00X/004 future nuclear CATOBAR carrier thread

[Blitzo]

I think all prior rumours have referred to two separate hulls (and at two separate shipyards) rather than a singular hull. Simply based on rumours up to this point, for better or worse I think we have to operate on the basis of a CVN and a CV being pursued.

But I think what you wrote about the island design being compatible with both conventional and nuclear power has something worth exploring...

So, building on this, I wonder if what we are looking at with this island mockup, is that it is meant to represent the island design for both a nuclear powered carrier/CVN, and a new island design for a conventionally powered carrier/CV.

If we are operating with the assumption that the rear funnel structure actually represents a smokestack, the question is how do we reconcile it with the idea of a CVN being built at DL, and the possibility of a CV being built at JN as well?

One possible unifying answer, is that the island mockup is a new design that is meant to be compatible with a CVN as well as a CV.

The picture below as reference:
- The highlighted green part is the island for the CVN, with a commensurately much smaller deckspace footprint. The green cross over the rear smokestack indicates that the smokestack is "removed"/not present on the actual real CVN.
- The highlighted red part encompasses the island and the smokestack in total, which has a deckspace footprint similar to CV-18.

In other words, there are two "island configurations":
- CVN island configuration -- island only (green)
- CV island configuration -- island and connected smokestack structure (red)

The benefits of having a common "island design" between the CVN and CV is somewhat obvious -- they can keep the internals and subsystems arrangement of the CVN and CV basically the same, with some minor benefits in construction but most of the benefits would be in training ship crew.
The benefits of having a rear-set, connected smoke stack structure for the CV configuration (versus integrated into the island like on CV-18), could be to reduce the interference of the exhaust with the primary island's activities and subsystems (radars etc).
In other words, the CV island configuration is a bit of an improvement from CV-18 by having a rear-set smoke stack structure, while also offering island commonality with the sister CVN.


Now, what this entails for the mockup itself, imo is how do we make sense of the island mockup we see and the position of the island mockup?
Because what we'd be seeing is a "CV island configuration" (island and connected smokestack), but emplaced very aft on the ship, in a position more consistent with that of a CVN rather than a CV.

I see two possible answers in turn to that question:
A) They want to test the maximal permutations of the possibilities for CVN and CV island configurations and island placements; so they are basically testing a CV island configuration (which has the largest footprint and most "structure" to work with) in the newest island placement which is in the rear of the ship (i.e.: a CVN island placement). In other words, trying to hit two birds with one stone. The actual CVN would have a CVN island configuration (i.e.: no smokestack) in the same position as we see on the mockup (very aft on the ship), and the actual CV would have a CV island configuration as we see on the mockup but in a slightly more forward position relative to where it is on the mockup.
B) A slightly less likely answer (imo) is that the actual CV will have its island placed in the location as on the mockup (very aft). In that case, what we are seeing is still a case of trying to hit two birds with one stone, where the actual CVN would have a CVN island configuration (i.e.: no smokestack) in the same position as the mockup, while the actual CV would have the CV island configuration as we see on the mockup in the same position as the mockup as well.

 

[Aspide]

It shouldn't be a problem to make a compatible island more integrated, like this, for example.

 

[Blitzo]

It shouldn't be a problem to make a compatible island more integrated, like this, forView attachment 162050 example.

Well yes such a configuration would basically be going back to the CV-18 Fujian island which features the smokestack integrated in the main island structure.

What I'm suggesting is that they've deliberately chosen an island design that is suitable for use in a CVN, while also being able to be suitable for a CV (the latter by "attaching" a connected but rear-set smokestack structure). The CV island configuration in a sense, is deliberately thus seeking to separate out (aka make the smoke stack note integrated) from the primary "common island design".

 

[ACuriousPLAFan]

This is a great picture. If you imagine the aft half of the island to get truncated away, you would immediately get an island for a nuclear carrier. There wouldn't be any need for redesign or re-validation. I think what we are looking at here is an island design that is compatible with both conventional and nuclear power.

