by Larry Bond
“Nicely done, Mr. Lavoie.” Rudel’s praise was always public. Reaching up, he pressed the talk button on the intercom and said, “Sonar, conn, report all contacts.”
“Conn, sonar, only white noise from the ice, sir. Not even biologics.” Sonar would have reported anything, of course, but Rudel’s check was the last step. Since the encounter with the Delta IV, the only other Russian vessels they’d detected had been two distant icebreakers.
Picking up the Dialex handset, Rudel called the torpedo room. “Mr. Palmer, are you ready?” Jerry knew that the captain’s question was also pro forma. Palmer and the torpedo gang had been ready since six that morning, when Jerry had visited the torpedo room before breakfast.
“LaVerne’s loaded in tube four and is ready in all respects, sir.”
“Very well.” Hanging up, Rudel looked at Lavoie and said, “Stan, you have my permission to prepare the tube and launch the UUV when ready.”
“Prep the tube and launch the UUV when ready, aye sir.” Executing a rough facsimile of a pirouette, Lavoie crossed over to the right-hand side of the periscope stand by the fire-control consoles.
“FT of the Watch, flood down, equalize, and open the outer door on tube four.”
While the fire-control tech prepared the tube, Jerry started leafing through a file folder until he found a sheet of tracing paper labeled “LaVerne #3.”
“Sir, tube four is flooded, equalized, and the outer door is open.”
“Stand by . . . Launch,” Lavoie ordered.
The fire-control technician pressed the firing button and reported, “Tube four fired electrically.”
A moment later, Palmer’s voice reported, “LaVerne’s away. No problems.” There had been no detectable sound in control and only a slight pressure change as compressed air spun up the turbine pump and ejected the vehicle out of the tube.
“Conn, sonar,” called out the sonar supervisor. “We have the UUV’s motor running normally, bearing one two five.” That matched Jerry’s planned course for the first leg of her journey. He laid the tracing paper down on the chart. It showed a back-and-forth lattice of lines, spotted with colored symbols. Timed waypoints marked the end of each path of the search pattern. A faithful robot, LaVerne would follow these lines, programmed into her memory, until she reached the point marked “end,” in a little over forty hours from now.
Captain Rudel walked over to the chart table and watched Jerry lay the plotted track over the chart. “We’ll remain here for another half hour. I want LaVerne well away before we start moving on. I want to make sure the UUV hasn’t been detected.”
Jerry checked the chart. “Understood, sir. Recommended course to Point Hotel recovery position is two eight seven.”
“Mr. Lavoie, you heard the Navigator.” Rudel glanced at the clock. “Get us under way at zero one thirty-five hours on that course. Maintain normal patrol quiet, but have sonar keep a sharp watch to the southeast. I want to know if there’s any reaction at all to the UUV.”
Lavoie nodded, “Understood, sir.” Comfortable with the situation, Rudel left control smiling.
Jerry looked around the quiet, smoothly running control room. “We’re halfway there. I hope the rest of the surveys go as well as the first nine.”
LaVerne swam away from her launch point at three knots, her slowest and quietest speed. An hour and twenty minutes later, she reached her first nav point. Rising steadily, she quickly reached the surface, raised a small antenna, and listened for the GPS satellites. There were four above the horizon, and LaVerne fixed her geographic position within twenty feet. This would ensure an accurate survey.
She dove back into her element, heading for the start of her search grid. The UUV’s most important sensors for this mission were its high-resolution side-looking sonars. They used very high-frequency sound beams to map the seabed. As well as mapping the depth and shape of the bottom, the type of return could hint at the bottom type—rock, sand, mud, whatever. She would store the information until she returned to Seawolf, where the data would be downloaded.
LaVerne skimmed over the seabed at a height of one hundred feet and at a speed of five knots. She had to be high enough off the ocean floor to get the desired swath width. The idea now was to cover as much ground as possible, sweeping an area over a thousand yards wide and fifteen miles long. Each survey zone was a fifteen-by-fifteen-nautical-mile box, and LaVerne would diligently scan almost eighty-five percent of it before returning to Seawolf.
