09III/09IV (093/094) Nuclear Submarine Thread

[azesus]

Super Big Forum says 093A is taking idea from European style or old school USN style like SSN Narwhal using taller and compact one body reactor to allow higher efficiency natural circulation with gravity weight and temperature difference, delay the requirement for reactor coolant pump usage and thus reduce reactor noise, in contrast to LA's more emphasis on higher total output and faster top speed, when Admiral Rickover taking the reactor that was supposedly use on USN's nuclear surface fleet. Because PLAN 093A would be more of defensive position, so slower top speed but quieter is more suited

 

[jobjed]

Super Big Forum says 093A is taking idea from European style or old school USN style like SSN Narwhal using taller and compact one body reactor to allow higher efficiency natural circulation with gravity weight and temperature difference, delay the requirement for reactor coolant pump usage and thus reduce reactor noise, in contrast to LA's more emphasis on higher total output and faster top speed, when Admiral Rickover taking the reactor that was supposedly use on USN's nuclear surface fleet. Because PLAN 093A would be more of defensive position, so slower top speed but quieter is more suited

CJDBY ranges from moronic fanboys to legit insiders. You're gonna have to specify and link the exact thread where this claim is made.

 

[Totoro]

While the claim may or may not be true, the logic stated in it seems quite sound. China indeed is in a position where its SSNs would be better off prioritising low noise over speed. Everyone needs quiet subs, of course, but there's still a curve involved, and different navies had differently set priority curves for interdependency of speed and noise. Soviets, for example, emphasized speed more than US, due to their doctrine to use SSNs more as interceptors, compared to US ones which had to patrol large ocean areas. China might have indeed decided that they need even less speed than what US had with LA class.

And type of reactor described, is indeed better suited for natural circulation, and thus lower noise. Interestingly though, we had that one article from 093 designer where they claimed 093 already uses natural circulation to some degree. I believe that was refering to variants of 093 prior to these low hump ones. (perhaps to that one variant with a more pronounced hump?)

 

[azesus]

It was a "General Forum Discussion" by some above average intelligence hobbyist just like this one discussing general logic, there is no legit insider nor any specify link, Pop Big is just a retired low level admin paper pushing bureaucrat, and Flower Hua is just a low level acoustic data tester, no one "inside" so to speak would wasting their time in a forum, except there was a very knowledgeable guy KKTT, but he disappeared, must have been asked to "drink tea"

 

[taxiya]

For lack of a better idea, a new reactor design is probably the leading hypothesis. However, it should be noted that the Astute has a similar beam to the 093 and the LA and Virginia classes have even smaller beams than the 093, so a large reactor resulting in a hump doesn't seem to be a perfect fit as an explanation. Also, the Astute has a very long sail and is also positioned further aft compared to the sail on the 093.

Agree with the rest but need to remind that 09III is double hull construction? So although its exterior is bigger, its pressure hull maybe smaller, therefor require a hump on the exterior for the protruding.

 

[taxiya]

One more thing to note (don't know if others have mentioned), the 09IIIs with humps all have the one line trim/drainage/vent (what's the term?) , the previous variant has multiple slits on different levels.

 

[taxiya]

While the claim may or may not be true, the logic stated in it seems quite sound. China indeed is in a position where its SSNs would be better off prioritising low noise over speed. Everyone needs quiet subs, of course, but there's still a curve involved, and different navies had differently set priority curves for interdependency of speed and noise. Soviets, for example, emphasized speed more than US, due to their doctrine to use SSNs more as interceptors, compared to US ones which had to patrol large ocean areas. China might have indeed decided that they need even less speed than what US had with LA class.

And type of reactor described, is indeed better suited for natural circulation, and thus lower noise. Interestingly though, we had that one article from 093 designer where they claimed 093 already uses natural circulation to some degree. I believe that was refering to variants of 093 prior to these low hump ones. (perhaps to that one variant with a more pronounced hump?)

There was a research paper by Naval Engineering University (at Wuhan) published in Jan 2015 titled "Study on Control and Optimization for Natural Circulation Transition Process of Integrated Marine Reactor". The paper was part of research work on a X type Marine Reactor Program.

 

[Tam]

Agree with the rest but need to remind that 09III is double hull construction? So although its exterior is bigger, its pressure hull maybe smaller, therefor require a hump on the exterior for the protruding.

The use of the term single and double hull is misleading, when designs are tend to be hybrids, and the ballast tank arrangement differs by section.

The front of the sub would be double hulled, as well as the taper on the rear. Meaning the ballast tanks are all around an inner cylinder, or ballast tanks wrapping around an inner hull.

In between a sub can have sections that are monohulled, with no ballast tanks; or sections that have shoulder ballast tanks, where in the ballast tanks are on top. Some people also call this single hulled. Sections that have ballast tanks on the side are somehow called double hulled. European SSKs like the Gotland, Type 212 and 214 designs are all shoulder mounted ballast tanks all along its length. The Russian Amur/Lada class is also shoulder mounted. The Kilo class, Song and Yuan class have ballast tanks along the side, with the front and rear sections being wrapped around. The Japanese Soryu class is a hybrid, the front and rear sections are double hulled, or ballast tanks around an inner hull, but the middle doesn't have ballast tanks, and is single hulled.



I suspect that on the Type 094, the front section is wrapped around ballast tanks. The next section with the sail has the ballast tanks to to the side until you reach the section with the hump and ballistic missiles are. On this hump, and its quite visible, the ballast tanks are on the top where the hump is, and this section does not have side mounted tanks, making it single hulled and allow for more room within. Once you are past this section, you have side mounted ballast tanks, and then the taper to the rear propeller would have wrapped around tanks.

I suspect that on the Type 093 (small hump), the entire hump section is a shoulder mounted ballast tank which extends to the aft and forward ballast tanks that wrap around the sub. The sink hole, which is the term for the lines of holes where the air comes out of the ballast tanks, extends as a single line from the aft tank, to the middle shoulder tanks, and to the forward tanks. This would be consistent to the structure of the Type 094 I described above where the two subs are basically same sub with this middle section changed, and share common sections.

If you move the ballast tanks from the side to the shoulder, this frees more room on this entire section, and that can be used to house a larger reactor. The hump itself is there to create additional ballast tank volume.

 

[Tam]

One more thing to note (don't know if others have mentioned), the 09IIIs with humps all have the one line trim/drainage/vent (what's the term?) , the previous variant has multiple slits on different levels.

There is a humped version with dotted sink holes, which is the term you are looking. There is only few images of that to speak about, but no lack of satellite images on them. These have affirmed hatches on the hump. My guess is that the PLA isn't ready to go full public on them. Maybe in time.

 

[Mirabo]

Funny how we speculate the PLAN isn't ready to go public on the latest 09IIIB...

This sub is no longer a secret, it's only a matter of time before everyone goes "yup, that's a new submarine."

I trust that the 09V won't be a long wait from now.