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

[gelgoog]

The 093B designers would have made the size large enough to fit exactly as much quieting technology as the design demands. A larger diameter does not confer a decrease in noise, it only makes it easier to fit quieting equipment. You're still capped at however loud your reactor + mechanical noise are.

The 093B is a constrained design. To reduce the development time they are likely not making major changes to the internal hull.
I think it is just a demonstrator of certain advanced technologies to be used in later generation subs. It will help the submarine builders also gain experience with submarine construction until the later next generation submarine designs become available. And last but not least will help reduce the gap between Chinese nuclear submarines and Western nuclear submarines in terms of both technology and numbers.

I'd defer to the expertise of the designers, if they knew that the size they determined for the 093 will fit the necessary equipment, it's probably true. I don't think teams of dozens of professor and post-doc engineers would go "whoops we forgot to make room for quieting equipment on the sub".

Engineering is the art of making things possible. Short deadlines to get submarines into construction likely have precluded an entirely new hull design at this point.

There is no real barrier for them to make the sub larger. Russia has an equivalent nuclear sub industry and they've dabbled with massive designs.

Their largest designs were catamarans however. Take the Typhoon class for example. It has multiple pressure hulls. So there are limitations based on technology. The latest Russian submarines seem to be focused on miniaturizing both weapons and weapons platforms.

Larger size mainly lets you fit VLS which we later realized is pretty damn useful. But 093 design era was around the LA/Seawolf period, where the convention was in subs as stealthy torpedo boats.

Back when Type 093 was designed Chinese technology for that (VLS, sub launched cruise missiles) was not as advanced as it is today.
Putting VLS back then would have risked massive project delays or even project failure.

Virginia block 6 for example has 2020s US precision manufacturing tech, which is top 2-4 in the world, and top 1-3 reactor designs. And it was a hull/systems designed around 2010s.

Block VI is not out yet. I personally think the latest Virginia submarines defeat the purpose of the design. It was meant to be a relatively cheap mass produced attack submarine. They made it larger than originally intended to add the VPMs, and for whatever reasons killed the rapid construction rate in the process. Worse of all is the VPMs are still restricted to firing the Tomahawk, which they could have already launched from torpedo tubes. So why bother. Fixing this long term will require IMHO a new submarine design and developing modern weapons which can fully use the VPMs.

Due to these decisions they will have Los Angeles class submarines retiring sooner than they can build Virginias to replace them. Losing their numbers advantage long term in the process. They retire like two submarines a year and build one a year.

It is pretty pathetic considering the US have two submarine shipyards. The Russians of late seem to be launching 1 SSN and 1 SSBN a year. Which is like two submarines a year. But the Russians also seem to have stopped construction of new nuclear submarines. Only continuing ongoing construction projects since the invasion of Ukraine started. Likely issues with budget allocation as the nuclear submarines are big ticket items costing like $1.5 billion USD each at a time the army needs more funds. We will see if they finally order new subs this year or not.

So it is extremely unlikely to be worse than a base 093 that was designed with 90s precision manufecturing and late 80s reactor.

The thing is not that many base 093s were produced and they will be massively outnumbered by 093Bs.

 

[para80]

Their largest designs were catamarans however. Take the Typhoon class for example. It has multiple pressure hulls. So there are limitations based on technology. The latest Russian submarines seem to be focused on miniaturizing both weapons and weapons platforms.

The design of Typhoon/Akula was intended to keep its draft within existing infrastructure requirements. It wasnt a technological restriction, in fact the design was rather unconventional and challenging from a technological POV.

As for the Americans, this is what happens when no boats are ordered. The yards scale their workforce and supply base to demand. Its not a matter of competence or expertise but economics. The turnaround is going to happen, and the production output will rise significantly assuming funding remains steady.

This is all relatively OT obviously here, but the gist is, comparing production output vs what China is doing right now with Huludao is always going to be apples and oranges. All relevant countries can produce submarines quickly if the cash and resources are there. Even Russia, because the vast chunk of budgeting goes into somewhat maintaining the industrial base for nuclear powered submarines.

 

[ACuriousPLAFan]

093B is the J-16/F-15EX of submarines. Do not diss them. But yes, J-20 of subs will come in couple years.

Unfortunately, for the subsurface fleet, such analogues don't work.

Firstly, the 095s are meant to succeed thr 039Bs in both roles and functions. They are not the same as J-20 + J-16 duo in the PLAAF.

In the meantime - If you want an underwater missile truck, go for the Block 5 Virginias. But then, that literal swimming baguette isn't going to be good - Namely, through sacrificing the SSN's agility (which is one of the defining natural features of SSNs) in order to fit more multipack VLS tubes to stand-in for the retiring Ohio SSGNs.

More multipack VLS tubes onboard = Greater size = Greater displacement = Reduced agility. If agility is to be maintained, greater amount of power must be demanded from its reactors = Either a major/extensive redesign of the SSN is required, or might as well go with a brand new SS(G)N design.

Therefore, if underwater missile trucks are to be desired, the PLAN might as well have several SSBNs that are fitted with multipack VLS tubes instead of SLBMs. In this regard, both the multipack VLS tubes and SLBMs should be made to be swappable with one another, instead of having to go through extensive refits like what the first 4 Ohio boats did.

 

[TK3600]

Unfortunately, for the subsurface fleet, such analogues don't work.

Firstly, the 095s are meant to succeed thr 039Bs in both roles and functions. They are not the same as J-20 + J-16 duo in the PLAAF.

In the meantime - If you want an underwater missile truck, go for the Block 5 Virginias. But then, that literal swimming baguette isn't going to be good - Namely, through sacrificing the SSN's agility (which is one of the defining natural features of SSNs) in order to fit more multipack VLS tubes to stand-in for the retiring Ohio SSGNs.

