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

[Totoro]

I agree then, if we are talking per one third of the whole building, two SSNs in the high state of readiness and two more in low state.

I do expect two thirds of the building would be making SSNs and only one third would be making SSBNs. Even if that means "only" one ssbn per two years. Which is still a mighty fast pace. Basically, one could easily upkeep a 15 boat strong ssbn fleet with such a pace. At this point, having many more SSNs than SSBNs in production might be more desirable for Chinese navy, as long as ssbn number are still increasing.

 

[Interstellar]

It is always a pleasure to read Bltizo's work.

 

[schrage musik]

Four SSNs per production way.

The way I envision it, is that in slot 1, all of the modules for the SSN are brought into the production way from the module fabrication facility and some additional work is done on them individually. Then they are all moved to the rear to slot 2, where some of the individual modules get joined together. Then all of those larger joined modules get moved laterally to slot 3, where those larger modules are further joined to two halves of the full SSN or even the full SSN. Then it is finally moved forwards again to slot 4 where the last bit of work is done before it goes to get painted and launched for fitting out.

The nature of that kind of arrangement means four SSNs can be worked on simultaneously, as each slot would be able to accommodate either a whole SSN (slot 4), a nearly complete SSN (slot 3), a number of large modules for an SSN (slot 2), or the individual modules for an SSN (slot 1).



In other shipyards, like Newport News, their equivalent of the assembly hall (their MOF building) has four SSN sized "slots" all lined up next to each other. What that means is each slot receives modules (such as from the SMOF building next door) and work is done on those and they are assembled together in the same slot without being moved around. Instead, the modules for each SSN stays in the same slot from when the first module is introduced to when the SSN is launched. The fact that they have four SSN sized slots means they are able to simultaneously work on 4 SSNs at once in theory.

For BHSIC, the floor area of the assembly hall clearly corresponds with space for 12 SSN sized "slots".
Unless the hall is high enough for gantry cranes to straight up lift new modules above and behind an existing near complete submarine, the only way they can make use of the 12 SSN slots (or 4 SSN slots per production way) means they will have to use a U shaped production line per production way.

Putting it another way, the BHSIC is sort of like a 4 stage "pulse" production line, with the only difference the all of the modules would be introduced at stage 1, whereas other yards like Newport News are static.


edit: added photos to illustrate. The second photo compares a Virginia SSN and an Ohio SSBN (all taken at same altitude on GE of course), with a rough microsoft paint (TM) job done to show how I would imagine the modules for an SSN might get introduced, worked on and assembled with each other, to allow 4 SSNs to be worked on simultaneously in each production way.

View attachment 50904 View attachment 50903

Amazing article. Was really looking forward to it, and i am not disappointed. The article is great.

I do think that 4 SSNs per production way is really not a realistic expectation. The huge size of this facility clearly indicates to me that it been designed to be able to accomodate a surge in production if required. My belief is that, unless the PLA is facing an imminent threat of war, each production way will only be assembling 2 SSNs at a time. So either Slot 1 + Slot 3 or Slot 2 + Slot 4 will be used for the SSN with the free slot next to it being used as a parking space for modules and parts that go into the sub.

I do not think we have any information yet of Bohai's expected production plan to be able to conclude that the facility will work like a 'pulse production line'. I'm expecting a SSN to start and finish assembly in the same slot, at least not untill there is any evidence or even an indication of a different assembly technique.

This means a maximum of 6 SSNs or more realistically 4 SSN + 1 SSBN will be in assembly at a time.

 

[Blitzo]

I agree then, if we are talking per one third of the whole building, two SSNs in the high state of readiness and two more in low state.

I do expect two thirds of the building would be making SSNs and only one third would be making SSBNs. Even if that means "only" one ssbn per two years. Which is still a mighty fast pace. Basically, one could easily upkeep a 15 boat strong ssbn fleet with such a pace. At this point, having many more SSNs than SSBNs in production might be more desirable for Chinese navy, as long as ssbn number are still increasing.

