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ougoah

Brigadier
Registered Member
If people think beyond tabloid headlines and ignorant military fanboys, these sorts of closer proximity events are excellent opportunities for all sides to test things out and use as opportunities to deceive.

If there was an Astute class or whatever nearby, they would quite unlikely be operating in full wartime condition to hide their actual abilities. No F-22 is going to fly near China without Luneburg Lens. No submarine operating right next to adversary ASW are going to sail in full stealth mode. The Russians sailed their Kilo class (okay fine it was non-AIP but point stands) above water and no doubt running with extra noise when they sailed around the UK.

All this would only be for acoustic SIGINT. If the Americans have sailed Seawolfs and Virginias around SCS, it would be excellent opportunity for China to continue testing and evaluating their non-acoustic and acoustic ASW. Chinese ASW developments may have lots of theories and prototypes they want to test out. Without actual top notch submarines to test on, what better way to evaluate, verify, amend, improve etc than with actual US and UK subs you suspect should be in the vicinity?

I wouldn't be surprised if Chinese military leaders and industry members get excited at these opportunities.

We should remember that adversary subs would likely be using similar methods of enhancing their acoustic signatures to hide their actual ones. Or a game is played where they try to figure out how decent China's ASW is and both are constantly playing mind games and trying to hide ability while finding out as much as they can about what the adversary has managed to learn and what they might be thinking from information collected.
 
O

ougoah

Brigadier
Registered Member
Of course UK tabloid needing to write a piece about how their ASW managed to find Type 093s that were not hiding is rather pathetic and honestly unsurprising. Even China does these types of propaganda headlines on occasion (back in the day about antique Song class sneaking past US carrier group ASW to surface next to super carriers). It just isn't targeted at knowledgeable military observers who understand there is a hell of a lot more behind all this.
 
Gloire_bb

Gloire_bb

Captain
Registered Member
ougoah said:
If there was an Astute class or whatever nearby, they would quite unlikely be operating in full wartime condition to hide their actual abilities.
Click to expand...
Submarines often do just that. And for adversaries difference between "combat" operations and "peacetime operations" is often very fickle.
As is doing things not very coherent with UNCLOS and even charter of the United Nations.
ougoah said:
No submarine operating right next to adversary ASW are going to sail in full stealth mode.
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They do. Unless it's explicitly done in a situation where being sneaky is impossible (say, surface transit).
p.s. Chinese asw operators and submariners never lacked proper training targets. The problem isn't really lack of opportunities rather than what're you going to do with them.
 
MarKoz81

MarKoz81

Junior Member
Registered Member
Gloire_bb said:
Actually no in this case. RN was considered to be the go-to navy for underwater warfare during the CW. Furthermore, it's widely considered that it retained ASW skills better than the USN during the pax Americana.
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That's not entirely wrong but also not an accurate representation of what happened.

The USN was better in terms of both ASW and submarine warfare during the 80s and the 90s. Royal Navy had better experience in the littorals and with conventional subs but they did not have comparable airborne ASW assets or underwater infrastructure and they started falling back in terms of nuclear submarine tech. British submarines are very underrated but RN did not have the funding to brute-force technological development in all areas. So they grabbed advantage where they could - hence the pump-jets and conformal sonars.

What happened in the 00s that allowed RN to retain advantage in ASW was that USN withdrew dedicated ASW ships like the Spruance class and cut the funding for ASW aircraft. Reductions in funding meant that Arleigh Burke despite nominally having the necessary sonar is not used as a sub-hunting platform because there were no subs to be hunted and budgets needed to be cut somewhere - so ASW skills went first.

Britain retainted its dedicated ASW ships - Type 23 frigates - and focused their naval aviation on ASW roles because of the loss of Invincible-class carriers. When USN focused on air and missile defense and relied on numerical superiority and their excellent subs for ASW, RN had no such option and as a result they retained the full set of ASW skills. So it's not that RN is better than USN but USN simply neglected ASW due to the size and quality of its submarine fleet. But that doesn't mean that USN is bad at ASW or that RN are somehow uniquely good at it.

Tam said:
The subs got pinged. It doesn't matter if you're quiet when you are pinged. My bet is that the subs deliberately got close enough to record the QE's sound signature, and it doesn't matter if they are detected or not as long as they collected the ship's sound signature, such as the noise of its propellers, engines, induction motors. Probably got a truckload too. I don't even think they even tried to hide, for the purpose of sending a message. The reason why 093s are used instead of 039s is because the SSNs are capable of keeping up with the carrier.
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It is very difficult to find the sub with active sonar unless you already know its approximate location. In the situation we're talking about the subs would be "pinged" as a form of letting the crew know they were found. For a surface ship to be able to paint the sub with active sonar they need to get so close that even 09III would hear them. That's not the best idea since it is a viable strategy to sacrifice an SSN to weaken the escort by sinking an ASW ship hunting the sub so that another sub can exploit the weaknesses and sink the carrier.

