FFG 054/054A Thread

[tphuang]

I think we just have to play the game of wait and see when it comes to Chinese ASW capability. There is no question that they have a new generation of sonar coming out (there was an article a while back talking about the sonars being developed for the latest Chinese ships/subs). And we've seen pictures of Chinese TAS, but no concrete signs that they are on any Chinese surface combatants. But I think when the next batch of 054 comes online (the one that supposedly uses CODOG configuration), we will see more ASW equipment. And same with the report corvette. However, I'm actually putting more hope on an ASW helicopter. Clearly, Ka-28 isn't the long term answer. Z-8K is too large and production rate is too low. Z-9C is too small and short-legged. Z-15 is still 5 years away. This is where the big problem lies.

btw, here are some pictures of 529 at the ESF

 

[crobato]

All this is true, and I'm not denying chinese progress in the submarine sonar sector but the point was surface ship sonars.

Ofcourse you could argue that the chinese waters are more suitable for MF/HF sonars but that coin have a anotherside; MF/HF just happens to be also older generation technology and like you said limited to coastal operations. For size and role of the chinese modern large surface combatants, something better would be desirable. Chinese naval precense and operational ability is as weak as its weakest link...

MF and HF sonar is not---and I repeat NOT---old technology. That's like saying X and S band radar is old technology, and UHF/VHF is where the latest is at. That will also be like saying a tuba is more advanced than a trumpet, the former produces lower frequencies than the latter.

Frequency itself is not a technology issue, as much as a high or low note from a musical instrument. Its a design choice. You choose low frequency for volume search and spread, but it lacks resolution. You chose high frequency for resolution, but it lacks spread. You choose medium frequency as a compromise between the two. Its the same with radars.

There is nothing hard for making low frequency. You only need to make low pitch sound. How you do that? You increase the size of the transducers for one thing, bigger the lower, the smaller, the higher. You will notice the same relationship with musical instruments, like the strings of the piano. Or with loudspeakers, like the tweeter vs. the boom box.

Your low frequency sonar may be good in detecting whales hundreds of kilometers away, but it will have problems detecting a small mine not far from your bow. In many cases, its better to have both.

For the 054A, the bow sonar can serve as a MF/HF part. The LF part can be done through a towed array.

 

[Gollevainen]

Yeas the frequenses are not old technology, but the sonars are. In the old days there were only HF sonars then came the technology to MF sonars and then LF. Thats the pretty much the pattern with all major sonar producers. Alongside came the switch from searlight-type sonars to skanning sonars. Apparently the chinese selfmade sonars fitted still in Jiangweis were the searchlight-type.

All major naval powers have adopted the hull mounted LF sonars for their main ASW vessels. HF/MF may have their advantages in certain sectors, but the detect submarines in blue water coditions, its not adequate. Detecting mines is a completely different issue and for example soviet BPKs and SRKs had small HF/MF sonars fitted alongside the larger LF sonars. Unfortunately I'm detecting the illfamous "chinese way of doing thigs" -explanation to smooth out the weaknesses of PLAN. ASW is still the main obstagle to it being true bluewater force, there is no denying of that.

 

[crobato]

I think you got your definitions mixed up. Searchlight sonars are still around, and they can mechanically scan.

As for size, the one on the new Horizon class isn't that physically big either if you ever seen a picture of it. Which goes to tell you, that you can't use size to judge what is inside. For that reason we can't tell what is truly inside the 054A either. You just cannot put "bigger" bow sonars into the hull of the ship without dealing with drag issues. Also do note that hull sonars aren't just located in the bow, there may be one right underneath the hull itself.

Low frequency sonar has been around for a long time, and it is far from a recent development. For a long time its the only way to detect submarines because LF sonar is the only one that can travel across water in respectable distances. Its actually much harder to create a high frequency device because the hydrophones require much faster harmonics. There is more development being put into high frequency sonar because you need HF for precision undersea mapping. HF also does better in tracking and identifying shoals of fish, or thermal layers, and can simply resolve objects better. Torpedoes for one thing, should use HF and MF sonars; its the only thing that would provide sufficient tracking accuracy, as well as differentiation of proper targets. Anything that would require any form of imaging and mapping would require HF/MF sonar.

LF sonar does not do very well in a littoral environment. It won't do very well tracking an SSK or a midget sub in littoral waters. Modern trend in ASW is one word: littoral. That's not just the Chinese way, that's everyone's way right now.

