00X/004 future nuclear CATOBAR carrier thread

[Blitzo]

The carrier mockup in Wuhan might be getting a new modification to its island.

The images below show an alleged procurement announcement on a renovation project to an existing structure. The renovated structure is 20 meters in length and 30 meters in height, with requisite windows, openings, doors, railings, etc.

Interesting.

This CGI comparison done a few years ago by 大包00 is somewhat speculative (particularly for 003 at the time and definitely for "004" which is just their own speculation), but it does compare the relative sizes of the other carrier islands reasonably.

If the length of the new island is 20m overall or 20m footprint deckspace, that would definitely lend itself more to a singular island size you'd expect for a CVN rather than a CV.


Also worth noting on the Wuhan mockup, as they adjusted the island between CV-16 design, to CV-17 design, to CV-18 design (progressively shorter/smaller), I don't think they actually cut down the structural footprint on the mockup itself in terms of footprint taken on the "deck" of the mockup. So if this tender is for a new island I wonder if they'll rebuild it from the "deck" up or if they'll just add another layer or shorten one of the upper layers while keep the base structure as it is.

 

[Alfa_Particle]

Since no one posted it, this is the structural model published alongside the procurement announcement.


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[ACuriousPLAFan]

The carrier mockup in Wuhan might be getting a new modification to its island.

The images below show an alleged procurement announcement on a renovation project to an existing structure. The renovated structure is 20 meters in length and 30 meters in height, with requisite windows, openings, doors, railings, etc.

Just an additional screenshot from the procurement announcement. Posted by @Captain小潇 on Weibo.

Since no one posted it, this is the structural model published alongside the procurement announcement.
View attachment 132380

From:

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I don't see that illustration in the procurement announcement?

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[ACuriousPLAFan]

Interesting.

This CGI comparison done a few years ago by 大包00 is somewhat speculative (particularly for 003 at the time and definitely for "004" which is just their own speculation), but it does compare the relative sizes of the other carrier islands reasonably.

If the length of the new island is 20m overall or 20m footprint deckspace, that would definitely lend itself more to a singular island size you'd expect for a CVN rather than a CV.


Also worth noting on the Wuhan mockup, as they adjusted the island between CV-16 design, to CV-17 design, to CV-18 design (progressively shorter/smaller), I don't think they actually cut down the structural footprint on the mockup itself in terms of footprint taken on the "deck" of the mockup. So if this tender is for a new island I wonder if they'll rebuild it from the "deck" up or if they'll just add another layer or shorten one of the upper layers while keep the base structure as it is.

In the meantime, @Captain小潇 on Weibo reasoned there won't be a (half-)sister ship to Fujian, given the noticeably lack of any procurement tender offer/announcements for the construction of such warship to occur.

Seems like China's Project 048 will have deviations. China's 4th aircraft carrier will be nuclear powered. Pop3 was right.

 

[gelgoog]

If another conventional powered CATOBAR was built I think it would come with gas turbine engines. The long startup times of steam turbines make them poorly suited for modern warfare. The fact the Type 003 comes with the steam turbines is probably more of a legacy trait due to it being originally designed to use steam catapults which would use steam generated from the boilers more than anything else.

I agree that the next carrier to be built will likely be nuclear and they won't be building more conventional carriers. But I think this isn't necessarily a good idea for China in the short term. Since conventional carriers are typically cheaper to operate and China needs to get more experience with carrier ops, having at least some conventional carriers would likely be a good idea.

 

[Blitzo]

If another conventional powered CATOBAR was built I think it would come with gas turbine engines. The long startup times of steam turbines make them poorly suited for modern warfare. The fact the Type 003 comes with the steam turbines is probably more of a legacy trait due to it being originally designed to use steam catapults which would use steam generated from the boilers more than anything else.

I agree that the next carrier to be built will likely be nuclear and they won't be building more conventional carriers. But I think this isn't necessarily a good idea for China in the short term. Since conventional carriers are typically cheaper to operate and China needs to get more experience with carrier ops, having at least some conventional carriers would likely be a good idea.

If they were to build another conventional carrier I doubt it would be gas turbine.
A gas turbine conventional carrier will lack any commonality with CV-18 (meaning more costs for different logistics/support for something important like propulsion), as well as not benefit the transition to CVNs (as CVNs also use steam turbines as well as part of their drive train).

This is even considering whether they have a suitably series of gas turbines that can be used on a properly sized carrier in the first place, that can be used with sufficient risk.



