00X/004 future nuclear CATOBAR carrier thread

[FairAndUnbiased]

Guys, IMHO we should take one step back to see the bigger picture then we probably could come to a conclusion on what kind of carrier PLAN need next.
On an official term, what is "the mission this generation of Chinese must accomplish"? Obviously it is so called the reunification of motherland.
Who's responsibility it is? My money is on President Xi and his administration.
President Xi is approaching his 70th birthday next year, and rumor says (and I am not responsible for this rumor) he is looking for one more term (5 years) in the office. By then he is approaching 75 and probably would not take another term (just see how Joe Biden is doing in his late 70s & early 80s).
If all above were true, then the year 2027 is a critical milestone to achieve the target of reunification of motherland aca. recover Taiwan.
To achieve this target, what arm forces PLAN need? Would 3 carriers (CV-16, CV-17 & CV-18) together with the Rocket Army be enough to deter potential hostiles approaching 500nm to the east of the island?
Here are my assumptions:
1. Carriers, no matter which one, is not aiming Taiwan. PLAAF alone is enough to obtain a full control of air dominance over the island.
2. The soul purpose of these carriers is to cruise at the east of the island preparing for any hostile movement from West Pacific and South Sea. Based on the principle of 料敌从宽 it is capable to estimate the amount of fleets coming for raid.
3. In this case the endurance of carrier is not a key factor, but probably the number of carried flights.
4. Furthermore as the technical evolving philosophy of PLAN is, as so many people mentioned, 小步快跑, which means huge pace of technical development under time pressure is unlikely to happen, especially in front of this tremendous strategic target.

So jump to the conclusion, the #4 carrier (not Type 004) would probably be similar to CV-18 with improvements preparing for future CVN about to come.

Though I am happy to be proven wrong which would only indicating one thing but only:
The PLAN is not going to passively respond to hostile movements during the recover progress of Taiwan but push the line further, deep into Pacific.

All of us will see this coming.

this is why I think SMR+combustion combo might be the way to go for 004, with SMR for base load and a combustion engine for peak load.

there is a theoretical basis for this in civil electrical engineering.

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Thus these plants usually runs at 100% of capacity. That means that the most efficient nuclear power capacity is to build as much as the lowest constant demand - the base load.

Why don't all countries with the capability simply have 100% reactors then? Not only because of expense, but because demand varies throughout the day. Electrical power in general cannot be stored at scale, demand must be kept up with supply instantaneously.

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especially over long periods of time. Likewise, demand varies throughout the course of carrier operations. Sometimes the ship is at cruise and reactor power is overgenerating. At other times it needs massive power for flight ops to work.

Why has this not been a problem in the past? EMALs is very different in terms of power requirement than steam catapult. Steam catapult uses gas expansion principle. It requires a reservoir of steam, which is generated by constant heat from the boilers, which reactors can provide. Nimitz has a huge steam reservoir and this is why steam catapults are so reliable and successful. It does not require electricity, because the steam reservoir is actually an energy storage device - the energy is stored in the enthalpy of vaporization of water.

EMALS uses electricity. The peak electrical demand during flight ops is much higher than the baseload electrical demand. That means complicated long term storage schemes must be used. These have reliability issues, especially in a shooting war. Large batteries, capacitors and flywheels do not like being shot. They tend to explode or light on fire when shot. They also have relatively low energy density.

The alternative to energy storage is to just generate it on the spot. In civil electrical engineering, the fastest starting generation stations are gas turbines. A civilian gas turbine can go from stationary to full power at 150+ MW within 10 minutes. A naval gas turbine which is smaller and optimized for very fast startup can probably go from stationary to full power within 5 minutes.

 

[Blitzo]

"Successful" by US standards of success. No one claims China delivered every single system it conceived with 100% success, but until it has a debacle like the Zumwalt I will always believe Chinese military procurement is simply in a different league from America's.

Not compared to China, which is the only relevant comparison here.

Even compared to China, I do not think that it is reasonable or constructive to describe US military procurement as a "shitshow".

They have examples of program overreach, and those programs are often characterized by poorly defined requirements, technological overreach, concurrency, or a combination thereof.

But the sheer number of successful programs that the USN have successfully developed is such that the problematic projects that they have experienced, does not outweigh the long term track record of very successful projects, many of which outmatch other competitors in both technological sophistication, scale of procurement, but also outright capability.

