by Tom Clancy
Initially it was theorized that the Soviets had somehow staked out one particular route, that their submarines were able to follow it at high speed. Russian skippers were known to pull some crazy stunts, and perhaps they were trusting to a combination of inertial systems, magnetic and gyro compasses attuned to a specific track. This theory had never developed much of a following, and in a few weeks it was known for certain that the Soviet submarines speeding through the ridge were following a multiplicity of tracks. The only thing American and British subs could do was stop periodically to get a sonar fix of their positions, then race to catch up. But the Soviet subs never slowed, and the 688s and Trafalgars kept falling behind.
The Dallas was on Toll Booth station to monitor passing Russian subs, to watch the entrance to the passage the U.S. Navy was now calling Red Route One, and to listen for any external evidence of a new gadget that might enable the Soviets to run the ridge so boldly. Until the Americans could copy it, there were three unsavory alternatives: they could continue losing contact with the Russians; they could station valuable attack subs at the known exits from the route; or they could set up a whole new SOSUS line.
Jones’ trance lasted ten minutes — longer than usual. He ordinarily had a contact figured out in far less time. The sailor leaned back and lit a cigarette.
“Got something, Mr. Thompson.”
“What is it?” Thompson leaned against the bulkhead.
“I don’t know.” Jones picked up a spare set of phones and handed them to his officer. “Listen up, sir.”
Thompson himself was a masters candidate in electrical engineering, an expert in sonar system design. His eyes screwed shut as he concentrated on the sound. It was a very faint low-frequency rumble — or swish. He couldn’t decide. He listened for several minutes before setting the headphones down, then shook his head.
“I got it a half hour ago on the lateral array,” Jones said. He referred to a subsystem of the BQQ-5 multifunction submarine sonar. Its main component was an eighteen-foot-diameter dome located in the bow. The dome was used for both active and passive operations. A new part of the system was a gang of passive sensors which extended two hundred feet down both sides of the hull. This was a mechanical analog to the sensory organs on the body of a shark. “Lost it, got it back, lost it, got it back,” Jones went on. “It’s not screw sounds, not whales or fish. More like water going through a pipe, except for that funny rumble that comes and goes. Anyway, the bearing is about two-five-zero. That puts it between us and Iceland, so it can’t be too far away.”
“Let’s see what it looks like. Maybe that’ll tell us something.”
Jones took a double-plugged wire from a hook. One plug went into a socket on his sonar panel, the other into the jack on a nearby oscilloscope. The two men spent several minutes working with the sonar controls to isolate the signal. They ended up with an irregular sine wave which they were only able to hold a few seconds at a time.
“Irregular,” Thompson said.
“Yeah, it’s funny. It sounds regular, but it doesn’t look regular. Know what I mean, Mr. Thompson?”
“No, you’ve got better ears.”
“That’s cause I listen to better music, sir. That rock stuff’ll kill your ears.”
Thompson knew he was right, but an Annapolis graduate doesn’t need to hear that from an enlisted man. His vintage Janis Joplin tapes were his own business. “Next step.”
“Yessir.” Jones took the plug from the oscilloscope and moved it into a panel to the left of the sonar board, next to a computer terminal.
During her last overhaul, the Dallas had received a very special toy to go along with her BQQ-5 sonar system. Called the BC-10, it was the most powerful computer yet installed aboard a submarine. Though only about the size of a business desk, it cost over five million dollars and ran at eighty million operations per second. It used newly developed sixty-four-bit chips and made use of the latest processing architecture. Its bubble memory could easily accommodate the computing needs of a whole squadron of submarines. In five years every attack sub in the fleet would have one. Its purpose, much like that of the far larger SOSUS system, was to process and analyze sonar signals; the BC-10 stripped away ambient noise and other naturally produced sea sounds to classify and identify man-made noise. It could identify ships by name from their individual acoustical signatures, much as one could identify the finger or voice prints of a human.
As important as the computer was its programming software. Four years before, a PhD candidate in geophysics who was working at Cal Tech’s geophysical laboratory had completed a program of six hundred thousand steps designed to predict earthquakes. The problem the program addressed was one of signal versus noise. It overcame the difficulty seismologists had discriminating between random noise that is constantly monitored on seismographs and genuinely unusual signals that foretell a seismic event.
The first Defense Department use of the program was in the Air Force Technical Applications Command (AFTAC), which found it entirely satisfactory for its mission of monitoring nuclear events throughout the world in accordance with arms control treaties. The Navy Research Laboratory also redrafted it for its own purposes. Though inadequate for seismic predictions, it worked very well indeed in analyzing sonar signals. The program was known in the navy as the signal algorithmic processing system (SAPS).
“SAPS SIGNAL INPUT,” Jones typed into the video display terminal (VDT).
“READY,” the BC-10 responded at once.
“RUN.”
“WORKING.”
For all the fantastic speed of the BC-10, the six hundred thousand steps of the program, punctuated by numerous GOTO loops, took time to run as the machine eliminated natural sounds with its random profile criteria and then locked into the anomalous signal. It took twenty seconds, an eternity in computer time. The answer came up on the VDT. Jones pressed a key to generate a copy on the adjacent matrix printer.
