SSN Seawolf Class Attack Submarine, USA
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Originally posted by sgstars:
interesting.
i thought the trend was to go into ULF sonar or VLF sonar arrays ? strategypage has an interesting articles about heavyweight torpedos today.
apparently no modern wire guided torpedo has been fired since wwII if you take the strategypage article seriouslly and dont count the USS Scorpion.
i'd like to add it has to do with the salinity of the water and the various thermoinclines. hardware will only take you so far. under the cooler and denser (supposedly more saline layer), the sub is more quieter than one which is in the warmer and less dense thermoincline layer (im not too sure on this, my knowledge of this is pretty vague)
anyone knows what are the thermoinclines for our waters ? our Sjoormens/Vastergotlands were adapted and Tropicalized to adapt for our waters right ?or was it more of a install air-conditioning for warmer waters in singapore vs cold baltic waters ?
what about the indonesian Kilos and Malaysian Scorpenes ? are they adapted too ? ATM RTN has no submarine vessels right ?
sg waters are too shallow to have thermoclines which is layer of distinct change in water temperature (and sometimes even temperature inversion).
Both salinity, density and temperature of water has large effects on the speed of sound travels under water. It is possible to mask a submarine's presence by dodging below the layer because of the change in the speed of sound at the layer causes the sound to be largely contained to one side of it.
To investigagte POSSUB contacts in such an evironment will require sonobouys to be dropped at depths both above and below the layer, hence making it more tedious.
The problem with Active Sonar is that everybody know's you're in the neighborhood, the fairly large neighborhood. Most submarines have active-intercept arrays that tell them the bearing of the Active sonar ping, and can relay such information to their surface counter parts or fleet intelligence.
With 2 or 3 other submarines just sitting around, a fleet that goes around active-pinging at ghosts will allow the enemy to triangulate their positions and heading easily. Hence active sonar isn't the solution to the submarine problem.
http://en.wikipedia.org/wiki/Thermocline
As for this page -> http://www.fas.org/man/congress/1997/h970318n.htm
The information there is almost 11 years old and slightly dated to the point of inaccurate. Would appreciate if you have more current information.
The USN Improved LA class Subs have already gained abilities deploy underwater mines (gps guided) as well as UUVs (unmanned under water vehicles) as off-ship sensors.
Of course, this is not to say the Russians aren't keeping up.
3 new classes of Russian submarines to look out for: The Amur (SSK export name Lada), Borei (SSBN) and the Graney (i think...). The Graney might actually be a smoke screen for another SSN that may supersede the Akula II. The class name popped up over the net some time ago but I can't seem to recall it for the life of me.
Still, the Kilos and Akulas (I and IIs) were relatively successful and are now heading for the export market. It seems that the Russians have something better coming up.
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Originally posted by Fingolfin_Noldor:
The Sonar 2087 being installed on the British Type 23 frigates is a Towed Low Frequency Active Sonar. These days subs are so bloody quiet, it's time to go back to the good o' Active Sonar.
There's a lot of research going into sonar-armed UUVs. Basically, these unmanned vessels will scout around. If they trigger an attack from enemy subs, then asw assets can focus on the attack area. Kinda like UAVs do with SAMs. Also much better than static hydrophone lines as the patrolling area is flexible.
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Originally posted by Shotgun:The problem with Active Sonar is that everybody know's you're in the neighborhood, the fairly large neighborhood. Most submarines have active-intercept arrays that tell them the bearing of the Active sonar ping, and can relay such information to their surface counter parts or fleet intelligence.
With 2 or 3 other submarines just sitting around, a fleet that goes around active-pinging at ghosts will allow the enemy to triangulate their positions and heading easily. Hence active sonar isn't the solution to the submarine problem.
Ah.. you forget a few things. There's no reliable IFF that exists underwater, nor is there a viable long range communication system. Short range is possible, but you must know where the other submarine is. In fact, friendly fire incidents between submarines is quite possible. Also, there's no way that a ship can possibly travel quietly. Propellors near the surface generate too much cavitation and noise. There's also the option of having a wave following sensor which the Russians have.
