Collapse Depth

The ship began turning immediately, and the white bands shifted radically on the screen. Assuming that the contact’s course and speed remained constant, the ship could change course like this and calculate with a fair degree of accuracy the distance and course of the contacts: it was the art of Target Motion Analysis. Performed skillfully, this would allow them to choose a safe place to arise to periscope depth. But turning also unveiled the section of ocean that had been behind the submarine, its acoustic blind spot, or baffles. As they turned, two more white bands emerged.

“Wonderful,” said the captain.

Leer was back in sonar and on the mike. “Conn Sonar, two new contacts coming out of the baffles. Eight now in all.”

“We see them,” said the captain.

“Sonar, conn, we’ll take two minutes on this leg an then do another maneuver.”

“Aye sir.”

Jabo looked away from the console and saw Lieutenant Maple standing there with a green book of all the ship’s piping diagrams. He was breathing heavy, the mask of his EAB was fogged from perspiration.

“Are you here to solve the mystery of the Freon?” said the captain.

Maple nodded, and opened the book to the page he’d saved. “Right here,” he said. “Freeze seal piping. It’s the only Freon pipe anywhere down there. Yaksic went down there and the valve was wide open. He shut it, but it probably dumped the whole system.”

“Freeze seal,” said Jabo. “Fuck.” He cursed himself for not thinking of it. Whenever maintenance was done on a high pressure water system, the water had to be isolated from the work, lest the workers be sprayed by water that was high pressure, high temperature, or, in some cases, radioactive. Good practice required that the work, and the workers, be protected by at least two closed valves. But sometimes, by virtue of the location or other unusual circumstances, two valves weren’t available. In these cases, flexible tubes of Freon could actually be wrapped around the pipe, and freeze a slug of water in place, a frozen chunk of ice that could seal a system amazingly well — Jabo had seen them perform hydrostatic pressure tests with 1000 psi against freeze seals. So throughout the ship ran purple pipes linked to the central Freon reservoir, in case this kind of work was necessary.

Yaksic had appeared in control at Maple’s side.

“Yaksic, any good reason that valve may have been operated?”

“None sir, not even by accident. It’s out of the way, just above the deck plates in lower level.”

Jabo’s internal clock ticked — enough time had gone by, they needed to make another maneuver, he didn’t want to waste a second getting to periscope depth. “Sonar, conn, turning to port for TMA.”

“Aye sir.”

“Left full rudder, aye sir, my rudder is left full.”

“Make your course two-three-zero.”

“Make my course two-three-zero, aye sir.”

The ship swayed again, and Jabo watched the CODC display. Thankfully, no new contacts appeared, although the eight they had to track now presented a daunting enough challenge. The picture was starting to form in his mind of the ocean over their heads, the relative position and size of the fishing boats. He’d chosen the course two-three-zero because it looked like it might be a safe path to PD, and because it kept them generally on track, although they were so slow he didn’t see how they could ever make it up on their voyage to Taiwan. Jabo started thinking about periscope depth, the preparations to ventilate, calculated how long it might take them to replace the ship’s bad air with good: fast with the blower, faster with the diesel, fastest with both. Petty Officer Hurd, the fire control operator, had appeared at the side of the conn — it would be his job to plug and unplug Jabo’s EAB as he spun around on the scope. There was a lot of chatter in control, rigs being reported, people looking up facts about Freon and Phosgene. Jabo forced himself to focus on the CODC. His job at the moment was to get the ship up to the roof, so they could get the bad air off and the good air on. Everyone else would take care of everything else, but his job was to get the boat up if the course was good.

It was not.

Leer came into control, without his EAB so he could hustle faster.

“Put that fucking thing back on,” ordered Jabo.

“Turn right!” said Leer. “We are driving bearing rate on Sierra Six!”

The captain came over to the CODC, he and Jabo both saw that Leer was right. The Sonarmen could actually listen to the contacts with their headphones, didn’t have to wait for the data to accumulate in visual form on the screen, and what Leer had heard was very, very close. By “driving bearing rate,” Leer meant that the Alabama’s own motion was causing the change in bearing rate, as opposed to any motion by the contact — which meant they were dangerously near.

“Right full rudder!” said Jabo.

“Right full Rudder aye sir…my rudder is right full…”

The big ship swung right, and the bright band of Sierra Six’s noise bent away from them, but it was so close now…