On 26 October 2006 a Chinese Song-class diesel-powered attack submarine was seen on the surface near the aircraft carrier USS Kitty Hawk (CV-63), beyond the ship's horizon but reportedly within torpedo range. The Kitty Hawk battle group was near Okinawa. Reports of the incident imply that the sighting was a surprise to the U.S. battle group, reminiscent of the embarrassment when a Soviet Victor III-class submarine put up its sail near a U.S. carrier during the latter stages of the Cold War. Both incidents can be read as wake-up calls for U.S. ASW, and the current incident can be read as proof that this capability has stagnated since the end of the Soviet threat. Because the Song is a current-generation diesel submarine, the incident will also fuel fears that the largely passive techniques developed against Soviet nuclear-powered submarines are ineffective against the diesel submarines operated by countries such as Iran.
The Chinese have long seen the U.S. carrier force as a major factor in the mainland's ongoing attempt to force Taiwan to come to terms. When China tried to impress the Taiwanese with long-range missile exercises in 1996, U.S. carriers operated in the Taiwan Straits. The Chinese military press carries articles about anti-carrier measures that broadly mirror those the Soviets developed: missile-carrying bombers and surface ships and torpedo- and missile-carrying submarines. The Chinese have Russian-developed wake-following torpedoes, and they also have a submarine-launched Sub-Exocet-style missile. From a Chinese perspective, displaying a submarine near a U.S. carrier would be a major deterrent triumph.
It is easy enough to imagine why the Song was not detected. Sonar conditions in the South China Sea are notoriously bad, so active detection at any distance may have been quite difficult. A diesel-electric submarine running on batteries can be very quiet. Detection requires knowledge of its acoustic signature, and that in turn requires exposure to that particular type of submarine. Until very recently Chinese submarines have not operated widely afield, and thus the Song signature may not have become known in detail. (Much of the story of U.S. Cold War submarine operations involved gathering acoustic intelligence, so that in wartime Soviet submarines could be detected and tracked.)
Terrible sonar conditions are a double-edged sword. If the submarine is on her own. she has to depend either on her own passive sonar or on her periscope or radar to detect a surface target. If the surface ships suffer from short sonar ranges, so does the submarine. Using the periscope or radar opens the submarine to active or passive radar detection. Radar may be a relatively safe option in parts of the South China Sea, because the submarine radar signal will become trapped in a duct below the level of shipboard radar detectors, but it would be difficult for the submarine to he sure of that. Trapping may not protect the submarine from aircraft looking down into the duct from above. Nor can it protect the submarine from periscope-detection radar.
More generally, carriers gain immunity from attack by diesel submarines because of their high speed. It is difficult at best for a slow submarine-a Song is probably capable of 22 knots submerged, but for no more than an hour, and possibly for a lot less-to catch one. The submarine's odds improve dramatically if she can wait in a strait through which the carrier has to pass, or if the carrier's movements can somehow be predicted, e.g. if the carrier commander is foolish enough to follow a pattern that the submarine or the submarine's command can observe. The speed problem is why U.S. Cold War carriers were endangered only after the Soviets deployed nuclear-powered submarines. One argument in favor of switching to nuclear power for all U.S. carriers was that they gained sufficient sustained speed to evade virtually all submarines.
The previous caveat, that the submarine can strike if somehow the carrier's movements can be predicted, may be significant, and it may be the most important information to be deduced from the recent incident. Ocean surveillance has a vital but largely unsung role in naval warfare.
Many current discussions of network-centric warfare assume that the United States has a monopoly on this technique. Future war is often seen as a contest between sophisticated sensors on our part and numbers on the enemy's. That may be unfortunate. If the enemy has his own sensor net, then the contest may be more one of mutual deception (the attempt to destroy the enemy's information so as to degrade his force). Moreover, an enemy who uses netting will gain insights into our operating practices that no amount of reading of our publications can provide him.
During the Cold War, the Soviets had their own ocean surveillance system, just as we had ours. We called theirs the SOSS (Soviet Ocean Surveillance System), although it seems that the Soviets never had a single integrated program. They appear to have been interested in a netted system before we were, hut they were clumsier and, most important, they did not take the step of disseminating the picture to their deployed fleet. That made for sluggishness that would probably have had considerable wartime costs.