Likewise, the hull may likely be a totally new design with nuclear power in mind but fitted with conventional propulsion instead. This would not be hybrid power but one-or-the-other. It would after all be far easier to put conventional boilers in place of nuclear reactors than vice-versa. My personal opinion is that China won't be building a nuclear aircraft carrier anytime soon, but if one were to be built, the design would already exist and validated (conventionally).

So with that said, the rumor about a conventional hull and a nuclear hull being built at the same time may actually be referring to the exact same ship!

So, building on this, I wonder if what we are looking at with this island mockup, is that it is meant to represent the island design for both a nuclear powered carrier/CVN, and a new island design for a conventionally powered carrier/CV.

If we are operating with the assumption that the rear funnel structure actually represents a smokestack, the question is how do we reconcile it with the idea of a CVN being built at DL, and the possibility of a CV being built at JN as well?

One possible unifying answer, is that the island mockup is a new design that is meant to be compatible with a CVN as well as a CV.

The picture below as reference:
- The highlighted green part is the island for the CVN, with a commensurately much smaller deckspace footprint. The green cross over the rear smokestack indicates that the smokestack is "removed"/not present on the actual real CVN.
- The highlighted red part encompasses the island and the smokestack in total, which has a deckspace footprint similar to CV-18.

In other words, there are two "island configurations":
- CVN island configuration -- island only (green)
- CV island configuration -- island and connected smokestack structure (red)

The benefits of having a common "island design" between the CVN and CV is somewhat obvious -- they can keep the internals and subsystems arrangement of the CVN and CV basically the same, with some minor benefits in construction but most of the benefits would be in training ship crew.
The benefits of having a rear-set, connected smoke stack structure for the CV configuration (versus integrated into the island like on CV-18), could be to reduce the interference of the exhaust with the primary island's activities and subsystems (radars etc).
In other words, the CV island configuration is a bit of an improvement from CV-18 by having a rear-set smoke stack structure, while also offering island commonality with the sister CVN.


Now, what this entails for the mockup itself, imo is how do we make sense of the island mockup we see and the position of the island mockup?
Because what we'd be seeing is a "CV island configuration" (island and connected smokestack), but emplaced very aft on the ship, in a position more consistent with that of a CVN rather than a CV.

I see two possible answers in turn to that question:
A) They want to test the maximal permutations of the possibilities for CVN and CV island configurations and island placements; so they are basically testing a CV island configuration (which has the largest footprint and most "structure" to work with) in the newest island placement which is in the rear of the ship (i.e.: a CVN island placement). In other words, trying to hit two birds with one stone. The actual CVN would have a CVN island configuration (i.e.: no smokestack) in the same position as we see on the mockup (very aft on the ship), and the actual CV would have a CV island configuration as we see on the mockup but in a slightly more forward position relative to where it is on the mockup.
B) A slightly less likely answer (imo) is that the actual CV will have its island placed in the location as on the mockup (very aft). In that case, what we are seeing is still a case of trying to hit two birds with one stone, where the actual CVN would have a CVN island configuration (i.e.: no smokestack) in the same position as the mockup, while the actual CV would have the CV island configuration as we see on the mockup in the same position as the mockup as well.

Interesting observations.

Though, just a view of my own - Wouldn't it be better for the fore and aft island superstructures to be completely separate (i.e. having twin island superstructures), instead of having one connecting/integrating segment in between? Something like the twin island superstructures on the 076 LHD Sichuan, which results in one or two additional aircraft parking space(s) on the flight deck (if not the elevator deck and well on Sichuan). This applies for both steam turbine engine (i.e COSAS) and gas turbine engine (e.g. COGAG) options.

Since you did mention that the island superstructure of the conventional option has a flight deck space footprint similar to CV-18 - Perhaps it'll be even better if they minimize the footprint further and as best as possible?

