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


Totoro

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A little bit of info that could be useful for new SSN build rates. US Newport news, which builds Virginia class, has quite a small hall for final assembly, but at the same time, it's easily definable it's likely all that's done there, just the final assembly. So it could be quite comparable to the Chinese production procedure. Unlike using the GD's Groton building halls or the British hall for Astute assembly (where it seems whole sections are made right there in the same hall)

Anyway, Newport news's hall is 129 by 93 meters. It has two slipways. While the submarine build list has occasionally "laid down" date of the next submarine coming after the "launch" date of the previous sub, in more instances that's not the case. Yet, when looking at the imagery of subs they made, it becomes (almost) apparent that indeed they ARE alternating building subs in one slipway, then another. So even though the laid down date may seem to leave some room before launch, it is very likely there is still some preparatory work needed, which indeed interferes with two subs being made in the same slipway in a given amount of time.

So basically, even though Newport news launched subs in:
2005, 2007, 2009, 2010, 2012, 2014, 2016, 2017, 2018 and 2020, they launched them from alternating slipways and building berths.

Initial subs took 3 years from laid down to being launched, block II and later subs took roughly year and a half. (of a note, GD's yard obviously has a different building procedure as they take the very same Virginia class sub from laying down to launching subs just one year)

But as written before, being laid down is obviously not the start of the assembly procedure. At least some months seem to be required, from launching one boat, to preparing the berth to start assembling new modules.

So, IF Virgina and it's building process at Newport News would be a point of comparison, true time for one slipway to eject a new submarine would likely be around 2 years when the procedure is familiar. And possibly 3 or 3.5 years for the initial subs, when the procedure is new and has to be learnt. Indeed, when one looks at time between launches for alternating subs at NN, that time is always 2 to 3 years. So 2 years is possible, but it may not be possible to drop the construction below that limit.

While the mentioned hall at Newport news has 4 set of tracks in total, two for each half of the building, only one half of the building hall is used per one submarine. 47 meters by 129 meters.

Using the Huludao new hall for comparison, it has 3 sections. Each of those sections has 2 set of tracks. And each section is 44 by 288 meters.

In NN building it is likely that one set of tracks into each building spot is used for either for workers and machinery, or for bringing in and furnishing modules not yet mated with the rest of the sub, and the rest of the sub is one the other set of tracks,

at Huludao, It's likely the one out of two set of tracks for each building site (out of 3 sites in total) is for work/furbishing/getting new empty modules. And parallel to that there is the track where two subs, each in different set of completeness, is positioned.

So when one sub is moved out of the hall, the sub behind it moves up a bit, and the new set of workers, which previously finished up the previous sub, works on it. It's sort of/kind of a mini pulsed line, where one set of workers and machinery stays stationary and receives a new sub to do the work they're most proficient at.


Still, a sub needs a certain amount of time to be finished. If NN is the comparison point, then subs at huludao, with all 3 sections of the hall working, will initially need 3.5 years to launch, with that dropping to 2 years after a decade of experience. There is likely room for 3 or so subs being worked on at the same time in one third of the entire hall, with two set of tracks. Of course, not all 3 are in the same state of completion. When one is almost finished, the third one likely has just several modules in the hall, with other modules not even arriving before the first sub launches and allows space for the whole pulse line to move a bit.

Anyway. Assuming whole building hall with 3 sections has each section launch a sub in 3.5 years in the beginning and launch a sub in 2 years after years of experience: in the first 3.5 years one might be looking at roughly 9 submarines launched. In next 3 years another 9, in the following 2.5 years another 9 and in the next 2 years another 9. That's 36 submarines in 11 years from the first launch.

That may be the best performance case scenario. It's always possible actual production rates due to unforeseen events complicate the learning curve. Still, with that new building hall with two more sections being built - overall production rate from all 5 sections may eventually not only meet 36 subs in 11 years but go over it, by some margin.
 

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Bltizo

Lieutenant General
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Anyway. Assuming whole building hall with 3 sections has each section launch a sub in 3.5 years in the beginning and launch a sub in 2 years after years of experience: in the first 3.5 years one might be looking at roughly 9 submarines launched. In next 3 years another 9, in the following 2.5 years another 9 and in the next 2 years another 9. That's 36 submarines in 11 years from the first launch.

That may be the best performance case scenario. It's always possible actual production rates due to unforeseen events complicate the learning curve. Still, with that new building hall with two more sections being built - overall production rate from all 5 sections may eventually not only meet 36 subs in 11 years but go over it, by some margin.

The southern new assembly hall would likely kick in halfway through the decade, at which point the personnel working in the existing eastern hall would be able to work in the southern hall as well, which likely builds exclusively SSNs, but would have the benefit of building the same type of submarine presumably on similar infrastructure but with more clearance space between the tracks that might make them a bit more efficient.

To me, the initial ramp up of nuclear submarine construction at the new Bohai facility is a given going to be a gradual climb.

