The U. S. submarine force no longer holds any significant acoustic advantage over a growing number of frontline Soviet nuclear-powered attack submarines (SSNs). Further, the funding necessary to regain any Past advantage is simply not available. These are realities that the United States must come to grips with today, before tomorrow’s war finds us fighting with yesterday’s equipment and tactics.
Acoustic advantage, like nuclear superiority, is not easy to quantify. It involves complex measures of broadband- and spectral-radiated noise levels, the ability to process these signals (at machine and human levels), and increasingly, one’s ability to exploit the sonar environment. While future gains in all these areas are almost a certainty, the immutable laws of physics will eventually lead to a condition where it is impossible to distinguish a target signal from the natural background noise of the ocean environment.
While we have not yet reached this limit, we face another sort of physical barrier. As target-radiated noise levels decrease, dependence on that end of the acoustic spectrum least affected by natural propagation losses increases. This very low frequency (acoustic) [VLF(A)] regime, while suffering least from losses incurred during travel from target to sensor, unfortunately requires extremely long-range sonars to yield directional information. Thus, while submarine sensors are capable of detecting these VLF(A) signals at moderate to long ranges, they yield few clues as to the target’s location. This disconcerting situation exists until higher frequency signals become available. Herein lies the crux of the acoustic dilemma. These higher frequency signals may not be available until either the target is inside minimum effective weapons’ range or the Soviet submarine has first counter-detected own ship. In fact, as both U. S. and Soviet quieting efforts have led to decreased detection ranges, the issue of acoustic advantage generally becomes academic.
For example, with an expected detection range of 20,000 yards, a 10% acoustic advantage translates into a 2,000-yard standoff capability. Compare this manageable situation with one where initial detection ranges are reduced to inside 2,000 yards. This same acoustic advantage now yields a mere 200-yard standoff. Given the uncertainties associated with the sonar environment, it becomes a toss-up as to which sub gains the critical initial detection.
The conditions that have led to this state of affairs are many and varied, ranging from better Soviet submarine housekeeping practices to the legal acquisition of critical Western technologies to espionage. While the cause of acoustic parity is not the issue, the fine line that separates acoustic advantage from acoustic parity is worth thoughtful delineation.
Present acoustic realities require that the submarine force critically appraise not only its tactical methods, but also its attitudes regarding Soviet SSNs. While some facets of the military can be accused of portraying the Soviets as ten feet tall and next to invincible, the submarine force probably could be found guilty of underestimating its Soviet counterpart. It has for so long been a race between the U. S. Corvettes and Soviet Edsels that operational superiority has, until recently, been considered axiomatic. As this superiority is called into question, so too must the organizational perceptions it has helped to create.
It is an understatement to say that the members of today’s submarine force are very self-assured regarding their ability to successfully engage the enemy. Far from detrimental, World War II submarine commanders would probably attest that such cockiness is absolutely necessary for success. Yet, the foundation of this attitude deserves attention. The basis of our perceived superiority must be born of confidence in our own abilities, not in the questionable hopes of an enemy’s inabilities.
Few familiar with SSN operations would find fault in the readiness level of the force. The ships are training, day in and day out, under conditions that we expect to find in wartime. Those anticipated wartime conditions, however, must be questioned. If the percentage of relatively long- range, controlled attacks is expected to be small, it would seem such exercise scenarios should be infrequent. They are not. If coordinated dual SSN operations are required affect a favorable exchange ratio, the force should be praticing with such conditions daily, not just paying lip set vice to the difficulties such operations entail.
The SSN has been, and will undoubtably continue to be, a principal offensive arm of the striking fleet. Acoustic parity will not alter this. However, the manner in which the Navy employs this weapon system requires much thought. Consider the principal mission of U. S. SSNoffensive antisubmarine warfare (ASW). The tactics currently employed in ASW are really one-on-one, SSN- versus-SSN tactics, where the implicit assumption is that the United States will control the engagement and, when ready, fire the first shot. Thus the problem becomes one of gaining a favorable firing aspect, making weapons ready and, anticipating counterfire, making ready to evade Acoustic parity is forcing tacticians to rethink this scenario. The submarine force is now beginning to turn its attention more toward the melee or close-in engagement the rules of which are completely different. Here, at distances often inside minimum weapons’ range, detection Or and counterdetection are made almost instantaneously. No longer does an SSN have the luxury of refining its fire to control solution or “polishing the cannonball.” No longer is it a simple matter of when to shoot and how to evade.
Perhaps a lesson can be learned in the Navy’s own backyard from those whose lives hinge daily on close-in battle performance—namely, the fleet’s F-14 and F/A-18 aviators. When they talk about checking their sixor about their disdain for flying solo missions, sub-mariners had better listen. Acoustic parity and Soviet force levels demand that, at worst, an engagement result in a one-for-one exchange. While SSN consort operations cannot guarantee even this, it could go a long way toward realizing that end.
