“We’re about to slow down to go to PD,” said Bannick: periscope depth. “We’ll get a fix while we’re up there.”
Jabo spent another fifteen minutes reviewing the chart, where they were and where they were going, satisfying himself that they were safe. He made an entry on the deck log, noting the time: 0625.
“Ahead one third,” ordered Bannick.
“Ahead one third, aye sir,” responded the helm as he rang it up. The engine order telegraph dinged as the engine room answered the bell.
Just a few feet away, the sonarmen came alive as the ship slowed and their acoustic environment became visible to them again. At ahead flank, they’d made so much noise that they couldn’t hear a thing, but as the ship slowed it became quiet again, and to sonarmen, it was like removing a blindfold after many hours.
Sounds emerged in every direction. Behind them, a distant cargo ship with battered screws steamed in an efficient great circle route across the Pacific. A lonely whale moaned plaintively far to the north. Below them, the tectonic plates of the ocean floor groaned as they shifted.
Through all that, a junior sonarman heard something exceedingly odd on his headphones: a faint pinging. He jerked upright, put his hands over his earphones, and closed his eyes in concentration.
“What have you got?” asked the supervisor.
“Not sure…” he said. “But think it might be active sonar. Straight ahead of us.”
“Oh fuck,” said the supervisor, making a quick note in his logs. He turned a switch so he could listen to the same thing as his watchstander. “Do we have anything else on that bearing?”
“Nothing.”
The submarine, as part of its mission to remain quiet, relied largely on “passive” sonar, meaning they just listened for noise with an array of exquisitely sensitive listening devices. It also had, but rarely used, “active” sonar. This was the science of emitting a pulse of sound into the water and waiting for it to hit something and bounce back. The nature and the timing of the echo could reveal much about the target, most importantly its bearing and distance.
Because of the preternatural quiet of a vessel like the Louisville, other vessels using passive sonar had little hope of finding her. So active sonar was the platform of choice for everything thing that hunted her: planes, ships, and other submarines. A sonarman on a submarine was trained to react to the pinging of active sonar the same way an infantryman in the bush would react to sound of a ratcheting shotgun.
It was extremely faint, and it took the supervisor a while to hear it, but there it was: a series of regular pings, about one second each and one second apart. Definitely electronic, definitely manmade.
“How does it comp?” he asked.
Another watchstander was furiously keying a computer on the side, comparing the frequency of the pinging signal to their vast electronic library of known active sonars, friend and foe.
“It doesn’t match up to anything,” he said. “But it sure as hell sounds like active sonar.”
“Yes it does,” said the supervisor.
He picked up the microphone, exhaled, and spoke.
“Conn sonar, we have possible active sonar at three-zero-zero, designating Sierra One. Recommend battle stations.”
Jabo jerked his head up at that, and looked at Bannick. He fully expected him to immediately call away battle stations; that’s what he would have done. The Chief of the Watch actually put his hand on the alarm. Bannick hesitated, glanced nervously at Jabo, and then hunched down to look at the CODC, his computerized sonar display. He picked up the mike and spoke into it. “Sonar, conn, I don’t see anything at three-zero-zero.”
The sonar supervisor stepped into control. Jabo sensed some disdain from him toward the young Officer of the Deck. “Sir, I listened to it myself. It’s extremely faint but it’s regular and its electronic. Recommend battle stations.”
“Did you get a match?”
“No!” he said, unable to hide his frustration. “Not yet. But it is without question manmade. We need to call it.”
“I concur,” said Jabo. “Along that bearing, it could be our target.”
Bannick exhaled jaggedly. “Let’s not freak out here,” he said. “Why would our target be using active sonar?”
“You need to tell the captain,” said Jabo. “Now.”
Bannick didn’t say anything, but looked toward the ladder, as if his relief might show up and spare him from having to make any tough decisions. Aggravated, Jabo walked briskly to sonar.
There was a brief look of surprise from the sonarmen as he entered. “Can I listen?” he said, and a watchstander nodded, handing him a set of headphones.
After a few seconds he could hear it — it was impossibly faint, and he gave credit to the man who first heard it. It reminded him of one of those hearing tests the navy made him take once a year. But there it was, a faint, regular electronic beeping. “Shit.”
He took the headphones off and handed them back.
“Where are you going, sir?”
“To tell the captain,” he said.
Just as he reached the door, the watchstander at the middle console stopped him. “Wait…” he said.
Jabo paused.
“It’s gone,” he said.
“Shit!” said Jabo. “Are you sure?”
The sonarman waited, his eyes shut, straining to hear it again.
“It’s gone. Not a trace.”
“Goddamn it!” said Jabo.
He walked back into control where Bannick smirked, having just gotten the word from the supervisor, his under-reaction vindicated. “Now let’s get my relief up here,” he said. “The smell of that bacon is making my stomach growl!”
MM3 James was staring at the copier, trying to pull it apart in his mind, piece by piece, before he did so in real life. He was a gifted mechanic, a skill set he found to be under-appreciated in the real world. People understood that electricians were smart, and that computer guys were smart. But guys who could look at a machine and understand it intuitively… they seemed only to impress each other. At least that was true until he got in the military, where keeping machines running, both in the Marine Corps and in the Navy, tended to keep people alive. So good mechanics were treasured.
The copier was small and complex, and clearly not designed for do-it-yourself maintenance. He pulled off the access panel and stared inside, saw in his mind how the dozens of tiny gears meshed and turned to pull a blank sheet of paper up, feed it through, and spit it out the other end with an image upon it. Picking up a single sheet of paper was a tricky mechanical challenge, and James admired the delicacy of it. He turned those gears by hand, saw that was not the problem.
He pushed the power button, nothing happened. He found an internal breaker that had tripped, reset it, and turned it on again. The machine tried to come to life, but with a horrible ratcheting sound, deep inside its guts, it shut down again. The sound actually made James happy; it confirmed that the problem was indeed mechanical. If it was something to do with the electronics of photocopying, he was screwed, but gears and motors were something he could fix.
Slowly he disassembled it, one component at a time, not putting anything aside until he understood its role in the machine. Finally he pulled out a shiny steel axel from inside the machine that held two white plastic gears on each end, each about an inch in diameter. One of them was missing about half its teeth.
“Bingo,” he said.
He pulled the damaged gear off the axel, and put it in his pocket.