unfortunately something China has to develop from scratch.

 

[montyp165]

Re: PLAN submarines Thread II

Acoustic signal management as a matter of point is also a significant factor in automobiles too, because the clatter of moving parts in the powertrain of a car not only transmits undesirable sound to the passenger compartment (comparable to a ship or sub), but also adds undesirable resonant wear and tear on engine/transmission components. The more inherently quieter a powertrain system is, the more reliable it is as a result. That's why I feel that a focus on increasing propulsion reliability in Chinese subs will also pay major dividends in the silencing department too.

 

[jackliu]

Re: PLAN submarines Thread II

I would guess the latest improved Yuan are probably comparable to Kilo in terms of stealth technology.

I thought Yuan is build upon what they learned from Kilo, which China had since the 90s, and Qing is build upon Yuan, so don't you think Qing is much more comparable to modern diesel subs? After all Kilo is 80s technology.

Or is that in your opinion that the latest Japan diesel sub Sōryū class is only comparable to Russia's 80s Kilo quieting technology?




And from what I read so far, here is the assumption that I know of.

1. Diesel subs's quieting technology is not worse than nuclear sub, especially when operating near Asia's shallow waters, however diesel lack endurance because it just don't have enough fuel, and it maybe much more louder than nuclear sub when going fast.

2. China's latest diesel sub the Qing class is comparable to Japan and German latest generation sub, they all uses the same generation of technology such as AIP, but they are probably not as refined, just like how 052C's AESA is ahead of DDG51's PESA, but the processing power is still not as good as Burks, however they are comparable in the technology.

3. China's nuclear sub are very much lacking due to their lack of experience with nuclear reactors, and this technology is not easily learned because it has very little dual use technology which China can import, so they can only research it on their own, even if they have all the modern technology and tools, it will still take countless man hours to design and test.

So if the above assumption are true, then why is China not mass producing diesel subs like they are doing with 052A frigs? They only need to operate in Asia water to defend their interest, which unlike US with it's nuclear subs are designed to go all over the world.

Of course, submarines are top secret technology, but from what we can gather from open sources, please correct me if anyone think any of those assumptions are false.

 

[paintgun]

Re: PLAN submarines Thread II

I thought Yuan is build upon what they learned from Kilo, which China had since the 90s, and Qing is build upon Yuan, so don't you think Qing is much more comparable to modern diesel subs? After all Kilo is 80s technology.

Or is that in your opinion that the latest Japan diesel sub Sōryū class is only comparable to Russia's 80s Kilo quieting technology?

i think tphuang suggests that the birth of the Qing class is not as an incremental improvement class over the Yuan, but as a one off test boat for sub launched ballistic missiles

it might just be comparable to the Yuans, albeit with modifications to fulfill that role

that assertion can be disproved by PLAN adopting Qing class as the next generation diesel submarine class and mass producing them

 

[paintgun]

Re: PLAN submarines Thread II

CDF had a conveniently related conversation about an alleged story where China was trying to procure an obsolete MTU engine from Germany for a state of the art submarine operation.

Where one can look as well is the track record of China's indigenous diesel engine development for marine and naval uses, which translates into subsequent machinery, tooling, and parts sophistication of submarine technologies.
Ie. the progress China made outside Soviet legacy technologies.

Those above, however are anecdotal, and still does not present anything factual about this, like you say, submarine is top secret issue.