 

[Blitzo]

Interesting observations.

Though, just view of my own - Wouldn't it be better for the fore and aft island superstructures to be completely separate (i.e. having twin island superstructures), instead of having one connecting/integrating segment in between? Something like the twin island superstructures on the 076 LHD Sichuan, which results in one or two additional aircraft parking space(s) on the flight deck (if not the elevator deck and well on Sichuan). This applies for both steam turbine engine (i.e COSAS) and gas turbine engine (e.g. COGAG) options.

Since you did mention that the island superstructure of the conventional option has a flight deck space footprint similar to CV-18 - But wouldn't it be better if they minimize the footprint further and as best as possible?

I suspect that having a separate smoke stack by itself wouldn't save that much more space (there are only so many rough areas on a flight deck you can put an island and a smoke stack, and the island in particular wants to be more after than forward, meaning the smoke stack naturally has to be aft relative to the island).

And there may still be some minor benefits in having a physical connection to the primary island -- stowage of equipment relevant to inspecting and maintaining the smoke stack structure, for example, as well as simplicity of construction, and possibly having to model for novel aerodynamic effects of having two separate structures (the latter was the case for QE class, and certainly they would have had to do so for 076 as well).

Also, my view is that the CV rumoured to be built alongside the CVN, will remain powered by conventional steam turbines, and gas turbines aren't a serious consideration, so read my prior posts with that in mind.
(It is also why a twin island/twin funnel design is not a possibility I entertained in context of trying to rationalize the mockup island)

 

[GTI]

So, building on this, I wonder if what we are looking at with this island mockup, is that it is meant to represent the island design for both a nuclear powered carrier/CVN, and a new island design for a conventionally powered carrier/CV.

If we are operating with the assumption that the rear funnel structure actually represents a smokestack, the question is how do we reconcile it with the idea of a CVN being built at DL, and the possibility of a CV being built at JN as well?

One possible unifying answer, is that the island mockup is a new design that is meant to be compatible with a CVN as well as a CV.

The picture below as reference:
- The highlighted green part is the island for the CVN, with a commensurately much smaller deckspace footprint. The green cross over the rear smokestack indicates that the smokestack is "removed"/not present on the actual real CVN.
- The highlighted red part encompasses the island and the smokestack in total, which has a deckspace footprint similar to CV-18.

In other words, there are two "island configurations":
- CVN island configuration -- island only (green)
- CV island configuration -- island and connected smokestack structure (red)

The benefits of having a common "island design" between the CVN and CV is somewhat obvious -- they can keep the internals and subsystems arrangement of the CVN and CV basically the same, with some minor benefits in construction but most of the benefits would be in training ship crew.
The benefits of having a rear-set, connected smoke stack structure for the CV configuration (versus integrated into the island like on CV-18), could be to reduce the interference of the exhaust with the primary island's activities and subsystems (radars etc).
In other words, the CV island configuration is a bit of an improvement from CV-18 by having a rear-set smoke stack structure, while also offering island commonality with the sister CVN.


Now, what this entails for the mockup itself, imo is how do we make sense of the island mockup we see and the position of the island mockup?
Because what we'd be seeing is a "CV island configuration" (island and connected smokestack), but emplaced very aft on the ship, in a position more consistent with that of a CVN rather than a CV.

I see two possible answers in turn to that question:
A) They want to test the maximal permutations of the possibilities for CVN and CV island configurations and island placements; so they are basically testing a CV island configuration (which has the largest footprint and most "structure" to work with) in the newest island placement which is in the rear of the ship (i.e.: a CVN island placement). In other words, trying to hit two birds with one stone. The actual CVN would have a CVN island configuration (i.e.: no smokestack) in the same position as we see on the mockup (very aft on the ship), and the actual CV would have a CV island configuration as we see on the mockup but in a slightly more forward position relative to where it is on the mockup.
B) A slightly less likely answer (imo) is that the actual CV will have its island placed in the location as on the mockup (very aft). In that case, what we are seeing is still a case of trying to hit two birds with one stone, where the actual CVN would have a CVN island configuration (i.e.: no smokestack) in the same position as the mockup, while the actual CV would have the CV island configuration as we see on the mockup in the same position as the mockup as well.