Active sonar on the other hand provides high resolution acoustic images. Something passive cannot achieve right now.
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You guys should also note that recent filed lawsuits against the USN were also over active sonar testing: http://www.nrdc.org/wildlife/marine/sonar.asp
And you can't kill whales with passive. You kill them by making them deaf with a loud ping at resonant frequency!
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Thats true. Theres been lots of concern over the use of Active Sonar and its impact on biologicals in the area.
In any case, I guess you've reinforced my point that even the use of Active Sonar does not really help in locating submarines. Fleets pinging away trying to look for submarines will only expose their positions. For now, submarines have the advantage...
I have heard of a satellite based method of hunting subs though... I'm not sure what level of development thats at..
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"There's no reliable IFF that exists underwater"
Always tot the US subs used the AN/BRA-34 (Demand assigned multiple access module) as send signals for sat based IFF.
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Originally posted by Shotgun:
Thats true. Theres been lots of concern over the use of Active Sonar and its impact on biologicals in the area.
In any case, I guess you've reinforced my point that even the use of Active Sonar does not really help in locating submarines. Fleets pinging away trying to look for submarines will only expose their positions. For now, submarines have the advantage...
I have heard of a satellite based method of hunting subs though... I'm not sure what level of development thats at..
How does this reinforce anything? I have said time and again that only active sonar can give accurate image of the area. Why do you think ultrasound provides pretty decent images of babies these days? The processing technology is already there. Passive sonar cannot work at all well in a littoral environment.
Ships are never quiet. Wave homing technology already allows the Russians to track waves made by ships and thus the ships in question.
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Originally posted by slim10:
"There's no reliable IFF that exists underwater"
Always tot the US subs used the AN/BRA-34 (Demand assigned multiple access module) as send signals for sat based IFF.
The surface of the water is notorious for blocking signals by virtue of reflections. You probably have to go near the surface to use it.
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Originally posted by Fingolfin_Noldor:
How does this reinforce anything? I have said time and again that only active sonar can give accurate image of the area. Why do you think ultrasound provides pretty decent images of babies these days? The processing technology is already there. Passive sonar cannot work at all well in a littoral environment.
Ships are never quiet. Wave homing technology already allows the Russians to track waves made by ships and thus the ships in question.
No thats not true at all. In fact, an sonar echo return from an active sonar only tells you there is an object there, IF it even returns an echo. Active Sonars faces severe limitations in littoral evironments and even open oceans where thermocline layers can reflect active sonar pulses.
An Active Sonar does not serve in any purpose as an IFF. Passive Sonar does that when we do blade count analysis, Turns Per Knot, and frequency analysis of engine noises etc. Correct me if I'm mistaken, another problem with Active Sonar is that it transmits over long distances, but the echo returns attenuate easily and is lost over a considerable short distance.
Wave homing technology is not reliable at best. Towed Decoys have demonstrated to be effective in spoofing wave-homing torpedoes. There are several other countermeasures as well.
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Just curious Fingolfin_noldor, not too sure if i m right on thisif you are saying that passive sonar technology has plateaued and the new developmental trends are in active sonar or ultra low frequency active phased arrays.
then why do destroyer doctrines focus on rabid active pinging of a sea area to hunt for subs and subs focus on passive sonar for detection and hunting of surface fleets and subsurface combatants ? the sub stays passive to avoid detection from surface and potential protector subs.
to suggest that subs are using active sonar to search and detect enemy surface and subsurface combatants seems like a complete abandonment of the traditional hunter-killer sub doctrine ?
instead of stealth and hunt, now you have an active, create a helluva lot of noise and draw attention to yourself hunt ? its turning classic anti sub doctrine on its head isnt it ?
this is the bit i dont understand. seems to conflict with what little i know about sub hunting doctrines.
unless u mean the new type low frequency active sonars cannot be detected by other combatants in the area (surface or subsurface). but surely the target that is being pinged, can identify the general direction and threat in the area ?