The UUV’s mission was to find places on the seabed suitable for automated acoustic sensors. She had to do it covertly, of course, to avoid alerting the Russians. The Russians, however, had long ago mapped this part of the Barents and more. It had been a simple matter to choose where their buoys would be emplaced.
The Amga autonomous submarine detection system was a heavily modified version of an earlier acoustic warning buoy. The cylindrical body was three feet in diameter and five feet long. The buoy was moored to the bottom, floating about sixteen feet off the seabed. Its only distinctive features were twenty-four three-foot metallic tubes running around the circumference of the cylinder. These were the passive hydrophones, the parts that actually received the sounds. The rest of the cylinder, top and bottom, and even the anchor that held it to the bottom, was coated with rubberized foam that hid it from any active sonar searching the area.
Inside the Amga buoy, a sophisticated computer listened to the ocean around it. Because the Russians were familiar with the area, they knew what sounds were typical: the sounds of ice, the sounds of sea life, even wave slap were stored in the computer’s memory. They also stored the sounds made by a submarine, both Russian subs and other countries’.
The designers had worked hard on the automated signal processing. They didn’t want the buoy sounding the alarm every time it heard something it didn’t understand. In engineering terms, it had to have a “low false-alarm rate.” So it used an intricate series of algorithms to assess the sounds it was hearing. For a contact to be valid, its noise pattern had to meet a majority of the preset conditions.
When LaVerne passed by one of the Russian buoys, it was two thousand yards away. That was close enough for the Russian buoy to hear the noise made by the UUV’s motor, but it wasn’t enough noise to trigger a response. According to the buoy’s electronic brain, this contact didn’t sound right. A submarine would make many different kinds of noises, from the many pumps, motors, and other equipment inside the sub’s hull to the flow of water around the hull, and they would be louder.
On the next pass, LaVerne was on the other side of the buoy, and even closer, but the Russian computer still ignored the UUV. Her mapping sonar swept across the buoy, but LaVerne was programmed to search the bottom. It noted the location of an anomalous fuzzy echo, but took no other action. That wasn’t part of its assigned task.
The two robots, both designed to search, studiously ignored each other as LaVerne worked its way past and away from her stationary Russian cousin.
Jerry wasn’t the only one watching the fathometer. In these waters, with the charts they had, the OOD, the quartermaster of the watch, even the sonar supervisor kept one eye on the display.
They’d had a bad scare earlier when they watched a seamount appear from out of the depths. In a little over three minutes, the bottom went from 128 fathoms beneath the keel to 47 fathoms. Fortunately, the seamount was right where it was supposed to be. Seawolf came up to 150 feet, 25 fathoms, to clear the obstacle.
Everyone on board remembered the vivid photos of USS San Francisco in the drydock after her high-speed interaction with an undersea mountain. Jerry was pleased that they weren’t taken by surprise. And then it happened.
The depth under the keel changed from twenty-two fathoms to ten in less than a minute, and that was with Seawolf creeping at five knots. There was nothing on the chart to indicate a rapid change in the bottom contour. In fact, there was no depth marking near their position at all—mare incognita.
“Yellow so
unding!” shouted QM2 Dunn.
The warning call, “yellow sounding,” alerted the OOD that the ship was entering potentially dangerous depths and required immediate action. A red sounding meant you were at the limit of the captain’s comfort zone and the OOD needed to call him immediately, in addition to any other actions. The actual warning depths themselves were chosen by the commanding officer. Given the uncertainty in their charts, Rudel had chosen a healthy ten fathoms for the yellow sounding and eight fathoms for the red sounding.
Jerry’s “Recommend we slow to three knots” was matched by the OOD’s order. They spoke at the same moment, then looked at each other and smiled, but only briefly. The OOD also changed Seawolf’s depth to 125 feet, just to be safe.
In another time, another place, Jerry had used UUVs to scout the bottom in front of an advancing sub, but there were none to spare here. Patty and LaVerne were both out, and Seawolf was headed for Patty’s recovery point. Maxine was in the torpedo room being prepped for her next run.
