Chinese submarines thread

[tphuang]

Re: Chinese sub thread

There is a possibility that the first 094 may have returned to Huludao to have the TAS fitted, although that will not explain the high water line of the two subs as both appear high and the same level. There is going to be a difference in the water line from the first sub, it would appear lower and it would not be equal to the other sub..

Are you talking about the one with the appendage? I wonder if we will ever get a better look at it. Actually, I've wondered if the 6 huge flank array sonar + bow sonar on 093 is enough for what it needs to do. It's just shocking to me that they didn't at least equip it with towed array sonar.

A look at Virginia class and all the places you can put sonar at, lol
Chin and sail sonar? never thought of it, lol.

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[crobato]

Re: Chinese sub thread

The appendage resembles something on the illustrations of the Borei, which also has a thin appendage on the tail. I guess the blimp shaped TAS on previous subs are no longer in fashion.

My guess is that the 093, which has the same tail as the 094, can also be fitted and upgraded with this TAS as well.

Huge flanking sonar is more important than TAS. The idea of TAS is that you can extend the range of the sonar by going as far from the submarine or ship where it is quieter and away from the hull noise. But as subs become quieter, hull sonars become more and more effective. Noise cancellation by electronics and software processing---taking the hull noise factor out of the equation---takes that even further, something to think about with today's powerful COTS digital signal processing and gaussian filters.

The thing about TAS vs. hull sonars is that TAS is limited in size. Like radar, sonar depends a lot in the size of the array, and the more of it the better. Nothing beats big flank sonar arrays and being multi on top of that. Smaller size arrays limits the frequency you recieve, and it won't be as low as you can get with a bigger array. The bigger the array, the lower the frequency, and the lower the frequency, the farther it travels on the water.

Low frequency flank sonars are the most important thing now in subs for long range detection, and I would say this, more important than TAS, asssuming you got a quiet sub. This does not mean TAS is useless, any aid helps so long it does not penalize you excessively on weight and energy use. I am surprised how many subs actually don't have flank sonars, the Kilo and Type 209 subs for example.

Chin or better known as bow sonar is standard on all subs. I'm surprised about putting sonar on the sail. Usually you want to put a radar on it instead for surface surveillance and navigation reasons.

 

[Pointblank]

Re: Chinese sub thread

The appendage resembles something on the illustrations of the Borei, which also has a thin appendage on the tail. I guess the blimp shaped TAS on previous subs are no longer in fashion.

My guess is that the 093, which has the same tail as the 094, can also be fitted and upgraded with this TAS as well.

Huge flanking sonar is more important than TAS. The idea of TAS is that you can extend the range of the sonar by going as far from the submarine or ship where it is quieter and away from the hull noise. But as subs become quieter, hull sonars become more and more effective. Noise cancellation by electronics and software processing---taking the hull noise factor out of the equation---takes that even further, something to think about with today's powerful COTS digital signal processing and gaussian filters.

The thing about TAS vs. hull sonars is that TAS is limited in size. Like radar, sonar depends a lot in the size of the array, and the more of it the better. Nothing beats big flank sonar arrays and being multi on top of that. Smaller size arrays limits the frequency you recieve, and it won't be as low as you can get with a bigger array. The bigger the array, the lower the frequency, and the lower the frequency, the farther it travels on the water.

Low frequency flank sonars are the most important thing now in subs for long range detection, and I would say this, more important than TAS, asssuming you got a quiet sub. This does not mean TAS is useless, any aid helps so long it does not penalize you excessively on weight and energy use. I am surprised how many subs actually don't have flank sonars, the Kilo and Type 209 subs for example.

Chin or better known as bow sonar is standard on all subs. I'm surprised about putting sonar on the sail. Usually you want to put a radar on it instead for surface surveillance and navigation reasons.

However, without a towed sonar array, someone can hide in your baffles and then shove a torpedo up your rear because you didn't detect them during a conflict... or they can follow you around and snoop.

 

[nero]

Re: Chinese sub thread

can then JIN-class SSBNs lauch the YJ-62???

any updates on the RSM-54 which the chinese r eyeing ???

 

[crobato]

Re: Chinese sub thread

However, without a towed sonar array, someone can hide in your baffles and then shove a torpedo up your rear because you didn't detect them during a conflict... or they can follow you around and snoop.

