You did not mentioned in your blog but what is your opinion on the following that supposedly is already factored into the design and development of the type 093/094 and reasons given why some China-watchers feel that it has reached improved Los Angeles acoustic level :
(i)That China Ship Scientific Research Centre has already developed relatively advanced guide vane propeller and that seven blade propeller with cruciform vortex dissipaters is already installed in the indigenous Song class and hence likely on the 093/094;
(ii)Research at Qingdao's 4808 Factory already has demonstrated sound isolation couplings to the circulation pump of fresh water system within the steam cycle;
(iii) Achievement in advanced composites materials in absorbing vibration and sound; and
(iv) Successful breakthrough in high-temperature gas-cooled reactor in propulsion .
For iv), I don't see any evidence that pebble bed reactor is used as propulsion other than internet speculations. Timelines just have no way of working. Even for 095, the reactor work probably would've been completed a few years ago. I'm not technologically proficient enough to know if pebble bed reactor could work on a nuclear submarine. But there is no indication at this point, they have developed pebble bed reactor that could work with a nuclear sub. It seems like domestically they are going through a lot of advances in conventional reactors and it would be far easier to go with that.
As for propeller technology, I think that's only part of the noise level. The majority of noise still comes from within the inner hull .
And i'm sure they have made a lot of advances in noise isolation, but the first 2 093s were built in the late 90s/early 2000s, which was only 10 years after the last 091. The submarines themselves didn't get much larger and beam might be even less based on my GE measurements. They probably had to dedicate more space for propulsion unit and safety to allow 093s to operate over longer endurance. At the same time, more space was needed to install flank array sonars and such. So 093s most likely had less space available inside inner hull for active/passive noise cancellation technology while having to deal with more noise making parts and higher speed requirements. I think the improvement in Chinese shipyards and industrial technology have been more evident in the 10 to 15 years since the first 093s were laid down. So optimistically speaking, the new 093s and the next generation 095s would have much greater improvement in stealth.
By now, Chinese industry is significantly advanced to manufacture propellers of same quality as those on Victor III . In terms of machinery , I doubt China could not match Soviet technology from 60s and 70s .
I agree Chinese machinery and industrial capabilities are much greater than Soviet 70s technology. My point was just that the original design of 093 was not stealthy. And also that Victor III got quieter in the later build with improved Soviet shipbuilding and access to more advanced tooling. Now, the 2 093s were probably built in the late 90s and early 2000s at Huludao shipyard, which is not the most commercially advanced shipyard. China has gone through huge improvement since that time in every aspect of submarine shipbuilding. I would expect the most recent builds with the modifications they have made to be a lot quieter. But we won't find out until more information comes out.
