In the Navy's Future: The Small, Fast Surface Ship

^t^e small, fast ship exposes herself to enemy torpedo ^or missile attack. In the case of attack by a super­sonic cruise missile, however, the difference in prob­^ability of missile acquisition between a ship traveling 50 or 80 knots and one towing a sonar at 10 knots or °ne at dead stop is simply not significant. Just like conventional escorts, the small, fast ship would rely °ⁿ her point defense systems to meet a missile at­tack. One additional factor tends to make the fast escort less of a missile target than the larger current ASW escorts. Small ships present less of a target to airborne surveillance radars than do their larger coun­terparts. It should also be remembered that the enemy may not wish to expend its limited number of faissiles on any type of escort, regardless of size.

Torpedo attack is another possible threat to the ^small, fast ship. However, the small ship presents a ^smaller underwater target area than does a larger one. When the fast ASW escort comes to a stop in the ^sptint-and-drift tactic, she can quickly search the •mmediate area with an active dipping sonar to as­sure that there are no submarines within torpedo ^range. If there are, the escort can immediately launch an over-the-side torpedo against the submarine. Moreover, the probability is very low that a sprinting ship screening in a large-area, dispersed formation, ■Would slow down or stop directly in the path and within range of a torpedo-firing submarine. Even if this were to happen, it is doubtful that the sub­marine would be instantly ready to fire torpedoes without first computing fire control solutions based °n analyses of target motions. In the rare case of such ^a close-in duel, the outcome might favor the ship that first searches with active sonar and most quickly localizes the target for attack. The submarine is doc­trinally less likely to search actively because active ^Search deprives her of her most salient advantage, the ability to remain undetected.

Advantages of High Speeds of Advance: Admittedly, ^s°me students of antisubmarine warfare maintain ⁽hat speeding up a moving force actually increases its vulnerability, since the higher noise level could make *t more subject to acoustic detection. But this argu­ment fails to account for the fact that our surface ^ships are already detectable by passive acoustic sen- ^s°ts, even while they are moving at moderate speeds. The Soviet surface surveillance system must also be ^Credited with a reasonably good ability to discover the general location of our surface forces without re­acting to submarine sonars for initial detection. Their ocean surveillance system is probably effective for coaching submarines during their approach to our surface ships. It may not, however, be very good at identifying specific contacts, so the Soviet submarine would be presented with a difficult target selection problem. The character of the noise that is radiated by a fast-moving force does not readily lend itself to easy classification by passive submarine sonars. Thus, the additional noise put into the water by fast speeds of advance would provide the enemy submarine with more detection, probably redundant to that available from the surveillance system, but would be little help in target identification and selection.

In addition, if the Soviets were forced to perform target identification solely by acoustic means against a U.S. force containing a wide variety of surface ships, they would find such identification even more difficult in the face of sophisticated U.S. acoustic countermeasures. For these reasons, then, it is likely that a higher speed of advance would not increase the vulnerability of a moving force. Conversely, there arc- valid reasons why high speed might actually reduce the vulnerability of that force.

First, we should address the many obvious advan­tages which accrue to a higher wartime speed of ad­vance. Carrier task groups capable of 28 knots or more could, for example, transit more rapidly to operating areas within the mission radius of their strike aircraft. The fast escort could also screen for combat support ships such as those of the Sacramento class (AOE-1) which in wartime could transit at their 27-knot top speed to an urgent replenishment ren­dezvous with a carrier task group or other dispersed forces. The high speed of the fast escort would pro­vide these logistics ships with greater mobility.

Faster speeds of advance could also improve the resupply and reinforcement of NATO forces in the event of a European conflict. Modern container- ships—some with speeds in excess of 30 knots—arc- available for fast transatlantic sealift, but current ASW screens for these ships are not able to take ad­vantage of their high speeds. The transit time dif­ference between current and potential sealift speeds of advance is about four days, a saving of time that might be crucial if NATO were called up to repel an invasion by Warsaw Pact nations.

The shorter transit times would reduce the expo­sure of those ships to attack and reattack by enemy submarines and bombers. In the case of enemy bombers, this reduced exposure would be mostly a result of the shorter time spent in transit within range of airfields in the Warsaw Pact nations. In the case of submarines, however, several other factors would further reduce the targetability of a fast- moving force.

