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by **bengtsson** » Wed Nov 14, 2007 11:43 am

Tim Jacobs wrote:Ok. Some sites are acting like this was a new incident. But, the article is definately about the '06 incident. It ref's ADM Fallon as being in PACOM. He's been in CENTCOM since 16 Mar 07.

I believe you're right. I've seen this happen on alot of sites that track military activity. I've seen four year old incidents turn up posted as if they are new. Frustrating

Bob B.

by **Tim Jacobs** » Tue Nov 13, 2007 8:38 pm

Ok. Some sites are acting like this was a new incident. But, the article is definately about the '06 incident. It ref's ADM Fallon as being in PACOM. He's been in CENTCOM since 16 Mar 07.

by **Werner** » Tue Nov 13, 2007 8:34 pm

I thought we were talking about the '06 incident. The Daily Mail article carries no dates at all except it's posting date of 10 November, 07.

by **Tim Jacobs** » Tue Nov 13, 2007 8:31 pm

Hate to sound like a real skeptic, but the description in the news item at the very beginning of this thread reads like a repeat of the incident from Oct 06. Look at it and lay it along side the reporting from Oct 06.

Was there actually another incident? Or is this a replay from the anniversary?

by **bengtsson** » Tue Nov 13, 2007 1:44 pm

One last thought on the Chinese Sub thing. A standard procedure of both surface and submarine vessels is to take a reading of water temperature and salinity versus depth [pressure is a constant] this gives the vessel a profile of where the layers are and how distinct they are. If I am going to try and get into a task force, I'm only going to do it with a nice profile of layers to deflect the active sonar and hold my noise within the layer so that other subs have trouble hearing me, unless they operate within the same layer. Then I'm dead meat!
The long and the short of it is. Operating conditions determine what the Chinese sub commader felt brave enough to do. My small first hand experince tells me that you never dare to believe that an enemy can't or won't do with his weapons sytems what you can do with yours. It's dangerous to feel invulnerable due to our technological superiority. It isn't carved in stone and may be more a political belief than a reality. I think that is what Chuck was trying to say. The free market place of ideas and technology is not owned by the US. The potential enemies have the ability to access high levels of it , buy and sell it and use it. Of course then I may be wrong. But I admit the possiblity

Bob B.

by **Guest** » Mon Nov 12, 2007 3:20 pm

Werner wrote:In point of fact, we're discussing a sub that surfaced within the carrier's formation, not the use of a weapon.

How far from the carrier? The article merely said the sub surfaced within viable weapons range. Presumably any ASW screen around the carrier must extend further from the carrier than the submarine's viable weapon range. So if the submarine surfaced within weapons range, she would by default be inside the surface group, even if she is 20 miles from the carrier herself.

by **Werner** » Mon Nov 12, 2007 3:09 pm

In point of fact, we're discussing a sub that surfaced within the carrier's formation, not the use of a weapon.

by **Guest** » Mon Nov 12, 2007 2:44 pm

Werner wrote:
Anonymous wrote:
Didn't say she was caught unaware. She may very well have been quite aware all along. But it is still possible that she simply sat silent as the US group approached, and really didn't do any active penetration. The key issue was did she penetrate the US ASW screen in a way that implies high likelihood of being able to repeat the performance in wartime.

That depends on whether the Kitty Hawk group had a war-time level of speed and ASW operation in action at the time, and weather the Chinese submarine actually intercepted the US group, or whether she was in the right place at the right time by luck. BTW, I say intercepted because I think it is highly unlikely a diesel submarine could actually "shadow" a surface group due to speed restriction and noise consideration during snorkle operation.
If you assume the USN force was moving at 19 knots and was detected two convergence zones away, that is 2 x 33km, and assuming the submarine can move 10 knots quietly, that means the sub had to be at the wide end of a cone not more than 35km either side of the carrier's course and 67km downrange in order to make this interception.

If the carrier changed course 30 degrees, the probability of interception is cut in half.

