Sunday, November 4, 2007

More on 054A

SR-64 is one of the less known, but extremely important sensors on PLAN ships. We see it on 052B/C, 051C, 054A, 071 and 054. Although no formal information is out on SR-64, it is generally believed to have the scan rate and computational power needed to track multiple low flying supersonic anti-ship missiles. A commonly flown figure is that it has a detection range of 12 KM against sea-skimmers. There is also the more improbable figure of 100 km posted by Koxinga of CDF. Either way, it's location, scan rate, radar band all point to its role as tracking sea-skimmers. Many people have suspected that it has the same role as the radar that looks like Bandstand on Kashtan equipped ships. However, we've seen SR-64 on 071 and 054, which do not have Type 730 CIWS. It's clear that track or plot data from SR-64 goes into the combat system rather than straight into Type 730 CIWS. At the moment, it's a little unclear which sensor provides the mid-course update for the missiles. It could be the light-bulb datalink, which provides mid-course update for Anti-ship missiles, but maybe also provide update for HH-16. The Sea Eagle search radar, with its 12 rpm scan rate, does not seem to have the necessary refresh rate to provide updates for HH-16. SR-64 may have the additional responsibility of mid-course update on top of tracking sea-skimmers and surface targets. Or, some other less known sensor may be providing the mid-course updates. If continuous illuminations of FCRs is required, only a maximum of 4 targets can be engaged with 8 missiles. Since only terminal illuminations is required, 054A can theoretically engage against 8 targets simultaneously (although much less in actual practice) with the number of missiles limited by the number that can be launched during that time frame and also be limited by the number that the system can provide mid-course update for. Either way, we can conclude that 054A at the current time has much better multi-target engagement capabilities than prior PLAN ships with HH-16.

The often overlooked part of 054A's air defense are Type 730 CIWS and AK-176M. I wrote several posts on SDF in the past on Type 730's capabilities. Many people believe that Type 730 is inferior to Kashtan, because it does not have the gun+missile combination of Kashtan. In reality, PLAN was never too impressed by the performance of Kashtan in test trials. In terms of sensors, it has its own FCR + E/O tracker like Goalkeeper, Palma and Kashtan. And I think we can safely assume that it is integrated into the air defense system with all the sensors. The help of SR-64 would be extremely vital for Type 730. Especially in the case of 052C, where Type 730 CIWS pretty much has to deal with all sea-skimmers below 10 m, SR-64's main data recipient will probably be Type 730 CIWS. Although, with its own high frequency FCR and E/O tracker, it can track and shoot down targets independently. At this moment, I do not have the figures on Type 730 CIWS. Although, it is believed that Type 730 CIWS can encounter multiple supersonic missiles like Goalkeeper. I've read an article that has detailed account of Goalkeeper's performance versus multiple targets, but the only place online that seems to have this is this link. A good description is as follows:
This system can track up to thirty targets, engaging the four most urgent. It will minimize the salvo length to engage as many targets as possible and is thought to be able to deal with two pairs of sea-skimming missiles as little as five seconds apart.

It is generally believed that Type 730 CIWS was required to at least match, if not exceed, the performance of Goalkeeper. Which means, with the help of on-board sensors, each Type 730 CIWS can handle 4 or 5 concurrent sea skimmers.

Finally, the most overlooked part of 054A's air defense is probably AK-176M. The one overly hyped main gun that everyone seems to know about is the Oto Melara super rapid 76 mm gun. It seems like China evaluated Oto 76 with French 100 mm pre-TianAnMen Square and decided at that time, the 100 mm was better. Later, they evaluated between AK-176 and French 100 mm and preferred AK-176. To bring out some of the reasonings used (copied off my original SDF translations):
  • they originally compared oto 76 with the 100 mm naval gun to see which one was better to import and they picked 100 mm one and AK-176 turned out to have even more advantages.
  • at that time, OTO-76 did not have the automation level of 100 mm gun. at that time, it was also easier for China to develop guided munitions for 100 mm. And 054's 100 mm was simplified by over 40% in sensors, but it's high speed shooting reliability is not good
  • Firing rate and muzzle velocity are extremely important for China due to the requirement to counter anti-ship missiles. That's where AK-176M has serious advantage.
  • China started to develop 76 mm around 92 to 94. After improving on AK-176, it did not bother to look at the super rapid OTO-76. The muzzle velocity of OTO-76 is 920 m/s, whereas AK-176 is 980 m/s. Over 5000 m, the flight time is 2.5 second shorter. Also AK-176 fires off 10 more rounds.
  • After china improved on AK-176M, it is much faster at replacing rounds than OTO-76. Auto-reload is important, the improve AK-176 can achieve reload in no time, whereas OTO-76 is behind here
  • You can always improve on sensors/automation (newer electronics) and projectile guidance (use newer rounds), but muzzle velocity, firing rate and reloading speed are extremely important too.
  • Also, the figure given for accuracy is only for single round 1000 m. When firing 60 to 90 consecutive shots, there is no difference. Also, AK-176's munition is better than OTO, as it can better defend against multiple targets in high threat environment.
I can't testify to every statement made there, but most of it did make sense to me when I first read it. Either way, China put AK-176M and a brand new FCR (different from the 100 mm's FCR) on 054A and 071, so it must be quite impressed with their performance.

Theoretically speaking, each 054A has the capability to track many targets at different flight profiles (even the fast + low ones) and also the capability to engage many of them at the same time. It's clearly quite an advanced air defense frigate (although not as sophisticated as those European "AAW frigate"). With the next set of 054 sensors currently on 891 undergoing tests, it would be interesting to see how much more capable the next batch of 054A will be. I'm looking forward to update more on Type 730 CIWS and 054A sensors + other parts like it ASuW and ASW capability in a future post. Until then, I hope this gives a good initial overview on 054A's air defense capabilities.


timurelame said...

Will PLAN order more ships from Russia after all the Sovremennys

Feng said...

Depending on what kind of ship. They did buy a medical ship a while back (or at least rumoured to have). They may still be buying Zubrs. Other than that, I just don't see why they would. The Russians simply do not produce anything as advanced as 054A or 052C at the moment. And for the subs, I think Kilos will be the last orders they get. Sovs are out of date in every sense.