Using evasive steering, a fast-moving force can provoke enemy submarines to proceed at undesirably high (noisy) speeds in order to position themselves for an attack. This approach problem could become so difficult at high speeds that many submarines would be unable to close to effective cruise missile range. Moreover, the greater the launch range from which a submarine is forced to fire her cruise missile, the more effective are our anti-missile defenses. It is important to remember that all cruise-missile sub­marines are also capable of launching torpedoes. It is a reasonable assumption that they would attempt to close for short-range torpedo attacks after completing missile attack. Up to now, the torpedo has been a potent threat to surface ships, but the fast, evasive surface force would help reduce the probability that the torpedo would be fired. Of course, since the high speed only reduces—but does not eliminate—the opportunity for enemy torpedo attack, an inner screen for torpedo defense must be maintained. Such a screen can be provided by using active dipping so­nars in combination with sprint-and-drift tactics. One final point—a fast-moving submarine attempt­ing her approach on a high-speed force radiates a great deal of additional noise and is herself much more readily targeted by the passive sonars of ASW escorts.

Improved Tactical Mobility and ASW Localization and Attack: In a widely dispersed formation, the greater the distance between ships, the longer it takes to reorient their stations in response to changes in the tactical situation. A conventional 27- or 30- knot escort ship in a distant ASW or AAW screen sta­tion requires several hours just to reorient to a new screen axis or to take a vacant screen station. How­ever, a dispersed formation with high-speed escorts has the mobility not only to change axis rapidly, but to react, for instance, to early warning of an impend­ing bomber raid by moving from distant ASW sta­tions to the preferred close-in air defense stations.

Tactical mobility is more than just a desirable as­set; it has become a virtual necessity as a result of the recent trend toward long-range passive sonars. Ships conducting passive search with towed arrays typically do so on screen stations anywhere from 30 to 50 nautical miles away from the ships they are protect­ing. This distance keeps the passive sonar clear of noise patterns radiating from the protected force and at the same time extends the radius of protection to match the increased range of submarine-launched antiship missiles. Nevertheless, the long distances involved mean that current ASW escorts on these sta­tions would require excessive amounts of time to ad­just stations even for a simple change of base course. In this case, greater speed is absolutely essential.

Just as it can contribute to the tactical mobility of the overall surface force, the high speed of the new surface combatants has great potential for improving the localization phase of the ASW problem. For example, the fast ship towing a passive sonar can maneuver rapidly to extend the baseline between two successive detection bearings to the target, thus fix­ing the target’s position with greater certainty. The same tactic attempted by a slower ship might not work at all, since the target submarine would have ample time to move to a new position where sound propagation phenomena, such as annular sonar cover­age, might make it very difficult to redetect.

High speed also plays a valuable role in the attack phase. With a 15- to 20-knot speed advantage over a Soviet nuclear submarine, the fast combatant could overtake the target and attack her with over-the-side homing torpedoes, provided she can be coached to the area by another ship’s active sonar. With a new ASW standoff weapon, the fast escort could close to attack range in even shorter time. During the termi­nal phase of the attack, the fast ship could use eva­sive maneuvers to reduce chances of being hit by ^a torpedo launched by the submarine—assuming, that is, a submarine taking fast evasive action could even launch an effective torpedo counterattack.

Coordinated Tactics Using ASW Aircraft: The idea that each naval unit must always be autonomous and able to perform naval missions independent of other units is a luxury the Navy can no longer afford. 1° fact, coordination between ships and aircraft is an important feature of the modern ASW operational concept. It will become even more important in time. The typical naval task group or convoy, for example, will normally have ASW aircraft available for tactics coordinated with the fast ASW escort. For wartime naval operations, we could expect to see large numbers of land-based patrol aircraft such as the P-3C deployed over the important sea lines of communication, especially in the vicinity of our sur­face ships. In addition to their assigned patrols in the forward sector of a moving force, the P-3s serve as excellent attackers for long-range towed array detec­tions made by the fast ship. The patrol plane is pre­ferred in this role because it has adequate speed, en­durance, range, and expendable ASW sensors—all of which are essential to reacquire the target initially localized by the fast escort.

Passive towed array sonar detections may occur at extremely long ranges where positional accuracy of the target is poor and where areas of uncertainty are large. When aircraft carriers are a part of the task group, there would be numbers of S-3A ASW aircraft available to perform the reacquisition and attack role. ASW v/STOL (vertical or short takeoff and landing) aircraft launched from the small deck carrier would he an alternative to the S-3A. But either type of air­^craft should be adequate in speed, endurance, and Payload to conduct the large-area search needed to reacquire the target in a minimum of time. Helicop­^ters carried by the escorts, aircraft carriers, or even ^by some convoy ships would also be useful, but to a ^lesser extent than P-3s and S-3s. They would be best relegated to follow-up against shorter-range contacts ^where position uncertainty is not large and where the ^acquisition task is not degraded by the helicopter s k'sser signal processing capacity, relatively smaller Payloads, and limited time on station.