The submarine does not have to actually be at the same point at the same time as the carrier. She only needs to put the carrier within "viable weapons range" to successfully intercept the target. If the weapons range is 20 km and we are talking about an ASM, then cone is now 55 kms for a 19 knot target. If the weapons range is 100 km then the cone is huge.

by **bengtsson** » Mon Nov 12, 2007 2:38 pm

Anonymous wrote:Wouldn't the USN have detected the Chinese sub if the Kitty Hawk group were using active Sonar? The silence of the conventional submarines are not worth a damn at close if the enemy was willing to expose himself by pinging away to find it.

Both sides were probably running silent.

A good chance that active sonar may have found it and a very good chance not. Active sonar is far from a sure thing in all but ideal water conditions. The task force had about a very small chance of not being picked up on passive sonar even without pinging. Pinging just advertizes that you ASW vessels out there. The many wakes, knuckels and possible temp and salinity layers can defeat active sonar very easily. It's all about how good the sub commander is. If he knows his stuff, active sonar is often defeated.
In the late 60s early 70s it was not uncommon for the US Sub in naval exercises to photograph the stern of a Carrier or it's props underwater. This was posted on the bulletin board outside the conference room to my first hand knowledge more than once. It was not popular amoung the surface warfare officers, but the truth is the truth.
In the Falklands war, the one Argentine sub [claims to have] made a number of torpedo attacks on British units. They all failed due to torpedo/fire control problems. But the RN never made an attack on a real Argentine sub. Bad sonar conditions, but it shows that active sonar is almost always 'hit and miss'.

Bob B.

by **Werner** » Mon Nov 12, 2007 2:23 pm

Anonymous wrote:
bengtsson wrote:Just had a thought as I was driving this morning. Remembering some time spent on the passive sonar of a submarine , the possibility that the Chinese sub was caught unaware by the approach of the Carrier task force and been where she was by mere chance is most unlikely.
The USN taskforce would have been heard by the Chinese passive sonar at great distance. Even more so if the USN escort vessels had their active sonars in operation. This would be heard a great distances and thus the Carrier Task Force could be avoided hours before it appeared on the horizon. I don't think chance was in play here.

Bob B.

Didn't say she was caught unaware. She may very well have been quite aware all along. But it is still possible that she simply sat silent as the US group approached, and really didn't do any active penetration. The key issue was did she penetrate the US ASW screen in a way that implies high likelihood of being able to repeat the performance in wartime.

That depends on whether the Kitty Hawk group had a war-time level of speed and ASW operation in action at the time, and weather the Chinese submarine actually intercepted the US group, or whether she was in the right place at the right time by luck. BTW, I say intercepted because I think it is highly unlikely a diesel submarine could actually "shadow" a surface group due to speed restriction and noise consideration during snorkle operation.

If you assume the USN force was moving at 19 knots and was detected two convergence zones away, that is 2 x 33km, and assuming the submarine can move 10 knots quietly, that means the sub had to be at the wide end of a cone not more than 35km either side of the carrier's course and 67km downrange in order to make this interception.

If the carrier changed course 30 degrees, the probability of interception is cut in half.

by **Guest** » Mon Nov 12, 2007 2:08 pm

bengtsson wrote:Just had a thought as I was driving this morning. Remembering some time spent on the passive sonar of a submarine , the possibility that the Chinese sub was caught unaware by the approach of the Carrier task force and been where she was by mere chance is most unlikely.
The USN taskforce would have been heard by the Chinese passive sonar at great distance. Even more so if the USN escort vessels had their active sonars in operation. This would be heard a great distances and thus the Carrier Task Force could be avoided hours before it appeared on the horizon. I don't think chance was in play here.

Bob B.

Didn't say she was caught unaware. She may very well have been quite aware all along. But it is still possible that she simply sat silent as the US group approached, and really didn't do any active penetration. The key issue was did she penetrate the US ASW screen in a way that implies high likelihood of being able to repeat the performance in wartime.

