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Thread: Naval submarine free play exercise question

  1. #1
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    Naval submarine free play exercise question

    Well i know the follwing excercises in these articles are old news and discussed here on WAB but I have some questions.

    Are some of the excercises where diesel subs sink carrier groups completely free play (even though I know alot of them have plenty of artificial rules).

    This article

    The “Exercises Aren’t Real” Argument: My Response

    The examples below are from exercise scenarios, but some will say that one cannot draw conclusions from exercises because they cannot fully duplicate the reality of combat. Some might also say, erroneously, that exercises are only meant to be instructional, using scripted situations with predictable conditions and rules to train the crews on drills and procedures rather than to actually “fight the ship.” In this kind of exercise, the crews are basically just practicing their various skills, such as gunnery, damage control, and learning how to operate damaged or degraded systems. In other words, they are about learning about combat, not engaging in it. In these exercises, there are no winners or losers, and certainly no one calls the media to report a “success” in such exercises. This is just part of the complex exercise equation, and it is not the part that interests me. What does interest me are the so-called “Force on Force” exercises where there are indeed winners and losers. In many exercises there often are unscripted or free-play evolutions that closely simulate combat, and no ship has any special advantage or disadvantage. The purpose of these evolutions is not to train crews, but to fight and hopefully win. As Robert Coram put it, “In a free-play exercise – no scenario and no rules – the orchestrated performance was tossed out. There is no better way to select and test combat leaders than by free play. Free play means winners and losers; it means postexercise critiques…Careerists hated free-play…True combat leaders loved it.” In these evolutions, rival crews do their very best to win, as there are considerable bragging rights endowed to the winners. Realism is important in these exercises. Exercise Tandem Thrust 99, an unscripted multinational “free-play” exercise, was “as close to war as we can possibly get,” said Commander Al Elkins, US Navy. “We’re in this exercise like we’re in a hot war. When our aviators take off, they have no idea what kind of threat is coming.”

    No reasonable person would suggest that a ship that regularly fails in free-play exercises is nevertheless in good shape for combat, and vice-versa. Now assume for just a moment that, rather than a list of failures, I will present a detailed list of US Navy successes in exercises instead. Suppose a modern US Navy destroyer had “sunk” an “all gun” World War II-vintage Turkish destroyer in a hypothetical free-play exercise. It would be outrageous for the obviously outmatched Turkish Navy to say “Yes, but exercises aren’t reality. In a real battle, my old ship and her guns would have clobbered that new American destroyer and her Tomahawk missiles.” That would be preposterous, and so is the claim that free-play exercises, like the ones described below, are inherently meaningless. The fact is that consistent free-play exercise results (successes or failures), are useful, meaningful, and provide reasonable analytical tools. And if free-play exercises are not meaningful, then why does the US Navy invest so much time and money to participate in them? Because these types of exercises frequently reveal both the good and the bad news about how a navy might fare in a real war. I would propose referring a couple of the many interesting quotes one gets when googling 'purpose naval exercise'. I did not see a single 'just having a good time' and ‘shooting the breeze' statement. While not always the case, the standard, blanket explanation employed by US Navy apologists that all defeats (even in free play or unscripted exercise evolutions) are purely because the US ships or aircraft involved were operating under some sort of artificial restriction, limitation or handicap is also often rather spurious, exaggerated, overly convenient, deceitful, and just a cop-out, and I will deal with that matter in due course.

    On yet another level, some will also claim that since exercises are conducted in relatively small areas, it is easier for diesel submarines to detect and attack surface ships. In real life, the oceans are much bigger and it is more difficult for a diesel submarine to position itself to attack a much faster carrier battle group. I would ask those who support this argument to consider two things.

