PLAN Aircraft Carrier programme...(Closed)

Jeff Head said:

There is truth in this, depending on the time difference between the two and depending on the priority the PLAN and PRC place on getting their CATOBAR capability into service.

Then, if it is very high, IMHO they would be negligent in not pursuing both and taking the first one that became available to them.

However, if it is low on the priority list (for whatever reason) then it would make sense to only pursue the more advanced technology and accept it whenever it was ready.

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Well it isn't only priority, but cost, and also whether investing in a single EMALS programme rather than both an EMALS and steam cat programme may bring forward the EMALS readiness date.

So if the cost of funding a steam cat industry is high, they might forgo it entirely.

Priority of CATOBAR (and thus, whether they pursue a steam cat) will be dependent on the PRC's naval missions, as well as the amount of time for EMALS development (i.e.: how long will it take to only develop EMALS, versus EMALS + steam cat? Will the latter detract from resources that could've gone to developing only EMALS? If they choose the former will they expedite the date compared with the latter?)
Cost of steam cat, will be dependent on how much of the technologies the PRC had ready.

I think they would've made the choice years ago to decide whether to pursue EMALS or EMALS + steam cat. Personally I think they would've chosen the former.
Better to focus all resources on one rather than two. Perhaps the technology available at the decision making time would've made EMALS a practical option within the medium term (I expect the decision would've been made 2000ish, with development of well over a decade, maybe two). Considering at that time the PLAN was 10+ years away from getting then-Varyag anyway, I think a slight wait for EMALS versus a slightly earlier steam cat would've been nothing to them.

If that were the case, and unless they were absolutely on the brink of having it ready like right now in terms of test launches, then I would expect to see both of these carriers they are starting to build right now almost certainly be STOBAR.

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I think that depends on when the two carriers are built. There's no reason one can't be delayed a little, just long enough for a catapult to be ready.

There's obviously many factors both for and against our respective scenarios, we just don't know which one pulls more strongly on the PLAN lol.

This was posted over on Pakistan defence.net... not sure if relevant. (translate the graph and picture labels perhaps?)

If I may interject briefly, I think we don't have enough facts regarding the Chinese EMALS program. We know it's being actively pursued, and perhaps it's further along than previously thought. We can all agree that PLAN needs and intends to have operational catapults on its carriers, be it steam or EMALS.

The important unknown is China's plan for its future carrier fleet, or more specifically, the timeline for operational CATOBAR carriers.

For the time being, I think China is content with STOBAR carriers for the next decade or two before moving on to CATOBAR. So the question is this: is 15 or 20 years enough time for China to develop a reliable EMALS for its future CATOBAR carriers?

Keep in mind that China's EMALS program is likely already over a decade old at this point, and an additional 15 years would make a gestation period of 25 years or more.

Of course, this is not to say that China is not also actively pursuing steam catapult technology, but there is very little information on its status or progress compared to the EMALS program. I did a some more digging around on China's steam catapult program and found that there has been almost nothing new in the past nine years or so, leaving me with the impression that this program is now dormant or dead.

All of the above leaves the impression that EMALS is the active track. Whether this impression conforms to reality, we simply don't know for a lack of facts.

On balance, based on the information gathered, it seems plausible that China may have gone all in for EMALS, which would be consistent with its stated strategy of 'leapfrogging' in 'frontier' fields while 'copying and absorbing' in 'established' fields.

Some more research papers for the EMALS programs just for kicks. The specificity of these are interesting and implies a very active program.

by78 said:

If I may interject briefly, I think we don't have enough facts regarding the Chinese EMALS program. We know it's being actively pursued, and perhaps it's further along than previously thought. We can all agree that PLAN needs and intends to have operational catapults on its carriers, be it steam or EMALS.

The important unknown is China's plan for its future carrier fleet, or more specifically, the timeline for operational CATOBAR carriers.

For the time being, I think China is content with STOBAR carriers for the next decade or two before moving on to CATOBAR. So the question is this: is 15 or 20 years enough time for China to develop reliable EMALS to for its future CATOBAR carriers?

Keep in mind that China's EMALS program is likely already over a decade old at this point, and an additional 15 years would make a gestation period of 25 years or more.

