09V/09VI (095/096) Nuclear Submarine Thread

ZeEa5KPul

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With the exception of the first paper, these were all published between 2016 and 2019, right around the time the Type 09-V was wrapping up design (I believe it was mentioned somewhere earlier that the design was sent to the shipbuilder in November 2017). How long of a publishing embargo is there on these papers?
 

Hendrik_2000

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Seem like the new Huludao shipyard is ready to start building the new type 96 submarine . Great news
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Chinese Navy Steps Closer To New Generation Of Nuclear Submarines
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I cover the changing world of underwater warfare.

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It seems likely that the Chinese Navy’s next[+]
H I SUTTON

New evidence at the Bohai shipyard in China points to the construction of the next generation of nuclear submarines for the Chinese Navy (known as the PLAN). While many have argued that the new Type 095 and 096 subs will be built there, it is only now that the infrastructure is largely ready. The new submarines will be important if the PLAN wishes to patrol the open Pacific, or routinely venture into the Indian Ocean. Analysis of commercial imagery shows a new launch barge has recently been completed at the site. From an intelligence standpoint, this is an important indicator.

In an
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, the Office of Naval Intelligence (ONI) expects China’s submarine fleet to grow from around 66 boats today to 76 by 2030. This will include 6 more nuclear-powered attack submarines, which is what the Bohai yard at Huludao builds. So the work at the new Huludao facility will play a key part in the expansion. The ONI points to this fact, stating, “Current expansion at submarine production yards could allow higher future production numbers.”

So it is not a great leap to say that the new construction halls and dry dock at Huludao will be used to build new nuclear-powered attack submarines. These are expected to be the all-new Type-095 Tang Class which may be China’s answer to the Virginia Class. I estimate that at least 9 will need to be built to reach the 2030 projection. This is because three of the existing boats are reaching the end of their operational lives. The Type-091 Han class were China’s first generation nuclear submarines and entered service in the 1970s. Three of the class, laid down in the 1980s, are still in service. The rest are the newer Type-093 Shang class which first entered service in 2006.

Work on the Huludao expansion started in 2014 with large new construction halls built on reclaimed land. The hall has three construction bays, each large enough to house two submarines. The buildings themselves were complete by 2017, but it is only recently that they have been connected to the dry dock where the submarines will be launched. A new launch barge has been put in place to transfer the submarines from dry land into the water. So China now has the facilities lined up to start launching Type-095 submarines.
1592575222784.png
 

Hendrik_2000

Lieutenant General
I really don't understand why the barge is position between rail and dry dock. And why they need the dry dock in first place Don't they completed the submarine inside the construction hall.

Why not transfer from rail to the barge and slowly lowered the barge No need for dry dock like this video? Confused
 

Mirabo

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I really don't understand why the barge is position between rail and dry dock. And why they need the dry dock in first place Don't they completed the submarine inside the construction hall.

Why not transfer from rail to the barge and slowly lowered the barge No need for dry dock like this video? Confused

Because the dry dock can be used for maintenance and repairs if there are no new boats being launched from the yard.

It also saves space since you don't need to build rails extending all the way to the sea, and then having to find space for a drydock somewhere else.

The dry dock might also be used to do some additional work or finishing touches on the boat immediately after launch, without transporting the hull to another part of the shipyard.
 

Blitzo

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I really don't understand why the barge is position between rail and dry dock. And why they need the dry dock in first place Don't they completed the submarine inside the construction hall.

Why not transfer from rail to the barge and slowly lowered the barge No need for dry dock like this video? Confused

For the purposes of launching a submarine, the drydock is unnecessary if you have a mobile barge or mobile drydock.

But for the purposes of fitting out, maintaining or refitting a submarine, having a drydock is useful.


For Bohai, they just happen to have a drydock and the barge connected, and it's a workflow that works and for the launch process I wouldn't say it is any better or worse than what the launch process that HII has for launching their submarines.


======


Also, in response to the HI Sutton article, cross posting what I wrote over on CDF, imo the article is not terrible but it makes a few potential mistakes:

The idea of 09V having a large diameter only makes sense if it's double hulled -- but we know there have been rumours for ages suggesting 09V is meant to be single or hybrid hulled instead. Also, if 09V has a beam as large as Akula, it will be too big for the SSN rail gauge which is only 7.34m, and each of the SSN slots are only 22.5m wide -- which won't provide enough clearance for a 13+ meter wide submarine like Akula.


