Evanoff relayed the command to Hydroacoustic, and Stepanov returned his attention to his First Officer. “As we begin the journey to our patrol area, what is your most significant concern?”
“That we might be trailed by an American submarine,” Pavlov answered. “But that is highly unlikely,” he added. “Yury Dolgoruky is the quietest submarine in our Navy.”
“You must always assume worst-case,” Stepanov countered. “An American submarine could have detected our surface transit and tracked us once we submerged.” Pavlov looked at Stepanov skeptically as the older man continued, “If so, where would the Americans be?”
Pavlov examined the navigation chart, studying the outline of Kildin Island and the half-dozen bottom-contour lines circling the island.
He answered, “If an American submarine has detected us, they would likely be tracking us on their towed array. Under normal circumstances, they would trail us from behind. However, we are still operating in shallow water, and the Americans would have to shadow us in water deep enough for their towed array. Assuming their array droop characteristics are similar to ours, at ten knots they could not deploy it in water shallower than one hundred fifty meters.”
Pavlov studied the bottom contour curves, then placed his finger on the 150-meter curve, on Dolgoruky’s port quarter. “That would put them somewhere around here.”
“Excellent deduction,” Stepanov said. “Station yourself as Command Watch Officer. If there is an American submarine following us, find it.”
Pavlov announced to the watchstanders that he was stationed as the Command Watch Officer, with the authority to direct shipboard operations as if he were the commanding officer. He then pointed to the spot on the navigation chart.
“Michman Glinka. What is the course to intercept a contact at this position, headed east at ten knots?”
Glinka entered the parameters into the navigation chart and a line appeared. “Bearing three-two-five.”
Pavlov turned toward the Watch Officer. “Captain Lieutenant Evanoff. Come to course three-two-five and deploy the towed array.”
North Dakota’s Sonar Supervisor, standing behind the sonar consoles on the port side of Control, evaluated the changing parameter of their contact, then made his report.
“Possible contact zig, Master One, due to upshift in frequency.”
The fire control technicians and Lieutenant Molitor examined the time-frequency plot on their displays, watching the frequency of the tonal rise. Lieutenant Commander George Sites stopped behind the consoles, and after the frequency steadied up, he announced, “Confirm target zig. Contact has turned toward own-ship. Set anchor range at five thousand yards.”
Tolbert stopped beside his Executive Officer, examining the displays. Dolgoruky had turned toward the north as expected. In the worst-case scenario, Dolgoruky and North Dakota could be headed directly toward each other. Although submarine collisions were uncommon, they did occur. In these very same waters, USS Baton Rouge, a Los Angeles class fast attack submarine, had collided with a Russian Sierra class submarine.
Tolbert planned to ensure there was no repeat of that incident. He had to maneuver North Dakota, but needed to know Dolgoruky’s course so he didn’t make the situation worse.
“I need a solution fast, XO.”
Sites nodded and scanned the combat control consoles, his eyes squinting as the three operators slowly converged on a common solution. A minute later, Sites informed the Captain, “I have a solution. Master One is on course three-two-five, speed ten.”
Damn. Dolgoruky was on an intercept course. They either knew they were being followed or had guessed where North Dakota was with incredible accuracy. Tolbert had to get off Dolgoruky’s track.
“Pilot, come to course zero-four-five. Ahead standard.” They would move out of Dolgoruky’s way, let her pass, then fall in behind.
The Pilot entered the commands and as North Dakota turned to the northeast, Petty Officer Second Class Reggie Thurlow, stationed as the Broadband operator, pressed his headphones to his ears, listening to the unusual sound.
“Sonar Sup, Broadband. Picking up mechanical transients from Master One.”
Chief Bob Bush donned the Broadband headphones and listened to the distinctive sound. It was much quieter than on other Russian submarines, but recognizable nonetheless.
Bush reported, “Fire Control Coordinator, Sonar Supervisor. Picking up mechanical transients from Master One. Sounds like towed array deployment.”
Commander Tolbert listened to the report with concern. Range to Dolgoruky had decreased to four thousand yards. The United States had scant data on the new Borei class submarines, and he had no idea at what range North Dakota would be detected.
Stepanov checked the red digital clock at the front of the Command Post. They had deployed their towed array ten minutes ago, enough time for Hydroacoustic to check all sectors. Captain Lieutenant Evanoff must have been watching the clock as well, because he slipped the microphone from its holster.
“Hydroacoustic, Command Post. Report all contacts.”
The Hydroacoustic Party Leader’s reply came across the speakers. “Hydroacoustic holds three contacts. All three contacts are merchants to the north.”
Stepanov joined Pavlov in front of the hydroacoustic display, searching for patterns within the random specks. Pavlov was not yet convinced. Narrowband detections were not instantaneous like broadband. The algorithms needed time to generate. As the two men examined the display, a narrow vertical bar rose from the bottom of the display. The Hydroacoustic Party Leader’s report arrived a moment later.
“Command Post, Hydroacoustic. Hold a new contact on the towed array, a sixty-point-two-Hertz tonal, designated Hydroacoustic five, ambiguous bearings zero-one-five and two-six-zero. Sixty-point-two-Hertz frequency correlates to American fast attack submarine.”
Pavlov and the submarine’s Watch Officer turned in their Captain’s direction. Stepanov announced, “Man Combat Stations silently.”
The two Command Post Messengers sped through the submarine, and three minutes later, Dolgoruky’s Central Command Post was fully manned. Stepanov caught Pavlov’s attention and nodded.
“This is the First Officer,” Pavlov announced. “I have the Conn and Captain Lieutenant Evanoff retains the Deck. The target of interest is Hydroacoustic five, classified American fast attack submarine. Track Hydroacoustic five.”
The men at their consoles focused on their duties, and with Pavlov taking the Captain’s position, Stepanov assumed his First Officer’s role of Tracking Party Leader. Stepanov moved behind the two fire controlmen, and it wasn’t long before they converged on the same solution. The American submarine had crossed in front of them and was now traveling down Dolgoruky’s starboard side in the opposite direction.
As the range between the two submarines began to open, Hydroacoustic made the report Stepanov expected, “Loss of Hydroacoustic five.”
Stepanov asked his First Officer, “An American submarine has detected us and is moving into position behind us. What is your recommendation?”
Pavlov studied the geographic display, then replied, “We should deploy a mobile decoy, then engage the electric drive to reduce our sound signature and turn to break contact.”