In order to do that they have to go around all the way to the back of the sub, and that is assuming you can even keep up with a nuclear sub in the first place. This also assumes you have to escape the zone of detection from the passive flank sonars.

A lot of subs really don't have TAS, especially smaller conventional ones due to the space they require. The trend among conventionals is to get them with passive flank sonars, like the Oyashio, which was designed in them with mind, while its predecessor, the Hayashio, lacked passive flank sonars.

 

[crobato]

Re: Chinese sub thread

can then JIN-class SSBNs lauch the YJ-62???

any updates on the RSM-54 which the chinese r eyeing ???

The Jins cannot launch the YJ-62 without conversion. You have to convert the SSBN into an SSGN, or cruise missile type. But that is not likely to happen until the Jins are considered obsolete by the PLAN with even newer SSBNs and the PLAN is looking for a way to make the sub useful. The Xia right now is more likely to be converted into an SSGN given that its size is not likely to able to convert to the JL-2 which is much larger than a JL-1.

 

[tphuang]

Re: Chinese sub thread

can then JIN-class SSBNs lauch the YJ-62???

any updates on the RSM-54 which the chinese r eyeing ???

why would you want it to launch YJ-62? You want SSGNs in the future to launch DH-10 or other Tomahawk like LACM.

They seem to be testing numerous missiles on 052C right now. I personally don't think YJ-62 is the most advanced missile.

Also, there is a difference between bow mounted sonar and chin mounted sonar, Virginia is said to be the first one to have one.

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[crobato]

Re: Chinese sub thread

There is nothing new about a chin mounted sonar. You can name a sub from any part of the world except the US, and it has a chin mounted sonar. Think of any sub randomly, like lets say a Kilo. Yup. Song. Yup. Type 214. Yup. And so on and on.

What makes American subs unique in the world is the use of a true bow sonar. When I mean bow, I mean the sonar is located right at the epicenter or bore center of the bow itself. Kind of like the way you see radar on large planes like B747. By putting it on the bow, they are using a spherically shaped array, which gives a large coverage or point of view. However this design means that you cannot put torpedo tube openings in the front for a forward shot. The tube openings have to be along the sidesa and aimed at an offset. This sort of sonar is standard and common with US subs like the 688 class.

A chin mounted sonar would take up half of the hemisphere of the bow. Rather than use a spherical array, this sonar is more likely to use a cylindrical shaped one, a low fat cylinder standing top to bottom. The advantage of this is that it makes better use of space to create a large sound transducer, the cylinder, which is bigger than the sphere. That allows for a wider and lower spectrum of frequencies to be used. As you might expect, you do sacrifice some field of view to the front top of the sub something a spherical array would have covered.

Subs can only use one or the either due to the limitation of the ship's draught. What may be unique about the Virginia class is that the sub's draught must have been deep enough to use both.

 

[Pointblank]

Re: Chinese sub thread

In order to do that they have to go around all the way to the back of the sub, and that is assuming you can even keep up with a nuclear sub in the first place. This also assumes you have to escape the zone of detection from the passive flank sonars.

A lot of subs really don't have TAS, especially smaller conventional ones due to the space they require. The trend among conventionals is to get them with passive flank sonars, like the Oyashio, which was designed in them with mind, while its predecessor, the Hayashio, lacked passive flank sonars.

The Americans were often able to successful shadow Russian nuclear missile submarines with their submarines by hiding in their baffles, before the advent of a towed sonar array. The Americans frequently stationed attack boats near Soviet ports and known Soviet paths. And they did this with high frequency.

Many new conventional submarines are equipped with a towed sonar array; The German Type 212 and 214 submarines are equipped with towed sonar arrays, the Canadian Victoria class submarines are equipped with towed sonar arrays, and the French Agosta class submarines are fitted with them, etc.

 

[crobato]

Re: Chinese sub thread

That was also before the advent of flank arrays, which is also a fairly recent phenomenon among subs, which greatly increased detection along the sides and to the reat. The 688I was the first US sub to have them built outright, and for the Soviets, the Victor III. I'm not sure if some of the subs you mentioned have a TAS due to the size and space limitation.