That is exactly what I suggested in an earlier post. They want to keep everything as consistent as possible and only change the propulsion. So in hindsight, maybe GTs would make the designs too disparate.

To me, this makes the most sense out of what we’re seeing.

Think I’ve also previously posited about the important flexibility CVs can bring. For the countries that don’t outright ban nuclear powered vessels in their waters, it can look very imperialistic making a port call with a CVN (no doubt hyped up by propaganda or astroturfed colour revolutions), and it requires much more extensive infrastructure and security at the foreign port, so much so that you might as well consider building an entire naval base, and boom, you’re painted as the evil empire.

 

[Engineer]

I think all prior rumours have referred to two separate hulls (and at two separate shipyards) rather than a singular hull. Simply based on rumours up to this point, for better or worse I think we have to operate on the basis of a CVN and a CV being pursued.

There could be many reasons on how those rumors come about that we could speculate on, but I feel PLAN might want to validate this clean-sheet design with conventional propulsion before going ahead with nuclear propulsion. We have seen such incremental approach with 001->002->003 so I am not convinced there would be a huge jump when it comes to 004.

Now, what this entails for the mockup itself, imo is how do we make sense of the island mockup we see and the position of the island mockup?
Because what we'd be seeing is a "CV island configuration" (island and connected smokestack), but emplaced very aft on the ship, in a position more consistent with that of a CVN rather than a CV.

I see two possible answers in turn to that question:
A) They want to test the maximal permutations of the possibilities for CVN and CV island configurations and island placements; so they are basically testing a CV island configuration (which has the largest footprint and most "structure" to work with) in the newest island placement which is in the rear of the ship (i.e.: a CVN island placement). In other words, trying to hit two birds with one stone. The actual CVN would have a CVN island configuration (i.e.: no smokestack) in the same position as we see on the mockup (very aft on the ship), and the actual CV would have a CV island configuration as we see on the mockup but in a slightly more forward position relative to where it is on the mockup.
B) A slightly less likely answer (imo) is that the actual CV will have its island placed in the location as on the mockup (very aft). In that case, what we are seeing is still a case of trying to hit two birds with one stone, where the actual CVN would have a CVN island configuration (i.e.: no smokestack) in the same position as the mockup, while the actual CV would have the CV island configuration as we see on the mockup in the same position as the mockup as well.

Option C: we should interpret this as extra space added ahead of the island on the new design rather than the island shifting aft. The 003 has its stern extended compare to 002 as this was the only way to lengthen the ship without making major modification to the rest of the hull. With a clean-sheet design, this lengthening could be done on the hull forward of the island, and we should see this being reflected on the mock-up.

Option D: they made enough change to the internal arrangement to allow the island to shift. For example, they could place the boiler rooms/nuclear compartments directly ahead and aft of the rear turbine-compartment, which would allow them to shift the island by 20~30m. However, I see this as very unlikely as it goes against what I call "design heritage". It would be more likely for the internal arrangement to be near-identical to 001/002/003 aside from modification needed to support nuclear propulsion.

 

[ACuriousPLAFan]

Another ground-level shot of the mockup island superstructure. Posted by @邱小姐上梳妆台 on Weibo.

 

[Expert1324]

The smokestack is unfortunate, but at least I just want the 004 to have a fantail balcony this time.

Able to do Jet engine testing and maintenance on board is a must have capability in this day and age.

 

[no_name]

Another ground-level shot of the mockup island superstructure. Posted by @邱小姐上梳妆台 on Weibo.

View attachment 162063

Actually looks alright from this angle.