“Hmph.” Jones tore off the page. “‘ANOMALOUS SIGNAL EVALUATED AS MAGMA DISPLACEMENT.’ That’s SAPS’ way of saying take two aspirin and call me at end of the watch.”
Thompson chuckled. For all the ballyhoo that had accompanied the new system, it was not all that popular in the fleet. “Remember what the papers said when we were in England? Something about seismic activity around Iceland, like when that island poked up back in the sixties.”
Jones lit another cigarette. He knew the student who had originally drafted this abortion they called SAPS. One problem was that it had a nasty habit of analyzing the wrong signal — and you couldn’t tell it was wrong from the results. Besides, since it had been originally designed to look for seismic events, Jones suspected it of a tendency to interpret anomalies as seismic events. He didn’t like the built-in bias, which he felt the research laboratory had not entirely removed. It was one thing to use computers as a tool, quite another to let them do your thinking for you. Besides, they were always discovering new sea sounds that nobody had ever heard before, much less classified.
“Sir, the frequency is all wrong for one thing — nowhere near low enough. How ’bout I try an’ track in on this signal with the R-15?” Jones referred to the towed array of passive sensors the Dallas was trailing behind her at low speed.
Commander Mancuso came in just then, the usual mug of coffee in his hand. If there was one frightening thing about the captain, Thompson thought, it was his talent for showing up when something was going on. Did he have the whole boat wired?
“Just wandering by,” he said casually. “What’s happening this fine day?” The captain leaned against the bulkhead. He was a small man, only five eight, who had fought a battle against his waistline all his life and was now losing because of the good food and lack of exercise on a submarine. His dark eyes were surrounded by laugh lines that were always deeper when he was playing a trick on another ship.
Was it day, Thompson wondered? The six-hour one-in-three rotating watch cycle made for a convenient work schedule, but after a few
changes you had to press the button on your watch to figure out what day it was, else you couldn’t make the proper entry in the log.
“Skipper, Jones picked up a funny signal on the lateral. The computer says it’s magma displacement.”
“And Jonesy doesn’t agree with that.” Mancuso didn’t have to make it a question.
“No, sir, Captain, I don’t. I don’t know what it is, but for sure it ain’t that.”
“You against the machine again?”
“Skipper, SAPS works pretty well most of the time, but sometimes it’s a real kludge.” Jones’ epithet was the most perjorative curse of electronics people. “For one thing the frequency is all wrong.”
“Okay, what do you think?”
“I don’t know, Captain. It isn’t screw sounds, and it isn’t any naturally produced sound that I’ve heard. Beyond that…” Jones was struck by the informality of the discussion with his commanding officer, even after three years on nuclear subs. The crew of the Dallas was like one big family, albeit one of the old frontier families, since everybody worked pretty damned hard. The captain was the father. The executive officer, everyone would readily agree, was the mother. The officers were the older kids, and the enlisted men were the younger kids. The important thing was, if you had something to say, the captain would listen to you. To Jones, this counted for a lot.
Mancuso nodded thoughtfully. “Well, keep at it. No sense letting all this expensive gear go to waste.”
Jones grinned. Once he had told the captain in precise detail how he could convert this equipment into the world’s finest stereo rig. Mancuso had pointed out that it would not be a major feat, since the sonar gear in this room alone cost over twenty million dollars.
“Christ!” The junior technician bolted upright in his chair. “Somebody just stomped on the gas.”
Jones was the sonar watch supervisor. The other two watchstanders noted the new signal, and Jones switched his phones to the towed array jack while the two officers kept out of the way. He took a scratch pad and noted the time before working on his individual controls. The BQR-15 was the most sensitive sonar rig on the boat, but its sensitivity was not needed for this contact.
“Damn,” Jones muttered quietly.
“Charlie,” said the junior technician.
Jones shook his head. “Victor. Victor class for sure. Doing turns for thirty knots — big burst of cavitation noise, he’s digging big holes in the water, and he doesn’t care who knows it. Bearing zero-five-zero. Skipper, we got good water around us, and the signal is real faint. He’s not close.” It was the closest thing to a range estimate Jones could come up with. Not close meant anything over ten miles. He went back to working his controls. “I think we know this guy. This is the one with a bent blade on his screw, sounds like he’s got a chain wrapped around it.”
“Put it on speaker,” Mancuso told Thompson. He didn’t want to disturb the operators. The lieutenant was already keying the signal into the BC-10.
The bulkhead-mounted speaker would have commanded a four-figure price in any stereo shop for its clarity and dynamic perfection; like everything else on the 688-class sub, it was the very best that money could buy. As Jones worked on the sound controls they heard the whining chirp of propeller cavitation, the thin screech associated with a bent propeller blade, and the deeper rumble of a Victor’s reactor plant at full power. The next thing Mancuso heard was the printer.
“Victor I-class, number six,” Thompson announced.
“Right,” Jones nodded. “Vic-six, bearing still zero-five-zero.” He plugged the mouthpiece into his headphones. “Conn, sonar, we have a contact. A Victor class, bearing zero-five-zero, estimated target speed thirty knots.”