The 054A didn't seem to me being marketed primarily as a blue water vessel. The PLAN can face more grave threats of opposing subs in its littoral waters, so they're not incorrect that they need to take care of the backyard first. After all, they are surrounded by nations that field quite a number of SSKs. In fact, everything about the PLAN seems to mean, deal with their own backyard first, before moving to the next stage.

For long range detection anyway, you need passive sonar, and passive sonar is the one that being used most of the time. Pinging in low frequencies is not going to do any good for you, since you will be broadcasting your presence instead.

However, putting passive sonar in the bulb in the bow of the ship, this is a less than optimal position, and while it can work and good to have that option, it is affected by some flow and hull noise. Better have TAS or VDS here, but that has drag issues. So what you really need are helos and sonobuoys.

If you want to deal with drag issues caused by the bow sonar shaped like a bulb, you would want a longer and wider hull, and in that sense, a destroyer better fits the bill. I'm not looking at the 054A to provide serious ASW capabilities, I would prefer something bigger like a modded Luhai and anything that will carry two helicopters. I like having 16 cel AshMs because half of those cels can be potentially converted to ASROC that will fit inside the cannisters.

 

[crobato]

Here is something more that can teach.

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Another link that is helpful.

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"The first mention of a People’s Liberation Army Navy (PLAN) designation for a sonar was the EH-5 on the Jianghu frigate in 1975. It reportedly also was on 25 of the Jianghu frigates in variants I through IV from 1975 until 1986. Photographs show HF bow dome sonar on Jiangwei frigates. The Jiangnan V frigate had a sonar designated an EH-5A, which would seem to be an improved version. The next Chinese sonar designation was not evident until 1991 when the SO-7H was installed on the Jiangwei I (FF 539 to 542) and Jiangwei II (FF 521 to 524) frigates. Photographs of Jiangwei ships in drydock clearly show a medium-size bow dome, and models or drawings on display support this observation. This transducer location indicates very strongly that these Chinese sonars are the more modern scanning type."

 

[maozedong]

sinodefence.com dosn't mention DDG 167,168(169) anti sub sonar,I read from credible chinese magazine <Ordnance Knowledge>,that 052B anti sub sonar is the improved MGK-335EM-03,same as Sovremeny destroyer.from the article,seems it already domestic.

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I can't find 051B anti-sub sonar from all sources.
also the magazine called 052B as PLAN first anti-sub destroyer,the anti-sub weapon definitely much better than 051B,I think because this reason,052B dosn't need 2 helicopters.
the article about the sonar:
Antisubmarine, 052 B and the use of "Sovremeny"-with a MGK-335 MS-E sonar system, it based on the MGK-335 EM-03, according to the needs of the mainland's naval be improved, with the main goal of a passive search capabilities and automatic tracking, Target Identification , torpedoes, warning, and low / high frequency (LF / HF) underwater sound of encrypted communications, ranging, friend or foe identification capabilities, and its range of 260 scanners. Submarine detection distance of about 10-12 km, the torpedo detection distance of about 2 km, effective distance of 30 km range, calculation accuracy of about 10 degrees, the underwater sound of encrypted communications distance of 20 kilometers.

 

[Gollevainen]

Well the information what Maozedong gave pretty much sums it up; like I said, the sonars onboard latest chinese large surface combatants are DUBV-23 or local derivation (In 112,113 and 167 I belive alongside few modernised Ludas) and the Platina or local derivation onboard the Sovremennyys and most likely in 052b/c and 051Cs.

Given the size of the sonardome in the 054/A, I belive that the sonars onboard those are SO-7H or some improved variant of it.

Of the large vessel sonars, both Soviets/Russians and French have moved few generations of those conterpory sonarsystems (DUBV-23 and Platina) and if the sonar fitted in 054s would be better than those, why it isen't fitted in the destroyers fielded at the same time?

 

[adeptitus]

If anyone is interested, there's a picture of MGK-335EM-03 sonar here, along with stats on age 101:

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My thought is that if the PLAN really wanted an ASW frigate, they could've imported a sonar suite from Russia, maybe something like the Zarya-ME (see page 100 above) with under-keel, towed, and dipping sonars. But the fact remains that the PLAN isn't a true blue-water navy and money doesn't grow on trees.

IMO what the PLAN aimed for with the 054A is a balanced multi-role (or "General Purpose) frigate, like what the RN did with Type 23 Frigates. The evolving threat from AShM's dictated that most of the munitions $$ went to VL-SAM system & its sensors. Just the Sea Wolf missiles alone on the Type 23 probably costs more than all the other weapon systems on that ship combined.

The weapon systems on submarines have also evolved. Gone were the days when subs had to sneak up and fire its short ranged torpedoes. Today they could receive satellite data link and unleash missiles from hundreds of km away. So, given a limited amount of resources to work with, you have to prioritize accordingly.

