Voyage of the Devilfish

Pacino’s relief quickly faded. “Attention in the firecontrol team,” he called out to the room. “We’ve gained a little time but the Magnum may come back around when it realizes it’s been had. I’m going to try to get some weapons out before the Mark I system shuts down on high temperature. And since we no longer have sonar contact on Target One we will be firing on our best guess. Carry on.” Pacino paused, eyeballing his officers, adrenaline pumping, sweat pouring… an intense mix of feelings almost sexual.

“Firing-point procedures,” he said, voice low and tight.

“Tube one. Target One, passive circler, ten thousand yards…”

The Kaliningrad had had no accurate range at the time of launch so the Magnum swam out the bearing line toward the aimpoint — the point that the target, hull number 666, was expected to be at expected detonation time, ten minutes after launch. The Magnum was using its active sonar to ping and “listen,” attempting to pick up the enemy. Its program codes had been modified by the underice subroutine. Normally the sonar would ping and pay attention to any solid return ping, but since this action was happening under the icecap, the ice rafts and pressure ridges and stalactites would return a ping as well as an enemy submarine. The subroutine instructed the Magnum to use the doppler filter, the device that rejected stationary objects and only examined moving ones. When a ping went out from the torpedo, return pings at the same frequency were disregarded. Only pings with an upshift or downshift in frequency passed through the filter since a moving object physically changed sound waves. If it moved toward the listening ear, the object’s speed compressed the sound waves — and the frequency went up. Motion away rarefacted the waves, shifting their frequency down. Like a moving train’s whistle would be shrill and high-pitched when the train approached, low-pitched and fading when the train went away. So the torpedo “listened” not for return sonar pings, which would be ice dumbly reflecting the sound, but for pings higher or lower pitched than emitted by the nosecone transceiver. But oddly, none of the return pings passed the doppler filter. None were upshifted or downshifted. Nothing but false returns from the ice. The torpedo was stumped. It was now 17 kilometers from the Kaliningrad, and the range to the enemy, the 666, had probably been much less at time of launch. The next line of coded instructions told the Magnum to continue to a range of 20 kilometers from its launch point, and if there were no hints of the target, to execute the default-turn-back and run until it either found the target on the return vector or reached a point 10 kilometers from the launch point. Twenty kilometers from the launch point the Magnum torpedo gave up. It had been unable to find the target and it was time to turn back and execute its nuisance-explosion. In response to its program, the Magnum ordered its rudder over five degrees, made the 180-degree turn in less than a minute and headed back and east toward the launch point. After 14.5 kilometers of backtracking without a sniff of the target, the Magnum initiated the arming of the nuclear warhead. It was, so to speak, resigned if disappointed. It would have been much more fulfilling to have detonated mere meters away from the 666. But at least its detonation 10 kilometers from its launch point would do some harm to the target. With the arming sequence begun, the Magnum had no thoughts about what would happen to it in the moments following the nuclear detonation. Like a human driving toward orgasm, the torpedo was a highly goal-oriented being. The only thing in its “mind” was getting to its detonation position and exploding. Never mind the aftermath.

USS DEVILFISH

The Mark 50 Hullcrusher torpedo in Devilfish”s tube had been waiting a long time. For over two hours its gyroscope had been spinning, its central processor had been awake and the fuel lines had been pressurized. It had been programmed with the solution to Target One ever since the target was acquired fifteen minutes earlier. Every few minutes the solution to Target One had been updated, making the Hullcrusher hypersensitive to Target One’s every move. The outer door of the tube was open. The small clearance between the tube and the torpedo was filled with water at outside pressure. The water had heated up, from the the nosecone, home to the flat sonar transducer, was cold, feeling the water temperature outside the ship. When a slight electrical signal came down the guidance wire at the torpedo’s stem section, the weapon “tensed.” The signal was the final target solution update, now locked in, as the control room firecontrol console’s SET key was pressed. A locked-in solution meant that launch was less than a minute away. The torpedo was ready.

“Ship ready!” Stokes called out.

“Solution ready,” from Scott Brayton.