In the media, we have often heard about the growing submarine threat from China. How much of a threat is this really going to be. I don't profess to know the answer of this question, but I can possibly examine what PLAN's underwater fleet will look like in the next few years.
First, we can start with the imported subs, since their status is relatively transparent. We know that China imported 2 873 and 2 636 submarines in the 90s. I think the first 2 was originally destined for Soviet navy, whereas the second 2 are the improved export versions of kilo. These should all be superior in acoustic level to the previous Soviet exported kilos. The 8 new kilos that were delivered in 2006 are most likely similar to the 2 636 in terms of acoustic, but its combat system and sonar are upgraded. In fact, the major improvement for these boats was supposed to be the much advertised Club missile (or Sizzler as USN calls it). Interesting enough, they had trouble with this missile right from the start. Supposedly, they have to make fixes/upgrades to each batch of Club missile they received. In a way, it is not too surprising this is done, because many people have speculated that China has upgraded the sonar/combat system. We've seen kilo subs spending long periods of time in the docks of major submarine building shipyards like JN. Either way, we have only recently received a report on 1 successful firing of Club missile from 636M. Either way, these 12 kilos will be expected to serve ESF and SSF in the coming years.
Secondly, the 039 series of submarines are China's most recent diesel subs. This is one of the best illustration of Chinese military advances in the past decade. When the original 039 was launched in 1994, it happened to suffer many problems. And acoustically speaking, it probably wasn't really a shining moment in PLAN history. After that, we saw 3 more 039 of a new variant coming out from 2001-2003 with several noticeable changes (including a new sail). And after that, we had 3 years of mass production of a slightly modified variant of 039 with changes like drainage hole alignment, the curvature joining sail to the hull, upgraded sonar and combat systems. By the way, I have to give props to Crobato for summarizing all the differences. These 3 variants are what western observers typically refer to as the Song class. The final variant numbered anything from 8 to 12, so we are probably looking at a total of 12 to 16 Songs. Although, the difference between the pennant of the first Song and the first Yuan would indicate a maximum of 20 units. Kanwa apparently believes that there are 12 Songs, because its contacts with MTU indicated 12 set of engines (MTU 16V-396) exported for Song. In 2004, we saw the launching of the first 039A (aka Yuan) sub. It appeared to be double hulled and larger than Song subs. It featured a kilo like hump and was dubbed the "Chinese kilo" and "Chinese Amur" by different observers. However PLA seemed to look at it as just an upgraded Song. According to several people much more knowledgeable than I, Yuan does not represent a generational leap over Song in acoustic level. This is not too surprising, since PLAN favours more of an incremental improvement approach rather than a generational improvement approach. This new 039A went through probably 2 years of sea tests before joining PLAN. It features a generally more hydrodynamic looking hull, flank array sonar + AIP engines (at least reportedly). We waited for 3 years before firm evidence of new Yuan units being launched in JN and Wuhan. As seen in the recent photos, there are at least 2 units of a new 039A variant (with changes in drainage holes, sail modifications, flank array sonar placements) launched in the past couple of months. We've just recently saw another 039A unit of this improved variant that already seemed to have joined ESF. We've also seen possibly a new major modification of 039 series (possibly 039B?) in Wuhan with a different looking hump, possibly larger hull and possibly other changes (we need more photos!). In my opinion, this new 039B submarine probably will need about 2 years of sea tests before mass production. So, we might see a couple of years 039A mass production (meaning around 3 a year) before 039B is put into mass production. With all the 033s and early 035s retiring, it's hard to see them not mass producing the improved 039A. By 2010, we will probably see the lone 039B + 7 to 9 039As + 12 to 16 039s. (I guess 20 to 25 039s)?
Thirdly, what about 033 and 035s? Most of the Ming class subs are still relatively new hulls (like Jiangwei of submarine) and can do the role of patrol, surveillance, laying mine and distract more powerful subs from the quieter 039 class. From the above estimates, there will be about 35 3rd generation subs in 2010. According to sinodefence, there are currently 17 035s serving in NSF and SSF. I would expect most of them to still be service in 2010, but 033s to be retired. Of course, there may be some other 033s remaining active in a training role. So, PLAN will have a conventional fleet of around 50 submarines in 2010.
Fourthly, what will be the future of Chinese conventional submarines? This is really a complex question, because many people suspect 039 maybe the last series of pure diesel submarines with PLAN. We've heard anything from going strictly nuclear in the future like USN to producing min-nuke subs for hi-lo combination to Magnetohydrodynamics submarines. To be honest, most of these ideas sound pretty crazy to me. I do think China will go for more nuclear submarines in the future as it seeks to project more power, but the long Chinese coastline will always provide the need for the cheaper and defensive diesel submarines. Even so, I'm not sure when we will see the successor series to 039.
Finally, what have we really learnt about the nuclear submarines? If the recent Google Earth pictures told us anything, it would be that there are more 093s/094s out there than all the unclassified Western sources indicated. We've seen pictures of 3 094s docked Huludao and another dao recently. We've also seen evidences for probably at least 5 093s (2 in service, 1 in google earth photo docked, another in dry dock and another about to be transported to dry dock). A source on Chinese bbs said a few months back that there were 5 093s and 3 094s launched at the end of 2005. I would say that it was a shocking revelation at the time, but the Google Earth photos seem to corroborate with that. At the same time, he said there will be 8 093/095s and 5 094s launched by the end of 2010. You may be shocked by the mention of 095 here, but we've seen a company involved in the 095 project accidentally leaked the news that it's suppose to finish development of 095's reactor vessel in the 5 year plan of 2006-10. So, it's not too shocking that the first 095 might be launched by 2010. Of course, it might be another 3 to 4 years before 095 can join service. Now, if we include the 3 serving 091Gs and 2 092s, there will be around 18 nuclear submarines by 2010 (although not all of them will be in service).
The recent years have been a period where much of the old Chinese submarine fleet have been replaced with newer and more capable submarines. The combat system, sonar and torpedo of the new submarines are also a generation ahead of the pre-2000 level. It looks like China will certainly move to more of a nuclear fleet in the future as it seeks more power projection. But at the same time, it also is modernizing in all the other areas and increasing power projection. So, I don't really think the submarine modernization is really much more emphasized than other part of the fleet.