    Firstly, many US surface combatant ships were sunk in the open ocean by slow, primitive diesel submarines in World War II, including the carriers USS Yorktown, USS Wasp, the escort carriers USS Liscombe Bay, USS Block Island, the cruisers USS Indianapolis and USS Juneau, the destroyers USS Mason, USS Reuben James, USS Satterlee, USS Jacob Jones, USS Hammann, USS O'Brien, USS Porter, USS Henley, USS Buck, USS Bristol, USS Leary, USS Leopold, USS Fechteler, USS Fiske, USS Eisele, USS Shelton, USS Eversole, USS Frederick C. Davis, and many other types of surface ships. US battleships were damaged by submarine attacks and taken out of action for months as well. In the case of the battleship USS North Carolina, one of the most powerful and up-to-date ships of her time, and far more advanced than the ships destroyed at Pearl Harbor, she was taken out of action for two months by a single torpedo fired by the Imperial Japanese Navy’s submarine I-19. In addition, the Imperial Japanese Navy’s 71,890 ton supercarrier Shinano was also sunk by a diesel submarine, as was the 36,000 ton fast battleship Kongo. Submarines also claimed five of the largest British carriers.

    Secondly, consider that even though carriers and surface ships are more advanced today, and are still much faster than conventional submarines, that does not give them any additional life insurance because in a war the enemy diesel submarine will know a) where the US Navy ships are coming from and b) where they are likely headed. They do not have to catch up to a carrier battle group making more than 30 knots; they can just wait for it, and no one can predict exactly where en route they are waiting. The only protection the US Navy will have is solid Anti-Submarine Warfare (ASW) skills, and as we will see in this paper, the assumption that the US Navy has such skills is not well-founded. Today's diesel submarines are far better than those of the past, and with the US Navy now concentrating more on the dangerous, noisy and shallow waters of the littorals, if anything, the potential threat from quiet conventional submarines is greater now than it was in World War II.

    One more thing about exercises. I have noted over the years that our US Navy friends expect to always win, by virtue of possessing what they earnestly believe is superior technology (on which some say the US Navy has grown overly-dependent, and consequently, rather sloppy) and/or superior training. They simply cannot fathom the results when things do not go their way all the time. When a US Navy F-18 squadron beats a foreign squadron in a dogfight, for example, US Navy supporters do not ask questions about exercise parameters. They just assume that American technology and training were better, so case closed. However, when a US Navy ship or squadron loses in a competitive free-play or unscripted exercise, the response is rarely "Well, you can't win them all," or "You win some, you lose some." Sadly, the more typical response is to call a foul at the very concept of being beaten. Were the conditions unfavorable to the US Navy? Was the exercise unfair to US forces? (As if war could ever be “fair”) Remember former Vice President Bush, a Navy veteran, who said the following after a US ship shot down an Iranian airliner: “I will never apologize for the United States of America. I don't care what the facts are." I find this quote very much in keeping with the culture of evasion, excuse-making, blame-shifting, buck-passing, and denial in the US Navy, and I urge you to keep this in mind as you read this paper. Denial, in the words of military commentator Stan Goff, is indeed “the grandest of American appetites.”

    As for methodology, the first section relies on qualitative rather than quantitative data. The reason for this is simple. As Captain Dean Knuth, US Naval Reserve (Retired), will attest later in this paper, the US Navy keeps a tight lock on its exercise evaluation data, especially on the ones that include potentially embarrassing failures. These exercise reports are not available to the general public, and attempts to make them public have been suppressed by the Navy. Under these conditions, a statistical analysis is not likely. In fact, after conducting a thorough search of the available unclassified materials, I could not locate even one such study, and one can be sure that is just what the US Navy wants. This is a discussion paper, and thus my purpose is merely to ask questions and raise issues, rather than to comprehensively answer all of them. My task here is to try to put the pieces together, and see if any conclusions can be supported or extrapolated. Although helpful, one does not always need reams of statistical data and tables to recognize a plain fact especially when history, common sense, and credible authorities support the conclusion. We do not require a statistical analysis to understand universal truths. I always liked the way Bruce Russett stated his methodology, so I shall indicate my concurrence by quoting him directly: “My intention is to be provocative... The argument is not one subject to the principles of measurement and the strict canons of hypothesis-testing – the mode of inquiry with which I feel most comfortable. Nevertheless the subject is too important to leave untouched simply because the whole battery of modern social science cannot be brought to bear on it.”

