yeah. A report made in 2009 by the USN office of naval intelligence (ONI) and unintencionaly posted on the internet. Later removed but not before spreading in the net. It doesnt paint a good picture of china´s sub quietness. But some people in this forum dont believe it because it included type 095 in it, when the sub wasnt/isnt built yet. Most probably it was an assumption based on the performance of the type 093. This was supposed to be a classified document. More reliable than internet forums IMO.
Actually that oni report has been largely disregarded by us for a few reasons apart from just 095's "projected" quietness.
They basically reused that graph made from a mid 90s report on the PLAN.
They also got common facts wrong such as YJ-62's range, so they really didn't seem to put much effort into that report.
The major problem is with nuclear submarines. this is a very specialized technology that major powers guard zealously, and cant be advanced by dual-purpose civilian tech. Since china only started heavily spending in military in the last 20 years, it lacks far behind the other nuclear sub producing nations.
Ok that's BS.
The soviets substantially improved the quietness of their subs during the cold war by importing japanese
civilian precise milling equipment. Now I'm not saying simply precisely milling a propeller is the end all to submarine quietness, but improvements in the civilian technology industry will inevitably benefit the military industrial complex as well and this includes nuclear submarines.
And throwing words around like "very specialized technology" doesn't really help your cause. We can apply your argument to VLO as well, it is also "specialized technology" which "cant be advanced by dual purpose civilian tech" (I dispute this -- advances in civilian industry will also bring advances in this area) -- yet china is clearly not very stagnant in VLO.
as of this point we still do not know how good 091G, 093 really are. Some say 093 have 688 SSN levels of quietness, others say they're even less than victor III.