Phoenix Sub Zero

Two decks below a small solenoid valve opened in an ultrahigh-pressure air line leading to the firing ram, a large piston with the high-pressure air on one side and water on the other. The air side of the ram became loaded with the air at over 3,000 pounds per square inch, the surface area of the piston translating the pressure to a force of 200 pounds per square inch as it pushed against the water on the other side of the ram. The water side realized the same pressure spike, the pressure in the torpedo tanks soaring, the water spilling into vents in the aft end of the tube, rocketed the torpedo from the tube. In little more than a second two tons of Mark 50 torpedo had been accelerated to three g’s and cleared the tube. The ejector ram, now at its end position, came to rest, the air side venting inboard in a tremendous crash, pressurizing the entire ship and temporarily deafening the torpedo-room crew in spite of their Mickey Mouse ear protectors.

In the control room David Kane’s eardrums slammed from the pressure of the torpedo launch. Before his hearing returned to normal he barked the next order:

“Tube two, shoot on programmed bearing.”

Seconds later the second torpedo left its tube and turned back around to the east on a medium-speed run to enable.

For the next fifteen minutes, the Nagasaki torpedo gaining steadily on it, the Phoenix launched torpedoes every forty-five seconds, the weapons leaving the ship and turning back around to head east.

After twenty-three torpedoes had been launched, Follicus turned around to face Kane and Mcdonne.

“Sir, the last torpedo is loaded in tube four. Should we shoot or save it?”

Mcdonne spoke up, knowing Kane would want a recommendation.

“I say save it. Captain. Never know when we’ll need an insurance policy.”

Kane decided he’d be damned if they found a spare torpedo in his hull’s wreckage … if it came to that.

“No, XO. Firing point procedures, tube four.”

When the last weapon had left the ship, leaving the torpedo room empty, the torpedoes enroute to or already at their preprogrammed hold points waiting for the emergence of the Destiny, sonar chief Edwin Sanderson clapped his hands against his headset, his eyes nearly bulging out of his head.

“Conn, Sonar,” he called, his iron control lost for a moment as he spit out the words—“Nagasaki torpedo is going active. Range gate shows it’s within 2,000 yards.”

Chapter 17 Sunday, 29 December

WESTERN MOUTH, STRAIT OF GIBRALTAR

The guidance-and-attack computer of the Nagasaki torpedo had half the power of an American-made Cray supercomputer but also took up only a cubic meter of space aboard the thirteen-ton torpedo. The sonar system of the weapon was sophisticated and sensitive, able to hear a surface warship fifty miles away, a submarine thirty to forty in ideal sound conditions with a target radiating a typical amount of noise. The power of the computer was used mostly in sifting the several hundred thousand gigabytes of sound data it picked up from the sea, including tonal frequencies in a narrowband processor, all the analysis done in real time, just as Hegira’s Second Captain system did, except that instead of displaying the data, the torpedo’s computer relayed the analysis to the target-interception subroutines. The interceptor programs calculated the swiftest interception course and speed to the target — the torpedo attempted to avoid unproductive tail chases, instead aiming itself toward a point in the ocean where the target would be in the future, a sort of smart football aiming not for the wide receiver but where he would be at the exact time of reaching the field. In this case the target parameter calculation was predictable since the target submarine had put the torpedo due astern. The Nagasaki could only aim for the target and order the propulsor to spin at maximum speed, giving it 128 clicks of forward velocity to the target’s mere seventy-seven.

The speed advantage had the torpedo steadily closing the distance to the target, gobbling up the sea between hunter and prey. The weapon had, in effect, been patient, content to drive in at maximum thrust and click off the minutes, waiting as the target grew nearer and nearer. Still, it was not easy being patient with the knowledge that the target was just ahead; had the unit been a cheetah pursuing a gazelle, its mouth would have been watering furiously at this point.