PLAN Carrier Construction

delft said:

Quite true. That why you need a ski ramp to reduce the speed necessary to get away safely, to perhaps 70%, which would halve the length of the cat and correspond nicely with the size of the ramp.

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Reducing speed, also known as slowing down, is counterproductive when the goal is to launch the aircraft in the shortest distance possible. The aircraft actually needs to increase speed to get away safely, which is what a catapult is for. A ski ramp does not add any acceleration to the aircraft, and does not reduce take off distance the way you have imagined.

One of the things that I've always felt was beneficial for future Chinese carrier development was the Ulyanovsk design, because having those blueprints greatly helps in the development of CVNs, particularly as the Soviets had several mature nuclear powered surface ship designs already, so incorporating those elements to Chinese carrier experience as it develops can only help speed up CVN design work.

montyp165 said:

One of the things that I've always felt was beneficial for future Chinese carrier development was the Ulyanovsk design, because having those blueprints greatly helps in the development of CVNs, particularly as the Soviets had several mature nuclear powered surface ship designs already, so incorporating those elements to Chinese carrier experience as it develops can only help speed up CVN design work.

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I may have missed it if mentioned before but does PLAN have the blueprints for the Ulyanovsk? do we know that as a fact or just speculation?

kwaigonegin said:

I may have missed it if mentioned before but does PLAN have the blueprints for the Ulyanovsk? do we know that as a fact or just speculation?

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Even if they did I doubt it would amount to much. I mean its a forty year old carrier design, drawn up concurrent with the Kuznetsov. And if the Russians suddenly had issues with her I would lay money that Ulyanovsk has the same issues and more flaws hidden in here design. Add that the Chinese would push for there advanced goodies, have studied at close hand a number of western (albeit older) carriers. And it seems more likely that they will start with a clean slate.

TerraN_EmpirE said:

Even if they did I doubt it would amount to much. I mean its a forty year old carrier design, drawn up concurrent with the Kuznetsov. And if the Russians suddenly had issues with her I would lay money that Ulyanovsk has the same issues and more flaws hidden in here design. Add that the Chinese would push for there advanced goodies, have studied at close hand a number of western (albeit older) carriers. And it seems more likely that they will start with a clean slate.

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yeah I agree TE... I mean the basic design of a carrier even the recently launched Ford class is not exactly a state secret. General layout and blueprints are not that hard to come by. Heck anyone can just take a tour of the floating museums and get a pretty good feel of a CV LOL

kwaigonegin said:

yeah I agree TE... I mean the basic design of a carrier even the recently launched Ford class is not exactly a state secret. General layout and blueprints are not that hard to come by. Heck anyone can just take a tour of the floating museums and get a pretty good feel of a CV LOL

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For a conventional CV perhaps, not for something with a nuclear power plant. The Ulyanovsk's KN-3 nuclear powerplant was derived from the Kirov reactors, and that's something the PLAN at this point still doesn't have on any of their surface ships. The Soviets still had more experience with surface ship nuclear powerplants, and that would still be instructive in any case.

montyp165 said:

For a conventional CV perhaps, not for something with a nuclear power plant. The Ulyanovsk's KN-3 nuclear powerplant was derived from the Kirov reactors, and that's something the PLAN at this point still doesn't have on any of their surface ships. The Soviets still had more experience with surface ship nuclear powerplants, and that would still be instructive in any case.

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I do not disagree at all but I was refering more to the layout and design of the ship as oppose to the powerplant, subsystems etc. Powerplants are powerplants... if PLAN wants to 'study blueprints of nuclear powerplants there are much better ways of getting it than from the Ukranians. Like you said Kirov has them too they don't need Ulyanovsk blueprints for that.

Engineer said:

Reducing speed, also known as slowing down, is counterproductive when the goal is to launch the aircraft in the shortest distance possible. The aircraft actually needs to increase speed to get away safely, which is what a catapult is for. A ski ramp does not add any acceleration to the aircraft, and does not reduce take off distance the way you have imagined.

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Whats a matter Jr.????? little woman slap ya around, you're on a roll aren't ya, "reducing speed, also known as slowing down", sorry Master Delft, but you set yourself up for his attack, oh man, he musta been watching "Top Gun" again today. Delft, I don't think he's buyin your Emals in a Ramp, but I will give you credit for "stickin with your idea", and for originality, I'm picturing something like a roller coaster, but it would take more torque and horsepower to pull that Flanker UP the ramp......"reducing speed, also known as slowing down" we gotta "sticky" that one somewhere, classic Eng! Put some sugar in your TEA bro...

kwaigonegin said:

I do not disagree at all but I was refering more to the layout and design of the ship as oppose to the powerplant, subsystems etc. Powerplants are powerplants... if PLAN wants to 'study blueprints of nuclear powerplants there are much better ways of getting it than from the Ukranians. Like you said Kirov has them too they don't need Ulyanovsk blueprints for that.

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That's definitely a good point, and having that extra technical know-how would at the very least better enable the PLAN to avoid the mechanical pitfalls that the French fell into with the CdG when they modified their sub reactor design for surface ship use.

Engineer said:

Reducing speed, also known as slowing down, is counterproductive when the goal is to launch the aircraft in the shortest distance possible. The aircraft actually needs to increase speed to get away safely, which is what a catapult is for. A ski ramp does not add any acceleration to the aircraft, and does not reduce take off distance the way you have imagined.

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The ski ramp lets an aircraft get away at lower speed but also at a lower lift coefficient than needed for sustained horizontal flight, so at a lower induced drag. This gives it time to accelerate in the air enough to reach horizontal flying speed even in the case of failure of the critical engine at the moment the wheel chocks are retracted by the ship. That is the concept behind the use of a ski ramp with multi-engine aircraft. You will have to differentiate between the case of take off with engine failure when the aircraft drops its external stores two seconds after leaving the ramp and that without engine failure. In current ships the aircraft with engine failure at the beginning of the take off run will leave the ramp with about 60% of the speed in the case without. With cats the difference might be zero as the cat senses the acceleration at any moment and compensates.
I choose 70% of the speed at which aircraft are launched according to USN norms because that gives a nice factor of 2 in the length of the cat, but the real speed norm will have to be decided by the designers based on simulations. Perhaps the speed might be less but the size of the ski ramp in Adm K and Liaoning seems to be half of the length of a USN cat.
I learned the principles of the use of ski ramps at university in lectures about V/SOL aircraft design some forty years ago.