Seas of Crisis (7 page)

Chapter 7

J
effrey, Bell, and the sonar officer, Finch, stood side by side in the aisle behind sonar supervisor Senior Chief O’Hanlon’s seat. Contact would be made with
Jimmy Carter,
and identities verified, using a secure undersea digital acoustic link. This system sent verbal or text messages in code, in a frequency band around one thousand kilohertz—fifty times above the range of human hearing. Each transmission’s frequency jumped thousands of times per second, and the beam could be tightly focused toward the intended recipient, making it almost impossible for an enemy sonar to notice, even at close range.

“You think we’ll hear
Carter
hailing us before we detect her broadband or tonals?” Bell asked Finch and O’Hanlon.

Lieutenant (j.g.) Allan Finch was in his mid-twenties, short and thin, with a serious personality. A naval officer generalist assigned to sonar only for now, he was sensible enough to know that on matters of real-world operations, Senior Chief O’Hanlon—with ten years’ more experience and a permanent rating as sonar tech—could run rings around him.

“Let’s hope so, Skipper,” O’Hanlon replied. “Arctic acoustic conditions are way too tricky this time of year. The nominal range of our comms is about the same as the maximum range of our ADCAPS.” Around thirty miles. “Getting
Carter
on the phone would ease my mind about a friendly fire embarrassment.”

Two hours later, close to the rendezvous point, Bell went to silent battle stations as a precaution. Jeffrey sat at his borrowed console in the rear of the control room. Making the meeting with
Carter
even trickier was that a gale had blown in from the west, with winds that Sonar estimated as topping thirty knots. They got this figure by analyzing wave action in the larger polynyas under which
Challenger
passed every five or six miles. Bell ordered the sonar speakers turned on.

Background noise rose substantially with the storm. Sleet and freezing rain pelted the polynyas, causing hissing and drumming sounds. The wind made the summer ice cap, which averaged less than ten feet thick, bend and flex due to forces that ranged from sea swells carrying their up-and-down energy far under the edge of the ice, to the wind itself pressing against ice ridges that stuck up from the cap. The prevailing surface current, from the opposite direction, east, gained purchase against many downward bummocks, straining the ice even more.

The cap moaned and creaked continually. Sometimes, nearby or in the distance, it would emit a sudden loud
crack,
echoing off bummocks everywhere like rolling thunder, as multiple stresses fractured the cap and two adjacent sections either relentlessly squeezed together, piling up and fracturing more, or separated, making a lead of brand-new open water.
Challenger
’s sensors indicated that, with this gale, colder air was moving in, polynyas were freezing to slush, and the water temperature at shallow depth was dropping. Sonar conditions deteriorated.

“Sir,” O’Hanlon called out, “intermittent contact on broadband, man-made, bearing is roughly zero-nine-zero, range ten thousand or twenty thousand yards.” East, five or ten miles.

“That’s near the rendezvous point,” Sessions told Bell.

“Any acoustic link contact, XO?”

“Negative, sir.” Sending messages back and forth to
Carter,
composed by Jeffrey or Bell, would be part of Sessions’s job.

O’Hanlon frowned. “What we’re hearing doesn’t make sense.”

“Explain,” Bell said. Finch moved in and peered over O’Hanlon’s shoulder, then moved down the aisle and looked at the different sonarmen’s screens.

“Broadband signal intensity is stronger than it should be,” O’Hanlon said. “
Carter
is supposed to hold her position, while we approach.”

“Maybe she’s running late,” Jeffrey said.

“If I didn’t know better,” O’Hanlon responded, “I’d say there were two distinct broadband signatures, overlaid.”

The ice gave off another loud
crack,
and again the noise reverberated like thunder.

“Sir, that was a torpedo warhead detonating.”

“What?”

“We’re getting . . . Rapid bearing rates on both broadband signatures,
not
consistent with any known under-ice sound propagation effects! . . . Assess signatures are a sub-on-sub dogfight!” Bearing rate meant the contact was turning through the water compared to
Challenger
’s steady course.

There was another sudden loud noise. This time, cued in, Jeffrey could tell that it had a rumbling, throaty quality, very unlike the natural sounds from the ice cap.

“Loud explosion bearing zero nine zero!” a sonarman called. “Range approximately fifteen thousand yards. Assess as a high-explosive torpedo warhead detonating!”