Yes, the USN has certainly made a few poor program decisions in the post cold war unipolar moment that they are now suffering from (but they've also developed many successful programs in this timespan as well, many of which are world leading, but with the return of great power competition and a refocus of their priorities, they certainly have a track record of successful programs that cannot be ignored in a great power competition context. As such, making pronouncements of USN poor procurement as being a "shitshow" in a future, permanent way, is massively premature and could be a fatal assumption.

The PLAN and PLA have certainly pursued many successful programs in their own time, yes.
But the PLAN overall also sets relatively more conservative projects compared to what the USN does -- to the PLA's merit, but
Also, importantly we also do not know which unsuccessful projects the PLAN have pursued, nor what the true absolute and relative costs of its various big ticker projects are.

00X/004 future nuclear CATOBAR carrier thread

Uranium is 1000 times more energy dense than oil. So just consider the amount of space you will save. The nuclear reactor isn't that large. Here is a picture of a 175MWt nuclear reactor for ships. With people next to it for comparison. You would need like four of these to have equivalent power...

www.sinodefenceforum.com

No, pop3 doesn't explicitly mention that the costs of CVNs are now comparable to CVs, you have to read between the lines. It's certainly true that a nuclear reactor costs more than an oil-fired boiler, but the fuel costs over the lifetime of the ships more than makes up for it.

Nowhere in there can I see any reference about the costs of conventional propulsion to nuclear propulsion.

My interpretation of it is that in the past, when the idea of a CVN was first floated, the nuclear propulsion did not significantly face industry bottlenecks, but rather faced the challenge of being able to be funded since there were so many major programs under development at the time in the PLAN (and PLA as a whole), therefore they had to be careful as to which weapons development program to prioritize funding for, and which ones should wait.

For China now, as there are no longer any bottlenecks at all as described by pop3, it means that funding of course is no longer an issue at all.


That doesn't say anything as to the relative cost of CVNs to CVs -- only that the PLAN now believe they definitely have the money to fund CVNs...

My interpretation of what pop3 said might be wrong, or he himself might be wrong, but I don't accept the cost differential of these technologies in the US as some kind of universal constant. My conclusion will always be American incompetence and failure until proved otherwise.

I agree that it may be that the cost differential between CVs and CVNs for the PLAN may end up being different to that of CVs and CVNs in the USN.

But the extent of the relative difference in differentials -- and also the direction of that difference, possibly -- is not something that we can speculate for, and I think using the USN experience in assessing the cost difference between CVs and CVNs as one major useful bellwether for considering what the PLAN pursuit of CVN may be, is very reasonable.

 

[iantsai]

I would normally treat this kind of rumors as fanboy dream, but this is from pop3 and today is PLA Navy Day ...

It is astonishing if true. I always thought they would build at least another CATOBAR before starting on a nuclear-powered one, especially given the size of 003 and the fact that it is EMALS. True, he did not say the timing of 004, but if it's going to be too far down the road, it makes a lot of sense to build another 003.

In any case, this would indicate both the rapid progress in related carrier technologies (particularly the nuclear reactor) and China's carrier ambition. We'll have to see if there is really any truth to it or if pop3 is just getting carried-away on the Navy Day.

I think there would be a Type 003+ only if the type 003 is proven defective. If so, the PLAN would like to build a type 003+ to address the known deficiencies, ensuring the next nuclear-powered aircraft carrier standing on high ground.

 

[by78]

When did this onshore boiler testing facility commence construction? Looks like 2020 written on the back?

I believe the second image (that has 2020 written in the background) shows the contract signing ceremony for delivering the boilers, whereas the first image shows the ceremony marking the commencement of building the boilers, but I don’t know the date for that one.

My apologies for the imprecise language in my original post. I actually don’t know if Jiangnan has begun building the facility or not, but only that the project is ongoing.

 

[iantsai]

Absolutely. The so-called zero total failure rate is in particular unbelivable.

I remember an General of PLANF had semi-officially claim that their EM cat. is much better than that on the US Navy a few years ago. The figure he mentioned is hundreds to thousand times of test have been done, and no failure at all.

If what he claimed before at the early stage was true, and the figures of the weibo article above is also true, it is very very impressive for a whole new system that can perform such kind of stablility.

That's very very possible imo.

Think about the LCS, DDG-1000 and else weapon systems development failure you may read from the newspapers. The U.S. has abandoned a considerable part of its industrial capabilities during the last half century. Shortcomings in shipbuilding and industrial manufacturing are obvious for the United States.

