Deep Sound Channel (32 page)

"Sonar," Jeffrey said, "what's ambient Doppler show? Vortices from fins and flukes?

Ilse, can you help?"

"Look at this," Ilse said. She relayed Jeffrey a false-color picture of the turbulence. It had a circular cross section.

"Pancake eddies," Jeffrey said. "Enemy sub! Designate the contact Master 26! TMA team start a plot!" "She must be leaving on patrol," Wilson said.

"More likely a quick sortie to get her arse away from

the next incoming A-bomb," Morse said.

"It's a diesel boat on batteries," Sessions said. "It's too quiet to be nuclear."

"COB," Jeffrey said, "don't lose it. Put the LMRS in trail, right in her baffles!" Jeffrey grinned, forgetting the pain in his leg. "Captain, we can follow Master 26 right out to sea.

"

ABOARD VOORTREKKER, LEAVING

The air in the control room still smelled very foul, even after three days of round-theclock repair work and a jury-rigged new forward fan room installation.

"Synchrolift rolled out against the detents," Van Gelder said. "Outer subsurface blast doors closed behind us. Captain, we're ready to blow negative and get under way."

"Very well," Jan ter Horst said. "Bring us up ten meters smartly." Van Gelder passed the orders, in his role as diving officer when leaving port. He watched Voortrekker's depth decrease and hold. The pressure gauge declined by one bar exactly. The Agulhas Current caught the ship at once.

"Slow ahead," ter Horst said, "make revs for seven knots." Again Van Gelder passed the orders and the helmsman acknowledged.

"That's fast enough to not waste any time," ter Horst said, "in case the Allies try to hit the bluff again. Not that ground-penetrator gun bombs would get through all the layered armor under the hostage camps, but we better hope the next one doesn't go off underwater."

"It seems less and less likely there'll be another blast, Captain," Van Gelder said. Ter Horst harrumphed sarcastically. "Either that or they know they missed and they want to get us lulled before the next one! Seven knots lets us stay quiet and at this depth avoids a surface wake—no need to draw attention to ourselves. It also gives that Daphne-class pig boat a chance to draw ahead."

"Er, I concur, sir," Van Gelder said, abashed.

"Port ten degrees rudder," ter Horst said, "steer two zero five."

"Aye aye," Van Gelder said. "Steering two zero five, Captain."

"Very well," ter Horst said. "Stand by for the Umlazi halocline."

"Helm," Wilson said, "left standard rudder, make your course two zero five."

"Left standard rudder, make my course two zero five, aye," Meltzer said. In a few moments Jeffrey heard, "Steering two zero five, sir."

"Very well, Helm," Wilson said.

"Commander," Ilse said, "we should be coming to another halocline. Salt content will decrease about two parts per thousand seawater."

"Very well, Oceanographer," Jeffrey said. "Helm, can you compensate for decreased buoyancy with up-angle on the sternplane functions?"

"Not the way she's been handling, sir," Meltzer said, "not at this speed without the bowplanes. We'll have to run the low-rpm variable ballast pumps."

"Very well," Jeffrey said. "COB, at your discretion."

"Adjusting buoyancy with quiet centrifugal variable ballast pumps, aye," COB said. " Ilse, you can't imagine how much it helps to know a halocline's coming. Sometimes when we hit one, it's like being in an elevator and the cable broke."

"It's quieter this way too," Jeffrey said. "We can do the pumping gradually."

"You're welcome," Ilse said.

Jeffrey watched Challenger's depth decrease and her nose come up slightly. Then she dropped back down to proper depth and trim as she entered the less salty water bowfirst.

"You're an artist, COB," Jeffrey said.

"This boat's a work of art," COB said.

At $3.7 billion, the most expensive SSN in history, she better be, Jeffrey told himself. Challenger's construction drew on quality control standards so demanding Admiral Rickover himself would've been jealous. Defense analysts in the know had called the new ceramic fast-attack boats an RMA, a revolution in military affairs, one of the most important advances in undersea warfare since the advent of nuclear propulsion and deterrent strategic missile subs. Jeffrey knew the pressure was on to prove his vessel's worth, or there might never be another in the U.S. Navy, even if the good guys won this war.

"Captain," Jeffrey said a minute later, "something's been preying on my mind."