“This shouldn’t be happening,” Bell said. He hesitated, for only a moment. “Sonar, can you estimate the speed at which those submarines are moving?”

“Not yet,” Finch reported, “but from the intense broadband we’re getting they have to be doing flank speed.” All out, as fast as a vessel could go.

“Contact on acoustic intercept!” a different sonarman called. Acoustic intercept was used to warn of another submarine’s sonar going active. “Assess as melee pinging by one of the vessels involved in combat!” Melee pinging was used to find the adversary and get an accurate target range while both subs made wild maneuvers.

“Identify active sonar system,” Sessions ordered in his role as fire control coordinator.

“Impossible, sir,” Finch told him after O’Hanlon shook his head. “System frequency unknown due to unknown target speed and Doppler shift.”

“Very well, Sonar,” Sessions said. “Captain, we need a more reliable acoustic path to understand what’s going on.”

“Concur,” Bell said. “If they’re doing flank speed their passive sonars will be almost deaf from flow noise. . . . So . . . Chief of the Watch, rig ship for deep submergence.”

“Deep submergence, aye.”

“Helm, make your course zero nine zero. Ahead full, make turns for thirty-five knots. Thirty degrees down-bubble, make your depth eight thousand feet.”

Patel acknowledged, far more self-confident now.

Challenger
’s bow nosed steeply down, so steeply that Jeffrey’s seat tilted back uncomfortably as he sat facing toward the stern. His inner ears’ sense of balance told him that straight up meant not the overhead but the top screen of his console.

“Nav,” Bell ordered, bracing himself against his console as it and he tilted forward, “tell me when we’ve covered five nautical miles along the bottom.”

“Aye-aye, Captain.” Meltzer was gripping a handhold on the overhead, standing sideways with his legs splayed wide, as the deck beneath his feet turned into a hillside.

Challenger
went deeper and deeper. “Hull popping,” O’Hanlon called out. With
Challenger
’s ceramic-composite hull, it sounded more like a crunch. The ship was being squeezed inward by the pressure of the ocean, but this was what she’d been designed to do: achieve total waterspace dominance by seizing the low ground near the ocean floor and then exploit her tactical superiority.

She began to level off. “Sir,” Patel reported, “my depth is eight thousand feet.” The outside pressure was more than three and a half thousand pounds per square inch—almost two hundred fifty times atmospheric pressure at sea level.

“Sir,” Meltzer called out, “own ship has moved five miles.”

“Very well, Nav. Helm, all stop.”

“All stop, aye, sir. . . . Maneuvering answers, all stop.”

“Helm, back full until our way comes off.”
Challenger
still had considerable momentum; she’d halt much faster this way.

“Sonar and Fire Control Coordinator, tell me what’s happening up there.”

“Insufficient data,” Sessions responded.

“Request put ship on heading due north,” Finch said, “to present starboard wide-aperture array for optimal analysis.”

“Helm, on auxiliary maneuvering thrusters, rotate your heading to due north.”

Patel acknowledged and worked a joystick.

The wide-aperture arrays, one along each side of the ship, consisted of three widely spaced rectangular hydrophone complexes attached to the hull. Because they were big in two dimensions, and were held rigidly in three dimensions by the stiffness of
Challenger
’s hull, they could perform extremely detailed analyses of sounds to either side of the ship, in signal processing modes not possible with even the latest towed arrays.

“My heading is due north, sir.”

“V’r’well, Helm,” Bell said.

Sonarmen and fire-control technicians conferred and worked their keyboards. A tactical plot began to form on Sessions’s main console screen, repeated on other displays around Control.

“Two ships in combat, Captain,” Sessions stated. “Both appear to have flank speed of approximately twenty-five knots.”

Jeffrey was surprised.
Slow by modern standards. Unless
—

“Getting definite tonals,” O’Hanlon said. “Both ships nuclear-powered.” Sound was traveling directly down from the dogfight, immune to the confusing effects at shallower depth.

“What classes?” Bell demanded. Knowing this was essential. It would tell him who fought whom.

“Torpedoes in the water,” a sonarman called. “Engine noises indicate ADCAPs.” An electric-like screaming came over the sonar speakers. “Noisemakers and acoustic scramblers in the water!”