“Recommend turn to port, new course zero five zero.” That was at right angles to their old course. There was little on the chart to recommend port over starboard, but the coast lay some distance to starboard.
“Left standard rudder, steady on course zero five zero.” Greg Wolfe was OOD again, and followed Jerry’s recommendation almost before he finished. As Seawolf swung onto her new heading, Wolfe asked simply, “Depth?”
“I dunno, Greg. You’ve pretty much run out of our allowed depth band. We’ve only got twenty-five more feet left to play with. We’ve still got twelve fathoms under our keel. We can afford to wait a beat.”
At speed, Seawolf could turn almost like an aircraft, but creeping at three knots, her bow took almost a minute to swing ninety degrees. Jerry watched as the fathometer showed twelve fathoms as they finished the turn; then suddenly it read sixteen, then twenty-two fathoms.
“Steep slope, especially considering our speed,” remarked Wolfe. Jerry nodded agreement. “If it’s that steep, we’ll only need a few minutes on this course . . .”
Jerry lost his thought as the numbers on the fathometer changed again. They dropped to thirty fathoms, but then spiked upward, to twenty, fifteen, ten, then eight almost too fast to read.
“Red sounding!” exclaimed Dunn.
“Helm, back one-third! Captain to control! Diving officer prepare to hover.” Wolfe’s order cut their speed quickly to zero. A slight shudder could be felt on the deck.
The chief of the watch had passed the OOD’s call back to Rudel’s stateroom almost as soon as he had said it. The captain appeared dressed in gray sweatpants and a dark sweatshirt as Wolfe and Jerry considered their options over the navigation plot. Surprised by the captain’s dress, Jerry remembered it was past three in the morning.
Rudel joined Wolf and Jerry at the chart table.
“Sudden shallowing on two sides, sir,” explained Wolfe, and Jerry showed their course changes and the depths. Aside from Seawolf’s annotated track, there were only the barest hydrographic data.
Rudel ratified Wolfe’s actions. “Nice job, mister.” He paused. “To both of you”—including Jerry. “The bow sonar cannot double as a bumper.” It was just an offhand remark, but all three knew exactly what would happen if Seawolf struck a submerged obstruction, even at three knots.
They all studied the chart for a few moments, then Wolfe sighed. “Same drill as last time, sir?”
Rudel nodded, frowning. “Yes. Backtrack five miles, and then make a ten-mile detour to port, then a new course to the retrieval point. What will that do to our arrival at rendezvous?”
Jerry did the math in his head while Dunn laid in the new course. “It adds an hour and a half to the transit at five knots. It eats into our margin, but we’ll still be waiting when Patty arrives.”
“That’s fine, Mr. Mitchell. Now use the rest of the transit, including that extra hour, to get some sleep. You don’t look so good, and I want you alert when we recover Patty.”
Reluctantly, Jerry headed for his stateroom. He knew Dunn was up to navigating for Wolfe, but if they hit something, it wouldn’t matter who was on watch, and what Jerry thought of their abilities. It was always the navigator’s responsibility, whoever was in control. Jerry still had to force himself to delegate.
It seemed only seconds later when Chief Hudson was shaking his shoulder. “Mr. Mitchell, can you hear me?”
Jerry’s initial response was a cross between “I’m awake” and “What time is it?”
Hudson ignored his confused mumble. “We’ve been buzzing your phone, but you didn’t pick up. Patty’s being recovered.”
Jerry’s head cleared a little. Good news, but he needed to be there. Should have been there half an hour ago. How long had they been buzzing him?
He was in the torpedo room moments later. They’d already brought the UUV into the torpedo room. Only after she was secured did TM1 Yarborough and the chief begin their work. Unfastening access panels, they opened up the vehicle from just aft of the nose to where the motor compartment filled the last quarter of its length.
Once the all-important disk drive had been removed, the rest of the torpedo gang started servicing Patty. They wiped her down with a little fresh water, started a long inspection checklist, and began replacing her battery packs. The UUV’s high-power lithium-thionyl-chloride batteries filled half her length. They could not be recharged. They had to be replaced by a fresh energy section for each run. This was the main limit on how many surveys Seawolf’s UUVs could make.