All of the above is not to say that China is not also actively pursuing steam catapult technology, but there is very little information on its status or progress compared to the EMALS program. I did a bit more digging around on China's steam catapult program and found that there has been almost nothing new in the past nine years or so, leaving me with the impression that this program is now dormant or dead.

All of this leaves the impression that EMALS is the active track. Whether this impression conforms to reality, we simply don't know for a lack of facts.

On balance, based on the information gathered, it seems plausible that China may have gone all in for EMALS, which would be consistent with its stated strategy of 'leapfrogging' in 'frontier' fields while 'copying and absorbing' in 'established' fields.

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I can't imagine the PLAN would be happy with STOBAR for the next two decades, maybe the next decade, singular, at most, and that's early 2020s, assuming FOC of a CATOBAR carrier by then.
Nor do I forsee an additional 15-20 years of development ahead of EMALS especially in addition to a previous decade already worked on -- it seems an impractically long time, longer than many space programs!


However I agree that EMALS is probably being fully funded with steam catapults more or less ignored.


Edit: I just realized that the left side exposed length of the shanghai facility could be for controlling a weight sled and giving it a distance to slow down and stop, like USN tests at lakehurst?

Test sled at lakehurst:


Google maps picture of lakehurst: note the similar "darker length" which is the catapult, while the "lighter length" is probably distance for the weight sled to stop. You can actually see the weight sled there.



And note the similar configuration of the circled "darker length" and the left side "lighter length"...

Bltizo said:

Edit: I just realized that the left side exposed length of the shanghai facility could be for controlling a weight sled and giving it a distance to slow down and stop, like USN tests at lakehurst?

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That could be it, almost certainly.

Engineer said:

That's like using massive amount of documentations on steam locomotives as premise to argue against skipping ahead to electric locomotives. Furthermore, those massive amount of experience, knowledge and documentation for steam catapults are only relevant for the US. China has no experience in building one, no knowledge in operating one, and no documentation that can be derived from any operational experience. While China may obtain manuals and documents from others, those are no substitute of actually operating a physical catapult. This is a similar idea as having documents on aircraft carrier operation being no substitute from actually operating a carrier.

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Exactly, and what about having or not having an industry experienced in providing steam cats.

Jeff Head said:

There is truth in this, depending on the time difference between the two and depending on the priority the PLAN and PRC place on getting their CATOBAR capability into service.

Then, if it is very high, IMHO they would be negligent in not pursuing both and taking the first one that became available to them.

However, if it is low on the priority list (for whatever reason) then it would make sense to only pursue the more advanced technology and accept it whenever it was ready.

If that were the case, and unless they were absolutely on the brink of having it ready like right now in terms of test launches, then I would expect to see both of these carriers they are starting to build right now almost certainly be STOBAR.

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I can imaging researching both options until the time large investment is necessary, which for China might well have been around 2005 after which only EM cats were pursued.

Bltizo said:

I think whether the PLAN adopts a ski jump + waist cat configuration is dependent mainly on whether they can maintain a sortie rate they want by simply having a four cat configuration instead. There are also other considerations, namely whether the extra aircraft spotting space of a pure CATOBAR layout on the bow may cancel out any disadvantages. Of course this is also dependent on how big the carrier is. A 65k ton carrier might not be big enough to accommodate two cats and a ski jump, and may only be large enough to have two cats (one bow one waist), who knows.

More importantly, we should also look at the assumptions for a ulyanovsk design -- namely, was there any credible evidence ever to suggest China had acquired plans for it? Personally I don't think there is.

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Man, there's 5 pages worth of posts in a day? I can't keep up with that.

There's no credible evidence about ulyanovsk design, that's very much true. Actually, the only mention of china acquring plans (outside of internet forums) i've found was a richard fisher article from 2009 allegedly citing Asahi Simbun newspapers. So that's certainly far from a credible source.

That being said, i was careful to mention ulyanovsk deck layout, not necessarily ulyanovsk design. After all, ulyanovsk was a nuclear carrier, while next chinese carriers are not expected to be nuclear fueled yet. As usual, there's no proof for that either, just the theory that IF those modules in dalian and shanghai are real test modules based on a real project, and IF they're for the same project, they could indeed point out a design that incorporates both ski jump and waist cat/s. If so, that'd be similar to ulyanovsk deck layout.