"What's that, Fire Control?"

"The ISLMMs, sir, the improved sub-launched mobile mines," Jeffrey said. "With respect, I want to recommend again that we deploy a few."

"X0, I agree with you completely that it'd be great to sink some Axis shipping, since we'

ve paid the price of admission to the bastion. But our top priority must be an undetected egress."

"But that's the point, sir," Jeffrey said. "If you think about the mission overall, it's not specifically an undetected egress that we want. What's required is the enemy not draw some connection between our presence and the Umhlanga Rocks event."

"Go on," Wilson said. Looking around, Jeffrey realized he had Commodore Morse's full attention too.

"It's a gamble to assume we'll get away without being detected," Jeffrey said.

"Granted," Wilson said.

"Submarining's a business of calculated gambles," Morse broke in. "If you don't feel your gut twisting, you're probably not doing your job."

"Then consider this calculation," Jeffrey said. "We're using a safety lane to escape. We might be spotted doing it. We may have been spotted already, for all we know. We have no way to tell since they'd ignore us. But, records of the detection would be made, even if unwittingly, in submarine deck logs and surface-unit Combat Information Center data, and sonar tapes and so on."

"Concur with that part," Wilson said.

"That means the opposition could eventually reconstruct that there was an extra submarine, us—that we were present and we weren't one of theirs."

"Oh dear," Morse said. "I think I see where you're going with this."

"The point is," Jeffrey said, "if we plant some mines, we're offering the Boers a red herring, an excuse or reason for us to have come by. That way when they investigate the nuclear explosion, their paranoia can still run wild. The board of inquiry can find it credible that we were in the area by coincidence, and then they start the purge we're hoping for."

Wilson actually smiled. "Very finely reasoned, Mr. Fuller. You're saying it's actually the lesser of two risks to launch some mines, in the bigger picture."

"Exactly, Captain. The fact we did plant mines suggests we weren't trying to hide completely, we weren't responsible for Umhlanga Rocks."

"You're not afraid that we'll make noise and draw too much attention just a little too soon?" Wilson said.

"Sir, the LMRSs haven't found a single SOSUS hydrophone this close inshore, and ones looking back at us from deeper water will be impaired by lots of reverb off the bottom's upslope. It'd take them hours of computer time to eke out and confirm our signature."

"That's true," Morse said. "It makes us tactically invisible."

"Yes, sir," Jeffrey said, glancing at his displays again. "If Master 7 and Master 23 here don't change course, in a couple of minutes we'll have a good window to launch from outside their detection envelopes."

"Very well, Fire Control," Wilson said. "Prepare to launch two ISLMMs. Make the runs be short, place the warheads at your discretion."

"Prepare to launch two ISLMMs, aye," Jeffrey said.

"Before we do I want to check our baffles," Wilson said. "Master 26 still holding course?" Jeffrey eyed his screens once more, then double-checked with COB, still piloting the LMRS in the diesel's wake. Jeffrey turned back to the captain. "Affirmative, sir, the contact's dead ahead, steering two zero five on batteries, range from us eleven thousand yards, no towed array. Sir, we're getting two side-byside opposing swirls in the turbulence. I think Master 26 has twin screws."

"That would make her a Daphne class," Morse said. "They're forty years old. . . Or maybe one of the Russian Tangos they bought used. Foxtrots have three shafts."

"Very well," Wilson said. "Our side's forced to use some reconditioned obsolescent hardware too. . . . Helm, on my mark all stop, then right full rudder and turn sixty degrees to starboard, then use auxiliary propulsors to cancel our remaining way. We'll drift with the current and listen with the wide-aperture arrays, while Fire Control prepares to launch the mines."

"Understood," Meltzer said.

"Mark," Wilson said.

"All stop, right full rudder, aye," Meltzer said. "Maneuvering acknowledges all stop. . . . Steering two six five, Captain. . . . We're holding inside the corridor, sir."

"Very well, Helm," Wilson said.

Jeffrey went to work. Deciding exactly where to put the total of four conventional bottom influence warheads was a nontrivial exercise, especially on short notice. Of course part of his mind had been planning for it all along. He'd lay a line across the current, not parallel to it, so one sinking vessel wouldn't drift downstream and set them all off each in turn. He decided a spacing of two hundred yards would be tight but not too close, spread across the safety lane. If no good targets used this particular lane today, eventually they would.