Here's a comparison of maximum detection ranges for passive and active sonar:

320px dystanse.jpg
  • "maksymalny dystans wykrycia sygnału" - maximum range of signal detection
  • "źródło" - source
  • "poziom" - level
  • "typ sonaru" - sonar type
  • "pasywny" - passive
  • "aktywny" - active
In the case of "level" the figure describes the difference in relative level between the source and levels of all other noise influencing the signal in the medium.

The equation and mechanics for passive and active sonar is different. In both cases the distance is dependent on the mechanics of acoustic wave propagation in water but for active sonar it is double distance because the signal is emitted from ship and has to reflect from the target and return to the receiver. For passive sonar it is just a single distance from the source of noise to the receiving array. The energy of the wave diminishes with the square of the distance - hence the the drop-off for active sonar is so drastic.

My post on Russian subs with some additional explanation:

Russian Military News, Reports, Data, etc.

Russia jets dropped a bomb on the course of a UK Type 45 Defender near Crimea https://www.dailymail.co.uk/news/article-9716689/Russian-military-fires-warning-shots-British-destroyer-fighter-jet-drops-bombs-path.html Soviet Union Style.
www.sinodefenceforum.com

My thoughts on what could have happened:

What the media outlets say is irrelevant, at best they're part of the information warfare apparatus, at worst they're straight up lying for attention.

Type 09III is very loud and their tactical uses are completely different - it won't be used to snipe carriers because it can't reliably do it. They're R&D and training ships.

If PLAN wanted to record the acoustic signature of QE it would do so with its conventional subs (since they need to be able to target it and they have no towed arrays) and for purpose of SSN with a towed array they would use a 09III equipped with one, creeping at minimum speed and noise level waiting for the carrier to come close. Conventional subs won't have a problem coming within range but SSN's as loud as 09III will, so what PLAN might do is send one 09III as a bait and try to force RN's hand without revealing the other 09III position.

In such scenarios submarines absolutely use acoustic enhancements to prevent the enemy from acquiring acoustic signatures. Acoustic signatures are not as important for submarines - those are equipped with very sensitive sonars and have powerful processing units - as for torpedoes which have to discriminate between targets and decoys when acquiring targets.
 
Gloire_bb

Gloire_bb

Captain
Registered Member
MarKoz81 said:
Britain retainted its dedicated ASW ships - Type 23 frigates - and focused their naval aviation on ASW roles because of the loss of Invincible-class carriers. When USN focused on air and missile defense and relied on numerical superiority and their excellent subs for ASW, RN had no such option and as a result they retained the full set of ASW skills. So it's not that RN is better than USN but USN simply neglected ASW due to the size and quality of its submarine fleet. But that doesn't mean that USN is bad at ASW or that RN are somehow uniquely good at it.
Click to expand...
As you've mentioned, RN kept skills. Furthermore, looking at their current ASW assets, as deployed:

1. World-class asw weapons and sensors, with a notable omission of available ASM. But... there is Sullivans in her CSG - so this isn't a problem this particular time.
2. Type 23 frigate (in medium-term to be complemented/replaced with type 26) - arguably still one of the best asw combatants around, thanks to high silent speed&very thorough sensor upgrades. Full asw fleet upgraded with 2087 sonar, 2150 integration already in progress(no units on QE cruise, though).
3. Dedicated hunter-killer submarine design. Astute isn't exactly a maximum of what's achievable at modern tech, but it's clearly a much more focused and dedicated torpedo boat than Virginia or Severodvinsk, it's significantly younger than Seawolf, and it's simply that much larger than the French Barracuda.
4. Full complement (two squadrons) of heavy ASW helicopters. Merlins are the only heavy western ASW helicopter in service and are handily more capable than MH-60r in this regard.
 
T

Tam

Brigadier
Registered Member
MarKoz81 said:
That's not entirely wrong but also not an accurate representation of what happened.

The USN was better in terms of both ASW and submarine warfare during the 80s and the 90s. Royal Navy had better experience in the littorals and with conventional subs but they did not have comparable airborne ASW assets or underwater infrastructure and they started falling back in terms of nuclear submarine tech. British submarines are very underrated but RN did not have the funding to brute-force technological development in all areas. So they grabbed advantage where they could - hence the pump-jets and conformal sonars.

What happened in the 00s that allowed RN to retain advantage in ASW was that USN withdrew dedicated ASW ships like the Spruance class and cut the funding for ASW aircraft. Reductions in funding meant that Arleigh Burke despite nominally having the necessary sonar is not used as a sub-hunting platform because there were no subs to be hunted and budgets needed to be cut somewhere - so ASW skills went first.

Britain retainted its dedicated ASW ships - Type 23 frigates - and focused their naval aviation on ASW roles because of the loss of Invincible-class carriers. When USN focused on air and missile defense and relied on numerical superiority and their excellent subs for ASW, RN had no such option and as a result they retained the full set of ASW skills. So it's not that RN is better than USN but USN simply neglected ASW due to the size and quality of its submarine fleet. But that doesn't mean that USN is bad at ASW or that RN are somehow uniquely good at it.



