by Larry Bond
Up ahead a rusted, dilapidated-looking tug, her stern lights burning brightly, showed the way out. Again for security reasons, Severodvinsk was not using her radar, and she would need a little help getting out of the bay in these foul conditions. Visibility was not good, but Petrov could still see the rocky shoreline of the submarine base to starboard and the pine-tree-covered island in the middle of the bay to port. The glowing lights from the city of Gadzhiyevo silhouetted the barren hills with a greenish gray hue.
The wind-driven rain stung his face, but Petrov hardly felt it. He was finally going to sea, on his own, no babysitters, and nothing Mother Nature could throw at him would dampen his spirits. A short toot and the flashing of the tug’s stern lights was the prearranged indication that the turning point was getting close.
“Attention navigation watch, five hundred meters until the turn,” squawked the loudspeaker. Petrov smiled, pleased that his commander of the navigation battle department, Captain-Lieutenant Dimitry Borisovich Ivanov, was on top of things. His announcement was right on time, and given the difference in distance perfectly matched that of the old and very cranky veteran tug captain.
Three minutes later, the tug sounded a long blast on her whistle and flashed her stern lights again—she was beginning her turn.
“Mark the turn,” announced Ivanov.
“Helmsman, rudder right full. Steady on course zero nine zero,” shouted Petrov down into the sail. Unlike Western submarines, Russian boats actually had a helmsman’s position in the sail, right below the cockpit, for surface running. That made it easier for the conning officer and the helmsman to talk to each other without using an intercom.
“My rudder is right full, coming to course zero nine zero, Captain.”
“Very well, helmsman. Just keep our nose on the tug’s stern and he’ll guide us through the channel.”
“Aye, Captain,” replied the sailor as he adjusted the rudder angle by pushing forward or pulling backward on the joystick control.
Petrov continued to scan from the left shoreline, to the tug, to the right shoreline and back again so as to keep Severodvinsk squarely in the middle of the channel. This was the most dangerous part of egress route. The channel between Sayda Guba and the Murmansk Fjord was very narrow. There would be little time to correct a mistake.
Because of the security concerns and the poor weather, it took Severodvinsk almost two hours to finally clear land and enter into the Barents Sea. After dismissing the tug, Petrov increased speed and barreled his way through the large swells. The wind picked up once they were outside the lee of the coast, and sea spray joined the rain in pelting the bridge watch. Every now and then Petrov would laugh, like a schoolboy on a carnival ride, as the boat fell into a deep trough. It was an exciting ride.
An hour and a half later, Severodvinsk dove beneath the stormy seas and proceeded on course to the buoy field.
~ * ~
3 October 2008
USS Seawolf
Jerry kept one eye on the fathometer. So far, readings matched the charts. “Seventeen fathoms under the keel. Point India bears zero nine five at seven hundred yards.” Jerry’s report put Seawolf within minutes of their next launch point. Number nine. “Present course is good.”
Although Lieutenant Commander Lavoie was OOD, Jerry was essentially conning the boat. His recommendations guided Seawolf to the right spot. Theoretically anywhere nearby would do, but Rudel had insisted on places with a smooth bottom. It would be bad luck to launch a UUV and have it strike one of the rolling hills or some sort of projection; a definite possibility in this neck of the Barents, which was shallower than usual.
“Maneuvering, conn. Make turns for three knots,” spoke Lavoie into the intercom. The engineering officer of the watch, or EOOW, was back in the bowels of the engine room and supervised the operation of the reactor and main propulsion system. He controlled the ship’s speed and responded to the OOD’s orders.
“Make turns for three knots. Conn, maneuvering, aye.”
“Watch your depth, Dive.” Lavoie’s second instruction was to the diving officer. As Seawolf’slowed, she became slightly negatively buoyant, because the water flowing over her dive planes worked like air over a plane’s wing and helped to keep the boat up. Less speed meant less lift. Chief Petersen needed a delicate touch to keep the sub at neutral buoyancy, where she would neither sink or rise.
Peterson moved water out of Seawolf‘s variable ballast tanks. She used her main ballast tanks to get underwater, but variable ballast tanks were used to compensate for small changes in the boat’s weight and to adjust her trim fore and aft. Peterson ordered a small amount of water to be pumped to sea to account for the excess weight.
The OOD waited another minute, then ordered, “Helm, all stop.”
“All stop, aye. Maneuvering answers all stop.”
Jerry watched the quartermasters update the chart. It was all by dead reckoning at this point, but the chart was still a check on the mental mathematics in Lavoie’s head. The nav plot showed them slightly past their intended position, but only by a hundred yards or so, the length of the boat. Stan Lavoie had the right touch. “Plot shows us on station,” Jerry reported softly. “Distance from planned position is within navigational error.”
“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 biologies.” 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.”
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p; “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 sounding!” 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 naviga
tion 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?”