Yes one third of the overall building aka one of the three "production ways" as I described it in the piece.

What I described was a U shaped production line in each production way that allows each of the four slots to be one stage in a four stage production line, from initial module arrangement to progressive module assembly and then to final assembly ready for painting and launch.

Assuming the overall facility is running all cylinders pumping with all slots used (SSN and SSBN, whichever mix one desires), I'm not sure what the overall production rate would be. I described 2 SSNs and 1 SSBN where 1 production way is used for SSN and 2 are used for SSBNs, but depending on how efficient the process is it might be more.

Amazing article. Was really looking forward to it, and i am not disappointed. The article is great.

I do think that 4 SSNs per production way is really not a realistic expectation. The huge size of this facility clearly indicates to me that it been designed to be able to accomodate a surge in production if required. My belief is that, unless the PLA is facing an imminent threat of war, each production way will only be assembling 2 SSNs at a time. So either Slot 1 + Slot 3 or Slot 2 + Slot 4 will be used for the SSN with the free slot next to it being used as a parking space for modules and parts that go into the sub.

I do not think we have any information yet of Bohai's expected production plan to be able to conclude that the facility will work like a 'pulse production line'. I'm expecting a SSN to start and finish assembly in the same slot, at least not untill there is any evidence or even an indication of a different assembly technique.

This means a maximum of 6 SSNs or more realistically 4 SSN + 1 SSBN will be in assembly at a time.

Yes, I do think 4 SSNs per production way (aka 12 SSNs overall at various stages of work at once) is definitely a theoretical ceiling. Whether they will end up using it in the near future is a different matter, however it goes without saying that the PLAN needs a large number of SSNs for its strategic requirements, to be at least the size of the RuN if not that of the USN.

For nuclear submarines, it's not really possible to surge them in a production line if a conflict was "imminent". From placing an order to commissioning takes many years. If the full capacity of the assembly hall is used, it would be based on overall strategic projections going forwards at least a decade.


as for the four stage "pulse production" line idea, it's more a way of making sense of how they could make use of all that floor space which is clearly oriented for each production way accommodating 4 SSN equivalents. Moving a hull from one part of a rail or line to an adjacent one as it progresses through module assembly and construction is not new; for example JNCX does it for destroyer production.

The other possibility to explain how they could use the 4 SSN slots in each production way is if the gantry cranes overhead were able to transport new modules overhead of a more completed SSN to the "back" (aka the east) of production ways so that work on a new SSN can occur from the east and move east (to the main exit/entrance) as they get progressively more complete.
In that case it would still be 4 SSN slots being used in each production way, but there would be a pair of "two stage" production lines per production way instead of one "four stage" line per way.

 

[schrage musik]

Yes one third of the overall building aka one of the three "production ways" as I described it in the piece.

What I described was a U shaped production line in each production way that allows each of the four slots to be one stage in a four stage production line, from initial module arrangement to progressive module assembly and then to final assembly ready for painting and launch.

Assuming the overall facility is running all cylinders pumping with all slots used (SSN and SSBN, whichever mix one desires), I'm not sure what the overall production rate would be. I described 2 SSNs and 1 SSBN where 1 production way is used for SSN and 2 are used for SSBNs, but depending on how efficient the process is it might be more.





Yes, I do think 4 SSNs per production way (aka 12 SSNs overall at various stages of work at once) is definitely a theoretical ceiling. Whether they will end up using it in the near future is a different matter, however it goes without saying that the PLAN needs a large number of SSNs for its strategic requirements, to be at least the size of the RuN if not that of the USN.

For nuclear submarines, it's not really possible to surge them in a production line if a conflict was "imminent". From placing an order to commissioning takes many years. If the full capacity of the assembly hall is used, it would be based on overall strategic projections going forwards at least a decade.


as for the four stage "pulse production" line idea, it's more a way of making sense of how they could make use of all that floor space which is clearly oriented for each production way accommodating 4 SSN equivalents.