It is very difficult to find the sub with active sonar unless you already know its approximate location. In the situation we're talking about the subs would be "pinged" as a form of letting the crew know they were found. For a surface ship to be able to paint the sub with active sonar they need to get so close that even 09III would hear them. That's not the best idea since it is a viable strategy to sacrifice an SSN to weaken the escort by sinking an ASW ship hunting the sub so that another sub can exploit the weaknesses and sink the carrier.

Here's a comparison of maximum detection ranges for passive and active sonar:

View attachment 75937
  • "maksymalny dystans wykrycia sygnału" - maximum range of signal detection
  • "źródło" - source
  • "poziom" - level
  • "typ sonaru" - sonar type
  • "pasywny" - passive
  • "aktywny" - active
In the case of "level" the figure describes the difference in relative level between the source and levels of all other noise influencing the signal in the medium.

The equation and mechanics for passive and active sonar is different. In both cases the distance is dependent on the mechanics of acoustic wave propagation in water but for active sonar it is double distance because the signal is emitted from ship and has to reflect from the target and return to the receiver. For passive sonar it is just a single distance from the source of noise to the receiving array. The energy of the wave diminishes with the square of the distance - hence the the drop-off for active sonar is so drastic.

My post on Russian subs with some additional explanation:

Russian Military News, Reports, Data, etc.

Russia jets dropped a bomb on the course of a UK Type 45 Defender near Crimea https://www.dailymail.co.uk/news/article-9716689/Russian-military-fires-warning-shots-British-destroyer-fighter-jet-drops-bombs-path.html Soviet Union Style.
www.sinodefenceforum.com

My thoughts on what could have happened:

What the media outlets say is irrelevant, at best they're part of the information warfare apparatus, at worst they're straight up lying for attention.

Type 09III is very loud and their tactical uses are completely different - it won't be used to snipe carriers because it can't reliably do it. They're R&D and training ships.

If PLAN wanted to record the acoustic signature of QE it would do so with its conventional subs (since they need to be able to target it and they have no towed arrays) and for purpose of SSN with a towed array they would use a 09III equipped with one, creeping at minimum speed and noise level waiting for the carrier to come close. Conventional subs won't have a problem coming within range but SSN's as loud as 09III will, so what PLAN might do is send one 09III as a bait and try to force RN's hand without revealing the other 09III position.

In such scenarios submarines absolutely use acoustic enhancements to prevent the enemy from acquiring acoustic signatures. Acoustic signatures are not as important for submarines - those are equipped with very sensitive sonars and have powerful processing units - as for torpedoes which have to discriminate between targets and decoys when acquiring targets.
Click to expand...


Does your active vs. passive sonar account for bistatic and multistatic sonars? For others who may not understand that means the transmitter and the receiver are in different locations. Examples of bistatic or multistatic sonars.

1.) Ship emits sonar. Another ship receives the echoes. B can also be a submarine.
2.) Ship emits sonar. Helicopter with dipping sonar receives the echoes.
3.) Emitting sonar from a VDS and receiving it from a TAS. This can be either from two separate lines, with the TAS towed far and the VDS towed near, or in a single line with the TAS on the far end and the VDS on the midsection or closer in the ship.

I'm sure the LFTAS and the latest CAPTAS has this.

The second point is that the Type 09III does not have towed arrays. You showed a chart in your other post. However, Type 09III is not the same submarine as the Type 09IIIA. The addition of a suffix does not mean the same in the Chinese system of designation as it does in the West. Suffix A supposing a variant can mean a relatively minor modification in Western terminology. In the Chinese however, it is big enough that it justify an entirely new ship class, Type 051B vs. 051C, 054 vs. 054A, 052/052B/052C/052D. The 09IIIA is a significantly different sub from the 09III that it should be referred to as a separate class. The ones that have the towed arrays are 09IIIA. The ones tha are deployed in the SCS are 09IIIA. 09IIIA are not training and experimental subs, even if there are subvariants and changes within the class. They are stationed in the sub base at Hainan which is not a training base, and these subs might be used as cover and escorts for the 09IV stationed in that base.
 
iantsai

iantsai

Junior Member
Registered Member
A new type 927 acoustic surveillance ship, with the pennant number 783 painted, is about to enter service at Huangpu Shipyards, Guangzhou. It's the 4th vessel of the class.

Behind PLANS-783, a new type 054A frigate is completing out in the dock. It's the #33 vessel of the class and the third of the new 20-ships batch. It may be launched in September.
131417bmgu29c9vvm6nvbc.jpg
 
D

davidau

Senior Member
Registered Member
ougoah said:
Of course UK tabloid needing to write a piece about how their ASW managed to find Type 093s that were not hiding is rather pathetic and honestly unsurprising. Even China does these types of propaganda headlines on occasion (back in the day about antique Song class sneaking past US carrier group ASW to surface next to super carriers). It just isn't targeted at knowledgeable military observers who understand there is a hell of a lot more behind all this.
Click to expand...
Pomes got the mouth, if nothing else.
 
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