There may indeed be such sufficiency in the ASW aircraft available to naval or convoy forces that not all Masses of escort ships would need to carry ASW requirements. For example, even our latest and most capable attack submarines used in a direct antisub­marine support role, using passive towed arrays for initial detection, would be likely to hand off long- range sonar contacts to ASW aircraft for prosecution.

helicopters. This could certainly mean a further re­action in ship size and displacement, but it would force a greater degree of interdependence between di­verse vehicle types. Some argue against this interde­pendence and, instead, would require each ship to be self-sufficient so that she would incorporate redun­dant ASW capabilities. However, the possible abun­dance of fixed-wing ASW aircraft in the operating area—all of which outperform the ASW helicopters—could certainly reduce ship helicopter

Fast Escort AAW Role: Although intended primar­ily as an ASW ship, the small, fast surface combatant can also make a significant contribution to antiair warfare, both as a radar picket and as a ship for area air defense using canister-launched missiles. As with ASW, one of the important requirements of the fast surface combatant’s AAW role is that she should pro­vide considerable capability in a relatively low-value platform. With the relatively lightweight but high- performance radars now available, it would be possi­ble to configure the fast surface combatant as a radar picket. In the radar picket role, the speed advantage

of this ship would enable her to deploy rapidly to cover the axis or sector from which an air attack might be expected to come. Speed would also enable them to maintain proper radar picket station relative to high-value ships, when at great distances.

Further, small AAW ships could employ highly ef­fective three-dimension air search radars, adequate to provide long-range detections and tracking of “Backfire” bomber raids in all but the heaviest elec­tronic countermeasure jamming environments. These ships could be armed with canister-launched AAW missiles which use active seekers rather than relying on the large heavy semi-active fire control directors now prevalent in the fleet. The resultant weapon suite would, like its ASW counterpart, be relatively lightweight and well suited to the small, fast ship and would complement AAW performed by larger ships. In addition to her own surveillance radar, the small combatant could use tactical data systems, video links from other ships, and airborne early warning aircraft for targeting the air threat. When radar detections are degraded by heavy electronic countermeasures, the small ship might be forced to rely on radar detections made by the larger ships (such as Aegis missile destroyers) or by airborne early warning radars. Armed with active seeker surface- to-air missiles, numerous small ships could provide the increase in firepower essential for handling the expected raids by large numbers of “Backfire” bom­bers.^[1]

When en route at high speeds of advance in a mixed screen composed of small, fast ships and large conventional escorts, the conventional ships would be unable to provide ASW protection. Instead, they would be stationed close in for AAW defense, while the small, fast ship would be optimally stationed for ASW screening using sprint and drift. The fast ship could, however, simultaneously perform AAW against the high-altitude air threat. The dispersal of AAW armament into a greater number of platforms would make it more difficult for the “Backfire” raids to penetrate task force air defenses. With some early warning from airborne early warning radar or other ocean surveillance assets, the task group commander could redeploy his fast ships in time to concentrate missile firepower along the threat axis or sector.

It is sometimes claimed that large ships are needed for AAW because only they can carry a very large number of surface-to-air missiles. This claim may have been supportable when the only way to carry quantities was to have one or two large mechanical launchers, such as the MK 26 Mod 1 or 2. However, now it is possible to carry the same number of mis­siles in canister box launchers at a fraction of the weight. A small ship could therefore carry a large magazine of surface-to-air missiles. It should be noted, however, that the number of missiles needed per ship is another issue, as it is not an unusual oc­currence in some firepower studies to find an AAW ship knocked out long before she has expended the majority of her missiles.

The Role of the Small, Fast Ship in Antisurface Ship Warfare: Just because the large ship is big enough to be armed with heavy guns (5-inch or 8-inch) in addi­tion to Harpoon surface-to-surface missiles does not mean that this larger ship will be more effective in antiship engagements than a small ship armed solely with Harpoon. In general, gunfire will provide only a marginal addition to antiship firepower already provided by missiles. Given the near-equivalency in armament, what attributes of the small, fast ship could possibly distinguish her from a large conven­tional ship in antisurface warfare?