    I would also add that it does not require a leap of faith to know that there is no such thing as an unsinkable ship, no matter how big it is, how many water-tight compartments it has, or how much armor plating it has. Nor does it require much imagination to comprehend that a nearly silent diesel submarine can most definitely stalk and sink even the largest surface warships (or, these days, noisy nuclear submarines) with relative ease. Such things happened in both World Wars, and they can happen today. Even Compton-Hall, whose writings reflect a slightly pro-nuclear submarine disposition, cautioned: “It is a great mistake to denigrate SSKs: they will continue to be a menace for the foreseeable future and the Soviet Navy knows it.” Those who deny these facts are in fact denying reality. As Aldous Huxley once said, “Facts do not cease to exist because they are ignored.”
    Is the US Navy Overrated? - Trans-Asian Axis

    And also this article which is too long so i'm simply going to give its title and the link
    "David vs. Goliath: Do Diesel Subs Feast on the US Fleet?"
    Is the US Navy Overrated? - Trans-Asian Axis

    Ive noticed that they bring up the collins vs Los angeles class incident. The subs had swapped roughly equal numbers of hits and were therefore more evenly matched. Comamnder Davies said that since the sub is larger the sub makes more nosie when going faster.

    One of Australia's Collins class submarines has hunted down and "killed" a state-of-the-art United States nuclear submarine in a series of mock attacks during an underwater warfare exercise off Hawaii.

    Officers in the exercise told The Sunday Age HMAS Sheean had held its own during two rigorous weeks of combat trials with the Los Angeles class attack sub, USS Olympia. The subs had swapped roles as hunter and prey and scored roughly equal numbers of hits.

    The role of seeking and destroying an enemy submarine is one of the most difficult faced by Australia's six new Collins class submarines. The success off Hawaii in August has boosted morale dramatically among submarine crews who have had to endure years of hearing their boats condemned as noisy and vulnerable.

    A 1999 report by the then CSIRO chief, Malcolm McIntosh, and former BHP managing director John Prescott said the Collins' combat system should be junked, the vessels were noisy and vulnerable to attack, their engines broke down regularly, a badly shaped hull and fin made too much disturbance when they moved at speed under water, the view from the periscope was blurry, the communications system outdated and the propellers were likely to crack.

    Commander Steve Davies, chief-of-staff in the navy's submarine force, said that during the past three years those problems had been fixed to the point where the submarines were able to match the best of the US Navy's giant underwater fleet.

    During its mock attacks on the Olympia and on two US destroyers, the Sheean fired 28 torpedoes. Commander Davies said "a respectable percentage" of shots Sheean fired at Olympia were hits that would have destroyed the powerful US vessel.

    Commodore Davies, Australia's most experienced Collins commander, said the two vessels were very evenly matched. The submarines also practised landing special forces.

    The exercises provided a crucial test for the Australian submarine, which has been as much criticised at home as it has been feted abroad.

    The Olympia, 110 metres long and 12 metres across the beam, is twice the displacement of the Sheean, at 80 metres by eight metres. The Olympia carries up to 120 crew; the Sheean 45. Many of the Americans are engineers caring for their reactor.

    The Collins is powered by diesel and electric motors and its roles include undersea warfare - finding and destroying other submarines - destroying enemy warships and merchant ships, surveillance and intelligence collection, support for special forces and covert transport.

    Commander Davies said the US sub's size was not an advantage: "It just means you make more noise when you go faster."

    He said cooperation with the US submarine force had increased significantly recently. "That has come about because they're interested in the Collins class and in our submarine force generally."

    While the Americans run the world's most powerful submarine arm, they acknowledge that changes in international conditions in the past decade and new priorities have left them with tactics to learn from the small Australian submarine arm.

    Commander Davies said Australian submariners were used to operating in shallow water. "That's one of the things the Americans are looking towards us for experience in.

    "Ten years ago their submarine force was chasing Russian submarines around the deep ocean. Now, as with all submarine forces, it's more focused on closer inshore operations, intelligence collection or working with special forces. They're looking to us as a submarine force which has a long experience in that sort of thing."

    The six Collins' combat systems are to be upgraded further and they will get more modern torpedoes. Those the Sheean used in its clashes with the Olympia were developed in the 1970s; the Americans used a far more sophisticated generation.