 

[crobato]

Well the information what Maozedong gave pretty much sums it up; like I said, the sonars onboard latest chinese large surface combatants are DUBV-23 or local derivation (In 112,113 and 167 I belive alongside few modernised Ludas) and the Platina or local derivation onboard the Sovremennyys and most likely in 052b/c and 051Cs.

Given the size of the sonardome in the 054/A, I belive that the sonars onboard those are SO-7H or some improved variant of it.

Of the large vessel sonars, both Soviets/Russians and French have moved few generations of those conterpory sonarsystems (DUBV-23 and Platina) and if the sonar fitted in 054s would be better than those, why it isen't fitted in the destroyers fielded at the same time?

Most of the real advancement in sonars is in the backend. Remember the US used SQS-53 for decades since WWII, and BQQ-2/5 for three decades. It is the back end processing that counts today, where you can filter out the desired signals from literally a sea full of noise, and then compare the signals across an ever larger computer database. Not too long ago, sonar technicians would rely on experience and hunch. Computers came but at first they're limited. Today, hundreds if not thousands of signatures, including various biologics, are stored in a database where comparisons can be made quickly.

Modern computers also allow sonar technicians to calculate the speed of sound in various water conditions. Before it is hard to imagine how such calculations can be made without a computer, much less without calculators.

Todays backend systems have algorithms like Fourier Transforms to filter out noise, and perhaps, Baynesian analysis for comparing signatures against a database.

Even if the front end is based on an older design, the back end electronics, such as the signal amplification and processing, will still make the over all system far more capable and sensitive than its original form. In the same way that many search radars still use the ubiquitious revolving parabolic array for decades now, but with modern back end systems behind them, these systems are far more capable than they were before.

Given the state of the PRC electronics and computer technologies, we can expect the back end systems to be nearly right in front.

Reviewing a few things.

- Looking at the bow sonar along does not tell you much about the hull sonar, since bow and hull sonar are two separate things. The hull sonar itself would be set to the middle of the hull.

- Any boat or sub MUST have at least medium frequency. The reason for this is that MF is required for the prosecution of the target. LF lacks the resolution and tracking precision for attacking a target. A boat that has nothing but LF is only good for searching things, but not destroying it.

- Without any actual measurements, we cannot determine exactly and empirically, how big or small the potential size of the 054A's bow sonar. And that's only the bow sonar, you still need to measure the hull sonar separately.

- The ones on the exported Sovremannies are enhanced, indicated by the M symbol, and would have been digital. In the Kilos for example, the same MGK-400 designation is used, but the MGK-400EM used on the new exported Kilos are all digitalized.

 

[tphuang]

sinodefence.com dosn't mention DDG 167,168(169) anti sub sonar,I read from credible chinese magazine <Ordnance Knowledge>,that 052B anti sub sonar is the improved MGK-335EM-03,same as Sovremeny destroyer.from the article,seems it already domestic.

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I can't find 051B anti-sub sonar from all sources.
also the magazine called 052B as PLAN first anti-sub destroyer,the anti-sub weapon definitely much better than 051B,I think because this reason,052B dosn't need 2 helicopters.
the article about the sonar:
Antisubmarine, 052 B and the use of "Sovremeny"-with a MGK-335 MS-E sonar system, it based on the MGK-335 EM-03, according to the needs of the mainland's naval be improved, with the main goal of a passive search capabilities and automatic tracking, Target Identification , torpedoes, warning, and low / high frequency (LF / HF) underwater sound of encrypted communications, ranging, friend or foe identification capabilities, and its range of 260 scanners. Submarine detection distance of about 10-12 km, the torpedo detection distance of about 2 km, effective distance of 30 km range, calculation accuracy of about 10 degrees, the underwater sound of encrypted communications distance of 20 kilometers.

no, ordinance knowledge proves absolutely nothing. The entire talk about 052B getting MGK-335 sonar system is basically what Kanwa reported. And when it comes to Kanwa claiming that Chinese ships are using cloned version of Russian sensors, you know how much faith i have in that. The figure given proves nothing.

The truth is very few people know what's the latest on these ships.

The only really good recent article I read is this one.

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It talks about all the major sonar projects on the latest subs + H/SJG-208 towed linear sonar array on an ELINT ship (interesting)

In general, the internet sources on sonar of 052B is a little sketchy. If we check a commonly quoted one.

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It talks about a hull sonar call SJD-9 with a range of 12 km + TLAS-1. But the thing is, I don't really see an opening for towed array sonar.