CV-18 Fujian/003 CATOBAR carrier thread

[antiterror13]

An Electrical Busbar is literally a single solid piece of metal, with electrical cables to each of the loads (catapults) and batteries (energy storage groups).
There's no reason for one to go bad as it has no moving parts. The only thing that moves are the electrons.

So many things could go wrong even in the busbar, thats why in electrical power system, Circuit Breakers and Protections are the ultimate important devices

I think what the US lacking is the technology of circuit breaker on DC power system, there is no circuit breaker for HVDC power system in civilian system (National Grid)

From my memory is that China is the first to successfully develop MVDC circuit breakers, I think thats the main different between the US and Chinese system of MVDC

That also the reason why the British took that approach to choose MVAC of the QE carrier as the British didn't have the MVDC technology

MVDC is superior to MVAC in many ways

 

[Paulo R Siqueira]

that is not exactly like tesla design being based on morrison’s. there has not been any major advance in state of art in CATOBAR carrier layout between Fujian and either soviet CATOBAR designs. it is not unreasonable to say a catobar carrier designed by a house with no prior experience in the field referenced other catobar designs from anywhere in the last 60 years to arrive at their work.

Exactly, the USS Kitty Hawk(CV-63) say so.

 

[Blitzo]

Electrical circuit breakers or isolation switches in a power electronics design isn't anything special.

In the realm of civilian power electronics, China is far ahead of the USA in terms of technology and widespread deployment at every level from transmission lines down to each home and electric car. All would incorporate circuit breakers and isolation switches. And I suspect that the civilian sector leads in terms of technology in China with the military piggybacking off this.

Given this situation and the prior knowledge of the Ford EMALs design flaws, I stand by my statement that it would be incredible for Chinese EM cats to have been designed with the same elementary flaws that the Ford has.

And given how critical the Ford EMALs design flaws is, any half-decent design which avoided this fundamental error would be a better technology.

We also have to consider that the Fujian carrier was launched some 9 years after the Ford carrier. Given the advancements in power electronics over the past 9 years, you would also expect better tech to have been applied to Fujian.

So in all, "I think it is fair (assessment) to say that the Chinese Navy is installing a more advanced EMALS system than the US Navy has with the Ford."

As I in my last post, I agree that it is reasonable that the intuitive flaws of the USN EMALS and arrangement on Ford would have been likely sought to be avoided on the Fujian.
The power management and electrical engineering side of it (outside of the catapult itself) that you are describing, is one thing which I agree that they likely would have changed.

However, that doesn't mean we can just go and say the overall system is more advanced or superior to that of the USN's EMALS, because there are many moving parts (literally) as part of the overall EM catapult+power management system. That is to say, even assuming they have a logical energy management system that doesn't have the same issue as Ford, they are still developing a new catapult system and having to integrate it on a big deck carrier in a complex maritime that will present its own challenges that need to be ironed out, and also

This is also the PLAN's first go at implementing an aircraft catapult on an aircraft carrier from operating and developing no CATOBAR carriers of any sort before. Not to mention the variety of other advanced subsystems on Fujian as well, which does include a number of firsts.


So no, at this stage it's way too early to say that the Fujian's EM catapult system is "more advanced" than that of Ford. It's a sweeping and indefensible statement, and overambitious. Let's wait to see how it performs on the carrier first.
It not an impossible or even necessarily unlikely outcome that Fujian's EM catapult could be more advanced than the USN's EMALS. But right now there is no reasonable basis to proclaim it with such confidence.

While @Blitzo may be keen to posit that 003 is not even the final form of what the PLAN may envision for their serial-production ready 100,000 ton nuclear variant that is expected to centre around a 3-lift + 4-cat config so as to bring it on par with the 'benchmark' as established by the Ford-class, and I'd be ready to agree that he's most likely correct, I think it's also worth bearing in mind the USN has spent over six decades (and counting) of designing, building and operating nuclear carriers with 4 lifts (longer still if we were to start from the advent of 'supercarriers' that began with the Forrestals), which had long been accepted as an well-optimised layout for a US supercarrier... until the Ford came along with her 3 lifts.