But the question is what the sustained "full capacity" of nuclear submarine construction will be once the eastern assembly hall and new southern assembly hall are both running at capacity (likely mid to late 2020s).
I.e.: the first 5-6 years of running the new facility, might be relatively "conservative". But the subsequent 10 years afterwards is where things might start to kick in. One only needs to recall what PRC destroyer production was like initially going from the restart of 052C production at JN, before they ramped things up at JN and then got DL involved...
Obviously I'm not suggesting the PLAN are aiming to launch double digit nuclear submarines in a year like they did with destroyers, but I wouldn't be surprised if they were a bit more ambitious than foreign commentary have traditionally observed re their nuclear submarine requirements...
 

Totoro

Captain
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I'd just like to amend my above projection as i didn't take into account the staggered production process sufficiently.
So, on the example of the larger assembly hall, with 3 lines working near parallelly and in each of those 3 lines 3 submarines being assembled at different pace (different stages of assembly), and IF one assumes 2022 as first submarine launch:
then the second sub from the same line could come around 2023, third one in 2024, fourth one in 2025, sixth in 2026, seventh in 2028, eight in 2029, ninth in 2030, 10th in 2031.
Since there are three separate lines, 2 more subs would come after each one mentioned here. But would have to separated by several months. Since all the halls seem to share the same painting (and anechoic tile assembly?) hall and the same final slipway for putting the boats into the water.

So in ten years some 28 subs might be launched from that hall, at some highest capacity.

Of course, It's perfectly plausible that the initial 5 or so years will indeed see much slower pace, until everyone gets familiar with the process and the subs.

Also, the single painting hall and launch dock might be an issue when both buildings and all 5 assembly lines are going full pace. That's five submarines per year being put in the water.
 

Bltizo

Lieutenant General
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Also, the single painting hall and launch dock might be an issue when both buildings and all 5 assembly lines are going full pace. That's five submarines per year being put in the water.

I think the whole point of having a dedicated painting hall is to facilitate a faster launch rate per year by virtue of division of labour -- most nations submarine construction just paint their submarines in the same location that they are assembled (i.e.: the Bohai equivalent of the eastern and southern assembly halls).
But they took the time to build a dedicated paint hall for SSN sized boats, meaning they feel like investment in that structure is worth it just to eke out that extra bit of efficiency, or they are expecting to launch quite a few boats per year to make it worthwhile -- or both.

The launch platform/pontoon won't be an issue; after all the time taken to launch a submarine is less than a day, all you have to do is wheel out a submarine onto the pontoon and sink it into the water and then put the submarine into the fitting out area, which is not exactly small.


Looking back onto the commissioning rate of various nuclear submarines from Sevmash during the cold war, I can't help but wonder once the new Bohai facility is running on all cylinders, whether there might be a year or two where they're also able to achieve double digit launch of nuclear subs like they did with destroyers...
 

AndrewS

Colonel
Registered Member
Looking back onto the commissioning rate of various nuclear submarines from Sevmash during the cold war, I can't help but wonder once the new Bohai facility is running on all cylinders, whether there might be a year or two where they're also able to achieve double digit launch of nuclear subs like they did with destroyers...

With a destroyer production surge, you know the shipyards also have commercial work to always keep busy.

But if we ever see 10 nuclear submarines being launched from Bohai, I don't see that as anything except prepping for a full-scale war.
 

AndrewS

Colonel
Registered Member
I think the whole point of having a dedicated painting hall is to facilitate a faster launch rate per year by virtue of division of labour -- most nations submarine construction just paint their submarines in the same location that they are assembled (i.e.: the Bohai equivalent of the eastern and southern assembly halls).
But they took the time to build a dedicated paint hall for SSN sized boats, meaning they feel like investment in that structure is worth it just to eke out that extra bit of efficiency, or they are expecting to launch quite a few boats per year to make it worthwhile -- or both.

The launch platform/pontoon won't be an issue; after all the time taken to launch a submarine is less than a day, all you have to do is wheel out a submarine onto the pontoon and sink it into the water and then put the submarine into the fitting out area, which is not exactly small.

I have to say that I'm surprised to see another construction hall

I think the launch rate per year is only part of the reason.

The biggest issue to me is the long-lead time of submarine construction.
You see the Virginia SSNs currently taking 6 years from start to finish.

Building more specialist facilities means submarine production time is reduced, so they can enter service earlier.
This also accelerates the submarine development learning cycle in terms of design, build and test.

My guestimate is that with efficient facilities and Chinese working hours, they could easily reduce construction time to 4 years.

A secondary benefit would be more surge capacity if larger numbers of submarines needed to be built.
 

gelgoog

Major
Registered Member
Not necessarily a full-scale war given the obsolescence and small numbers of the existing PLAN nuclear submarine fleet.
A build rate like that could happen. But I think it is unlikely.
 

OppositeDay

Junior Member
Registered Member
PLAN’s nuclear submarine fleet is the biggest obstacle to China’s new goal of building a modern military force by 2027. I think we can expect high building rates if things go smoothly.
 

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