... Also I find it a bit funny that Chris Carlson is finally seemingly admitting that the new facility is for nuclear submarines, despite being so strongly against the idea in 2017. Even in early 2019, when I had a conversation with James Fannell, apparently Chris Carlson was still of the opinion that the new Bohai buildings weren't for nukes.
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.... what is very useful in article is the satellite picture showing the completed barge in position. We've known for a while that the barge would soon be complete, so it's nice that we have a picture of it.
 

Hendrik_2000

Lieutenant General
I though the reason for larger diameter has much to do with installation of raft inside the submarine and nothing to do with single or double hull
I can understand that any naval structure is cramp by nature with so many equipment and crew facilities competing for space . The other reason is vertical cruise missile tube that require bigger diameter

But I thought China has implemented the raft construction with their latest submarine type 93 III.

Yes Chris Carlson change his tune now I always thought it is obvious from the beginning that the Huludao facility is for building the new submarine Your article convincingly prove that But there is always tendency of western analyst to deny any Chinese progress in building better arsenal. It is wishful thinking really and denial mentality.
Here is his conclusion as to why the facility cannot be submarine construction hall which is faulty since they were observation from satellite and can't be verified of its accuracy How can you determine slab thickness for sofar?
Pile configuration is questionable too because we don't know what material that China used for pile ? And did he know what type of soil in Huludao ? clay, sandy, loam?
  • The foundation of the new building is insufficient to support the weight of a completed nuclear submarine The foundation’s pile configuration is designed primarily to stabilize the newly placed dredged sand to improve its load bearing capability and to mitigate uneven settlement.
  • The foundation slab is also rather thin for supporting the weight of a large, heavy vessel. A thickness of a meter, or more, is usually needed to bear such a huge load.
  • The design of this foundation can support objects that weigh several hundred tons, but not several thousand tons
 
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ZeEa5KPul

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The idea of 09V having a large diameter only makes sense if it's double hulled -- but we know there have been rumours for ages suggesting 09V is meant to be single or hybrid hulled instead.
Between single/hybrid and double hulls, which is more technologically advanced?
Also, if 09V has a beam as large as Akula, it will be too big for the SSN rail gauge which is only 7.34m
Why's the SSN rail gauge at BSHIC so narrow? I believe that it's >8m at other comparable yards.
Even in early 2019, when I had a conversation with James Fannell
Where was this?
 

Blitzo

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Between single/hybrid and double hulls, which is more technologically advanced?

It's not so simple and I don't want to answer it in a way that makes it sound like "PLAN should go for X rather than Y cause X is more advanced".

However, previous PLAN SSNs have been double hull, and it's been rumoured for quite a while now that 09V will likely be single or hybrid hull rather than double.


Why's the SSN rail gauge at BSHIC so narrow? I believe that it's >8m at other comparable yards.

7.34m is fine for an SSN. For example at Newport their gauge is just over 8m.

newport news launch.jpg

More importantly, the actual rail gauge itself doesn't mean the cradle of the submarine is fixed to the rail gauge.
See this picture of a Virginia being launched at Newport -- the cradle platform itself (the green square structure below the submarine) is overall at least 2-3m wider than their rail gauge itself. The rail gauge only supports the wheels (the blue twin wheels below the green square structure) which helps move the cradle -- but the cradle and the submarine atop it can be significantly wider than the rail gauge itself.

USS-Indiana-SSN-789-Launch.jpg


Where was this?

Over the internet a private conversation.
 

ZeEa5KPul

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Thanks for the response @Bltizo. What do you think of Sutton's assertion that 09-V is not likely to use a pump-jet propulsor? @by78 posted some scientific studies of various pump jets; given that the work was published in 2016 (and I presume held under a publishing embargo for some time), I feel that China has had enough time and experience with this design to field it on the Type 09-V/VI - do you agree?

Also, do you think the Type 09-V/VI will have full electric propulsion?
 