The problems of working two or more SSNs together are well known. These problems are inevitably the result of conflicting requirements: to remain covert while at the same time, communicating required information between friendly platforms. Until now, that problem has been largely neglected because of the perceived ability of a U. S. SSN to overwhelm its adversary in the SSN-versus- SSN scenario. It is time to address this thorny issue of dual SSN command, control, and communication (C3) and to develop a working solution.
Further, acoustic parity does not appear to be a problem that readily lends itself to passive tracking and engagement techniques. Given a close encounter, U. S. SSNs must be able to rapidly switch from passive to active mode of operation, to gain a position abaft the target’s beam, where the target can neither effectively search nor engage, and to maintain that position until the target is neutralized. Such close-in active engagements require both aggressive tactics and expert shiphandlers—and here rapid advances are possible. The submarine force is gifted with an abundance of expert tacticians, capable of quickly developing and implementing the necessary operational guidelines. The shipdriving expertise is resident, by the very nature of today’s operational requirements, in every submarine commanding officer. The need, then, is to subject this new operating environment to careful analysis, generate the required guidance, and begin to develop fleet-wide tactical operating experience.
A simple reality of acoustic parity is this: U. S subs are going to get jumped by Soviet submarines, and probably more often than the force cares to admit. Of necessity, the target ship will immediately assume a defensive posture. There are two keys to handling this situation effectively. First, the submarine must successfully evade the incoming weapons. This is purely defensive. Second, the submarine should rapidly switch to the aggressive, offensive operations discussed previously. Only in this way can the submarine force ensure the exchange ratios necessary to defeat a numerically superior opponent.
The ability of U. S. submarines to adequately defend themselves and quickly regain the offensive initiative must be improved. Several areas require attention:
► Countermeasures: The history of acoustic countermeasures is like that of their electromagnetic counterparts. A device is developed to be applied in a specific threat environment. Soon after entering the fleet, the threat changes in response to the countermeasure. A new countermeasure program gets under way, and the cycle continues. This is not an unbreakable chain. Instead, the submarine force could learn from the rest of the Navy and develop a close- in point-defense weapon system.
The development of a hard-kill countermeasure will serve two immediate purposes: First, it will slow this cat- and-mouse game of countermeasure/counter-countermea- sure; second, and perhaps more importantly, an effective hard-kill system will allow the SSN commanding officer to quickly transition into an effective offensive posture. This is not to say that the commander will devote less attention to the incoming fire. In a successful acoustic countermeasure deployment, the chances are high that the decoyed weapon will shift from a search mode to a terminal homing mode. Whether you are on the sending or receiving end of a sub-on-sub exercise torpedo attack, terminal homing is terminal homing, and without the benefit of sight it is at times nearly impossible to decide on which target the torpedo is homing. The luxury of assuming that own ship is out of danger is simply not available. The result is that evasive actions take lots of time.
Hard-kill countermeasures should change that. Either the incoming torpedoes are destroyed or they are not. The commander, basing his reaction on this straightforward indicator, will more rapidly be able to train his sights on the target at hand. This rapid reengagement is the key to a successful outcome.
To acquire a hard-kill capability will be expensive. It will require substantial funding and a concerted research and development effort. While this is at odds with current fiscal burdens, it is a realizable goal. The question is whether the Navy is willing to sacrifice a unit of force level for the expected gains such a system will bring about in SSN-versus-SSN exchange ratios. It is a difficult decision, both tactically and politically. While additional platforms remain attractive, the quantitative gains possible through this and other upgrades favor vertical cuts.
►Burst Acceleration: The ability to evade an incoming torpedo is heavily dependent upon the submarine’s ability to rapidly accelerate to maximum speed. While powered by the most sophisticated and reliable nuclear propulsion plants in the world, the submarine force’s ability to quickly “get up on the step” needs to be improved. A variety of methods, most notably polymer boundary layer injection, have been proposed. Tomorrow’s engagements require that this process be moved out of the labs and into the boats.
► Reengagement: Generally speaking, today’s SSN tactics will not result in a rapid switch from a defensive to an offensive posture. Such a transition is directly affected by countermeasure employment, burst acceleration capability, and fleet tactics. While some measures currently taken during torpedo evasion may appear offensive, all are, in fact, defensive. This is a logical modus-operandi given the premise that a majority of engagements will occur under conditions that are controlled by the engaging submarine. Thus, for those rare encounters when the submarine is placed on the defensive, simple survival is adequate to ensure favorable long-term exchange rates. When that premise is found wanting, as it is under conditions of acoustic parity, such purely defensive posturing becomes unacceptable. Submarine force tactics must provide rapid and active reacquisition, track, and destruction of the shooter. Good words, but ones that must be translated into action through aggressive tactics, required to maintain the upper hand.