Once the SOSS had been discovered, we tried to measure its capabilities. That is why, throughout the Cold War, carriers again and again tried to evade the "tattletales" trailing them. How long they could remain clear was a measure of Soviet capability. Probably there were also orders not to try to evade under some circumstances so that the Soviets would not be too sure of our own capabilities against their system. That might apply particularly to the extent of our knowledge of just what the Soviet space-based surveillance system could and could not do. Such knowledge in turn would be key to a vital wartime attempt to deceive the Soviet system, or to use it to attract and destroy Soviet antiship forces. This was network-on-network warfare.
Think back to the Song incident. How did a relatively immobile diesel-electric submarine get into position to attack a fast carrier? Perhaps it was chance, and perhaps the carrier always follows the same path back to her base in Japan. During the Cold War, diesel submarines often "sank" carriers in exercises when the carriers were "mod-locked" into small boxes so that the submarines would get the chance to hit them. That is, they could attack when they did not have to connect with fast freely maneuvering carriers in the first place. A carrier following a prescribed path is as good as mod-locked.
It' the carrier was not following a prescribed path, then the Song incident was a public demonstration of a Chinese equivalent to the old SOSS. It would certainly make sense that the Chinese have built up such a surveillance system. Their main current naval advisors are ex-Soviet officers who would have relied on the SOSS in wartime. They have bought weapon and platform elements of an anti-carrier system broadly analogous to what the Soviets had. The missing part is the SOSS equivalent. It would be a combination of distributed sensors and one or more central collating elements. As for the sensors, among other things, the Chinese reportedly have bought Russian high-frequency surface-wave radars, which provide solid coverage out ISO nautical miles to sea.
Perhaps we should call a Chinese SOSS the CHOSS. The existence of a CHOSS would have important implications for the U.S. Navy. One would be the value we place on very stealthy surface ship configurations such as that of the new DDG-1000 class. Stealth cannot be absolute; a platform is stealthy for some sensors but nol for others. Generally, anti-radar shaping works best against the sort of centimeter-wave radars used by patrol aircraft and missiles. It is unlikely to work against something like a high frequency surface-wave set. In the past, that seemed a minor issue because no airplane or missile could possibly carry such a radar. However, in a netted system the big radar array ashore cues the airplane or missile. It still carries a radar susceptible to stealth configuration, but merely assuring the airborne radar of a real target within a limited sea area makes an enormous difference. The radar can concentrate on a few weak signals and analyze their movements to filter out the spurious ones. The airborne platform may even be cued well enough for it to use a narrow-area sensor such as a laser radar (against which anti-radar stealth is unlikely to work very well).
More generally, a netted system uses a wide variety of sensors in combination, and no sensor-evading technology is likely to deal with all of them. Probably the appropriate counter to netting is not stealth per se, but rather some form of deception involving large numbers of platforms simulating real ones. In this case, a fast, relatively stealthy craft carrying large numbers of self-propelled long-range decoys might be useful. Perhaps that will ultimately be the main role of the littoral combat ship. As for stealth, we may become more interested in signature control. It is probably impossible, for example, to reduce the radar signature of a carrier (at any frequency) to that of say. a fishing boat. However, it may be relatively easy to increase the signature of one of her consorts so that an attacker cannot he sure which ship is the carrier, and thus must either expend far more weapons or come closer to find out which is which. What is clear is that electronic counters to surveillance are a force-wide issue involving forcewide command and coordination.
We may well already have moved in all of these directions; counters to enemy surveillance are generally not publicized. The point of announcing the various Cold War deception devices was to destroy Soviet confidence in their system. As long as they were unwilling to open a war with nuclear weapons at sea, they had limited numbers of missiles, and they assumed that it would take substantial numbers to destroy their main targets-carriers and Tomahawk-armed surface ships. Those numbers, incidentally, were set in part by our own investments in defensive measures such as Aegis. Deception might not defeat the SOSS. but it could slow its action badly enough to expose Soviet naval assets to destruction. Fleshing out SOSS data, for example, would expose the limited number of bombers with long-range sea surveillance radars.
The Song incident suggests that we are back in that surveillance/anti-surveillance chess game again.
Alan Shepard Launches Again
Military Sealift Command's advanced auxiliary dry cargo/ammunition ship USNS Alan Shepard (T-AKE-3) slides backward into San Diego Bay during a christening ceremony held at the National Steel and Shipbuilding Company (NASSCO) on 6 December 2006. The Shepard, named after Rear Admiral Alan Bartlett Shepard, the first American astronaut in apace and the fifth person to walk on the moon, is the third Lewis and Clark-class supply ship to be launched. She is scheduled to join the Fleet next summer.