    While smaller than the US nuclear boats, the Collins is one of the world's biggest conventional submarines. It was designed to cover long distances and the Sheean easily reached Hawaii without refuelling.
    Collins sub shines in US war game -

    They talk about going "faster" which brigns me to this
    PigBoatSailor said...
    One of the unfortunate reasons that SSKs have such a good reputation against SSNs is the nature of the excercises in which they are pitted against each other. In order to provide "training for all" a close encounter is forced - usually with the SSN screaming in at high speed from a distance - immediately giving the SSKs at an advantage.
    Again, without going into too much detail, I have done both the afore mentioned excercise (blew), and a week-long one with a diesel in which we were just hunting in a big chunk of ocean. In the second, more realistic, excercise, we wiped the ocean floor with the diesel. And these guys were not sloutches.
    Also, US SSNs have gotten a lot better at combined ops with surface and air assets. That will absolutely end an SSK right there.
    anonymous said...
    I was on the Miami during the initial testing of the AN/BSY-1 sonar system against Upholders in the north atlantic. We also developed hunt/kill tactics for ssk's during the period. The brit's are good sub drivers, and their diesel boys are some of the best. If a nook can identify, classify, and snapshot a ssk, all advantages are lost.
    SSK's are only good for one shot losses in most areas, and that's only if they are not identified while charging their batteries.
    The Stupid Shall Be Punished: Does Size Matter?

    Im starting to wonder how cabale modern diesel subamrines such as the U212/214,Gotland,Dolphin etc can be against Seawolf/Virginia class subamrines in excercises when older subs such as the Dutch submarine Zwaardvis can manage a kill on Carrier groups. I know US submarine design has changed with the Seawolf and Virgina and can sue natural circualtion however things like turbines,shafts etc still make noise at much higher speeds and boats such as the Virginia have newer types of sonars such as the LWWAA which are equivilant to using hydrophone grids.Since the paltform is moving I expect tripwire detections from Virginias to catch submarines unawares as wellas new ASW assets such as the SH 60R,SURTASS LFA, and upgrades to our subs esnors such as the AN/BQQ 10. However i'm still curious to think what you guys think will ahppen agaisnt the newest U212/214,Gotland etc.

    I'm not sureas of which excercises are really fixed and which are free play so I'm wondering if any of you guys would know.
    Last edited by Shadowsided; 16 Aug 07, at 03:23.

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    Uss North Carolina.


  3. #3
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    Quote Originally Posted by handball View Post
    It's an excercise they use mission kills in excercises btw which isnt the same as a hard kill.

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    Firstly, many US surface combatant ships were sunk in the open ocean by slow, primitive diesel submarines in World War II, including the carriers USS Yorktown, USS Wasp, the escort carriers USS Liscombe Bay, USS Block Island, the cruisers USS Indianapolis and USS Juneau, the destroyers USS Mason, USS Reuben James, , USS Jacob Jones, USS Hammann, USS O'Brien, USS Porter, USS Henley, USS Buck, USS Bristol, USS Leary, USS Leopold, USS Fechteler, USS Fiske, USS Eisele, USS Shelton, USS Eversole, USS Frederick C. Davis, and many other types of surface ships. US battleships were damaged by submarine attacks and taken out of action for months as well. In the case of the battleship USS North Carolina, one of the most powerful and up-to-date ships of her time, and far more advanced than the ships destroyed at Pearl Harbor, she was taken out of action for two months by a single torpedo fired by the Imperial Japanese Navy’s submarine I-19. In addition, the Imperial Japanese Navy’s 71,890 ton supercarrier Shinano was also sunk by a diesel submarine, as was the 36,000 ton fast battleship Kongo. Submarines also claimed five of the largest British carriers.
    The author offers some good points but they tend to ruin their credibility with statements like "slow, primitive diesel submarines".

    The Japanese and German submarines that sank those ships were hardly "primitive" by the standards of the day.
    The Japanese torpedo was also world-class.

    Next, some of the ships that he lambasts for getting sunk by submarines were hardly difficult targets. USS Yorktown and USS Hammann were both dead in the water and the Yorktown largely empty of her crew, having suffered unrepaired battle damage at Coral Sea and of course bombs and torpedoes at Midway.

    USS Porter was also damaged in battle before a Japanese submarine supposedly sank her (Japanese records don't even indicate that any of their subs fired on or sank a destroyer that day. More likely it was an American torpedo from a ditching Avenger).

