CV-18 Fujian/003 CATOBAR carrier thread

[bruceb1959]

with regards to Steam cats and EMALs - and I apologise now if this has already been addressed - are the requirements in terms of machinery spaces , and where the equipment goes, very similar ?( I understand that the mechanics are different ). The reason for my question being, could Steam CATs easily be replaced with EMALS at a later date? Or would the extent of changes make this non-viable?

 

[Blitzo]

hi @Lethe, can you add the speed?

The top speeds of some of those ships (especially ones in service) are still classified, so sometimes we only have estimates available...

I think the point of the shp to tonnage ratio is less about determining how that actually translates to speed, and more about showing the range of shp to tonnage ratios of a number of past and current carriers that were able to competently perform the fixed wing aviation role, relative to 002's potentially projected shp to tonnage ratio, to put 002's shp to tonnage ratio in context.

 

[Blitzo]

with regards to Steam cats and EMALs - and I apologise now if this has already been addressed - are the requirements in terms of machinery spaces , and where the equipment goes, very similar ?( I understand that the mechanics are different ). The reason for my question being, could Steam CATs easily be replaced with EMALS at a later date? Or would the extent of changes make this non-viable?

I think if a carrier was designed with space pre-allocated or pre-designed in mind to be upgraded for eventual EM cat refit, then that could the structural and internal changes necessary for changing between a steam and EM cat, and potentially make it a very viable option.
But if a carrier was not designed with that kind of forward thinking and only designed for EM cat then it would present additional difficulties.

IT also depends on the type of propulsion of the carrier itself of course, some types of propulsion may be more viable for powering steam vs EM cat, and vice versa, and some may be viable to power both types with minimal changes.

 

[Engineer]

with regards to Steam cats and EMALs - and I apologise now if this has already been addressed - are the requirements in terms of machinery spaces , and where the equipment goes, very similar ?( I understand that the mechanics are different ). The reason for my question being, could Steam CATs easily be replaced with EMALS at a later date? Or would the extent of changes make this non-viable?

Replacement is not viable. Both systems have different requirements, in turn affecting the layout of the engineering sections. Extra space gained by removing one system cannot be re-purposed for another.

For example, EMALS may need are extra generators to be placed beside the steam turbines, but there is no more space within the turbine room. One may think removing steam catapults frees up space, but the extra space spreads out in different sections of the ship. The turbine room remains the same size at the end of the day, so the exercise is pointless.

Basically, once a carrier is set to use one system, it is not viable to switch to another. To make matter worse, a carrier has a lifetime of 40~50 years. That means once a decision is made, the consequence will be felt for the same amount of time! That is why which catapult system to use is such a heated issue.

 

[Iron Man]

Replacement is not viable. Both systems have different requirements, in turn affecting the layout of the engineering sections. Extra space gained by removing one system cannot be re-purposed for another.

For example, EMALS may need are extra generators to be placed beside the steam turbines, but there is no more space within the turbine room. One may think removing steam catapults frees up space, but the extra space spreads out in different sections of the ship. The turbine room remains the same size at the end of the day, so the exercise is pointless.

Basically, once a carrier is set to use one system, it is not viable to switch to another. To make matter worse, a carrier has a lifetime of 40~50 years. That means once a decision is made, the consequence will be felt for the same amount of time! That is why which catapult system to use is such a heated issue.

I highly doubt any of us here know enough about either steam or EM cats to make such a definitive statement.

Steam cats need steam generators and the piping to send steam to the cats. EM cats need alternators and the cabling to send electricity to the cats. The design can incorporate enough space to accommodate the larger of the two systems from the beginning regardless of which is installed initially, so that there is not a need for space later on. I also do not see any compelling requirement that either the steam generators or the alternators need to be co-located with either the engines or APUs. If enough forward-thinking is designed into the carrier, it may be entirely possible to upgrade steam cat to EM cat during a midlife overhaul.

 

[Jeff Head]

If enough forward-thinking is designed into the carrier, it may be entirely possible to upgrade steam cat to EM cat during a midlife overhaul.

Well, IMHO, we know from the Essex overhauls that you can do about whatever you want if you are willing to spend the time and the money...even if you did not specifically plan on the types of upgrades you ultimately make.