Naturally the question becomes: "Was the 4th lift superfluous all along?"

And naturally the justification becomes: "The flight deck has been 'optimised' by the 3 lifts."

If after more than 60 years of operating CVNs the Navy can still find a reason to delete a major feature like a 4,400 sq. ft and 120 ton elevator in order to 'optimise' a supercarrier in serial-production for over 50 years, what else can they add or omit? What capability has the boat gained/lost from doing so? Can the Navy then claim there isn't room for improvement still?

I would think if one were to entertain the notion of a 'gold standard' in lift/catapult numbers and placements, the Ford-class may have a couple more decades yet to go before it can confidently claim its design is representative of what an "optimised" 100,000 tonner should look like.

So I'm of the opinion the PLAN will no doubt look to the vast experience of the US carrier programme as accrued by the trials and tribulations over many decades to inform their own approach to designing carriers that are best suited for China, for threat environments that are unique to China, as opposed to pursuing some sort of a vain goal of building analogues to 100,000 ton class US supercarriers for a reason as simple as: "American supercarriers are heretofore peerless, state-of-the-art and best-in-class, so a Chinese Ford is what China should build".

We can all debate the pros and cons of 2 lifts vs 3, or 3 cats vs 4. At the end of the day only the PLAN knows if they're actually giving up capabilities or not.

All that is not to say the PLAN shouldn't emulate the USN where it makes sense to. The next Chinese CV, be it another 003-pattern or a nuclear kind, could as well have an additional lift and catapult if the PLAN judges it advantageous to have them, and I would have no issue accepting the 003 as configured was a result of give-and-take for the PLAN, itself a process that was governed and limited by understandings and compromises from a time well before the first steel was cut over 6 years ago, before 002 was even launched.

Or, the next CV could as well retain a similar 3 cats + 2 lifts layout to 003, perhaps with appropriate positioning on an expected larger deck with a re-positioned island if nuclear, and personally I wouldn't be so surprised with it either.

As I've previously written, I think Fujian's configuration makes a lot of sense when it is a 85,000t conventionally powered carrier. Three catapults and two large elevators is absolutely fine.

But if you and others are suggesting that the flight deck configuration of Fujian is optimal for the PLAN's needs, rather than a reflection of a limitation of various (IMO sensible) design measures and risk reduction measures on Fujian, then I strongly disagree with you.


You wrote: "American supercarriers are heretofore peerless, state-of-the-art and best-in-class, so a Chinese Ford is what China should build" as if to demonstrate that it is not a sensible one.
But this is pretty close to what I believe, for the PLAN at this stage of their carrier aviation development, for a number of reasons that includes what I believe PLA requirements for their carriers are, as well as emergence of key vital technologies and greater willingness to take on a clean sheet carrier design, and in the case of flight deck configuration I do believe that the USN's many more years of operating busy flight decks and sortie generation rates aboard their CVNs is something the PLAN would want to emulate and informed emulation of something like flight deck configuration is a no brainer if the rest of the ship allows for it.

 

[taxiya]

Would be interesting to find out if this is an accurate description of the constellation of the two different EMALS.

In the American system, an exhausted energy store can be replaced by a still full energy store. With the assumed Chinese system, the aircraft to be launched would have to be brought to another catapult.

View attachment 91072

I guess that in the diagrams the red boxes are the power buses, the green circles are the power storage flywheels and the black boxes are launching motors.

I guess you meant that this is the US system.



And this is the assumed Chinese system.



Why do you assume that this is the Chinese system? It depicts THREE separate power buses, IMO there is ONLY one power bus. There is no difference between US or Chinese design, there isn't any technical reason for that.

One problem with US system (if it is right) is that all launching motors are connected to an AC bus. A motor is power consumer and a producer at the same time. All engaged AC consumers must be strictly in sync of frequency and phase. Otherwise they will feed back power to the grid and kill the grid. In practice, only one motor can be engaged at any time.

