PLAN Aircraft Carrier programme...(Closed)

joshuatree said:

That's possible but then the rate of fuel consumption would go up for the extra power needed? Do EMALS consume more power vs steam cats?

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You are right. With conventional propulsion, lets say on a 80.000 ton steam cat carrier like the cancelled french Porte Avion 2, you can supply decently only 2 steam cats. If you want to put in place 4 cats, nuclear propulsion is required.

For what I know, Em-cats are more efficient, so they should consume less energy. They are also more compact and take less room. With steam cats you need also a water desalination plant.

Hendrik_2000 said:

Here is the for people who poo poo the idea of catapult on Chinese carrier. They decide not too because they thought it is easier to integrate the J 15 seamlessly without any further training and not for lack of technology.

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I am not aware of anyone here on SD who has "poo poo'ed" the idea of Chinese catapults.

It is clear that they are interested and it is clear that they are working on it...and so some day they will have it.

The only question has ever been when?

Clearly, 001A, IMHO, is going to be STOBAR just like the Liaoning.

I have written numerous times why I thought that would be the case...and now it has been officaiily announced.

I believe it likely that they will have cats on the 002 carriers and that there will probably be two of those carriers. I think those carriers are going to be more like the USN Kitty Hawk, IOW, large, angled deck CATOBAR carriers that are convetionally powered.

Will their cats be steam or EMALS?

Hard to say at this point.

If they have the proper power system and available electrical power, they could be EMALS. I tend to think that the Chinese will be more incremental in their approach and go with steam cats for the 002 class...but I could also see them doing EMALS if they want to take that risk.

IMHO, it is more likely that the 003 Class will be nuclear powered and will use EMALs.

Time will tell.

Brumby said:

Jeff,
Maybe the aim for date is Oct 2016. Do you think it is doable given where they are and probably 3 weeks break for CNY?

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Carriers are typically built to the very highest of standards in terms of water tight integrity, steel usage, combat survivability, etc. The Chinese I believe would build theirs t no less strict standards.

I see a LOT of internal structural work needed on the modules that they are placing on the vessel at the current time. Of course there is also all sorts of electrical and plumbing finish and termination work that has to be done for each as well.

I addition, the entire matter of the bow and the stern of the ship is yet to be done, as well as the flight deck and island.

Could they get all of that done by October? I suppose it is possible, but I think it unlikely.

As I said, if for whatever reason there is pressure or motivation to get this vessel in the water/launched, earlier and then finish a lot of this work during the time they would normally be installing and outfitting the other, non-structural and non-major mechanics...then they can do that...but it just means they will spend longer outfitting.

I have not seen the Chinese to date take such measures or steps. Generally, the vessels they launch are at a very complete stage of major systems and all structural components complete.

So, they could do it, but I think it more likely that they will launch a more complete vessel and that that will be in 2017.

That is still a phenomenal time to launch from when they very initially began laying down components very late last year. it will mean that they will launch the carrier in something under 2 1/2 years.

I believe after launch it will be another year at least before they take it to sea, and then another year after that before they initially commission her and start working her up towards initial operational capability. So...my best guess remains, launch 2017, to sea 2018, commissioned in 2019. Something like that.

Don' t forget also for a future CVN, likely they have buy to Ukrainians Ulyanovsk design as they have a T-10, Su-33 prototype for copy.
They left Nikolayev with a quantity of documents !

Official announcements really almost funny we are sure since 3 months and in fact i got infos since almost a year.

FORBIN said:

Don' t forget also for a future CVN, likely they have buy to Ukrainians Ulyanovsk design as they have a T-10, Su-33 prototype for copy.
They left Nikolayev with a quantity of documents !

Official announcements really almost funny we are sure since 3 months and in fact i got infos since almost a year.

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Why should they have to buy the Ulyanovsk design? They have been studying flattop designs for donkeys years and there is no experience with a carrier built according to the Ulyanovsk design.
BTW I thought the carriers were designed in Leningrad.

were designed in Leningrad.

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Maybe but build to Nikolayev Shipyard and they need plans for build ... all the more big modern Soviet MSC are build to Nikolayev Kuznetsov, Kiev, Moskva, CG Slava, Kara also ! Kirov build to Leningrad.

Sczepan said:

EMALS need a lot of electrical energy in a very short time - and you don't have this at conventional powered ships

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You don't have this on a nuclear power ship either. EMALS uses fly wheels to store energy for burst release, just as the way steam catapult uses accumulators to store energy.

Engineer said:

You don't have this on a nuclear power ship either. EMALS uses fly wheels to store energy for burst release, just as the way steam catapult uses accumulators to store energy.

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I never really put much thought into that, but would have always believed they do this via some kind of capacitor. Is that more impractical than large flywheels, or what's the issue here?

For those who would like to know something about EMALS and how it works, here is a primer. This information is specific to the EMALS system that has been developed for the Ford class carriers of the US Navy, but would also be applicable in principle to any Chinese carrier desiring an EMALS system::

EMALS consists of six major subsystems:

- The Prime Power Interface
- The Launch Motor
- The Power Conversion Electronics
- The Energy Distribution System
- The Launch Control
- The Energy Storage System

Prime Power Interface:
This interface provides the connection to the ship’s electrical distribution system and delivers power to drive the energy storage system.

Launch Motor:
This is a 100,000 horsepower linear induction motor. It is a compact, modular, integrated flight-deck structure that converts electrical current into the electromagnetic forces needed to accelerate aircraft along the launch track. The system is designed to be able to tolerate a broad range of conditions and aircraft on the flight deck. A moving shuttle attaches to the aircraft in the same manner as existing steam catapults. After the aircraft launches, the electric current in the motor reverses to brake the shuttle to a complete halt without the use of any water brake.

Removing the water break deletes a layer of complexity to the system and also contributes to the rest and quality of life of personnel sleeping a couple decks below in junior officers quarters who now do not have to deal wth the sound of the water break's operation.

Power Conversion Electronics:
This system takes the power from the power storage system and converts it to a traveling wave of energy of the appropriate voltage and current to drive the shuttle along the launch track for the appropriate load (aircraft). Based on solid-state technology, the conversion electronics are packaged as compact modules in cabinets located below deck.

Energy Distribution System:
This system delivers the energy from the power conversion system to the launch motor. The system is comprised of cables, disconnects, and terminations to precisely deliver the power required. This incorporates a closed loop control system with real time diagnostic health monitoring that can detect launch anomalies within 500 microseconds and adjust the system to compensate for issues ranging from aircraft engine flameouts to blown tires.

Launch Control:
EMALS uses a state-of-the-art components to finitely deliver the current into the launch motor in real time. This allows more precise end-speeds to be achieved over a wider range of aircraft types and weights than with a steam catapult. System architecture with several layers of inherent redundancy is achieved using commercial off-the-shelf components where possible, and modularity is emphasized to ease installation and maintenance.

Energy Storage System:
Potential energy for EMALS is stored with a highly developed flywheel system that fully powers each cat stroke, even if the electrical power supply is temproarily disrupted. Enough energy is stored to power mulitple two- to three-second launches. The system is recharged by ship’s power system.[/U]