It was Will Hayes’s OOD watch when they retrieved Patty, and then Jeff Chandler’s. Near the end of Jeff Chandler’s watch, the XO came into control.
Lieutenant Chandler almost snapped to attention, “Afternoon, sir. Current course two two five at five knots at one hundred fifty feet. En route to retrieve LaVerne at . . .”
Shimko waved him off. “Very well, Mr. Chandler.” The XO headed for the chart table. Jerry and most of his quartermasters clustered around several charts of the Barents Sea. One petty officer sifted through a stack of computer printouts while two others annotated a chart. Another was compiling a table of distances under Jerry’s direction, while one petty officer plotted Seawolf’s position and watched the fathometer.
“What do you have for me?” asked the XO.
Jerry stepped away from the chart table, picking up a small map of the area. “Patty found four spots that match the criteria we were given—bottom type and contours, depth, and the rest. We can take a closer look at them after the two-day midpatrol break. I’ve roughed out a plan to cover them all.”
He showed Shimko the small map. “I’m still working the numbers to make sure we can still reach the remaining UUV launch and recovery points as planned. Until we actually start the second set of surveys, all I can do is estimate how long each one will take.”
Shimko agreed, reluctantly. “Just give me your best guesstimate. I’ll brief the Skipper, but I need your recommendations ASAP.”
Jerry glanced at the chart table behind him. “Twenty minutes, sir?”
“All right. Did Patty find anything unusual?”
Jerry gestured to the chart table behind him. “A gold mine of hydrographic data. I’ve got my guys working through it for obstructions, shoals, anything not on the charts.” He paused. “She also marked over thirty man-made objects. I’ve compared their locations with ones we knew about on the charts. Only a handful match. Most are new or uncharted.”
“Good. The same vessel that plants the sensors can examine those items.”
“Should we use the UUVs to classify some of the bigger ones? We can tell the vehicle to take photos and sonar images when it detects one.”
“No. A lot of that stuff is going to be old—leftovers from World War II or maybe just junk dumped out here. Besides, we have over two hundred new bottom contacts right now. We’d lose way too much time finding out which ones were worth exploiting.” Shimko smiled. “Wise man says, ‘Man who looks for noodle in hay
stack will be very hungry.’ ”
Jerry looked disappointed. Shimko reminded him, “We’ve got our own mission to finish, and I’d prefer not to poke around up here any more than we absolutely have to.”
“Yessir, I understand. I’ll have my course recommendations to you in a few minutes.”
Seawolf glided confidently over the seabed at a stately five knots. As they doubled back to the rendezvous location to pick up LaVerne, the bottom crested within five fathoms of her keel, but they were following in Patty’s path now. Jerry was confident of the data from the UUV, and his quartermasters were already adding Patty’s bottom topography data to their charts. They would leave the Barents with better charts than the Russians, at least where the UUVs had been.
The first of eight detail surveys had gone as planned. Lieutenant (j.g.) McClelland, the sonar officer, and Jerry had worked out a procedure to gather additional hydroacoustic information that they needed, while Jerry plotted their precise position. He now had almost every quartermaster aboard working in control. Either they were updating charts or plotting the detailed survey data. Jerry had to fight the urge to use the quartermaster assigned to the control room watch. Their activities took over the fire-control plotting table as well as the chart table in control. And the extra bodies made the space both crowded and stuffy.
Jerry noted and reported the proximity of several newly plotted man-made objects along their course. Patty’s navigational accuracy was precise enough to reassure the entire ship control team that they were well clear of any of them. According to his plot, the nearest object approached no closer than two thousand yards on Seawolf’s port side.
The Russian sensor buoy listened carefully as the sound from Seawolf grew louder. Its sound receivers covered a wide range of frequencies, and now it isolated tones, pulses, rhythmic sounds that were not only man-made, but fit its detection criteria. It still waited, though. It detected and classified the sounds from the intruder within minutes, but would they persist? Would they change?