    USS Juneau had also been badly mauled during the First Naval Battle of Guadalcanal and despite making a mere 13 knots, managed to avoid 2 out of the 3 torpedoes fired at her.

    HIJMS Shinano wasn't even complete, had an untrained crew and was also carrying dozens of civilians.

    I'm not trying to take anything away from the sub crews or their victims, but I personally wouldn't have pointed this out as "oh what a horrible thing for the Navy to lose all these ships to a submarine."

    Contrary to this guy thinks, US, German and Japanese subs were pretty damn deadly, no matter who or what you were.

    They were especially deadly if you were already a cripple, like so many ships on his vaunted list.

    Quote Originally Posted by handball View Post
    The battleship North Carolina was struck by a torpedo on September 15 1942.

    By the way, if you could, please avoid the use of all capital letters in your posts, it makes them rather difficult to read.

    Also, please stop by the Introduction forum and tell us a little bit about yourself

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    Thanks Tophatter You're the best this is why I Love WAB since we have very knowledgebale people here.

    On an unrelated note...We've had quite a surge of miltary and defense professionals lately its been hard to keep track, WAB is really growing I'd say this is probabaly the best board in terms of military knwoledge even superior to the like sof defencetalk, and IMHO.

    EDIT:I also found out that the Japanese Kadai class got sunk more times than they got kills LOL Not to mention the waters in which the Yorktown was in were highly cluttered from the debris which probabaly accounted for why it wasn't detected.
    Last edited by Shadowsided; 16 Aug 07, at 20:25.

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    Well our ASW has been improving active and passive and its a godo thing we're elasing these diesel/AIP boats from our allies. We've done plenty of thigns to improve our passive sonar withexperiments such as TESPEX.

    Forgive me if this quote is too long.
    The TESPEX experiments were conducted to determine whether or not the theoretical performance gains could be obtained under at-sea conditions. The results show that these new signal processing techniques offer some immunity to key limitations of current shallow water passive sonar technology. These include:

    • immunity to poor signal to noise ratios due to low (and reducing) target radiated noise, high ambient noise levels, and high strongly variable transmission losses;

    • immunity to poor array performance due to inappropriate physical assumptions underlying the beamforming techniques; and

    • shortening the often lengthy sequential process of detection, classification, and localization before a target can be engaged.

    The demonstration of the feasibility of environmental signal processing techniques during TESPEX provides nations with a firm basis on which to consider insertion of this technology into existing and emerging passive sonars. Environmental Source Tracking (EST) allows a single sonobuoy to localize and track a moving source, a capability not possible with conventional processing. Environmental Symmetry Breaking (ESB) provides passive vertical arrays, such as those in a distributed system, with the capability to "track before detect," which reduces the number of ambiguous target positions often occurring in matched field processing. The demonstration of generating modeled replica using only environmental parameters obtained from inversion of measured acoustic data means that apriori environmental data is not a prerequisite to employing passive sonars in unknown, hostile waters. The demonstration of the feasibility of passive surveillance using remotely controlled, unmanned equipment provides expanded military options for surveillance of both familiar national waters and hostile waters covertly.

    Advances in Technology

    Both TESPEX trials emphasized the role of the environment in signal processing, and the telemetry, via satellite, of the acoustic data. The several signal processing techniques investigated are all forms of what has become known as Matched-Field Processing (MFP). In MFP, an acoustic data base of some form is generated. This data base consists of elements, usually vectors of acoustic quantities referred to as replicas, which correspond to a source track or location. A source can then be located or tracked by matching (correlating) observations to the replica elements of the data base. While different countries emphasized different aspects of environmentally-based signal processing, the TTCP collaboration focused all nations on fundamental technology issues common to most approaches to matched-field processing.

    In TESPEX I, an acoustic source was successfully tracked by processing a single frequency on a single hydrophone. The technique, referred to as Environmental Source Tracking (EST), relies on the acoustic intensity variations resulting from the source motion through the complex propagation environment. The region was first characterized by making a series of radial tows of the source and the satellite-telemetered data was used to build, in near-real time, a regional data base which was then used to track the source along a variety of tracks in the region. These results demonstrated two novel ideas: (1) by relying on variations induced by the environmental it was possible to track a source passively using a single frequency and a single hydrophone - a task not possible with conventional processing, and (2) it is possible to characterize the acoustic propagation in a shallow water region using sparse direct measurements.

