Tiger's Claw

REPUBLIC OF CHINA SUBMARINE FÙCHÓU ZHE (AVENGER), SOUTH CHINA SEA

A SHORT TIME LATER

“We have received the latest position information on the Zheng He battle group, Captain,” the operations officer aboard the Taiwanese Type 800 submarine Avenger reported. He plotted the position on the chart in the con. “About thirty kilometers to the south.”

Captain Yao nodded. “We will be in range of their patrol helicopters soon,” he said. “Get a last GPS update for the inertial navigation system, then we will go to patrol depth and commence ultraquiet operations.”

“Yes, sir.” The submarine Avenger was at periscope depth now, getting radio messages and updating its position by a GPS receiver mounted on the periscope mast, but in seconds it received a final GPS update and the mast was lowered to avoid detection. The Avenger then commenced a steep dive to four hundred feet and began ultraquiet operations. The Avenger was a former Israeli Dolphin-class diesel-electric attack submarine, built in Germany, and was already one of the quietest submarines in the world, but on ultraquiet all possible means for extraneous noise was eliminated; the crew was even directed to walk carefully, not slam hatches or drop metal objects, and speak in whispers even on the intercom. Submerged speed was cut in half, which made the days that much longer, but hunting ships was a patient man’s game anyway.

Avenger was fitted with ten torpedo tubes, six of which were larger twenty-five-inch tubes capable of firing Tomahawk cruise missiles. Taiwan was not currently allowed to buy any sub-launched cruise missiles from the United States, so the larger torpedo tubes were fitted with liners that allowed them to fire twenty-one-inch diameter torpedoes; it carried a total of sixteen twenty-one-inch wire-guided torpedoes. Avenger was also armed with a new weapon system: IDAS, or Integrated Defense and Attack System, which was a torpedo-launched laser- or infrared-guided missile capable of attacking ships, land targets, and even antisubmarine helicopters at ranges out to thirty kilometers—IDAS was the first missile in the world to attack aircraft while the launch platform was submerged. Two of Avenger’s torpedo tubes, one forward and one aft, each carried a magazine of four IDAS missiles.

About an hour later the sonar operator whispered on intercom: “Captain, sonar contact, bearing two-five-zero, aircraft, sounds like a patrol helicopter.” The passive sonar could pick up any sounds traveling through the water, and computers analyzed the sounds and took an educated guess at what it might be.

“Slow to five knots, turn left heading one-six-zero,” Yao ordered. A patrol helicopter’s dipping sonar was probably one of the submarine’s most dreaded adversaries other than another submarine, and the only way to avoid being detected by its active sonar signal was to get as far away from it as quickly as possible while not being detected. It became a cat-and-mouse game as the helicopter transmitted its signal then moved, and the submarine had to respond with its own move.

“Let us try a simulated IDAS attack on this helicopter,” Captain Yao said. “Periscope depth, half standard rate. Stand by on IDAS, simulated attack on airborne target. Flood tube three.” The Avenger rose ever so slowly to a depth of sixty feet. “Bearing to helicopter?”

“Bearing to helicopter three-five-two.”

Yao turned the periscope until the lens was pointing toward three-five-two degrees, then slowly raised it above the surface. He immediately saw the helicopter, moving away from them. He locked onto the helicopter and hit the laser rangefinder. “Mark.”

“Range three thousand two hundred meters.”

“Simulate fire two IDAS.”

“Simulate fire IDAS . . . one away . . . two away.” Had they actually launched the wire-guided missiles, they would take steering cues from the periscope and laser marker to home in on its target.

“Good job,” Yao said. “Down periscope. Steady up on two-two-zero, simulate reloading tube three with IDAS. How far until the first escort?”

“Approximately ten kilometers, sir.”

Well within the active sonar range of a medium- or large-size escort vessel, Yao knew, but outside their own passive sonar detection range. Stealth was very important now. They made temperature measurements as they ascended and descended, which improved the computer models for determining thermoclines—marked bands of different temperatures through the water that might deflect sound or sonar—so they could pick the proper depth to head toward the target, but it was all educated guesswork. It was akin to a bowhunter stepping quietly through a forest toward where he thought the deer would be, using everything possible—wind direction, foliage, silence—to close in undetected. In the end, it usually came down to patience and luck.

Just then: “Single sonar ping, sir, bearing two-four-zero.”

The Communists had made a mistake—he used his active sonar to try to get a fix on them, which instead gave away his own location. “Getting a little anxious, are we?” Yao said under his breath. “Now, it would really help if you . . .”

“Second single ping!” the sonar operator reported, his voice still muted but noticeably excited. “Bearing two-four-seven, heading one-zero-zero, approximate range eight kilometers!”

“Up periscope,” Yao ordered. He turned the periscope tube to the proper bearing, then slowly raised it. A few clicks of magnification and he had the destroyer in his crosshairs. “You are mine, pigu,” he said in a low voice. He took several photos. “Down periscope,” he quietly ordered. “Stand by for simulated torpedo attack, crew,” he spoke on the intercom. “Flood tubes two and five, keep the outer doors closed, acknowledge.”

“All outer torpedo doors closed and verified, sir.”

“Very well. Simulated only, match bearings . . . simulate fire one . . . simulate fire two.” The WS-2A5 torpedoes were the standard Taiwanese torpedoes, designed and built in Taiwan but designed after the American Mk-48 torpedo. They were wire guided, with passive sonar detection as primary terminal guidance and active sonar guidance if the wire was cut and for a final range and bearing to the target. The wire transmission was two-way, so not only could the torpedo operator on the sub steer the torpedo through the wire, but the torpedo could send sonar signals back to the sub as it closed on its target. The torpedo swam as fast as fifty-five knots, slowed to forty knots to take a terminal active sonar fix, then sped up again to close in for the kill.

“Make your course two-one-zero,” Yao ordered. He turned to his executive officer, Zun Khong (Commander) Chein Si-yao. “Now we go after their carrier, Si-yao.”

“It is risky, sir,” Chein said. Chein Si-yao was far younger and less experienced than Yao, on his first extended cruise aboard the Avenger. “The battle group is only eight kilometers away, and several helicopters are airborne. If they start hammering away with their active sonars, they can swarm us.”

“We will let them sail past, and then try to come up behind the Zheng He for a shot,” Yao said. “I am not going to let this opportunity pass. The Communists expect everyone to run away with fear when they sail their big carrier battle group around—they will not expect anyone to pursue them.”

“Simulated strikes on Communist destroyer complete, sir,” Chein said as the seconds ticked past on his watch. “Successful engagement. Congratulations, sir.”

“Thank you, Commander,” Yao said, “but I want that carrier next. Continue scan for the Zheng He. Range and bearing as quickly as possible.”