EMALS is not something about microelectronics, bio-pharmacy, advanced materials or software engineerings, which are still advantage area of the United States. EMALS is an mid-range eletric power engineering application, in which China is very competitive and pratical.

 

[iantsai]

In principle, China's EMALS could well be equal or superior to USN's. But when there have been zero tests of this system in an operational environment at sea, declaring this to actually be the case seems premature. It is one thing to complete hundreds or thousands of tests on land in a physically stable, salt- and water-free environment fed by mains power supply and staffed with high-level engineers and specialist technicians. It is quite another to do it on an operational carrier at sea.

The ideas of modular design of the mordern industry could effectively ensure the reliability of technical verification of the whole system.

Btw, the EMALS are more of an electric energy storage system than of a steam piston mechanical system, which basically does not need to involve fresh water supply and other issues.

 

[Lethe]

EMALS uses electricity. The peak electrical demand during flight ops is much higher than the baseload electrical demand. That means complicated long term storage schemes must be used. These have reliability issues, especially in a shooting war. Large batteries, capacitors and flywheels do not like being shot. They tend to explode or light on fire when shot. They also have relatively low energy density.

The alternative to energy storage is to just generate it on the spot. In civil electrical engineering, the fastest starting generation stations are gas turbines. A civilian gas turbine can go from stationary to full power at 150+ MW within 10 minutes. A naval gas turbine which is smaller and optimized for very fast startup can probably go from stationary to full power within 5 minutes.

"Flight ops" may not be continuous, but they are certainly routine. For CV-18 with its larger air wing, in routine (i.e. non-combat) operations you would probably want to sustain two pairs of fighters on CAP, plus a KJ-600, potentially a J-15 buddy tanker also, plus an alert fighter on deck. If you are having to spin up gas turbines in order to conduct flight ops at all, they may end up running most of the time.

RAND

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a nuclear/gas turbine carrier option they designated CVN LX:

A 70,000-ton USS Forrestal–size carrier with an updated flight deck and hybrid nuclear-powered integrated propulsion plant with capability to embark the current large integrated air wing but with reduced sortie generation capability, survivability, ship speed, and endurance compared with the Ford class (CVN LX) [....]
Most of the cost savings for this alternative are derived from the aforementioned reduction in overall displacement and in eliminating one of the Ford’s two nuclear reactor power plants. For power generation, this concept variant, as envisioned, possesses a single, current A1B reactor plant, along with an arrangement of six Ford-class main turbine generators (MTGs). In a hybrid configuration, the concept variant was modeled to also include, notionally, four USS Zumwalt (DDG 1000) 35-megawatt gas turbine generator (GTG) sets that would be positioned above the ship’s hangar-deck level

 

[iantsai]

Thanks for the well-elaborated response.

To be clear, my query stemmed more from referencing the French Navy's own PANG programme, most notably of course is that the PANG will be a significantly larger hull than the CDG with over 75% projected increase in displacement to boot (75,000 tonnes vs 42,500 tonnes), which 004 will most certainly not have such huge mark up in tonnage over 003.

And yet with that in mind the MN still opted to retain the '2 + 2' config moving forward, even though the PANG is more than capable of hosting additional ones, certainly three cats instead of two at the very least.

The only sensible rationale I could discern, other than the always present cost considerations, is that the MN has found their current approach to carrier operations as reflected in the design and layout of current and future French CVNs the most optimised and ideal for their operational needs.

So I guess my bias is that while the USN has decided upon the '4 (cats) + 3 (elevators)' as some sort of a benchmark for optimal layout on an US Navy CVN of 100,000-tonne calibre, while keeping in mind the Americans themselves have also gone from decades of having 4 elevators in various sections of the deck/hull until they settled on the current config with the Nimitz class and now the Ford class, the question then becomes - is that already the 'most optimal' layout? Is there no room for improvement still? Of course not.

I'm sure the PLAN has evaluated this extensively. The likelihood remains, like you said, such allowances/compromises are outweighed by the PLAN's desire to be more 'conservative' with how they run their carriers as reflected in 003's design.

The possibility also remains, not ruling out future iterations and refinements as the Chinese carrier programme continues to mature, as the USN has done so, it could just as well be that the doctrines developed from operating 001 + 002 for a combined period of 12 years now may end up being the best course for the PLAN to follow, as evidenced by 003's design, and possibly for future hulls as well, nuclear or otherwise, not for averting the risk of 'doing too much too fast', but that 'it's already sufficient'.