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Originally posted by Shotgun:
No thats not true at all. In fact, an sonar echo return from an active sonar only tells you there is an object there, IF it even returns an echo. Active Sonars faces severe limitations in littoral evironments and even open oceans where thermocline layers can reflect active sonar pulses.
An Active Sonar does not serve in any purpose as an IFF. Passive Sonar does that when we do blade count analysis, Turns Per Knot, and frequency analysis of engine noises etc. Correct me if I'm mistaken, another problem with Active Sonar is that it transmits over long distances, but the echo returns attenuate easily and is lost over a considerable short distance.
Wave homing technology is not reliable at best. Towed Decoys have demonstrated to be effective in spoofing wave-homing torpedoes. There are several other countermeasures as well.
I never said Active Sonar ever served as an IFF. How do you suggest using a Passive sonar to detect anything if a skilled Submarine captain chooses to go into his silent mode? Passive sonar is only as useful as the sensitivity and how stupid the submarine crew in question, and because of the increasing level of quietness, the USN has resorted to working on active sonar again. Norman Polmar explicitly stated that the USN has to revamp its entire detection paradigm.
Let's take a look at this sonar system: http://www.globalsecurity.org/intell/systems/lfa.htm
This sonar system was installed on the USN's small fleet of ocean surveillance vessels. It is meant to operate alongside the SURTASS passive system.
Note these paragraphs:
The U.S. Navy plans to deploy a new submarine detection system, known as Low Frequency Active Sonar (LFA), throughout 80% of the world's oceans. LFA is based on the fact that very low frequency sound [100-1000 Hz] can travel great distances and detect quiet submarines. The LFA system uses intense sound, reportedly [the Navy has given a figure of 160 dB at about 2 km from the LFA] at levels in the range of 235 decibels or greater [the noise level of a jet engine is about 120 dB] generated by massive sound transmitters towed behind TAGOS-class ships.
Current passive SURTASS towed array sonars are limited in their capability to detect quiet submarines. Thus research has been going on for some time in the area of low frequency active (LFA) towed array sonar. LFA offers the potential for TAGOS ships to make longer range detections of quiet submarines.
The shallow-water acoustics problem has risen in importance due to the increased salience of regional conflicts where the US Navy may to encounter slow, diesel submarines close to shore. The shallow-water, slow submarine is significantly more difficult to detect and classify acoustically than the cold war threat, due to the complex propagation, high clutter, and low target Doppler. Effective sonar performance requires new processing algorithms which cannot be implemented on current Naval platforms due the high processing requirements. A Hybrid Digital/Optical Processor (HyDOP) is to demonstrate the feasibility of using embedded scalable high performance digital and optical processing to solve this problem. This requires application of computationally intensive algorithms which cannot be implemented in real time using conventional processors. A high-speed optical correlator being developed by the Naval Research Laboratory (NRL) will act as a coprocessor to an Intel Paragon XP/S-25 computer.
The TAGOS ships by the way, is probably the most capable vessels when it comes to detecting submarines. They are as large as a large frigate, and they don't carry anything else beyond the sonar and the processing computers. You can read more of the system in question here:
http://www.globalsecurity.org/intell/systems/surtass.htm
I'm not saying that passive sonar is altogether useless, but in this day of age, you use every single tool available to detect incoming threats. Of course there's still the option of using ASROC if all things fail...