Those reasons are likely the same factors why CV-18 used steam turbines and boilers rather than gas turbines -- because it actually offers some commonalities with future CVN technologies (steam turbine), some backwards commonality with CV-17, and also because it was a propulsion system they considered sufficiently mature to implement on a ship as important as a carrier.


The "long startup" times for steam turbines in a carrier actually isn't that important because a carrier will take a long time to startup anyway simply because of the sheer complexity of the various elements of the ship, crew, airwing, logistics and support, and while at sea it won't be doing sudden stops and starts anyway.

Since no one posted it, this is the structural model published alongside the procurement announcement.
View attachment 132380

From:

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I wonder if he just made that himself or if it is actually reflective of the geometry from a source.

 

[ACuriousPLAFan]

If another conventional powered CATOBAR was built I think it would come with gas turbine engines. The long startup times of steam turbines make them poorly suited for modern warfare. The fact the Type 003 comes with the steam turbines is probably more of a legacy trait due to it being originally designed to use steam catapults which would use steam generated from the boilers more than anything else.

Apart from what have been explained above - Having gas turbine engines will either require the island superstructure to be massive (i.e. Izumos and Trieste), or twin island superstructures will be needed (i.e. Queen Elizabeths and 076(s)).

It would be a massive step back in the progress of freeing more flight deck spaces for parking more aircraft for successive PLAN carriers down the line.

I agree that the next carrier to be built will likely be nuclear and they won't be building more conventional carriers. But I think this isn't necessarily a good idea for China in the short term. Since conventional carriers are typically cheaper to operate and China needs to get more experience with carrier ops, having at least some conventional carriers would likely be a good idea.

The entire process of designing, verifying, finalizing, building, fitting-out, sea trialing, commissioning and working up any CVs of substantial sizes before it can achieve IOC (let alone FOC) does take many years to complete. And if the duration required to go through the whole process for CVs isn't significantly shorter to the duration required to go through the whole process for CVNs to make actual tangible differences, then why bother?

My guess is that those planners in the higher echelons of the PLAN well understood that there is little way to rush these things to achieve the desired results, so they might as well go with a much better option.

 

[gelgoog]

China have long had 28 MW gas turbines. Supposedly they now also have 40 MW gas turbines.
The Queen Elizabeth class uses two 36 MW gas turbines.

Type 003 has 30% more displacement than the Queen Elizabeth class. I think this would not be difficult to achieve with existing Chinese technology and equipment.

The gas turbines are more efficient than a boiler and steam turbine configuration. So it would also increase the range of the carrier. Plus the gas turbine is way more compact which would increase the internal space of the carrier.

 

[Blitzo]

They have long had 30 MW gas turbines. Supposedly they now also have 40 MW gas turbines.
The Queen Elizabeth class uses like two 36 MW gas turbines.

Type 003 has like 30% more displacement than the Queen Elizabeth class.

"Supposedly". And are these gas turbines considered sufficiently mature for use aboard a ship as important as a carrier?

And what about the lack of commonality with previous conventional steam turbine carriers, or the lack of benefit for commonality with future nuclear carriers (again in terms of steam turbines), or the significant redesign needed for a gas turbine powered carrier (both intakes and exhausts)?

And are all those changes (needing time, money and risk), worth what little benefits a gas turbine conventional carrier can provide compared to a steam turbine conventional carrier? After all a carrier won't be suddenly stopping or starting, and it can't set off from port that quickly like a surface combatant will need to because of its long logistical tail.


A gas turbine carrier just doesn't make sense for the PLAN of 2024.

If it was 2010 and they had access to gas turbines of sufficient power and weren't starting with ex-Varyag/Liaoning, then sure maybe. But they're not starting from a clean slate now and there's just no benefits for changing to gas turbine propulsion if they were considering another conventional carrier.

 

[gelgoog]

We do not know what will be the configuration of the Chinese Navy. I do not think they will just ape the US configuration.

They already seem to have two LHD designs the Type 075 and 076. So I would not be that surprised if they decided to have more than one carrier type as well.

The US used to operate like that. They operated escort carriers and fleet carriers both.

The small escort carriers back then were used to guard other ships against submarines. Right now China has a similar problem in that the US has superiority in terms of numbers of submarines. The smaller carriers would enable building more of them. They would then have anti-submarine aircraft in them. The question is if something like the Type 076 would be enough or a larger flattop would be warranted. In case that kind of strategy is pursued in the first place.

The large fleet carriers were used to attack other surface ship formations. Today also for land attack.