The other possibility to explain how they could use the 4 SSN slots in each production way is if the gantry cranes overhead were able to transport new modules overhead of a more completed SSN to the "back" (aka the east) of production ways so that work on a new SSN can occur from the east and move east (to the main exit/entrance) as they get progressively more complete.
In that case it would still be 4 SSN slots being used in each production way, but there would be a pair of "two stage" production lines per production way instead of one "four stage" line per way.

Of course, SSN production takes years and there is also the issue that Bohai will need the additional trained crews to be able to do a surge. But my idea of a surge was more like how the USN pumped up SSN production during the 80s when the undersea warfare race with the USSR was at its peak. IF such an increase in production is ever desired, then Bohai will need both additional production facilities and additional production crews. The facility, IMHO, has the additional floor space for just such an increase in production.

My line of thinking is that if their production plans needed the facility to assembly 12 SSNs at a time during normal operations, they would have made it larger to be able to handle a possible increase in production.

The overhead cranes you are talking about are a very straightforward solution and very likely to be installed. What i'm still curious about is why they left so little space at the back of the building on the east.

 

[Blitzo]

Of course, SSN production takes years and there is also the issue that Bohai will need the additional trained crews to be able to do a surge. But my idea of a surge was more like how the USN pumped up SSN production during the 80s when the undersea warfare race with the USSR was at its peak. IF such an increase in production is ever desired, then Bohai will need both additional production facilities and additional production crews. The facility, IMHO, has the additional floor space for just such an increase in production.

I think the the overhead cranes you are talking about are a very straightforward solution and very likely to be installed. What i'm still curious about is why they left so little space at the back of the building on the east.

Regarding surge, I think it will depend on how quickly the PLAN want the yard to spool up to its maximum production capacity, if at all.

If they built this new facility from the outset with a plan to immediately start spooling up to maximum production capacity then chances are the ducks would already by much more in a row.

From where I'm sitting, I can see the navy having a requirement for a large number of nuclear subs to preferably enter service by the 2030s realistically. Assuming they are sufficiently competitive and funding is available for production and manning them.
The new facility could theoretically let them build a fleet of over 40 SSNs by the mid 2030s depending on how aggressive they are with funding and if there are no significant technical barriers

 

[schrage musik]

Regarding surge, I think it will depend on how quickly the PLAN want the yard to spool up to its maximum production capacity, if at all.

If they built this new facility from the outset with a plan to immediately start spooling up to maximum production capacity then chances are the ducks would already by much more in a row.

From where I'm sitting, I can see the navy having a requirement for a large number of nuclear subs to preferably enter service by the 2030s realistically. Assuming they are sufficiently competitive and funding is available for production and manning them.
The new facility could theoretically let them build a fleet of over 40 SSNs by the mid 2030s depending on how aggressive they are with funding and if there are no significant technical barriers

Production can only increase after the first 095/096 or any other next gen SSN/SSBN is built and finishes trials. This is how they did it with the 093. The jump to 095 is likely to be as big a technological leap as the 093 was over the 091. That's why I think the initial production rate will be quite low, despite the size of the facility. They will also need to train enough crews first. Regardless of the initial production rate, however, peak production rate will depend on how many SSNs bohai has been contracted to produce by say the mid 2030s, and that definitely would be a factor that determined the size of this facility. But has Bohai provisioned the facility for being capable of handling a possibly higher production rate, that is the question for me and I think it has.

Is there any facility that assembles subs the way JCNX assembles its destroyers? If there is, then that would make things very interesting, otherwise i'm still leaning towards the subs staying in one slot for the duration of their assembly.

 

[Tam]

Production can only increase after the first 095/096 or any other next gen SSN/SSBN is built and finishes trials. This is how they did it with the 093. The jump to 095 is likely to be as big a technological leap as the 093 was over the 091. That's why I think the initial production rate will be quite low, despite the size of the facility. They will also need to train enough crews first. Regardless of the initial production rate, however, peak production rate will depend on how many SSNs bohai has been contracted to produce by say the mid 2030s, and that definitely would be a factor that determined the size of this facility. But has Bohai provisioned the facility for being capable of handling a possibly higher production rate, that is the question for me and I think it has.