Mancuso leaned out into the passageway to address Lieutenant Pat Mannion, officer of the deck. “Pat, man the fire-control tracking party.”
“Aye, Cap’n.”
“Wait a minute!” Jones’ hand went up. “Got another one!” He twiddled some knobs. “This one’s a Charlie class. Damned if he ain’t digging holes, too. More easterly, bearing zero-seven-three, doing turns for about twenty-eight knots. We know this guy, too. Yeah, Charlie II, number eleven.” Jones slipped a phone off one ear and looked at Mancuso. “Skipper, the Russkies have sub races scheduled for today?”
“Not that they told me about. Of course, we don’t get the sports page out here,” Mancuso chuckled, swirling the coffee around in his cup and hiding his real thoughts. What the hell was going on? “I suppose I’ll go forward and take a look at this. Good work, guys.”
He went a few steps forward into the attack center. The normal steaming watch was set. Mannion had the conn, with a junior officer of the deck and seven enlisted men. A first-class firecontrolman was entering data from the target motion analyzer into the Mark 117 fire control computer. Another officer was entering control to take charge of the tracking exercise. There was nothing unusual about this. The whole watch went about its work alertly but with the relaxed demeanor that came with years of training and experience. While the other armed services routinely had their components run exercises against allies or themselves in emulation of Eastern Bloc tactics, the navy had its attack submarines play their games against the real thing — and constantly. Submariners typically operated on what was effectively an at-war footing.
“So we have company,” Mannion observed.
“Not that close,” Lieutenant Charles Goodman noted. “These bearings haven’t changed a whisker.”
“Conn, sonar.” It was Jones’ voice. Mancuso took it.
“Conn, aye. What is it, Jonesy?”
“We got another one, sir. Alfa 3, bearing zero-five-five. Running flat out. Sounds like an earthquake, but faint, sir.”
“Alfa 3? Our old friend, the Politovskiy. Haven’t run across her in a while. Anything else you can tell me?”
“A guess, sir. The sound on this one warbled, then settled down, like she was making a turn. I think she’s heading this way — that’s a little shaky. And we have some more noise to the northeast. Too confused to make any sense of just now. We’re working on it.”
“Okay, nice work, Jonesy. Keep at it.”
“Sure thing, Captain.”
Mancuso smiled as he set the phone down, looking over at Mannion. “You know, Pat, sometimes I wonder if Jonesy isn’t part witch.”
Mannion looked at the paper tracks that Goodman was drawing to back up the computerized targeting process. “He’s pretty good. Problem is, he thinks we work for him.”
“Right now we are working for him.” Jones was their eyes and ears, and Mancuso was damned glad to have him.
“Chuck?” Mancuso asked Lieutenant Goodman.
“Bearing still constant on all three contacts, sir.” Which probably meant they were heading for the Dallas. It also meant that they could not develop the range data necessary for a fire control solution. Not that anyone wanted to shoot, but this was the point of the exercise.
“Pat, let’s get some sea room. Move us about ten miles east,” Mancuso ordered casually. There were two reasons for this. First, it would establish a base line from which to compute probable target range. Second, the deeper water would make for better acoustical conditions, opening up to them the distant sonar convergence zone. The captain studied the chart as his navigator gave the necessary orders, evaluating the tactical situation.
Bartolomeo Mancuso was the son of a barber who closed his shop in Cicero, Illinois, every fall to hunt deer on Michigan’s Upper Peninsula. Bart had accompanied his father on these hunts, shot his first deer at the age of twelve and every year thereafter until entering the Naval Academy. He had never bothered after that. Since becoming an officer on nuclear submarines he had learned a much more diverting game. Now he hunted people.
Two hours later an alarm bell went off on the ELF radio in the sub’s communications room. Like all nuclear submarines, the Dallas was trailing a lengthy wire antenna attuned to the extremely low-frequency transmitter in the central United Sta
tes. The channel had a frustratingly narrow data band width. Unlike a TV channel, which transmitted thousands of bits of data per frame, thirty frames per second, the ELF radio passed on data slowly, about one character every thirty seconds. The duty radioman waited patiently while the information was recorded on tape. When the message was finished, he ran the tape at high speed and transcribed the message, handing it to the communications officer who was waiting with his code book.
The signal was actually not a code but a “one-time-pad” cipher. A book, published every six months and distributed to every nuclear submarine, was filled with randomly generated transpositions for each letter of the signal. Each scrambled three-letter group in this book corresponded to a preselected word or phrase in another book. Deciphering the message by hand took under three minutes, and when that was completed it was carried to the captain in the attack center.
COMSUBLANT — commander of the Submarine Force in the Atlantic — was Mancuso’s big boss, Vice Admiral Vincent Gallery. The old man was evidently contemplating a reshuffling of his entire force, no minor affair. The next wake-up signal, AAA — encrypted, of course — would alert them to go to periscope-antenna depth to get more detailed instructions from SSIX, the submarine satellite information exchange, a geosynchronous communications satellite used exclusively by submarines.