The question is whether this is what the Chinese want to do or not.

I personally believe that the Chinese will be happy to have their first six carriers be the following...and let them live out their lives like that, finding plenty of use for them throughout.

I believe that the last two then, will be the mold the Chinese move forward with there after.

2 x STOBAR (Liaoning Style)
2 x Conventional CATOBAR (Steam)
2 x Nuclear CATOBAR (EMAL)

Once the second nuclear CATOBAR comes on line, I expect sometime in the late 2020s, or early 2030s at the latest, they will be looking at another 15-20 years left on the LIaoning, whose replacement would them be an improved Nuclear CATOBAR carrier.

Anyhow...that's just my thinking.

Time will reveal (and in this thing long after I am dead and gone) how it will actually turn out.

 

[Iron Man]

Well, IMHO, we know from the Essex overhauls that you can do about whatever you want if you are willing to spend the time and the money...even if you did not specifically plan on the types of upgrades you ultimately make.

The question is whether this is what the Chinese want to do or not.

I personally believe that the Chinese will be happy to have their first six carriers be the following...and let them live out their lives like that, finding plenty of use for them throughout.

I believe that the last two then, will be the mold the Chinese move forward with there after.

2 x STOBAR (Liaoning Style)
2 x Conventional CATOBAR (Steam)
2 x Nuclear CATOBAR (EMAL)

Once the second nuclear CATOBAR comes on line, I expect sometime in the late 2020s, or early 2030s at the latest, they will be looking at another 15-20 years left on the LIaoning, whose replacement would them be an improved Nuclear CATOBAR carrier.

Anyhow...that's just my thinking.

Time will reveal (and in this thing long after I am dead and gone) how it will actually turn out.

It will depend on several factors, with cost being only one. How easy design-wise it will be to make the upgrade, how long it would take, how badly the PLAN wants to have the ability to launch aircraft of different sizes (e.g. UAVs) from all of its carriers, and of course cost.

 

[delft]

It makes sense not to burden aircraft carriers with U(C)AV's but leave those to smaller flattops like LHD's. These might be powered by gas turbines and IEP and have EM cats if those UCAV's need them.

 

[Lethe]

That only makes sense if you intend to limit unmanned aircraft to being significantly smaller than manned aircraft, and it's not clear why you would want to do that. Both ISR and strike roles would benefit significantly from larger platform sizes. With attentions directed to peer and near-peer conflict scenarios, China is not going to have a lot of use for Predator or even Reaper-class drones.

 

[Iron Man]

It makes sense not to burden aircraft carriers with U(C)AV's but leave those to smaller flattops like LHD's. These might be powered by gas turbines and IEP and have EM cats if those UCAV's need them.

IMO this is not the right way to think about UAVs. UAVs are not some kind of "burden"; they are going to be the norm for future carrier ops. Both carriers and LHDs will likely have them soon enough.

That only makes sense if you intend to limit unmanned aircraft to being significantly smaller than manned aircraft, and it's not clear why you would want to do that. Both ISR and strike roles would benefit significantly from larger platform sizes. With attentions directed to peer and near-peer conflict scenarios, China is not going to have a lot of use for Predator or even Reaper-class drones.

It's not clear to me that peer to peer combat automatically requires larger drones. What they need more than anything else against a peer is survivability, and this is dependent entirely on stealth, not on size.

My impression is that the types of drones that are intermediate in weight (3 to 8 tons) are proliferating much faster than either the lighter or heavier drones, at least in military use. X-47B-sized drones are about the same footprint as traditional fighters. The benefits of a smaller drone with a reduced footprint means that you get more capability with a smaller footprint. A UAV that is specialized in ISR with a side capability in refueling does not need to be large enough to carry multiple bombs and missiles, and is also far more expendable if located and attacked.

The benefits of EM cats extend further to significantly increased airframe life for manned fighters as well, not just ability to launch smaller aircraft, something I forgot to mention earlier.

I'm not saying they will definitely refit steam cats with EM cats (or even that the first CATOBAR carrier will be steam rather than EM), but this type of retrofitting is both not implausible technically and not without legitimate justifications militarily.