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Originally posted by sgstars:
Just curious Fingolfin_noldor, not too sure if i m right on thisif you are saying that passive sonar technology has plateaued and the new developmental trends are in active sonar or ultra low frequency active phased arrays.
then why do destroyer doctrines focus on rabid active pinging of a sea area to hunt for subs and subs focus on passive sonar for detection and hunting of surface fleets and subsurface combatants ? the sub stays passive to avoid detection from surface and potential protector subs.
to suggest that subs are using active sonar to search and detect enemy surface and subsurface combatants seems like a complete abandonment of the traditional hunter-killer sub doctrine ?
instead of stealth and hunt, now you have an active, create a helluva lot of noise and draw attention to yourself hunt ? its turning classic anti sub doctrine on its head isnt it ?
this is the bit i dont understand. seems to conflict with what little i know about sub hunting doctrines.
unless u mean the new type low frequency active sonars cannot be detected by other combatants in the area (surface or subsurface). but surely the target that is being pinged, can identify the general direction and threat in the area ?
I believe there's still work done on passive arrays, but there's certainly more work on active arrays done these days than before. No, submarines will not go active since it will compromise their stealth. Ships on the other hand, especially when you are talking about the average destroyer/frigate and not those corvettes that may come with water jets etc. to minimize their noise profile (though how much is another thing), have a lot fewer options and they need to maximise their abilities to detect submarines. To do that, you have to resort to developing new technologies that can do the trick. Though I have heard of Russian acheonic coatings that try to reduce the reflection of active sonar.
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Originally posted by Fingolfin_Noldor:
I never said Active Sonar ever served as an IFF. How do you suggest using a Passive sonar to detect anything if a skilled Submarine captain chooses to go into his silent mode? Passive sonar is only as useful as the sensitivity and how stupid the submarine crew in question, and because of the increasing level of quietness, the USN has resorted to working on active sonar again. Norman Polmar explicitly stated that the USN has to revamp its entire detection paradigm.
Let's take a look at this sonar system: http://www.globalsecurity.org/intell/systems/lfa.htm
This sonar system was installed on the USN's small fleet of ocean surveillance vessels. It is meant to operate alongside the SURTASS passive system.
Note these paragraphs:
The TAGOS ships by the way, is probably the most capable vessels when it comes to detecting submarines. They are as large as a large frigate, and they don't carry anything else beyond the sonar and the processing computers. You can read more of the system in question here:
http://www.globalsecurity.org/intell/systems/surtass.htm
I'm not saying that passive sonar is altogether useless, but in this day of age, you use every single tool available to detect incoming threats. Of course there's still the option of using ASROC if all things fail...
Well thats true. However, it has always been true that the USN would ping away with Active Sonar whenever they feel that they have been detected (which is often). So there isn't really much of a change in how a surface force would hunt submarines, even with this LFA technology.
The problem posed by the new generation of ultra-quiet submarines has already gone through much research as shown by the USN and RSwN's cooperation when they started "hunting" the Gotland. The problem so far identified is not just a problem with technology, but the lost of skill, and knowledge in ASW after the Cold War ended.
Still, there are good reasons to avoid the Active Option when hunting for submarines. Chinese call it, dun wanna "beat grass scare snake." It helps that your prey isn't aware that you are stalking it. =D
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Originally posted by Shotgun:
Well thats true. However, it has always been true that the USN would ping away with Active Sonar whenever they feel that they have been detected (which is often). So there isn't really much of a change in how a surface force would hunt submarines, even with this LFA technology.
The problem posed by the new generation of ultra-quiet submarines has already gone through much research as shown by the USN and RSwN's cooperation when they started "hunting" the Gotland. The problem so far identified is not just a problem with technology, but the lost of skill, and knowledge in ASW after the Cold War ended.
Still, there are good reasons to avoid the Active Option when hunting for submarines. Chinese call it, dun wanna "beat grass scare snake." It helps that your prey isn't aware that you are stalking it. =D
Sometimes you need to "carpet bomb" the snake to kill it. :P
But the Gotland and the Kilo is interesting. The Gotland's performance in one of the recent excercises was interesting in that the sub single handedly defeated a beach landing. The Kilo, because of its size, incorporated lots of acoustic quietening features that alowed it to stay silent (in fact, it can be described as a shrunken version of a Nuclear submarine since it uses the same hull form) and apparently in one Russian navy exercise, sunk quite a lot of ships on its own. The West is quite afraid of the submarine, especially when China has quite a few of them.