    In TESPEX II, a vertical array receiver was used to detect, locate, and track an acoustic source by matching received data against replica acoustic fields corresponding to different trial source positions. It was demonstrated that measured or modeled replicas could be used. For measured replicas, a data base of direct measurements can be employed, avoiding the complexities in generating accurate replicas using a sophisticated computer propagation model dependent on a fairly precise description of the ocean environment. Since conducting surveys to generate a measured replica data base may not always be practical, modeled replicas were also tested. There were several significant advances in environmentally-based signal processing in TESPEX II: (1) In order to simulate accurate acoustic replicas in a downward refracting shallow water environment, the sediment structure and geo-acoustic parameters are important considerations. In TESPEX II this was especially true for the first few acoustic wavelengths below the water-bottom interface. Since only gross average properties of the sediment were available, new environmental inversion techniques, based on parabolic-equation modeling, were successfully employed to characterize the sediment. (2) Techniques for extending direct measurements to predict measurements (replicas) corresponding to other depths were developed. (3) When only a single frequency is available for processing, there are often many ambiguous locations. Track-before-detect techniques showed that these ambiguities can be greatly reduced without significant additional processing.

    Benefits to National Programs

    The TESPEX data sets provided a cost effective means of improving, evaluating, and validating sonar performance prediction models and new signal processing techniques as well as identifying technology needs and technology insertion opportunities for the future. The exchange of acoustic propagation models and environmental signal processing algorithms among nations has strengthened each nation’s technology base from which improved national undersea warfare capabilities will derive. TTCP collaboration will continue on the application of environmental signal processing techniques to rapidly deployable systems and to multi-static active sonars. The immediate and future benefits to national programs are summarized below.

    Australia: Australia places great importance on the benefits derived from the TESPEX collaboration as they contribute to the key defense priority for the Australia Defense Force (ADF) of operational effectiveness in northern maritime approaches. The degree of success to which Australia can achieve this requirement is dependent on the collection and analysis of environmental and environmental acoustic data in these shallow tropical waters and the development of more accurate performance modeling for this region. The TESPEX collaboration has provided experimental data in this critical region (TESPEX II, Timor Sea), demonstrated rapid acoustic inversion techniques to derive environment parameters from acoustic data, and validated acoustic propagation models for shallow, tropical waters. Australia has specific interest in rapidly deployable systems and low frequency active sonars to enhance surveillance capabilities in strategic regions. The shared results and technologies from TESPEX will benefit Australia’s future research into these capabilities as well.

    Canada: Although undersea warfare commands a lower overall priority for the Canadian Forces (CF) than in the past, it remains an important capability. Canada looks forward to continued improvements in passive sonars and the eventual integration of active augmentation for low frequency sonars. Technological improvements gained from TESPEX in environmental signal processing will be critical to future developments. As an alliance partner Canada expects to have to operate in unfamiliar and complex littoral sonar environments. Environmental signal processing and environmental factors are thus highly relevant to anticipated CF operations. Deployed sensors will be used by Canada for self-protection, but it is not clear yet whether Canada will deploy expendable systems. It will probably be necessary, however, for Canada to assist in sensor system deployments and utilize data provided by such systems. Rapid environmental assessment techniques, whether from deployed or other operational systems, will need to be part of future CF operational planning. Matched field processing is seen as a necessary part of environmental assessment and an eventual operational sonar processing component.

    New Zealand: New Zealand’s sonar technology programs will continue to emphasize improvements to towed array and sonobuoy passive signal processing and to investigate the performance of multi-static active sonar with a view to augmenting the RNZN’s passive sonar capability with a low frequency active adjunct. The TESPEX collaboration has provided New Zealand with access to a substantial body of acoustic performance models and environmental signal processing techniques from which to draw for future national programs. The TESPEX I sea trail demonstrated the stability of acoustic fields in a test region of interest to the RNZN and showed that a limited amount of direct acoustic measurements in that region is sufficient to localize a target with Environmental Source Tracking using one hydrophone and one frequency ( a very attractive capability for upgrading sonobuoy processing).