Beyond the expected changes acoustic parity will bring to the SSN-versus-SSN tactical arena is the impact it will have on the U. S. Maritime Strategy. To begin with, the stand-alone SSN is no longer the ultimate ASW platform. Constraints limiting the physical size of on-board detectors have resulted in effective acoustic sweep widths smaller than that required for efficient search in most open-ocean areas. While submarine systems are being developed to close the gap, the advent of very large aperture arrays, deployed and operated by surface ships, has ushered in a new era in ASW search.
The ramifications of this are many. Perhaps most directly, the SSN’s role in carrier battle group (CVBG) direct support needs to be reexamined. While required to fulfill many necessary tasks in the CVBG direct-support role, it is perhaps asking too much to expect the SSNs to effectively sanitize their assigned sectors. If this is a task beyond the capability of the SSN as currently equipped, then a suitable substitute must be found, one which is not limited by a similar physical constraint. This asset, a sort of subsurface AWACS (airborne warning and control system), has as its beginnings the SQR-19 sonar system. If the additional capabilities of the new ocean surveillance ships (T-AGOSs) are taken into account and the C3 capabilities of the Ticonderoga (CG-47)-class cruiser are folded in, the off-the-shelf ASW capability required of such a surface platform is in existence today. This frees the SSN for the CVBG direct-support task to which it is best suited: namely localization, track, and if necessary, attack.
Another vital aspect of the Maritime Strategy is the SSN’s role north of the Greenland-Iceland-United Kingdom (G-I-UK) Gap in the early stages of conflict. If the submarine force’s mission is to sweep the Norwegian S of the submarine threat prior to CVBG operations, SSNs are going to need some help. Discounting moor sonar sensor assets as early targets during a hot war, CVBG is dependent upon surface and air ASW support. The following problems become immediately apparent.
►Unfavorable weather might preclude any type of sea platform from operating except for submarines
► Non-CVBG surface or airborne assets will be forced deal with attacks by Soviet naval aircraft
► Air assets will become less and less effective in a sea role as target source level decreases In other words, the conditions that led to acoustic parity the SSN-versus-SSN arena have likewise affected acoustic capability. How then can CVBGs sail into contested area and survive?
In peacetime, U. S. prepositioning of moored and ASW search assets should reflect a fairly accurate assessment of Soviet Northern Fleet submarine Suppose, for clarity of argument, that only two dispositions are available to the Soviet force In the first case all Soviet SSNs would be either in port locally deployed to the Barents operating areas. This condition, referred to as a compact disposition, would correspond to a non-alerted initiation of hostilities. This compact disposition, coupled with the geographical constraint of the region, should make a predeployed, high-density. U. S. nuclear attack submarine barrier an effective three to Soviet SSNs.
Given a compact prewar disposition then, the U. S fleet commander should consider an increase in forward deployed SSNs. The SSN screen should ensure that the CVBGs can immediately move into the Norwegian Sea allowing rapid forward support of NATO’s Northern Flank. The numbers of U. S. SSNs required to effectively contain a Soviet SSN breakout would be high because the SSNs’ limited acoustic sweep width. Only the geographical constraints of the area make such a screen possible. However, being possible and practical are not necessarily the same thing. The key to effective offensive operations would be an upgraded SSN C3 capability.
The second possibility, referred to as the diffuse disposition, would have all Soviet Northern Fleet submarines deployed beyond local operating areas, their positions Unknown at the outbreak of hostilities. In this alerted status, the SSN forward barrier would serve little useful purpose. In fact, were SSNs the only available U. S. assets to conduct sanitization north of the G-l-UK Gap, the attrition of Soviet SSNs required to sail a CVBG safely into this vital area could not be guaranteed. Instead, consider the CVBG which deploys with a large SSN direct-support screen. Given the tremendous search/detection capabilities Possible with the SQR-19 sonar system, the T-AGOS ships, and the rapid localization/attack potential of a large, properly deployed SSN screen (in concert with the CVBG’s ASW air assets), the offensive ASW capabilities of this force should be unmatched. Thus, if a diffuse disposition exists prior to conflict, the U. S. fleet commander should consider augmenting CVBG direct-support SSNs with forward-barrier SSNs.
Unfortunately, the United States cannot expect the Soviets to assume either a purely compact or purely diffuse disposition. However, by bringing to bear available wargaming, simulation, and analytical assets, the functional relationship between Soviet Northern Fleet submarine disposition and U. S. SSN posture should become clear.
Three conclusions may be drawn from this discussion. First, U. S. SSNs and land-based air assets cannot be expected to effectively sanitize the region north of the G-I-UK Gap given acoustic parity. Second, Soviet Northern Fleet SSN disposition should affect the deployment of U. S. SSNs. Third, the problem of wartime support of the Northern Flank is solvable, even under the assumed conditions of SSN-versus-SSN acoustic parity.
The submarine force must begin to develop the skills and tactics necessary to meet and defeat an enemy whose only significant disadvantage in the area of undersea warfare may be his lack of creative, aggressive, and individualistic tactical thought.