The silence ended when the sonar supervisor called, "Conn, sonar, single active pulse from Master 1." Moments later there was a second sonar pulse.
Mack ordered the chief of the watch to "Man battle stations torpedo," then took the conn from the officer of the deck.
With battle stations manned, the executive officer, in his role as the fire control coordinator, reported to the captain, "Master 1 is now bearing 169, BSY-1 range is 22,000 yards. He was not in a convergence zone."
Aboard Han 402, the Chinese commander felt as if he had little choice but to give his position away. His sonar had acquired only intermittent contact on the American submarine maneuvering in this area, and he needed to locate it in order to accomplish his mission: sink the submarine and then continue on against American merchant ships. He knew an American submarine was out there, but didn't know where, and didn't know it was Cheyenne. Unfortunately for him and his crew, however, he had thought that he was much closer to the Americans than his active sonar told him he was, 22,000 yards was out of torpedo range for his submarine, but not for Cheyenne's Mk 48s.
Those two active "pings" were a calculated risk on the Chinese captain's part. He knew his submarine was as noisy as a bull in a china shop and he suspected the Americans had been tracking him. Once he'd figured out that the American submarine had passed him he knew they could not be far off. If he waited too long, he would miss his chance to attack.
Aboard Cheyenne, Mack was trying to outguess the Chinese captain. He knew that Chinese submarines were notorious for having very poor sonar outfits, but he didn't think they were bad enough that the captain of number 402 would have no choice but to use his active sonar, giving away his own exact location. No, Mack thought. This does make sense. If the Chinese captain knew we were tracking him, he probably had figured that we knew his location, so all he was really doing was leveling the playing field-giving away information we already had in order to learn our location as well.
What this amounted to was that the Chinese submarine had gone active on the American submarine and both submarines now had an accurate firing solution. Mack didn't expect the Chinese captain to let this opportunity slip away. The Han was currently outside its own torpedo range, but that could change rapidly.
"Conn, sonar, the Han just started up again. It's making turns for twenty-five knots, sounds like she's really straining. They are closing quickly."
Captain Mackey reversed course to minimize the range closure white he ordered tubes one and two made ready in all respects.
"Torpedo room, fire control, make tubes one and two ready in all respects and open the outer doors."
When the outer doors were open, Mack turned back toward the Han and increased speed to full. Both submarines were headed straight for one another in an underwater game of chicken that could potentially ignite a third world war.
"Conn, sonar, we have a torpedo in the water! Type SET-53, bearing 163. It's active, Captain."
"Range to Master 1 is 21,000 yards," reported the fire control coordinator.
Mack looked around his control room. There was a look of horror in the eyes of the young sailors who had not yet been in the Navy for six months. "All stop," he ordered.
"All stop, aye, sir," the helmsman repeated. Seconds later he added, "Maneuvering answers all stop."
The normal procedure for countering a torpedo was turn and run, flank speed, in the opposite direction. This was not, however, a normal situation.
The U.S. intelligence community had managed to secretly buy three of the Chinese type SET-53 homing torpedoes from the Russians in a not-so-friendly transfer of technology. From their various tests, they had determined that the maximum range of the SET-53 was five nautical miles, or 10,000 yards. Even building in a large margin of error by doubling that range to ten nautical miles, or about 20,000 yards, Mack knew that there was simply no way that the Chinese torpedo could hit Cheyenne.
It did, however, make Captain Mackey furious, and not just because this was an act of war against the United States by a Chinese submarine. More than that, this was an aggressive action against him, his submarine, and his crew.
Cheyenne was not in any immediate danger-not yet, at least. Just in case, however, the captain calmly ordered, "Rig ship for depth charge."