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Originally posted by Shotgun:
Well thats true. However, it has always been true that the USN would ping away with Active Sonar whenever they feel that they have been detected (which is often). So there isn't really much of a change in how a surface force would hunt submarines, even with this LFA technology.
The problem posed by the new generation of ultra-quiet submarines has already gone through much research as shown by the USN and RSwN's cooperation when they started "hunting" the Gotland. The problem so far identified is not just a problem with technology, but the lost of skill, and knowledge in ASW after the Cold War ended.
Still, there are good reasons to avoid the Active Option when hunting for submarines. Chinese call it, dun wanna "beat grass scare snake." It helps that your prey isn't aware that you are stalking it. =D
Sometimes you need to "carpet bomb" the snake to kill it. :P
But the Gotland and the Kilo is interesting. The Gotland's performance in one of the recent excercises was interesting in that the sub single handedly defeated a beach landing. The Kilo, because of its size, incorporated lots of acoustic quietening features that alowed it to stay silent (in fact, it can be described as a shrunken version of a Nuclear submarine since it uses the same hull form) and apparently in one Russian navy exercise, sunk quite a lot of ships on its own. The West is quite afraid of the submarine, especially when China has quite a few of them.
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duplicate post bro
add to your point : China is no longer simply making Kilos. the frightening thing is, China is modifying and improving the Kilos. They recently exported some i think. cant recall where though.
improved Kilos are not good if it comes toSLOC denial. especially if it comes to the denial of oil flow to Japan and Korea if it ever came to that.
btw you know anything about the Japanese submarines ? apparently some of the very best non-nuke subs out there together with the Collins class but little information avaliable.
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Originally posted by sgstars:
duplicate post bro
add to your point : China is no longer simply making Kilos. the frightening thing is, China is modifying and improving the Kilos. They recently exported some i think. cant recall where though.
improved Kilos are not good if it comes toSLOC denial. especially if it comes to the denial of oil flow to Japan and Korea if it ever came to that.
btw you know anything about the Japanese submarines ? apparently some of the very best non-nuke subs out there together with the Collins class but little information avaliable.
China license produces Kilos? That's new to me. I thought the Russians still is the sole producer of the Kilo. Though I won't be surprised if the Chinese modified them. There are a few variants of the Kilos. The last variant had some new modifications that make it even quieter. The newer Lada class/Amur is said to be even quieter.
I'm not too sure about the Japanese (too much classified stuff out there really) but the Japanese ought to make top notch submarines. The latest class has AIP as well. The Collins class if I remember reading is based on the latest Swedish designs fitted with an American combat management system. Supposedly the Australians (if I am not wrong) produced their own sonar system (they are apparently quite good at it) though with other US/British components thrown into the mix. Maybe I can find some info on it digging through Janes (which isn't the best source out there, really)
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yea.
if you want some reading on the Chinese Kilo i think can read it here but not sure how credible is this
http://www.sinodefence.com/navy/sub/yuan.asp
supposedly based on the KILO and after sub transfer technology.
China sub building :
http://www.globalsecurity.org/military/world/china/newcon-ss.htm
http://www.heritage.org/Research/AsiaandthePacific/wm1001.cfm
http://www.afcea.org/signal/articles/templates/SIGNAL_Article_Template.asp?articleid=93&zoneid=22
http://www.wisconsinproject.org/countries/china/subs.html
the more i read on Chinese subs, the more i fear the china threat. they've been doing stupid stunts like the surfing up undetected close to the kitty hawk amidst and exercise and detected by JMSDF shadowing the george washington as it moved from yokohoma to seoul.
most disturbing this is.
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Originally posted by sgstars:
yea.
if you want some reading on the Chinese Kilo i think can read it here but not sure how credible is this
http://www.sinodefence.com/navy/sub/yuan.asp
supposedly based on the KILO and after sub transfer technology.