That depends on whether the Kitty Hawk group had a war-time level of speed and ASW operation in action at the time, and weather the Chinese submarine actually intercepted the US group, or whether she was in the right place at the right time by luck. BTW, I say intercepted because I think it is highly unlikely a diesel submarine could actually "shadow" a surface group due to speed restriction and noise consideration during snorkle operation.

by **Werner** » Mon Nov 12, 2007 2:00 pm

Since we are at peace, I doubt the task force was in a condition of full readiness as regards antisubmarine warfare. I am sure in these very austere times there are restrictions placed on the number of sonabuoys which can be employed, and we all know the use of active sonar has been restricted on environmental grounds (there is concern it deafens whales and other marine life).

In such a relaxed environment, a submarine could operate at snorkel depths more frequently and approach the carrier's track at a faster pace with little risk of detection, especially if a thermocline or halocline hides the submarine's noise.

by **Guest** » Mon Nov 12, 2007 1:56 pm

Wouldn't the USN have detected the Chinese sub if the Kitty Hawk group were using active Sonar? The silence of the conventional submarines are not worth a damn at close if the enemy was willing to expose himself by pinging away to find it.

Both sides were probably running silent.

by **bengtsson** » Mon Nov 12, 2007 1:07 pm

Just had a thought as I was driving this morning. Remembering some time spent on the passive sonar of a submarine , the possibility that the Chinese sub was caught unaware by the approach of the Carrier task force and been where she was by mere chance is most unlikely.
The USN taskforce would have been heard by the Chinese passive sonar at great distance. Even more so if the USN escort vessels had their active sonars in operation. This would be heard a great distances and thus the Carrier Task Force could be avoided hours before it appeared on the horizon. I don't think chance was in play here.

Bob B.

by **Werner** » Sun Nov 11, 2007 3:54 pm

The subs ought to be at least 1 convergence zone ahead of the carrier group, and 45 degrees to either side of the line of advance. The area between the subs and the ASW screen ought to have several ASW aircraft loitering, prepared to drop Sonabuoys and use dipping Sonar to localize any contact the submarine identified.

A diesel boat is essentially a mine field. It will be unable to chase or do much to get in front of the task force. It has to rely on strategy to place itself where the carrier group is likely to pass within weapons range.

An AIP boat is another matter. These boats are the future threat. Although they cannot sustain a campaign or extended deployment away from the homeland, they can certainly deploy in defense near friendly shores and intercept the enemy in a manner very similar to a nuclear ship.

by **bengtsson** » Sun Nov 11, 2007 3:21 pm

The area around the Carrier Battle Group is a noisy place. All those engines and props. All those active sonars. The US subs screening the group don't have the kind of silent enironment we all used to like. In that racket, a sub on electric drive going up the baffels of the group. Hard to hear it coming. Active sonar is a mixed blessing unless conditions are perfect. Passive likes a noise environment UNDER the sound level of the sub on electric drive , but sometimes if they have a specific frequency they are emitting, you can filter out the racket. Not always a sure thing if the sub is well designed.

Bob B.

by **Foeth** » Sun Nov 11, 2007 2:28 pm

It once more confirms that you cannot adequately protect a large carrier from silent diesel-electric subs and that in any serious conflict the US either runs in large 35 knot circles far far away from enemy territory or starts loosing the large carriers.

by **Guest** » Sun Nov 11, 2007 2:25 pm

Also what is the cone sticking out above the sail, and what is the horizontal projection behind the sail?

by **Guest** » Sun Nov 11, 2007 2:24 pm

What are the 4 thin vertical posts on the front of the Song class submarine? They certainly do not look like bollards or small sonar heads.

by **Guest** » Sun Nov 11, 2007 2:22 pm

Did the Kitty Hawk group have their ASW screen up? I would think unless the submarine was extraordinarily noisy, most diesel submarines would have high chance of being able to do this in peace time when the carrier group is not conducting ASW exercise.

Also, maybe the Chinese submarine was sitting still at a location that happen to be along the course of the Kitty Hawk, and only popped up to avoid getting run over. It seems hardly likely that real wartime military strategy could be based on submarines sitting still and silent and hoping the enemy will blunder into torpedo range.

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