“Chase thinks it sounds like a Foxtrot, sir, but not one he’s heard before. They’re running it through the library now.”
Antisubmarine ships and aircraft either carried or had access to a tape library of underwater sounds, everything from the gtunts and squeaks of fish and other marine life to the Characteristic noises made by various undersea vessels. It was ‘•often possible to match a particular set of sounds not only with a general class of submarine, but with the acoustical profile of It particular boat. Good Navy sonarmen could sometimes pick
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Keith Douglass
ARMAGEDDON MODE
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out old friends by ear alone, and Sonarman First Class Chase was one of the best.
Parrel came to a quick decision. “Ping him. I want to know if we’re on top of him.”
“We’ll give it our best shot, sir. Conditions aren’t very good below, though.”
“Understood. Call me when you have him nailed.” He handed the phone back to the waiting sailor.
Passive sonar was listening only, using sensitive underwater listening devices to locate a submarine by the sounds of its engines, pumps, and the rush of water across its hull. Biddle’s SQR-19 was a towed array, hydrophones trailing behind the ship that could pick up underwater noises as much as thirty nautical miles from the ship.
Biddle also mounted sonar equipment in her keel. Designated SQS-56, it could either listen passively or broadcast sharp pings of sound, then pick up the echoes from any subsurface targets. Unfortunately, passive sonar could give direction—at least to within a few degrees—but not distance. Active sonar gave distance but was limited both in range and by conditions in the water. The SQS-56 could pick up a submarine if it was within perhaps six nautical miles of the ship . . . but the range could be sharply reduced by shallow, warm, or highly salty waters, and all three of those conditions applied to this part of the Indian Ocean.
Worse from a tactical point of view, active sonar would alert the submarine to the fact that it had been spotted.
Parrel would feel a lot better knowing just where that sub was and where it was going. Peacetime or not, international waters or not, tensions were running hot in the Arabian Sea just now. Since early that morning, war had engulfed the India-Pakistan border, and these waters could become a shit-hot war zone any time now. Every man in the CBG knew how easy it would be for an attack to be launched by accident—the missile strike against another Perry-class frigate, the U.S.S. Stark in the Persian Gulf during the Iran-Iraq War, was a case in point— and one hell of an expensive target was trailing Biddle a hundred miles astern.
Foxtrot was the NATO code name for a class of diesel-powered attack subs first produced by the Soviets in the 1960s. Three hundred feet long, with a complement of seventy-eight
men, it was designed to hunt and intercept hostile task forces. The Russians had built sixty of them between 1958 and 1962, and most were still active, though some had been reported lost at sea. During the ’70s, the Soviets had manufactured nineteen for export: three for Cuba, eight for Libya … and eight for India.
In these waters, the contact could be either Soviet or Indian. Either way, the battle group’s new admiral was not going to care for potentially hostile subs getting too close to his command.
Minutes dragged by. Parrel was beginning to wonder what Mason was playing at when the CIC Officer called again.
“No joy on the pinging. Captain,” Mason said. “He may be out of range.”
Parrel scowled. “Understood. Alert the Air Officer. I want a LAMPS up ASAP. Maybe we can peg the contact with sonobuoys. And have the comm shack raise Jefferson, Admiral Vaughn’s going to want to know about this.”
“Aye, aye, sir.”
Parrel replaced the telephone handset, then walked to the starboard wing. He raised his binoculars and scanned the horizon toward the northeast. There was nothing there, no periscope wake, no oil slick, only endless blue water under a cloudless sky.
Submarines these days could launch homing torpedos from ten miles away … or pop a sea-skimming cruise missile from three hundred miles out. A Foxtrot would not be carrying SSMs, thank God, but the threat was serious nonetheless.