When the BSY-1 operator and the fire-control coordinator were satisfied with the TMA (target motion analysis) solution on Master 32, the Chinese Han class attack submarine, the captain ordered, "Firing point procedures, Master 32."
The combat systems officer reported the target course, speed, and range.
"Sonar, conn, stand by," ordered the captain.
"Conn, sonar, standing by."
"Match sonar bearings and shoot, tubes one and two, Master 32."
"Match sonar bearings and shoot, tubes one and two, Master 32, aye."
After the large piston of the torpedo-ejection pump ram drove home, the Mk 48 ADCAP torpedoes were ejected from their resting places at the same time that their Otto fuel engines were coming up to full speed. "Tubes one and two fired electrically," reported the combat systems officer.
"Conn, sonar, units from tubes one and two running hot, straight, and normal," came the report from the sonar supervisor as the two torpedoes executed their wire clearance maneuvers and accelerated rapidly to fifty knots en route to convergence with the Chinese submarine.
"Very well, sonar," Mack said. Then, a moment later, he asked, "Time to acquisition?"
"Eight minutes, Captain," answered the combat systems officer.
To Mack, it seemed like an eternity before he heard, "Unit one has acquired… Unit two has acquired."
"Cut the wires, shut the outer doors, and reload tubes one and two," Mack ordered now that the Chinese submarine's fate was in the hands of the Mk 48s. There was no escaping their relentless attack. The subsequent reverberations and breaking up sounds were deafening.
"Conn, sonar, we have a torpedo in the water, SET-53, bearing 089!" The sonar supervisor's excited report came just as the ocean started to quiet. Apparently the Han CO had launched a snap shot at the bearing of the incoming torpedoes as pan of a last-ditch effort prior to his certain death.
"Right full rudder, all ahead flank. Cavitate. Make your depth one thousand feet," Mack said, followed rapidly by his calm, but forceful words over Cheyenne's 1MC, "Rig ship for depth charge."
With the ship already at battle stations, the reports from Cheyenne's various compartments came in quickly to the chief of the watch at the ballast control panel. The engineering officer of the watch (EOOW) had ordered main coolant pumps shifted to fast speed, and the throttle man answered the ordered bell as soon as the pumps were reported in fast speed by the reactor operator.
In fact, the throttle man was a little quicker than the EOOW had expected. With the precision of his training, he had acknowledged the engine order telegraph backup to the captain's orders and was already nearing 50 percent steam flow. Now he was just waiting for the chance to complete his spinning open the main engine throttles, which he couldn't do until the steam generator automatic level controls allowed him to. The safeguards were there to prevent excessive level swell, which might result in carry-over of water into the steam piping.
Within minutes, Cheyenne was at flank speed, on course 185, and at one thousand feet. The bearing rate presented to the Chinese torpedo made no difference as the SET-53 locked on to the knuckle created by Cheyenne's powerful maneuver. That was a direct result of Mack's order to cavitate, and had formed over a thousand yards away from Cheyenne's current position.
"Conn, sonar, two explosions, bearing 055, range 8,540 yards." Knowing the depth of water and the sound velocity profile, sonar could determine the range by the difference in time between the direct path and the bottom bounce path of the incoming explosion noises.
Above the cheers in the control room, Captain Mackey ordered, "Chief of the watch, over the 1MC, secure from rig ship for depth charge."
When the word was passed, Mack picked up the 1MC microphone and spoke to the officers and men of Cheyenne. "This is the captain. Gentlemen, Cheyenne has sent another enemy submarine to its fiery grave. Excellent work. You can be truly proud of your teamwork, each and every one of you. Cheyenne is you. Carry on."
Replacing the microphone, he added, "Chief of the watch, secure from battle stations." Mack knew that the stand-down from the tension could easily be short lived, especially if the Han had been accompanied by quieter Kilo class diesels running on their batteries.
The officers adjourned to the wardroom for the captain's standard critique of the attack. Mack also had every battle stations sonar man there. This review was very positive, but Mack added a note of caution about not allowing their guard down. This was war, he pointed out, and the Chinese shouldn't be expected to sit back and watch their submarine force be devastated. Cheyenne and her crew needed to proceed with caution back to an interdiction point so that they could detect and attack some of those Kilos.