Cheyenne had received word that Independence was on station and awaiting her arrival. Mack and his crew were currently a little over 1,200 miles from Independence’s location. At flank speed, Cheyenne could be there in a little over two days, but travelling that fast could prove to be too noisy. At the slower but safer twenty-six knots, running in sprint-and-drift mode, Cheyenne would still make her rendezvous in less than four days.
Midway through the Celebes Sea, Mack received an update. Cheyenne was instructed to use extreme caution once she passed through the Celebes and Sulu seas and into the South China Sea. Naval intelligence was reporting that mines might have been laid there, and they could pose a danger to Cheyenne.
That was news. China typically deployed coastal and moored contact minefields — technology that certainly wasn’t obsolete, but which would not seriously threaten Cheyenne. Recent intelligence reports, however, indicated that the cash-strapped Russian military had sold the Chinese an unconfirmed number of “Cluster Bay” and “Cluster Gulf” antisubmarine mines, the latter of which could be used in 2,000 meters of seawater. That meant that Cheyenne would have to be on guard against the older, less advanced mines, and they would also have to watch out for the very real possibility that they might “come into contact” with these deep-water mines as well.
Mack was not pleased with this news, and he liked the next bit of intelligence even less. An extremely large Chinese surface and submarine fleet was currently forming, and naval intelligence expected them to leave Guangzhou Naval Base sometime within the next thirty-six hours. Naval intelligence assumed — and Mack agreed — that the Chinese force’s mission most probably consisted of two parts: hunting for any U.S. naval vessels in the area and, more specifically and more immediately, attempting to sink the U.S. carrier Independence.
Once they reached the eastern entrance to the Sulu Sea, Mack cut Cheyenne’s speed to ten knots. She would travel through the Sulu Sea slowly and quietly until she reached the Balabac Strait, south of the relatively tiny island of Palawan. That would be her last opportunity to listen carefully before entering hostile waters.
As planned, Cheyenne stayed slow and listened for any danger signs before entering the South China Sea to her southwest. The recently invaded Spratly Islands lay several hundred nautical miles away in the center of the South China Sea. These were reportedly heavily guarded by a large Chinese contingent intended to prevent another invasion of the islands.
After Cheyenne passed silently into the South China Sea, Mack ordered, “Deploy the TB-23,” calling for his crew to stream their passive “thin-line” towed-array.
Designed to detect very low-frequency noise at long distances, the TB-23 was one of the newest additions to the improved Los Angeles class submarines. Cheyenne was also one of the first submarines to receive this new system.
The TB-23, which was reeled into the submarine’s main ballast tank instead of being housed internally and running down the side of the pressure hull like the TB- 16, was so long that even with Cheyenne running at twenty knots, she would still be able to detect distant sonar contacts.
The towed-array worked beautifully, and its dozens of hydrophones detected more sounds than the submarine’s computers often knew what to do with. Everything from large fish to fishing trawlers had been detected on their submarine’s TB-23 since their abbreviated shakedown cruise and they were now very confident in its operation.
Almost immediately, the TB-23 detected a large number of contacts. Distance was hard to gauge with the TB-23;
the signals it picked up could be coming through a convergence zone, and without the sea room to maneuver very much, precision bearings and ranges were very difficult.
From the initial detections, Mack guessed that these contacts were from surface contacts very far away — over 100 miles. If he was lucky, these tonals would turn out to be from the Chinese task group sent to attack the Independence Carrier Battle Group that had entered the South China Sea south of Borneo.
Creeping along at five knots in a westerly direction, Mack took Cheyenne farther into the South China Sea.
The TB-23’s detections were correct, and so was Mack’s guess. The contacts were the Chinese task group, and it was very large indeed. It consisted of seven fast attack craft, four Jianghu class frigates, three Ming class attack submarines, and two Romeo submarines. The Chinese task group had two primary missions to accomplish: mine the South China Sea and sink Independence.
American carriers had been a thorn in the Chinese government’s side since the very beginning of this conflict. They had lost their first Han class submarine to a U.S. submarine accompanying Nimitz, but Nimitz herself was not currently a target. She waited outside the South China Sea, just south of Taiwan, ready to enter if the need arose. The danger of mines in the South China Sea was a serious one and was one of the major reasons that Nimitz waited out of harm’s way, at least for the time being. But the aircraft carrier Independence (CV-62) had now been in the South China Sea for over one month, and for the Chinese she was a big, attractive, and highly desirable target. After laying their mines, the Chinese task group headed directly toward Independence.
With the aid of overhead imagery, U.S. naval intelligence quickly guessed the Chinese task group’s mission, but they had no immediate way to inform Cheyenne. Since ELF coverage in the South China Sea was sporadic, the submarine was essentially out of contact until she came shallow enough for the floating wire to be able to copy traffic.
At 1000 hours on the day after entering the South China Sea, Cheyenne’s floating wire antenna reached close to the surface and stayed there just long enough to copy recent traffic. An S-3 from Independence relayed the latest intelligence on this rather large Chinese surface and submarine group. The message relayed through the ASWC (anti-submarine warfare commander) to CTF 74—Commander Task Force 74, also known as Commander Submarine Group 7, located in Yokosuka, Japan, also included Cheyenne’s new orders.
Cheyenne was instructed to pass silently near the Chinese task group and find out exactly how many submarines were operating in cooperation with this group.
Most Chinese surface vessels had only a limited ASW (antisubmarine warfare) capability, and so the main threat to Cheyenne would come in the form of attack submarines and maritime patrol aircraft such as the Chinese versions of the Russian 11–28 Beagle known as the Harbin H-5. These aircraft carried bombs and torpedoes, and could pose a serious threat to Cheyenne. Captain Mackey was counting on Independence’s F-14s to handle at least some of these aircraft.
In addition, there was also a shorter-range threat from Chinese helicopters that many of their surface combatants carried on board. Similar in concept to the American LAMPS program, the Chinese had dozens of Chinese models of the French Dauphin helicopter equipped for ASW operations. Once Cheyenne got close to the surface fleet, she would have to be extremely cautious.