Yuan Class AIP & Kilo Submarine Thread

Blitzo

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I don't know where you got that from. It's clear looking at Yuan vs Song that Yuan's inner hull is wider and allows for more noise reduction measure to be installed. I don't know how you can say it doesn't mean much.

I was speaking in terms of hull shaping.

But even external dimensions aren't necessarily representative, given the same space in a newer sub can use newer and more effective noise reduction methods than an older one. That said there is obviously a limit to how much noise can be reduced in a smaller versus a larger sub, but for the purposes of sensible comparisons of boats with near similar dimensions (eg kilo vs yuan vs soryu), it will be their internals that count.

An extreme example is comparing a mini sub with an SSN, which would be ridiculous.
 
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tphuang

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I was speaking in terms of hull shaping.

But even external dimensions aren't necessarily representative, given the same space in a newer sub can use newer and more effective noise reduction methods than an older one. That said there is obviously a limit to how much noise can be reduced in a smaller versus a larger sub, but for the purposes of sensible comparisons of boats with near similar dimensions (eg kilo vs yuan vs soryu), it will be their internals that count.

An extreme example is comparing a mini sub with an SSN, which would be ridiculous.

Nuclear submarine has a lot more stuff in there that produces noise that a diesel sub doesn't have, so that's a bad comparison. Having a stouter hull seems to be better also. We don't have diagrams, but we can guess based on similarities or Yuan to Kilo that they have similar noise level. Based on the people i've talked to, Oyashio class is a lot quieter than Kilo class, which would make sense since it came after Kilo class. The Australians picked Soryu class as the submarine to base their replacement of Collins class on, which should show you how quiet Soryu class is.
 

Blitzo

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I deliberately did say that comparing an SSN and a mini sub was an extreme example. An SSK then.

Look I wouldn't be surprised if oyashio and soryu were quieter than kilos and the early yuans. But my point for the last few posts has less been about which sub is quieter than which, and more about the problems of using only external dimensions and external shaping to judge noise levels, especially for subs of similar size but developed during differing eras (eg yuan and kilo)

As for Australia's Collins replacement, no one is saying soryu's performance is not making it a frontline contender, but other things such as it's displacement/endurance make it one of the only real viable contenders to meet RAN needs. Then there are also political factors to consider.
If any of the European shipyards had developed a four thousand ton SSK as well I bet we'd be seeing a fully fledged competition.
 

Air Force Brat

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I deliberately did say that comparing an SSN and a mini sub was an extreme example. An SSK then.

Look I wouldn't be surprised if oyashio and soryu were quieter than kilos and the early yuans. But my point for the last few posts has less been about which sub is quieter than which, and more about the problems of using only external dimensions and external shaping to judge noise levels, especially for subs of similar size but developed during differing eras (eg yuan and kilo)

As for Australia's Collins replacement, no one is saying soryu's performance is not making it a frontline contender, but other things such as it's displacement/endurance make it one of the only real viable contenders to meet RAN needs. Then there are also political factors to consider.
If any of the European shipyards had developed a four thousand ton SSK as well I bet we'd be seeing a fully fledged competition.

Blitzo, you have no idea how great it was to read about your avatar, I did wonder about it, and now the "reveal"! Love ya bruda, we could be related in light of this latest revelation????
 

antiterror13

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Yes, that's why I'm always a little skeptical when someone says a sub "looks" quiet. I mean, there are some hydrodynamic shapes that are more modern and would contribute to reducing noise, but I think the vast majority of the noise and noise reduction comes from inside.

For instance, 091 Han SSNs actually had quite a modern hull form but its insides were a mess, at least initially, which made it very noisy.

You do know that the first Han was built in 1970 when China was very very backward country .... I think it was a huge huge achievement for China in 1970 to be able to build a "modern" SSN, even now in 2015 (outside the big 5) no other countries has successfully built any SSN, including India. ...... But now in 2015, 45 years later ... China is a very advanced country and its economy is ~110x than it was in 1970 and the technology is much much much much better. Sadly some western media still use early HAN 091 SSN performance to gauge the technology of Chinese SSN, that is plain wrong
 

Blitzo

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You do know that the first Han was built in 1970 when China was very very backward country .... I think it was a huge huge achievement for China in 1970 to be able to build a "modern" SSN, even now in 2015 (outside the big 5) no other countries has successfully built any SSN, including India. ...... But now in 2015, 45 years later ... China is a very advanced country and its economy is ~110x than it was in 1970 and the technology is much much much much better. Sadly some western media still use early HAN 091 SSN performance to gauge the technology of Chinese SSN, that is plain wrong

I think you've misread my post entirely.
If anything, the fact that they came up with a relatively modern hull shape back then is impressive.
 

tphuang

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yes, i think this is the 32nd flotilla
 
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