"Captain," Jeffrey said, "I'm setting the mine software to wait twelve hours before arming, to give us a good chance to escape."

"Concur," Wilson said.

"I'll program them to detonate for submerged nuclear-powered contacts only. At our present depth, four hundred ninety feet, we're too far down for surface targets anyway. I'

m giving them the acoustic signature of the Rubis-class SSNs the Axis captured from France. I'm also downloading Russian machine noise characteristics, since we know the Axis bought some compact mobile reactor plants and other main components. I'm entering our best guess at the German modifications."

"Concur," Wilson said.

Jeffrey finished entering the presets on his console. He relayed the information to the weapons officer, Lieutenant Bell, Lieutenant Jackson Jefferson Bellthird-generation navy, first-generation commissioned officer, two battle Es on his ribbons.

"Close the outer door, tube seven," Wilson said. "Drain tube seven and remove the Mark 88—we can't really use it at short range anyway. Load the first ISLMM into tube seven. We'll launch the second one from there as well."

Jeffrey passed the orders, then watched the changes in the weapons status window on his console. Tube seven's door icon switched closed and the tube icon changed from green to red. The indicators changed

from FLOODED and EQUALIZED to NOT FLOODED. Then the

inner door emblem popped open, and the nuclear torpedo icon vanished. The screen told Jeffrey what he already knew. Tube one was busy with the LMRS, tube three was loaded with the other LMRS and flooded, and tube five—also flooded—held a Mark 48 conventional ADCAP whose gyros were spun up. All the portside even-numbered tubes were unavailable from battle damage. The hydraulic autoloading gear on all tubes was unavailable; the operating mode was shown as MANUAL.

"Captain," Jeffrey said, "recommend we place a third ISLMM in tube seven once we fire the first two, as a backup in case of any failures. The units were pretty beat up by the weapons compartment flooding, even if they check out okay now."

"Concur, Fire Control," Wilson said.

"Captain, once we're through the bastion, should we engage Master 26?"

"Let's talk about that," Wilson said. "Leaving a silent calling card, the mines, to support our cover story's one thing. A flaming datum while we're here is something else. We have to get our prisoner back to base for interrogation. Since they destroyed so much of the lab notes, us putting the written records through a scanner, downloading their diskettes, and sending off a microburst once we get out to blue water like we originally planned just isn't an option. If we're prevented from reaching the Cape Verdes physically ourselves, our side loses all the intel, which was half our cause for coming here."

"And if we're sunk too near this coast," Morse said, "not only are we a treasure trove for the other people, but when they explore the wreck, they'll find Otto's body."

"Mine too, sirs, respectfully," Ilse said. To Jeffrey she looked slightly pale at the thought, even in the reddish light. "If the fish find us before they do, they'll still have dental charts."

Jeffrey shivered. "That would ruin everything."

"Cheer up, XO," Wilson said. "That's also part of the job sometimes, passing up a lesser target in favor of a greater one."

"Yes, sir," Jeffrey said.

"Commander," Sessions called, "no new sonar contacts."

"Very well," Jeffrey said. "Captain, our baffles are clear."

"Very well," Wilson said. "Helm, make your course two zero five, ahead one third, make turns for four knots."

Meltzer acknowledged.

Jeffrey fidgeted. It seemed forever before the torpedomen could get the first ISLMM

cranked into the tube.

"Sir," Van Gelder said, "Sonar has detected a mechanical transient dead ahead, close to the bottom." "Range?" ter Horst said.

"Difficult to say. The signal strength was weak." "Educated guess?"

"It could be distant, or it could be close but with an unfavorable contact aspect angle."

"What did it sound like?"

"A clunk, sir. A torpedo being loaded, maybe."

"Probably some kind of sound short on that Daphne," ter Horst said. "Those boats are ancient, and even with the prewar modernization refit by our German friends, their crew training standards aren't up to yours and mine."

Van Gelder nodded. "We're close enough to home it doesn't matter. Still, they ought to be more careful."

"Make tube seven ready in all respects," Wilson said. "Tube seven, firing point procedures, improved sub-launched mobile mine."