PLAN Type 035/039/091/092 Submarine Thread

[nemo]

Re: PLAN submarines Thread II

There are several problems with your arguments.

Having a supercomputer does not mean you know how to use it. In this case, do you have the software or algorithm so simulate the cause of noise? It's not like you can get this kind of specialized software off the shelf, nor is anyone going to make their classified research. By the way, Japan just overtook everyone else, again, by a very large margin (4x).

Although there are a lot of Chinese advances, they still have quite a long way to go. One example -- bearing. Chinese are still behind on precision bearing. And more precise the bearing, the lower the noise the machinery makes.

And when you say Chinese excel in physics and material science, then what do you call Americans and Russians?

While I think Chinese subs are quieter than some people says, they are still behind. I don't believe 093 is around Victor III level -- Victor III was a quietness retrofit design, while 093 is a clean sheet design with quietness as a design goal. The first Soviet sub designed for quietness is Akula/Bars, so the 093 should be around that level. The next design will reflect lesson learned from that design.

 

[asif iqbal]

Re: PLAN submarines Thread II

China's CKX5680 Digitally Controlled 7-axis Contour Milling Machine

The Wuhan Heavy Industry Corp. just made a breakthrough in an 863 Project. This is the CKX5680 Digitally Controlled 7-axis Contour Milling machine. This is significant as it is specialised in building ship propellers, like this one, for aircraft carriers and submarines. They are much more precise than those 5-axis machines.

 

[nemo]

Re: PLAN submarines Thread II

A thought just occurred to me.

The claim that 093 is noisy come from the ONI chart of relative noise. What if they mistake updated/refitted 091 as 093?

From that chart, the improvement level from 091 to 093 is much less than quietness level improvement of US and Russian subs. Unless China is really that incompetent, that points toward quietness upgrade rather than a new design. The chart on the diesel subs showed that China wasn't that much behind Russia -- so why the huge disparity on the nuclear subs? Hence my suspicion that they mistake 091 mod with 093.

If that were true, then 093 may be yet detected, or ONI choose not to reveal that they can detect 093.

 

[i.e.]

Re: PLAN submarines Thread II

Ireally doubt "quietness" is really that essential for chinese-level of miniumum deterence.

for example china may well adopt a bastion defence tactic, sit its limited strategic misile submarines in Bohai Bay, guard it with rings of SSKs SSNs and Surface and Air assets. same thing in South China sea. let's say in Gulf of Tonkin.

USN SSNs in order to tail its targets they must go through the rings. raise the chance of failure and exposure.

 

[nemo]

Re: PLAN submarines Thread II

Ireally doubt "quietness" is really that essential for chinese-level of miniumum deterence.

for example china may well adopt a bastion defence tactic, sit its limited strategic misile submarines in Bohai Bay, guard it with rings of SSKs SSNs and Surface and Air assets. same thing in South China sea. let's say in Gulf of Tonkin.

USN SSNs in order to tail its targets they must go through the rings. raise the chance of failure and exposure.

Yes it does. JL-2 does not have enough range to hit US mainland target from protect sea. A noisy SSN means it's not useful for blue sea/long range operation -- the main reason for the nuke subs existence. Otherwise diesel subs will do just as well for cheaper cost.

 

[Hendrik_2000]

Re: PLAN submarines Thread II

A thought just occurred to me.

The claim that 093 is noisy come from the ONI chart of relative noise. What if they mistake updated/refitted 091 as 093?

From that chart, the improvement level from 091 to 093 is much less than quietness level improvement of US and Russian subs. Unless China is really that incompetent, that points toward quietness upgrade rather than a new design. The chart on the diesel subs showed that China wasn't that much behind Russia -- so why the huge disparity on the nuclear subs? Hence my suspicion that they mistake 091 mod with 093.

If that were true, then 093 may be yet detected, or ONI choose not to reveal that they can detect 093.

Those chart is old.Someone in CDF said that they issue those chart back in 1996 even before 093 and 091 show up. And the latest chart even show the noise level of085 which hasn't even build yet, Now how can they do that?

So while reading it take it with ton of salt.

Noise level come from 3 sources , Hydrodynamic, cavitation in propeller, vibration in pump due to minute imbalance.
Now propeller cavitation is based on the design and speed of propeller. The design of silent propeller is well understood. The problem is manufacturing it . for long time China can't buy CNC machine to manufacturer quiet propeller. due to embargo.

Pump vibration is again well understood. You can isolate vibration with pad or active vibration cancellation methods. It is common practice in industrial in plant facility.

Hydrodynamic is the function of body form and anechoic tile So based on those 3 reason we can expect the chinese submarine is as quiet as their counterpart

 

[kroko]

Re: PLAN submarines Thread II

Those chart is old.Someone in CDF said that they issue those chart back in 1996 even before 093 and 091 show up. And the latest chart even show the noise level of085 which hasn't even build yet, Now how can they do that?

So while reading it take it with ton of salt.

Noise level come from 3 sources , Hydrodynamic, cavitation in propeller, vibration in pump due to minute imbalance.
Now propeller cavitation is based on the design and speed of propeller. The design of silent propeller is well understood. The problem is manufacturing it . for long time China can't buy CNC machine to manufacturer quiet propeller. due to embargo.

Pump vibration is again well understood. You can isolate vibration with pad or active vibration cancellation methods. It is common practice in industrial in plant facility.

Hydrodynamic is the function of body form and anechoic tile So based on those 3 reason we can expect the chinese submarine is as quiet as their counterpart

Those? Is there any more charts from ONI, or are you refering only to the 2009 chart ?

I guess that ONI made an estimate about the future performance of the 095

As for the CNC, did china solved that problem, or they still struggling with it ?

 

[Blitzo]

Re: PLAN submarines Thread II

Those? Is there any more charts from ONI, or are you refering only to the 2009 chart ?

I guess that ONI made an estimate about the future performance of the 095

As for the CNC, did china solved that problem, or they still struggling with it ?

See post 1353.

I think what he means is befoe China opened up to the world some three decades ago the kind of high tech manufacturing equipment were uncommon through the country. Since then we all know of china's massive advances in industry and at present there shoud certainly be indigenous and foreign examples of such machines through the country up to world standards.

plawolf's post 1189 from a few months back is also good and still relevant.

 

[SinoSoldier]

Re: PLAN submarines Thread II

Yes it does. JL-2 does not have enough range to hit US mainland target from protect sea. A noisy SSN means it's not useful for blue sea/long range operation -- the main reason for the nuke subs existence. Otherwise diesel subs will do just as well for cheaper cost.

The JL-2 has a range of 12000 km which gives it the ability to hit the US.

 

[Blitzo]

Re: PLAN submarines Thread II

The JL-2 has a range of 12000 km which gives it the ability to hit the US.

I think the generally accepted range of that missile is some 8000 km...