Is there any facility that assembles subs the way JCNX assembles its destroyers? If there is, then that would make things very interesting, otherwise i'm still leaning towards the subs staying in one slot for the duration of their assembly.

I don't think the 093 is a good example, From beginning to end, it seems like an experiment one over another. Made two, then made one with a different design. Then made two again with a different design, and then one that might be a special mission submarine, so far in the last count. It didn't feel to me the class went into "mass production" at all. I don't think the last 093, the "hump" version, represents some form of mass production for the 093.

Historically, subs tend to show many evolutionary and incremental changes over the course of their production lifetime, as experience and new technologies continue to refine the subs. Kilo class, Viktor class, Akula class, the Song class, the Yuan class, they all have these incremental phases, blocks, mods, flights and versions, whatever you want to call it, of stepped refinement. The Virginia class can already be divided into three flights.

As the case of the Type 055 has shown, which defied the conservative "orthodox" view of PLAN ship development by observers, mass production of the 055, a new class with new technologies, was already checked and in progress even before the first ship even started trials to "prove" the design. This might come as a result of two factors --- a high confidence in their shipbuilding and design abilities, and a desperation to get the numbers up to reach a target quota.

 

[schrage musik]

I don't think the 093 is a good example, From beginning to end, it seems like an experiment one over another. Made two, then made one with a different design. Then made two again with a different design, and then one that might be a special mission submarine, so far in the last count. It didn't feel to me the class went into "mass production" at all. I don't think the last 093, the "hump" version, represents some form of mass production for the 093.

Historically, subs tend to show many evolutionary and incremental changes over the course of their production lifetime, as experience and new technologies continue to refine the subs. Kilo class, Viktor class, Akula class, the Song class, the Yuan class, they all have these incremental phases, blocks, mods, flights and versions, whatever you want to call it, of stepped refinement. The Virginia class can already be divided into three flights.

As the case of the Type 055 has shown, which defied the conservative "orthodox" view of PLAN ship development by observers, mass production of the 055, a new class with new technologies, was already checked and in progress even before the first ship even started trials to "prove" the design. This might come as a result of two factors --- a high confidence in their shipbuilding and design abilities, and a desperation to get the numbers up to reach a target quota.

Fair points all of them. I really dont disagree with anything, however the 055 came after the 052D which was already in production at an incredible rate. The supply chains, production facilities, production crews, and the navy crews to man them could all be switched over from the 052D if required. The only thing left was confidence in a new design and its associated subsystems and the PLAN took the risk with a high first production run.

None of these exist for the nuclear subs which have till date only seen surprisingly low production, and a 052D to 055 like analogy in production between the 093 and 095 is hard to argue for. This is not to say that the next SSN/SSBN designs aren't meant to be produced in large numbers, this facility settles that, and the urgency of expanding the subsurface force is also a given. But if we take the view that all 093 variants were more of a series of highly experimental designs that didn't really go into mass production in the sense that 052D, 055, 054A, Yuans or even arguably the 052C have then it reinforces the view that an initial high production rate for SSNs coming out of the new bohai facility is unlikely.

 

[gelgoog]

In the case of the 055 they already had proven the engines and most of the hull design. There were new elements like masts and so on but they were tested with land models.

So the risk was actually quite low.

This is not the same case for the nuclear submarines which will likely use entirely new systems. The engines should be different, as will likely be the periscopes, the control systems, the sonar, probably even the torpedoes and weapons systems. Does any current Chinese submarine even use a photonics mast?

If they engage in concurrency it is quite likely they will have major problems. I think they would be better off building two prototype submarines of each class, 095, 096, and then testing and improving the heck out of those before going forward with more production.