In China's system, that SINGLE bus is DC bus, in theory all motors can draw energy without the problem of damaging feed back.

 

[Blitzo]

I guess you meant the lower diagram is the assumed Chinese system. I also guess that the red boxes are the power buses, the green circles are the power storage flywheels and the black boxes are launching motors.

But why do you assume that the lower diagram is the Chinese system? That diagram depicts THREE separate power buses, IMO there is ONLY one power bus. There is no difference between US or Chinese design, there isn't any technical reason for that.

I believe he is speculating a Chinese arrangement that tries to avoids the single point of failure on the US arrangement.

 

[Richard Santos]

The Flanker is a superb aerodynamic platform, particularly when compared to the notoriously compromised Super Hornet design. In the naval realm the Flanker has been held back by lack of catapult launch enabling heavier payloads (including external fuel tanks for buddy tanking) and also by less sophisticated engine technology.

Once 003 and J-15T have resolved these issues, J-15 has a meaningfully higher performance ceiling than Super Hornet mostly because it is simply a larger aircraft, but also because it is a more aerodynamically sophisticated design. A fully-developed J-15 will have greater range and endurance than Super Hornet, better acceleration and top speed, generally better maneuvering characteristics, a larger and more powerful radar, and benefits from a large onboard IRST. Super Hornet will continue to feature in USN air wings at least until 2040 and the roles it will serve there as a complement to F-35B/C and eventually NGAD are the same roles J-15 will perform as a complement to the future J-31/J-35/J-XY aircraft. At comparable levels of development, Super Hornet's only performance advantage relative to J-15 would be its marginally lower RCS.



Yes. The advantage of Super Hornet, which it will retain in the near future, is that it has already been developed to a high level in terms of munitions compatibility, EW fitout and operation, buddy tanking, etc. J-15 has higher theoretical performance ceiling than Super Hornet, but that has yet to be achieved and will take some years to do so.

Can j-15 extend its range with drop tanks?

fundamentally, the current f-18 is a highly evolved derivative of a light, short range, land based kinematic air-combat fighter in the MiG-29 class. Most of evolution it has undergone had not been primarily intended to improving its kinematic air combat capability, but to enable it to operate from carriers and increasing its payload range performance in the strike role. Think of it as a formerly small, light, fast and maneuverable sports car that has been modified and then enlarged to carry 2 tons of cargo and go 300 miles with having to get gas. Kinematic performance suffered.

the j-15 also evolved from land based air combat fighter, but a heavy, long range kinematic air combat fighter. It also had to be modified for carrier operation. But because it was much bigger to start with, carrying 2 tons of cargo and go 300 miles without having to get gas required much less performance robbing modifications compared to the F-18.

f-18 is a direct descendant if a light short range air combat fighter struggling to fulfill a heavy long range strike fighter’s role. j-16 is the direct descendant of a heavy long range fighter than can much more comfortably take on a heavy long range strike fighter’s role. And if there were to go head to head in kinematic air combat, j-16 would benefit from not having been modified so much from its original kinematic air combat optimized origins.

 

[antiterror13]

I guess you meant the lower diagram is the assumed Chinese system. I also guess that the red boxes are the power buses, the green circles are the power storage flywheels and the black boxes are launching motors.

But why do you assume that the lower diagram is the Chinese system? That diagram depicts THREE separate power buses, IMO there is ONLY one power bus. There is no difference between US or Chinese design, there isn't any technical reason for that.

Three separate bus is very unlikely as it is very inefficient of delivering energy, like I said in the post #8255, with Circuit breaker on MVDC on Chinese system, applying single bus bar is possible and effective

 

[taxiya]

I guess that in the diagrams the red boxes are the power buses, the green circles are the power storage flywheels and the black boxes are launching motors.

I guess you meant that this is the US system.

View attachment 91119

And this is the assumed Chinese system.
View attachment 91120


Why do you assume that this is the Chinese system? It depicts THREE separate power buses, IMO there is ONLY one power bus. There is no difference between US or Chinese design, there isn't any technical reason for that.

