Phoenix Sub Zero

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.

“Close enough so that we do not miss. Be patient, Mr. First. We will get to a range of forty kilometers, then launch.”

Sharef and al-Kunis moved to the chart table, watching the bearing to the target plot out on the chart, the flashing dot indicating the target over ninety kilometers away at the northwest mouth of the strait. Sharef ran his hands through his hair, wondering how many more submarines he would have to find before he could make good the escape from the Mediterranean.

“Status of the weapons?” Sharef called to the deck officer.

“Large-bore tubes two through six are equalized to sea pressure, bow cap doors open, Nagasaki torpedoes spinning up now,” Tawkidi reported, glancing at the weapons status display. “We’ll be ready to launch in less than one minute.”

“Very good. Equalize and open bow cap doors to tube eleven and spin up the Dash Five.”