First, obviously there are her speed and tactical mobility. High speed enables a ship to conduct in­spection of unidentified contacts transiting across a wide front at a choke point barrier. The greater the number of unidentified ship contacts passing through the barrier, the higher the ship speed required to intercept each surface contact. Also, when airborne radar surveillance is available, as it is likely to be when we have control of the air, the fast missile ships can be rapidly positioned to intercept points that are within their missile range. From these intercept points, the fast ship can identify and, if required, engage several targets in sequence. A slow ship, on the other hand, might find it difficult to carry out this sequential tactic on a long barrier line against numbers of contacts.

Furthermore, the small ship presents a smaller radar cross-section than does the larger ship- Through selective use of electronic countermeasures deception, the small ship can be made to simulate the radar return of the largest ships in order to con­fuse the enemy’s target selection. There is, unfortu­nately, no convenient technique to make the large ship look small.

The small ship in antisurface ship warfare is pre­sumably lower cost than much larger ships. There­fore, small ships could be acquired and deployed in numbers which would prove useful in missions re­quiring presence. Furthermore, when numbers of ships are available to a fleet commander, he can either disperse or concentrate them as required to kting missile firepower to bear against enemy surface forces. Such a dispersal into numerous widely- separated locations to shadow Soviet ships may be- eome necessary in order to gain intelligence that may reveal their preparations for a preemptive strike.'* Ships on station could counterattack should the preemptive strike take place. For this task, quantity °f ships is preferred to only a few costly ships. Task force command, control, and communications could link all dispersed surface ships conducting surveil­lance over a wide area into a central reporting net.

High Unit Capability and Higher Force Levels: The fact that ships are small is no reason to regard them ^as any less effective than much larger ships. The small, fast ship could have her design restricted to only those systems that support the highest priority cnission areas. Consequently, in terms of capabilities ^chis ship can be regarded as being in the high end of ^the so-called high-low mix. But, because she is con­strained to use only the essential elements of a com­bat system, and because the ship is small, her cost tocans she can be affordable in greater numbers than larger ships. Moreover, because of the interaction of high speed with key weapon and sensor systems, the small, fast ship may indeed be more capable than ships of much greater size and displacement. In most of the high-priority mission areas, such as ASW, these more capable yet more affordable ships could fulfill the need for numbers without sacrificing unit capa­bility.

operational Considerations in a "Blue Water Navy:’ important as the fighting attributes of these ships ^may be, these alone are not sufficient to justify a small-combatant building program. Range, endur­^ance, and seaworthiness must also be considered, es- Pocially since experience has shown that a small ship generally tends to have a smaller operating radius. Nevertheless, the evidence indicates that naval de- S'gners can produce small, fast ships capable of meet- *ⁿg the range and endurance requirements of a “blue ^Water navy” in most scenarios. Maximum range for these ships, measured as a function of ship speed and ^Sea state, can be made transoceanic in many designs. Small, fast ships—like all naval vessels, including ^nuclear-propelled aircraft carriers and cruisers—will ^re<juire underway replenishment of one kind or another. It can be expected that the frequency of re­veling for the smaller ships will be slightly greater

Mansfield Turner and George Thibault, “Countering the Soviet Threat ^{in f}he Mediterranean,” Proceedings, July 1977, pp. 25-32.

than that of larger conventional hull, nonnuclear es­corts, but this slight difference need not be signifi­cant. For example, in the 3,300-nautical mile Atlan­tic transit from Norfolk to Gibraltar, the typical fast ship as small as 700 tons would need only one underway refueling, and some of the ships could make the entire transit without refueling.

Seaworthiness is also a vital consideration in the design of a small ship. Certain of these small, fast ships incorporate ride control features that enable them to operate quite well in high sea states. The goal should be to design the smallest militarily effec­tive ship which is capable of operating in high sea states.

Summary: The Navy has the technology in hand to build small, fast, multi-mission surface ships with considerable capability in the ASW, AAW, and an­tisurface ship mission areas. Certain key lightweight weapon and sensor systems make the small, fast ship feasible and attractive. These ships can be more effec­tive than many of their larger conventional counter­parts, particularly in ASW. Because of their small size, they would be less costly to acquire and to oper­ate. The lower cost of the new, small ships would xean that the U.S. Navy could afford them in greater numbers—that is, in the numbers of effective ships that the Navy must have if it is to meet the chal­lenge posed by the Soviet Navy. It is not suggested that the entire surface Navy be reconfigured around this new technology. Rather, the small fast ship can be introduced as a complement to existing conven­tional surface ships. Operational concepts have been devised which permit their effective integration into the fleet. If it is to carry out its mission in the years to come, the U.S. Navy must not fail to take advan­tage of this opportunity.