One problem with US system (if it is right) is that all launching motors are connected to an AC bus. A motor is power consumer and a producer at the same time. All engaged AC consumers must be strictly in sync of frequency and phase. Otherwise they will feed back power to the grid and kill the grid. In practice, only one motor can be engaged at any time.

In China's system, that SINGLE bus is DC bus, in theory all motors can draw energy without the problem of damaging feed back.

[continue] @Intrepid

US EMALS had two options. The one they chose was to achieve redundancy by sharing. However if they wanted to avoid the "out of sync" problem they would have chosen the "assumed Chinese system" by isolating all launch motors therefor enable all launchers to be safely used simultaneously.

 

[montyp165]

So no, at this stage it's way too early to say that the Fujian's EM catapult system is "more advanced" than that of Ford. It's a sweeping and indefensible statement, and overambitious. Let's wait to see how it performs on the carrier first.
It not an impossible or even necessarily unlikely outcome that Fujian's EM catapult could be more advanced than the USN's EMALS. But right now there is no reasonable basis to proclaim it with such confidence.

I'd say that given the greater developmental focus on EM technologies that China has invested in compared to the US, the implementation of the system on 003 would carry design innovations that the US wouldn't have considered wrt the PLAN's own operational requirements.

You wrote: "American supercarriers are heretofore peerless, state-of-the-art and best-in-class, so a Chinese Ford is what China should build" as if to demonstrate that it is not a sensible one.
But this is pretty close to what I believe, for the PLAN at this stage of their carrier aviation development, for a number of reasons that includes what I believe PLA requirements for their carriers are, as well as emergence of key vital technologies and greater willingness to take on a clean sheet carrier design, and in the case of flight deck configuration I do believe that the USN's many more years of operating busy flight decks and sortie generation rates aboard their CVNs is something the PLAN would want to emulate and informed emulation of something like flight deck configuration is a no brainer if the rest of the ship allows for it.

I'd have to part disagree on that, because if that were the case anyone with fixed wing carriers based on the same doctrinal concepts of the USN would just follow their operational model, but as the RN and Marine Nationale also historically and currently show if they had the same level of financial resources as the USN their approach wouldn't necessarily be the same (e.g. QE-class CVs and PA-NG), and if anything it was the USN that learned more from the RN on carrier ops than the other way around. It's important to learn from potential opposition's methodology to understand how they would perform in combat, but it's much more important for the PLAN to learn from their own operational requirements and direct experience.

 

[Blitzo]

I'd say that given the greater developmental focus on EM technologies that China has invested in compared to the US, the implementation of the system on 003 would carry design innovations that the US wouldn't have considered wrt the PLAN's own operational requirements.

As I wrote previously, I think it is not impossible that the PLAN's EM catapults may be more advanced than the USN's EMALS.

But it's too early right now to say.

I'd have to part disagree on that, because if that were the case anyone with fixed wing carriers based on the same doctrinal concepts of the USN would just follow their operational model, but as the RN and Marine Nationale also historically and currently show if they had the same level of financial resources as the USN their approach wouldn't necessarily be the same (e.g. QE-class CVs and PA-NG), and if anything it was the USN that learned more from the RN on carrier ops than the other way around. It's important to learn from potential opposition's methodology to understand how they would perform in combat, but it's much more important for the PLAN to learn from their own operational requirements and direct experience.

The RN and MN operated off the same requirements as the USN did, and they certainly did not have the financial and industrial capability to do so when considering their other military needs that needed financing.

Even the PANG is a reflection of limitations of the French industry and finances and almost certainly a reflection of lower sortie generation capabilities than the Fords, even when considering their lower displacement.
The QE class certainly is not a result of the same requirements the US has for its carriers either.


My belief is that the PLAN will require their true "standard" carrier type will have aviation and sortie generation capabilities that are non-inferior to that of contemporary USN carriers, and when the requisite industry capabilities are sufficiently high and the risks are deemed sufficiently mitigated, they will adopt a flight deck configuration that emulates that of contemporary US carriers.
Heck, CV-18 Fujian is already pretty close.