    United Kingdom: The United Kingdom undersea warfare program continues to place a strong emphasis on detection and prosecution of quiet, conventionally powered submarines operating in shallow water environments, associated with possible littoral water regional conflicts. Such operations bring many technical challenges, particularly those associated with the complexity of the shallow water acoustic environment and its rapid temporal and spatial variability. The TESPEX collaboration covering the measurement, interpretation, modeling and prediction of shallow water environments and the development of environmental signal processing techniques to exploit this knowledge is therefore of central and immediate relevance to UK military interests. This knowledge base is an essential factor in improving the effectiveness and capability of the current generation of active and passive sonars. In the future, development of new systems capable of exploiting the local acoustic environment in order to optimize sonar performance is anticipated. A high priority is being accorded within the UK research program to develop means for a rapid environmental assessment of such areas using remote satellite sensing, airborne sensors such as lasers and IR, and both air and sea deployed probes to determine water column and seabed characteristics. As part of this program the UK is increasing its research efforts on the use of matched field inversion techniques for determination of environmental parameters. The development of rapidly deployable seabed sensors forms an important part of the UK strategy for coping with the quiet submarine threat in shallow waters. The current TTCP collaborative activity in rapidly deployable systems has a component to study matched field processing applications to deployable sensors which will build on the advances from the TESPEX collaboration.

    United States: The United States continues to place high priority on development of an effective undersea surveillance capability for acoustically harsh, shallow water environments associated with littoral waters in regional conflict. Successful sonar systems will require the flexibility to adapt to rapidly changing conditions and to operate with other nations’ systems. The TESPEX collaboration has accelerated the US current understanding of shallow water environments and the development and validation of modeling and environmental signal processing techniques. The US will derive significant benefit to future ASW technology programs from the technology advances in TESPEX. Improvements to passive signal processing will include situational adaptation of the sonar operating parameters to in situ measurement of the local environment (using acoustic inversion techniques) and upgraded processing algorithms exploiting matched-field techniques. Rapid environmental assessment technology to characterize the littoral acoustic environment will benefit from extending the acoustic inversion techniques developed during TESPEX. The development of environmentally adaptive sonar technology will rely heavily on through-the-sonar measurement techniques that enable active sonar systems to probe the acoustic environment directly in order to improve performance predictions, adaptive beamforming algorithms, and matched-field processing. The United States will continue to invest in rapidly deployable sensor technology and multi-static active sonar technology where specific applications of environmental signal processing (building on the TESPEX work) will be emphasized.
    MAR TP-9: TTCP Environmental Signal Processing Experiments [TESPEX]
    SURTASS LFA is a great tool for protecting our carrier groups even though I don't find it a vaiable solution for close in littoral ASW because of shore based AScM batteries.
    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 at levels in the range of 235 decibels or greater [the Navy has given a figure of 160 dB at about 2 km from the LFA] 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.

    LFA has been under development for more than a decade, and has been tested perhaps 25 times in several oceans since 1988. The Navy has already tested LFA for over 7,500 hours. IOT&E of LFA was completed in October 1992, in the Gulf of Alaska, testing an engineering development model (EDM) of the LFA system installed in a converted, monohull research vessel. COMOPTEVFOR found the SURTASS LFA system potentially operationally effective and potentially operationally suitable.
    Low-Frequency Active (LFA)

    The system basically operates in the 100-1000Hz which is least affected by the ocean environment. Has several different modes including CW and FM.
    no tot mention each ping varie sin frequency and length which is well suited for the littorals waters froma sonar perspective.

    The SH 60R and its ALFS have done well and are in fullr ate production ehich is good since SSK aprint tactics are less likely to work now.

    Raytheon Awarded $16.5 Million Contract For Next-Generation Dipping Sonar
    Navy Awards Two Contracts For Airborne Low Frequency Sonar System
    Sprint tactics in this article ad more info for VDS sonars

    Wish we had more P-3's though

    Sea Sparker is also an interesting program

    Sea "Sparker" Snags SBIR/STTR Success (defense procurement, military acquisition, defence purchasing)

    ARCI si alo an important tool for our subs in the littoral battle.