More multipack VLS tubes onboard = Greater size = Greater displacement = Reduced agility. If agility is to be maintained, greater amount of power must be demanded from its reactors = Either a major/extensive redesign of the SSN is required, or might as well go with a brand new SS(G)N design.

Therefore, if underwater missile trucks are to be desired, the PLAN might as well have several SSBNs that are fitted with multipack VLS tubes instead of SLBMs. In this regard, both the multipack VLS tubes and SLBMs should be made to be swappable with one another, instead of having to go through extensive refits like what the first 4 Ohio boats did.

I waa thinking in analogy of modernized small sub and advanced big sub. Not their literal roles. J-16 in the sense of highly modernized systems(comparable quality to US) in outdated vessel. In terms of role closer to J-10.

They seem quite slow pace for 095. Slow reminds me of J-20. It was first flew a long time ago, only last couple year did it scale up. I think 093B will have to fill the gap until 095 is ready. But once it is ready, 093B will cease production quickly.

 

[ACuriousPLAFan]

I waa thinking in analogy of modernized small sub and advanced big sub. Not their literal roles. J-16 in the sense of highly modernized systems(comparable quality to US) in outdated vessel. In terms of role closer to J-10.

They seem quite slow pace for 095. Slow reminds me of J-20. It was first flew a long time ago, only last couple year did it scale up. I think 093B will have to fill the gap until 095 is ready. But once it is ready, 093B will cease production quickly.

In that case, a more suitable analogy would be J-20 versus new-built J-11BG if not J-11D (had it not been cancelled). Roles and functionalities are pretty important parts for consideration, still.

Either way, we're on the edge of entering the out-of-topic zone here.

 

[tphuang]

I would not waste anymore time comparing nuclear subs to other weapon systems.

What kind of operational freedom you get from a large fleet of 093B is probably as important as how quiet it actually is.

Basically, as long as 093B or 095 is moving along within first island chain, it can be found if there are enough USN and JMSDF assets around it. The interesting thing about having enough 093B is that there is simply no way that USN can track them once you have enough of these boats in the open Ocean. Even if they trip up SOSUS during peace time, if there isn't a VA class following all of them along, then you have boats that can't be spotted from space, has unlimited range that can sustain 20 knots. There is serious operational usage in that. There are things they can do like figuring out how to communicate with space or friendly underwater assets once they get into open seas. Apparently, PLA is really good with some of that.

Quantity is actually a huge quality.

 

[tphuang]

People don't think about availability long enough when it comes to submarine usage

The latest out of UK is a bunch of subs that never leave the port

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America has 37% of its nuclear submarine fleet in the port undeployable last year. And this will continue to get worse as the fleet ages and are asked to do long deployment.

As I said before, the number of subs America has at disposal for Westpac at any given time to do missions is probably not that many. And some of them I would imagine be used to track Chinese conventional fleet.

So that's why this is the decade when underwater balance of power might really change.

first you need those mini-nukes because then your lower cost fleet can spend more time at sea and need to be dealt with.

Then you can as many attack subs sailing around as possible so they can get more time outside of first island chain.

It is one thing to have 7 subs and only 1 or 2 can leave the port at a time. It's quite another thing to have 25 and 8 of them are out at patrol.

 

[AndrewS]

What exactly is everyone referring to in terms of "quieting equipment" and the need for "precision"?

Major things that come to mind for quieting:

1. Anechoic tiles to block incoming and outgoing sounds
2. Rafting of the internal structure and the resulting isolation from the external pressure hull
3. Quieter components such as fans and motors, using things like magnetic bearings which isolate the moving components from the structure
4. Propellor design and machining/casting precision
5. Natural circulation reactor design

The size of the pressure hull really could only affect items 2+5
But this has nothing to do with "precision" components.

Am I missing something?

 

[tphuang]

What exactly is everyone referring to in terms of "quieting equipment" and the need for "precision"?

Major things that come to mind for quieting:

1. Anechoic tiles to block incoming and outgoing sounds
2. Rafting of the internal structure and the resulting isolation from the external pressure hull
3. Quieter components such as fans and motors, using things like magnetic bearings which isolate the moving components from the structure
4. Propellor design and machining/casting precision
5. Natural circulation reactor design

The size of the pressure hull really could only affect items 2+5
But this has nothing to do with "precision" components.

Am I missing something?

the size of pressure hull mainly just affects 2 and 3 in your list. More space inside -> more space to isolate noise generating parts.

Precision machineries is to get all this stuff that spins to be quieter.

That's why we are kind of optimistic about the mini-nuke. It just has fewer of the machines that make noises.

 

[Blitzo]

What exactly is everyone referring to in terms of "quieting equipment" and the need for "precision"?

Major things that come to mind for quieting:

1. Anechoic tiles to block incoming and outgoing sounds
2. Rafting of the internal structure and the resulting isolation from the external pressure hull
3. Quieter components such as fans and motors, using things like magnetic bearings which isolate the moving components from the structure
4. Propellor design and machining/casting precision
5. Natural circulation reactor design

The size of the pressure hull really could only affect items 2+5
But this has nothing to do with "precision" components.

Am I missing something?

In terms of subsystems/quietening effects that are related to pressure hull diameter, I see 2, 3 and 5 all as potentially relevant.

2. because more diameter/volume means more rafting (or even having ability to install rafting if your pressure hull diameter is too small in an absolute sense)
3. because some quieter components may be put together into a complete system which is larger than louder components
5. natural circulation is important but I would also include that in an overall category of "nuclear reactor design quietening" which may require a "quieter reactor" to be larger in volume compared to a "louder reactor" of the same output