I don't think we know how large next carriers will be. There was just that one newsbit about next carriers being larger than liaoning. Whether that's by 5000 tons or 25000 tons - who's to know. That module in shanghai, IF relevant, does seem to point out to a single waist cat.

Sortie rate with 2 cats is pretty much the same as sortie rate on a carrier with two ski jump launch positions. Of course, that's short term sorty rate. Practical number of sorties by liaoning *after a certain number of launches* would be smaller than cat equipped and rampless carrier of same size, due to less planes carried due to less parking space.

I do suspect liaoning design, with the third far away launch position, can actually achieve a bit greater initial sortie rate than a two cat solution. But again, after a certain number of launches, liaoning layout would simply run out of planes. But then again, cats CAN malfunction, whereas ski ramp hardly can.

If we get to 3 cats versus liaoning layout, pure ski jump ramp, 3 cats would be able to do greater sortie rate. plus, again, the layout of the carrier would allow for a few/several more planes to be launched in total. Potential failure of cats is still there, but with adding cats, i think it's getting less and less of an issue. one cat down in a two cat carrier is 50% of launch potential lost. one down in three cats is 33% loss.

3 cats versus a solution with two ski jump launches plus a single waist cat offers more or less same sortie rate. Again, the latter would have a bit less planes. and possibly (this applies to all ski jump designs) less of a sustained, long term sortie rate, if there'd be ops happening 24/7 and it'd be hard to respot the aircraft that are parked after their first mission.

of course, 4 cats versus 2+1 layout are superior, though perhaps not so much better than a 2+2 solution.

One thing to consider is that ski jump ramp is more or less fixed in deck area it takes. So a 60k ton carrier would have more of deck area lost to it, percentage wise, than a 80k ton carrier. Even taking the ulyanovsk layout (which is far from perfect for PLAN) one could manage to find forward parking space for 10-12 j15s. Modifying the layout further could lead to half a wing worth of planes more. While certainly far from 30ish planes Nimitz can park on its bow, it's a decent improvement over liaoning.

I dont remember if i've mentioned this before, but i wanted to say that even if the next carrier leaves the shipyard with a ski ramp, it doesnt mean the ramp wasnt added in a modular way, and that the underlying design also had in plan a mid-life refit where ramp would be removed and more cats added. Especially with em cats which require less volume to put under deck. if enough space is planned for and enough added energy is planned for from the start, such a design move would be plausible.

Hey Bltizo,

I havent gone through the full paper so not sure whether it is accurate. But I think this shows a prototype of EMAL and the accuracy of their simulation model.

Bltizo said:

Well it isn't only priority, but cost, and also whether investing in a single EMALS programme rather than both an EMALS and steam cat programme may bring forward the EMALS readiness date.

So if the cost of funding a steam cat industry is high, they might forgo it entirely.

Priority of CATOBAR (and thus, whether they pursue a steam cat) will be dependent on the PRC's naval missions, as well as the amount of time for EMALS development (i.e.: how long will it take to only develop EMALS, versus EMALS + steam cat? Will the latter detract from resources that could've gone to developing only EMALS? If they choose the former will they expedite the date compared with the latter?)
Cost of steam cat, will be dependent on how much of the technologies the PRC had ready.

I think they would've made the choice years ago to decide whether to pursue EMALS or EMALS + steam cat. Personally I think they would've chosen the former.
Better to focus all resources on one rather than two. Perhaps the technology available at the decision making time would've made EMALS a practical option within the medium term (I expect the decision would've been made 2000ish, with development of well over a decade, maybe two). Considering at that time the PLAN was 10+ years away from getting then-Varyag anyway, I think a slight wait for EMALS versus a slightly earlier steam cat would've been nothing to them.




I think that depends on when the two carriers are built. There's no reason one can't be delayed a little, just long enough for a catapult to be ready.

There's obviously many factors both for and against our respective scenarios, we just don't know which one pulls more strongly on the PLAN lol.

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