    USA Upgrades Submarine Fleet Acoustics Under A-RCI Program (updated) (defense procurement, military acquisition, defence purchasing)

    Ive also heard that theresa new tactic taht US SSN's are willing to sue in certain conditions in which one SSN uses his LF bow array to illmiante the SSK's while the other SSN's in the wolfpack go for akill or trip wire detection with the LWWAA or something like that.

    Kinda sucks that the ADS was cancelled and Lockmarts LCS contract was revoked.

  7. #7
    Global Moderator Defense Professional
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    30 May 06
    Quote Originally Posted by urmomma158 View Post
    Kinda sucks that the ADS was cancelled
    USN and NAVSEA are now participants in Australias ADS2 tech. They're also backdoored into the Acoustic Daylight (Gen 2) program

    ADS2 significantly changes the opportunity for ROV and USV management by subs.

  8. #8
    Join Date
    27 Apr 05
    Silicon Valley

    RE: Naval submarine free play exercise question

    Secondly, consider that even though carriers and surface ships are more advanced today, and are still much faster than conventional submarines, that does not give them any additional life insurance because in a war the enemy diesel submarine will know a) where the US Navy ships are coming from and b) where they are likely headed. They do not have to catch up to a carrier battle group making more than 30 knots; they can just wait for it, and no one can predict exactly where en route they are waiting.
    That might be true for a amphib force but, not necessarily true for a CVBG. Any SSK or SSI (SSK/AIP) in say the Indian Ocean trying to catch up with and destroy a carrier launching aircraft heading for Afghanistan, has a mighty tall task ahead of it. The CVBG is running around with no particular destination other than staying close enough to launch aircraft to get deep into Afghanistan. If the CVBG is supported by SSN's, they knowing the areas the carrier will be the next day can work to insure no SSK's/SSI's are operating in that area long before the carrier arrives.
    Once a diesel gets above five knots, it is no longer the stealthy ship it once was. SSI's are good provided they don't have to exceed the amount of electrical power that would force them to re-charge quickly or while operating at high tempo. That is when they are no longer super quiet.

    Getting back to exercises held in the Norwegian Sea or off Hawaii, these have ROEs that are artificial in order to allow all participants to engage and learn from the experience. In areas where there are coastal islands, carriers running around the islands carriers are difficult to locate. Then there are other problems subs have in locating a carrier, fjords and rivers inject fresh water greatly affecting the sonar picture and the sub's ability to locate a carrier.
    In an exercise back in the late 1980's, a US carrier operating off the coast of Norway, used coastal islands, fjords and, freshwater rivers to hide from Soviet Naval forces undetected for ten days! All the while conducting flight operations and recieving COD flights from the UK.
    E-2's and F-14's were intercepting all patrol and SNA flights looking for the carrier. The Soviet Navy also had SSK's and SSN's looking for the carrier.
    Had this been real, the Soviet Navy realized that attacks could have been mounted against the Kola Pennisula and their ability to stop the attacks would have been limited because they could not locate the carrier. This plus losing contact with a US carrier east of Cam Rahn Bay, Viet Nam and fourteen days later while working with a second US carrier was located north of the Kuril Islands, is what convinced the Soviet Navy that carriers were a lot more than just a targets.

    The HMAS Shean versus the USS Olympia (in Hawaiian waters) was an exercise with a "688" sub when there were plenty of "I688's" that could have been used! Yes there was parity during the exercise but, what were the ROE's?
    If an when the US Navy becomes serious about sending a CVBG in harms way, it will be using SSN-I688's, SSN-21's and, SSN-774's to protect the carrier from not only SSN's, SSK's but, also SSGN's. Not one of the oldest operating SSN's when the threat is a quiet sub.

    Last edited by avon1944; 31 Aug 07, at 07:08.

  9. #9
    Defense Professional Dreadnought's Avatar
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    12 May 05
    Philadelphia, PA.
    Quote Originally Posted by handball View Post
    North Carolina (BB55) was torpedoed portside September 15,1942 and repaired at Pearl Harbor Oct. 1942. She was torpedoed by IJN sub I-15.
    Fortitude.....The strength to persist...The courage to endure.

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