Voyage of the Devilfish

“A lot faster than a Piranha,” Donchez said.

“What?”

“It has twin-reactors, each liquid-metal cooled. We’re guessing about three thousand megawatts between the two of them. Pretty big when you think that the Three Mile Island plant is only twelve hundred or thirteen hundred megawatts. That gives her about six hundred thousand horsepower at the screw.”

“Six hundred thousand shaft horsepower? Jesus.” Pacino thought a moment. “There’s no way a conventional screw could accelerate a boat like that with that kind of horsepower. The screw would cavitate, just spin in a cloud of steam.” He was thinking of the lectures at the Academy… a rotating screw blade in seawater created a low pressure area on one side of the blade, high pressure on the other. The high pressure pushed the ship while the low-pressure side sucked the ship forward. But if the pressure got too low the vacuum effect would form bubbles of steam, which would shriek as they collapsed in the high pressure of the sea away from the screw. The noisy bubble effect was called cavitation, the blades making cavities in the liquid water… “No cavitation,” Donchez said. “No screw, for that matter. She’s got a ducted propulsor. She’ll do forty-five knots easy. Maybe fifty.” Pacino looked at the blueprint. Under the shroud aft of the rudder were what looked like several rows of turbine blades. The submarine had essentially a water-jet propulsor. It would be quiet and efficient and fast.

“If she can do fifty knots,” Pacino said, “she could outrun a Mark 49 Hullbuster torpedo. Not that it matters. I doubt even a Hullbuster would do much damage to her hull, not with steel over water over titanium.” He shook his head. “Well, even if this thing is fast, it must take an hour for her to get up to speed.”

“Look at the bow section,” Donchez said. Pacino saw torpedo tubes going forward to the nose of the ship. And a sphere of equipment at the very tip of the inside of the nosecone.

“No,” Pacino said, “not polymer injection…”

“Yes, polymer injection. Enough for ten minutes. She’ll squirt a layer of polymer out the nosecone, make the skin slippery and she’ll just glide through the water like a ghost. She’ll accelerate fast enough to leave her paint behind.”

“Polymers won’t work in arctic-temperature water—”

“I hate to tell you this, Mikey, but it works down to 28 degrees Fahrenheit.”

“Why don’t we ask Congress to buy us a few of those?”

“Not funny, kid,” Donchez said, checking his watch.

“Let’s finish. This guy can dive to 7500 feet, and with the way titanium flows before it ruptures he can probably go down to 10,000 feet for a few minutes. That’s over six times deeper than you can go, Mikey. And yes, our Hullbuster torpedoes would implode from sea pressure at that depth. He’s armed with conventional 53-centimeter torpedoes, the new 100-centimeter Magnums and SSN-X-27 nuclear warhead land-attack cruise missiles — that is, if they’re cheating on the treaty and still loading cruise missiles…” You ain’t cheatin’, you ain’t tryin’, Pacino thought.

“And the 100-centimeter Magnum torpedoes can pursue at sixty knots for sixty nautical miles with a nuclear warhead. And even if you can evade one, it just drives back to the point where it thinks you should be and detonates. It doesn’t have to get close to kill your delicate little hull with a nuclear explosion. Meanwhile the OMEGA submarine is running like hell using his polymer system and avoids damage.

“And finally, the OMEGA has a thicker anechoic coating than previous classes. The coating does to sonar pulses what a stealth bomber does to radar pulses — absorbs them without reflecting them. In addition to quieting the submarine, any torpedo going active would not hear a return sonar ping from her hull.” ‘This boat is fucking invincible—”

“Damn near. Mikey, we need to get a recording of this boat’s sound-signature. And I want you to get it.” An SPL, Pacino thought. Sound Pressure Level. Obtained by putting an American attack submarine about ten feet away from a Russian submarine and using sophisticated recording equipment to record the different sounds and tonals from each bearing. In effect, a map of the target ship’s radiated noise. Each Russian submarine class made different noises. MacHinery rotated at a particular speed, created a distinctive note like a tuning fork’s pure tonal frequency. Each class had a few tonals that American sonars could detect and classify from miles away. The only way to get an SPL recording was to drive right up to less than a tenth of a shiplength away and maneuver around the target without him finding out that he was being recorded — literally driving circles around the target submarine. There was always, both Pacino and the admiral knew, the risk of collision. Pacino looked up at Donchez, who had been studying him.