China sub building :
http://www.globalsecurity.org/military/world/china/newcon-ss.htm
http://www.heritage.org/Research/AsiaandthePacific/wm1001.cfm
http://www.afcea.org/signal/articles/templates/SIGNAL_Article_Template.asp?articleid=93&zoneid=22
http://www.wisconsinproject.org/countries/china/subs.html
the more i read on Chinese subs, the more i fear the china threat. they've been doing stupid stunts like the surfing up undetected close to the kitty hawk amidst and exercise and detected by JMSDF shadowing the george washington as it moved from yokohoma to seoul.
most disturbing this is.
Actually, on another forum, some analyst fella (who has shown to be quite knowledgeable in a lot things, though he shuts up on certain issues immediately), he pointed out that incident possibly really wasn't orchestrated. For one thing, the submarine captain has a few options.
1. He can hightail out of there and risk getting detected and shot at.
2. Drift away in hope that he can get out of there quietly (which is doubtful since Chinese made subs are still not up to spec really). I would say that this might be a possible action but I don't know too much of the technical details. But, you might note that he was probably running to the limit of his submarine's endurance and might not be able to get of there quietly.
3. Surface and say, "Sorry for the intrusion. Let us get some oxygen and we will be on our way."
Of course, the real story might be really they planned to do that, but the submarine in question has no AIP and thus have no endurance for that sort of thing. They also must know the precise location of the Kitty Hawk battlegroup as well. I might be totally wrong of course.
Personally, I don't see China too much of a threat to the USN until the USN goes close to the shore or through some narrow chokepoint at the moment. Neither will they be a threat to us in the near future. However, if China finally gets its nuclear submarine force up to the level where the Russians have gotten to (which is really a decade or so away), then they will give us trouble. For now, well, just buy what we get hold of and either hope China doesn't give a damn about us.
Though I sure hope they aren;'t overspending. Seems to me that the rate at which they are acquiring new vessels is really fast.
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double post
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Originally posted by sgstars:
yea.
if you want some reading on the Chinese Kilo i think can read it here but not sure how credible is this
http://www.sinodefence.com/navy/sub/yuan.asp
supposedly based on the KILO and after sub transfer technology.
China sub building :
http://www.globalsecurity.org/military/world/china/newcon-ss.htm
http://www.heritage.org/Research/AsiaandthePacific/wm1001.cfm
http://www.afcea.org/signal/articles/templates/SIGNAL_Article_Template.asp?articleid=93&zoneid=22
http://www.wisconsinproject.org/countries/china/subs.html
the more i read on Chinese subs, the more i fear the china threat. they've been doing stupid stunts like the surfing up undetected close to the kitty hawk amidst and exercise and detected by JMSDF shadowing the george washington as it moved from yokohoma to seoul.
most disturbing this is.
Its not disturbing that China's doing this. The Russians and Americans used to shadow each other with submarines all a long. Its disturbing that the Chinese aren't talking about it and being transparent about their intentions and capabilities. IMO, this casts a long of doubts and suspicions on the Chinese even if they claim that their intentions are peaceful.
From the little that I know, Active Sonar is used for a few purposes. To scare away subs for one ("Carpet Bombing"). Another, to gain detail on where the very quiet sub ( u're sure its SOMEWHERE there) but highly elusive to what depth he's at.
Anyway, theres a lot of technical detail and operational details we don't know about how submarines carry out business. From what I understand, the edge now is with the submarines as long as they have accurate intelligence of who and what is where at when. There's no single passive or active solution to hunting submarines. Knowledge, efficiency, and experience aka "a good hunch" is necessary.
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Originally posted by Shotgun:
Its not disturbing that China's doing this. The Russians and Americans used to shadow each other with submarines all a long. Its disturbing that the Chinese aren't talking about it and being transparent about their intentions and capabilities. IMO, this casts a long of doubts and suspicions on the Chinese even if they claim that their intentions are peaceful.
+1
its how their actions and doctrine simply dont tally and dovetail with their expressed intentions.