Hissing, gurgling, and undulating siren noises intensified—Jeffrey realized he’d been hearing them already, almost drowned out by the noise of twisting and turning submarines with their propulsion plants going at maximum power.

“Sonar, turning own-ship east,” Bell cued Finch and O’Hanlon. “Helm, make your course zero-nine-zero. Ahead one third, make turns for eighteen knots.” Bell wanted to sneak closer, get right underneath the other two subs.

Patel acknowledged, this time it seemed with true relish.

Bell ordered him to stop and rotate north again.

“One contact is an Amethyste-Two,” O’Hanlon stated. A modern, refurbished French sub, captured and crewed by Germans. The Amethystes were slow and small, but maneuverable and deadly.

She’s not supposed to be able to get here. So much for intel about the Allies’ North Atlantic anti-U-boat blockades.

“Two more torpedoes in the water. F-Seventeen Mod-Twos.” French-made, they could go forty knots, slow for an antisubmarine weapon, but more than adequate for a twenty-five-knot target.

The other submarine had to be American if it was firing Mark 48 ADCAPs. The latest version could go over sixty knots.

“Second submerged contact appears to be a newer
Ohio
-class SSBN. Possibly
Nebraska
or
Wyoming.
” The
Ohio
-class boomers were built for maximum stealth, not speed. They only carried a dozen torpedoes and decoys, for self-defense. Their main weapons were the strategic deterrence of two dozen ballistic missiles tipped with multiple hydrogen bombs.

Jeffrey told himself this didn’t make sense. All boomers were assigned specific patrol areas and transit routes, large but not infinite. Higher commanders would never send a boomer toward where two American fast-attacks were set to rendezvous.

There were more blasts, deafening to Jeffrey’s ears with this closer range and direct acoustic path, as torpedoes exploded against noisemakers or decoys or ice bummocks. The throb and whine and hiss of submarines trying to kill each other continued.

O’Hanlon said something to Finch while pointing at one of his displays. Finch studied it, and nodded. “Captain,” O’Hanlon called for Bell. “Am getting additional tonals, intermittent traces, weak, suggesting an S-Six-W reactor aboard the American sub. Not an S-Eight-G.”

“What?”
Bell was incredulous.

“Confirmed! Conjecture American vessel is
Seawolf
class, emitting false tonals to disguise her identity!”

Jeffrey stood up.
“How big is she?”

“Acoustic shadow profile against noise of ice cap suggests approximately four hundred fifty feet.”

Carter.
It had to be.
Seawolf
was the same length as
Challenger
, about three hundred fifty feet. Real boomers were more like five hundred fifty feet. All three classes had the same beam—width—forty or forty-two feet.

“American submarine tentatively identified as USS
Jimmy Carter,”
Sessions announced.

“There’s nothing tentative about it,” Bell snapped.

“Harley’s been ambushed,” Jeffrey said. “He’s obeying his orders to not let
Carter
be detected. At least not detected as
Carter.”
There were two melee pings in fast succession, one much deeper in tone than the other.

“Active systems confirmed as one French, one probable
Ohio
class!” Even Harley’s sonar was mimicking a boomer.

In seconds, there were more torpedoes in the water, F-17s and ADCAPs screaming toward each other, their pitches shifting up and down from Doppler as their weapons techs steered them after moving targets—thus altering the speed at which they seemed to approach or move away from
Challenger
far below.

Both sides’ ROEs let them go tactical nuclear when more than two hundred miles from land. But the dueling subs were too close together for that in this melee—their own warheads would sink them right along with their opponent.

Bell turned to stare at Jeffrey. “If Harley limits himself to half his real flank speed, and acts like he only has four torpedo tubes instead of eight, and doesn’t dive deeper than an
Ohio
can, he’s terribly handicapped.”

“I know. What are the chances the Amethyste-Two might get off a report if we put a Mark Eighty-eight up her ass?”

The ultra-heavyweight Mark 88 fish were custom-made for
Challenger,
able to function as deep as the parent ship’s crush depth. With a diameter of twenty-six and a half inches, to entirely fill her extra-wide torpedo tubes, they came in both high-explosive and tactical atomic versions; twenty-one-inch-diameter ADCAPs could carry either type of warhead but would implode at about three thousand feet.