The ocean around them was empty.
Daminski looked at the broadband display as a bright line traced its way down the short-time screen. He squinted at the trace, moving his hand over the cursor ball, moving the spherical array beam to the bearing of the trace. When the cursor line was superimposed over the trace, Daminski shut his eyes and listened.
All he could hear was the frantic sound of the snapping of shrimp. He turned and looked at Hillsworth, face wrinkled in frustration.
“Just a bunch of fish getting it on.”
“Don’t worry, Cap’n. He’ll come. And when he does, we’ll hear him.”
“Let’s hope we hear him before he hears us,” Daminski said, returning to his sonar search.
The normally open control room was jammed with the majority of the ship’s officers. The room was dominated by the circular periscope platform with the observation seat that could rotate on a circular track during periscope exposure.
Now at depth, the control seat was folded down into a compact box with a cushion on top, the box serving as the captain’s command seat.
Commodore Sharef had called battle stations for the passage through the strait, bringing twelve men into the packed room. He stood at the computer chart display table. He was the battle stations attack officer, as tradition demanded. First officer al-Kunis stood next to him, acting as the battle coordinator, responsible for the functioning of the entire team.
On the periscope stand was Commander Omar Tawkidi, the navigator and third in command, who was stationed as deck officer. Lieutenant Commander Aby Haddad, the ship’s senior watch officer, was the junior deck officer. Reporting to the four senior officers were the main functions of weapons control, ship control, reactor control, and sensor control. At each of the stations two officers sat at the Second Captain console displays, except at sensor control, where four officers scanned the computer analyzed data coming in from the large hull arrays and the gyrostabilized linear towed array.
As the ship approached the mouth of the strait Commodore Sharef ordered the ship to dead slow ahead, just enough velocity to keep the towed array from dragging. He and al-Kunis took up positions in the sensor-control corner, watching the displays of the sonar system.
“Anything?” Sharef asked Sublieutenant al-Maari, the sensor-control officer at one of the displays. The sublieutenant turned toward Sharef, the young man’s earphones half-removed from his right ear. He shook his head and returned to his display.
“Deck officer, put in a Second Captain delouse.”
“Yes, sir,” Tawkidi said, turning to the ship-control console.
“Ship control, ten clicks and prepare for a delouse. Reactor control?”
“Reactor is ready,” the mechanical officer reported.
“Ten clicks,” the ship-control officer reported.
“Engine stop. Reactor control, commence delouse,” Tawkidi called.
The term delouse was handed down from old Soviet tactics, which the UIP’s Combined Naval Force had inherited with the Victor III submarine acquisitions. It referred to the Russian tactic of an attack submarine escorting a ballistic-missile submarine out of port. To ensure that no lurking American attack submarines were trailing the ballistic-missile ship, the Russian attack-escort sub would perform a detailed antisubmarine search of the sea in the vicinity of the ballistic-missile ship, an attempt to “delouse” her. The tactic had lived on in the Destiny-class, in which the Yokogawa Second Captain computer was able to perform a self-delouse by shutting down the entire propulsion plant, allowing the sonar systems to hear unimpeded by own-ship’s noise.
At the reactor-control console the mechanical officer inserted the command shutting down the reactor, dropping control rods into the liquid metal cooled core until the unit went subcritical and ceased heating the circulating liquid metal. The magnetohydrodynamic coolant pumps cut off, halting the liquid sodium flow, the conductive sodium acting as an emergency cooling system, keeping the core from melting from its residual heat. In the next compartment aft, the turbine generators spun down, their steam from the boilers now lost. Large automatic cutoff valves then shut, isolating the steam headers. The condensate and feed pumps in the lower level shut down next. The electrical power grid, responding to the loss of power input from the turbine generators, began drawing current from the battery in the farthest aft compartment until the ship was running on battery power alone. The Hegira’s main machinery silent, the ship coasted submerged, her computer system straining to hear the sounds of the ocean, the signal-to-noise ratio now dramatically improved as the submarine drifted in the strait 400 meters deep.
All but the smallest thousandth of a percent of the ocean’s noise was meaningless, random noise or biologies — fish.
And what nonrandom noise the computers did hear was inevitably merchant shipping. The merchant ships outnumbered the warships five hundred to one. There was the occasional warship, detected at long range from a bottom bounce, but rarely a submarine, since submarines accounted for less than one of every fifty of the world’s warships. Most submarines were short-range diesel boats designed for coastal defense. It would be odd to find a nuclear submarine as the first detection of the patrol, if this strange mission could be called that.
Sharef inserted several keystrokes, a new trace coming up on the screen in white, this trace the anticipated noise of a Los Angeles-class American attack submarine. The traces on the five-and ten-minute histories, with own-ship’s noise subtracted out, were fairly similar to the expected white curve. The curves would never completely coincide, but just the slightest similarity was usually enough to classify the target. In this case the data was evident.
“Definite contact. Commodore,” Tawkidi reported from one of the display consoles farther forward. “Seven-bladed screw, no cavitation, high-pressure, high-flow pumps, electrical turbine tonal at sixty-one cycles. The contact is submerged, bearing three one zero. Range is distant. The detection may be a surface bounce — we’ve got a good sound channel down to 700 meters.”
Sharef glanced at the ship’s chronometer. It had taken twelve minutes to integrate the sonar data to find the submarine waiting for them. The one disadvantage of the Hegira’s power module was its small battery. With the tremendous load of the Yokogawa Second Captain supercomputer and minimum ventilation loads, the battery could only last for a twenty-minute delouse.
“Battery power, reactor control?” Sharef asked.
“Twenty percent remaining, sir.”
Sharef frowned. “How long?”
“Maybe another five minutes, sir,” the mechanical officer reported. “Then we’ll have to bring the reactor back up.”
“Deck officer, can you keep the contact once we restart the plant?”
Tawkidi frowned over the sensor consoles, the other four watchstanders there concentrating on the screens, al-Kunis and Sharef’s presence making the area crowded.
“Yes, I believe so. Commodore. The computer has a definite trace now. The contact, as distant as he is, will stay within a few degrees of the bearing of initial contact. We can work with that, sir.”
“Very good. Restart the reactor and maneuver the ship for a range on the target, then prepare for torpedo attack.”
Within a few moments, the reactor plant systems were back on line, the computers were able to stay locked onto the target’s sonar emission.
Sharef drove Hegira across the line-of-sight to the target submarine and established a parallax range of ninety-two kilometers, an extremely long-range detection at the very limits of sonar reception.
“How close do you want to come before we shoot, sir?” al-Kunis asked.