Blitzo

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I though the reason for larger diameter has much to do with installation of raft inside the submarine and nothing to do with single or double hull
I can understand that any naval structure is cramp by nature with so many equipment and crew facilities competing for space . The other reason is vertical cruise missile tube that require bigger diameter

But I thought China has implemented the raft construction with their latest submarine type 93 III.


The diameter of a submarine is a function of its pressure hull diameter and its whether the submarine is single hulled or double hulled.

A single hull submarine means the entire overall diameter of the submarine is the same diameter as its pressure hull, see below:
edW0YjC.jpg


A double hull submarine means that the pressure hull diameter is smaller than the overall diameter of the submarine, which is the "outer hull". In the below picture, the smaller red circle is the pressure hull while the bigger yellow circle is the larger outer hull.

h1RU10Q.jpg



Now, the pressure hull of a submarine is the determinant of the amount of machinery, insulation and equipment and living space you can put into the main body of a submarine as a general rule of thumb (though one may argue some exceptions exist like Oscar class SSGN or the entire design of the Typhoon SSBN -- but let's ignore those for now).
In other words, if you want to put more machinery/insulation/etc into a submarine, you need a larger pressure hull.



So, let's say you have two different SSNs, both with a hull diameter of 10 meters.
One of these SSNs is single hulled, the other is double hulled.

The single hull SSN with a 10m diameter has a 10m pressure hull to work with to put all of its machinery and insulation into.

The double hull SSN with a 10m diameter has a pressure hull which is smaller than 10m, because the 10m diameter hull is merely the outer hull and not the pressure hull. For the double hull SSN, its actual pressure hull diameter is almost definitely going to be significantly smaller than 10m, usually up to 80% at most. That means the double hull SSN with a 10m diameter in reality only has a 8m pressure hull to put its machinery and insulation into.



09III is a double hulled submarine. Public info estimates its overall diameter at 11m -- meaning its pressure hull is likely 8.5-9m.

Everyone agrees that the pressure hull of 09V will be bigger than 09III, the question is not about the specifics of what kind of additional equipment or insulation it may have -- but rather it is important to first talk about what kind of hulled submarine it is.

If 09V is a single hulled or hybrid hulled submarine -- then it can likely retain the same overall diameter of 11m or so, but its actual pressure hull will be larger, perhaps as big as 11m in parts of the submarine.

OTOH, if 09V is double hulled, then if they they want to have a larger pressure hull diameter, that means the overall diameter (outer hull) of the submarine will have to increase as well. That is why the Akula SSN (for example) has such a massive overall diameter of 13.6m, because it has a larger outer hull to accommodate a larger pressure hull compared to previous Soviet/Russian SSNs.


The reason this is relevant is because the new Bohai facility's SSN rail gauge is 7.34m, and the width of each of the slots corresponding to the 7.34m rail gauge is only 22.5m wide.
If you're building a 13m diameter submarine, a rail gauge of 7.34m might be a bit small to support a submarine and cradle of that width (I think 12m might be at the upper limit) --- but more importantly, a 22.5m width slot means building a 13m diameter in that slot will not have enough clearance on either side of the submarine for effective construction to occur.


That is the reason I am skeptical to Chris Carlson's idea that 09V will have an overall diameter that is as big as Akula's, because...
1. He seems to believe that 09V will be double hull, whereas rumours have suggested it will likely be single or at least hybrid hulled.
2. He doesn't acknowledge that the rail gauge of 7.34m and corresponding construction slot of 22.5m width is likely far too small to build a 13+ meter wide submarine.



This is a useful starter article to read WRT single and double hulls (again, from HI Sutton, whose Covert Shores website is where his best work is rather than his articles on Forbes imho), and the source of the above two pictures:
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========


Thanks for the response @Bltizo. What do you think of Sutton's assertion that 09-V is not likely to use a pump-jet propulsor? @by78 posted some scientific studies of various pump jets; given that the work was published in 2016 (and I presume held under a publishing embargo for some time), I feel that China has had enough time and experience with this design to field it on the Type 09-V/VI - do you agree?

Also, do you think the Type 09-V/VI will have full electric propulsion?

I wouldn't put too much stock into the specifics of the depiction -- it is as speculative as we are, and likely less accurate than our rumours.
 
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