Take redundancy in consideration and I would say a third elevator is a must.

With only two elevator in hand, when you lost one of them or simply a status of maintenance required during a battle, the deck operation efficiency of the aircraft carrier would drop 50% from what is was supposed to be. That will greatly affect the situation of a battle.

 

[Aurora6666]

this is why I think SMR+combustion combo might be the way to go for 004, with SMR for base load and a combustion engine for peak load.

there is a theoretical basis for this in civil electrical engineering.

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Thus these plants usually runs at 100% of capacity. That means that the most efficient nuclear power capacity is to build as much as the lowest constant demand - the base load.

Why don't all countries with the capability simply have 100% reactors then? Not only because of expense, but because demand varies throughout the day. Electrical power in general cannot be stored at scale, demand must be kept up with supply instantaneously.

Please, Log in or Register to view URLs content!

especially over long periods of time. Likewise, demand varies throughout the course of carrier operations. Sometimes the ship is at cruise and reactor power is overgenerating. At other times it needs massive power for flight ops to work.

Why has this not been a problem in the past? EMALs is very different in terms of power requirement than steam catapult. Steam catapult uses gas expansion principle. It requires a reservoir of steam, which is generated by constant heat from the boilers, which reactors can provide. Nimitz has a huge steam reservoir and this is why steam catapults are so reliable and successful. It does not require electricity, because the steam reservoir is actually an energy storage device - the energy is stored in the enthalpy of vaporization of water.

EMALS uses electricity. The peak electrical demand during flight ops is much higher than the baseload electrical demand. That means complicated long term storage schemes must be used. These have reliability issues, especially in a shooting war. Large batteries, capacitors and flywheels do not like being shot. They tend to explode or light on fire when shot. They also have relatively low energy density.

The alternative to energy storage is to just generate it on the spot. In civil electrical engineering, the fastest starting generation stations are gas turbines. A civilian gas turbine can go from stationary to full power at 150+ MW within 10 minutes. A naval gas turbine which is smaller and optimized for very fast startup can probably go from stationary to full power within 5 minutes.

So we are talking about a hybrid power system onboard? A relatively small reactor for normal power supply & an addition for extreme scenarios?

To be honest hybrid never works well in one system. Check the hybrid car (HEV), it's more expensive and less reliable. It is a very innovative idea though but not sure if the PLAN is going to take that path.

If it is only brought to my attention in one of the CV-18 introduction and I quote: "福建舰采用舰船综合电力系统..." which literally means CV-18 equipped with a "Ship Integrated Power System" (not sure if the translation is accurate).

I read a paper somewhere saying this system contains multiple supercapacitors as reservoir of electricity generated. From my understanding the electricity generated from generators (nuclear or conventional) is not directly supplied to consuming departments but actually to a huge battery with high power discharge capability. In this case the hybrid system probably is not really needed.

Like I said the hybrid is a very interesting idea in case of use, which is capable to adapt different scenarios. However such concept would significantly increase the complicity of the power system and reduce its liability, of which is not the primary of military installations.

Due to my limited knowledge I cannot see more advantage onto it. Probably the professionals can develop this topic further for better understanding.

 

[iantsai]

So we are talking about a hybrid power system onboard? A relatively small reactor for normal power supply & an addition for extreme scenarios?

To be honest hybrid never works well in one system. Check the hybrid car (HEV), it's more expensive and less reliable. It is a very innovative idea though but not sure if the PLAN is going to take that path.

If it is only brought to my attention in one of the CV-18 introduction and I quote: "福建舰采用舰船综合电力系统..." which literally means CV-18 equipped with a "Ship Integrated Power System" (not sure if the translation is accurate).

I read a paper somewhere saying this system contains multiple supercapacitors as reservoir of electricity generated. From my understanding the electricity generated from generators (nuclear or conventional) is not directly supplied to consuming departments but actually to a huge battery with high power discharge capability. In this case the hybrid system probably is not really needed.

Like I said the hybrid is a very interesting idea in case of use, which is capable to adapt different scenarios. However such concept would significantly increase the complicity of the power system and reduce its liability, of which is not the primary of military installations.

Due to my limited knowledge I cannot see more advantage onto it. Probably the professionals can develop this topic further for better understanding.

They won't use hybrid power system in a warship.

Economy always has less priority than robustness in a warship design.