Collapse Depth

“Give it time,” said the captain. He’d pictured it in his mind like one of those computer animations the shipyard engineers used, a graph of the ship’s depth versus time as air flowed into the front tanks, lifting the front of the ship up, the ship’s overall buoyancy turning positive. But there was downward momentum to overcome, and the captain knew it would take a few long seconds for the ship to rise. He’d tried to calculate the bare minimum amount of air he could expend and achieve positive buoyancy, and he hoped he was right. He had two bold, horizontal lines in the diagram he was constructing in his mind. The higher one was test depth, which they’d already exceeded. Beneath that line was crush depth, which if they exceeded they would never again rise above. But between those lines was a third line, a third important depth limit. And the Captain knew that before their momentum changed, they would cross it.

“Still deeper,” said the Dive. “But the rate is slowing…”

“We caught it,” said the captain. “We’re going to come up.”

Suddenly, a new alarm rang through control, one no one had heard before, a primitive buzzing sound that came from the corner of control by the main ladder. On each side of control came a dull pop, one that made Kincaid jump. Something bumped against both sides of the hull. All but the captain were startled.

“What the fuck was that?” asked Kincaid.

“The BST buoys,” said the captain. “We’re going to be famous.”

• • •

Once the ship exceeded its test depth by a predetermined percentage, the explosive bolts that held the BST buoys to the outside of the hull detonated, and the buoys were released. Like so many key systems on the boat, there were two of them, redundant and identical, and both functioned flawlessly. Highly buoyant, they shot upward, untethered to the ship, until after twenty-one seconds they popped to the surface. A mechanical accelerometer sensed their stoppage, and the transmitters of both buoys began broadcasting a powerful, repetitive distress signal along a frequency that had been reserved by the Navy for just that purpose. The recorded message consisted of an SOS, a sequence of numbers that identified the Alabama, and the message SUBSUNK.

Three radio rooms placed on three different continents were manned around the clock by radiomen whose only job was to await a signal that, much like the message ordering the launch of nuclear missiles, they all hoped would never come. Like the buoys themselves, the listening posts were designed with redundancy in mind: one was at the Marine Corps base in Okinawa, Japan. The second was in Holy Loch, Scotland. And the third was deep within the United State’s Strategic Command, in Omaha, Nebraska. All three listening posts began alarming simultaneously, even the one in Holy Loch, which was half a world away. Quickly the message was decoded and handed to a duty officer at each station, who in turn notified his commanding officer, who in turn notified the Chief of Naval Operations. The CNO made a call to the president’s chief of staff, and the president of the United States was then awoken with the news that a United States Submarine was in distress. From the time the buoys were launched until the president was awoken took a total of sixteen minutes.

• • •

Throughout the history of the submarine fleet, there has always been a degree of fatalism inherent in the various theories of submarine rescue. Alabama, like all ships in her class, was fitted with three Logistics Escape Trunks, or LETs, designed to mate with a Deep Submergence Rescue Vehicle and allow the egress of crewmen. Assuming total disaster and loss of power, each LET had affixed to it a steel plate describing a series of hammer signals men in and outside the trunk could use to communicate with each other. It read:

ONE TAP means TANK IS FLOODED

TWO TAPS means TANKS IS PRESSURIZED

THREE TAPS means TANKS IS DRAINED

On the plate outside of each trunk of Alabama, someone had long ago scratched “ZERO TAPS means I’M DEAD.”