Making turns for 12 knots, the Alfas were running at a depth of fifty meters, not knowing that Cheyenne was approaching the area. They were heading toward Ingraham, closing in for what they thought would be an easy kill.
'Come to periscope depth,' Mack ordered the OOD.
'I want to alert Ingraham.'
Within minutes, Cheyenne was at sixty feet and the 'flash' message was sent via satellite to the lone frigate. The message included Cheyenne's estimated position and bearing to the two Chinese submarines and the fact that Cheyenne had tentatively classified them as Alfas.
'Conn, sonar. Masters 37 and 38 have increased speed. Blade rate indicates they're running at thirty-eight- make that forty knots, sir. It looks like they're making their move.'
Mack frowned. That wasn't what he'd wanted to hear. He'd wanted to remain silent until he launched his missiles, but that was no longer an option. Not with two Chinese Alfas racing to destroy Ingraham. There were few circumstances where Mack would have stood by and watched an American ship come under fire, and this wasn't one of them. He needed Ingraham. He needed it to guide Cheyenne's missiles over the horizon. Without Ingraham, Cheyenne's mission was likely to fail.
'Increase speed to flank,' he ordered. 'I want to intercept those Alfas. Come right to course 025.'
'Increase speed to flank and come right to course 025, aye, sir.'
Cheyenne's message, rapidly turned around at CTF 74 headquarters, galvanized Ingraham's officers and crew. The SH-60 crew members ran toward their helicopters, strapping their gear to their flight vests as they ran.
'Launch both helos,' the Ingraham captain ordered.
In the operations center on the frigate the sonar room was silent, listening. They had detected the two Alfas, bearing 310 and 320 from them, as soon as the Chinese submarines increased their speed to flank.
'Captain, sonar, we just detected what must be Cheyenne, bearing 235. She's running at flank speed also. It looks like she's trying to put herself in between us and the Chinese submarines.'
'Way to go, Mack,' Ingraham's captain said softly.
But the frigate wasn't out of the woods yet. The Chinese Alfas could accelerate up to forty-three knots submerged. On a good day, with a clean hull, Cheyenne maxed out at nearly forty knots which meant that the Alfas were going to arrive first.
Not if I can help it, the Ingraham captain thought to himself. 'Helm,' he ordered, 'come left to 235, all ahead flank.' He planned to head toward Cheyenne at his frigate's top speed. With luck and a strong tail wind, Ingraham just might have a chance.
Even running at flank speed, Cheyenne's sonar was able to detect Ingraham's maneuver. The bearing indicated to Mack that she was on station where she was supposed to be. It didn't take Mack long to figure out what her captain had in mind. On the 1MC, Mack himself ordered, 'Man battle stations.'
According to the BSY-1 computers, the range to the Alfas was closing fast. The Chinese submarines were heading southeast at forty-two knots, and Cheyenne was heading northeast at 38 knots. Mack would have liked to stay silent, but flank speed was Cheyenne's only hope of heading off the Alfas. Besides, at forty-two knots, the Chinese submarines had no chance of hearing Cheyenne's approach.
When the range to the closest Alfa, Master 37, reached 30,000 yards, Mack ordered tubes one and two made ready in all respects. He also ordered the outer doors opened. The range to the second Alfa, Master 38, was just under 33,000 yards.
'Sir,' the fire-control coordinator reported, 'we're in range of the first Alfa, Master 37. We'll be in range of Master 38 in three minutes.'
Mack nodded, but he did not give the command to shoot. 'I want to wait until they are within 28,000 yards,' he said. 'Tell me when Master 37 comes within that range. Firing point procedures, tube one, Master 37.'
Travelling at this speed, Cheyenne was relying on her BSY-! computers to give her any information she required on the positions of the sonar contacts. Because of her speed, sonar was not able to hear much beyond the water rushing by the hull.
As Cheyenne's BSY-1 computed range neared 28,000 yards, and the Ingraham's CIC (combat information center) reported the range to the Chinese submarines as 25,000 yards, the SH-60 Seahawks from Ingraham came into play, laying down lines of sonobuoys one after the other in an effort to determine the exact location of the Alfas. Once they had that information in their onboard computers, they could drop their own torpedoes on the Alfas.
The fire-control coordinator informed Mack the moment the range had decreased to 28,000 yards. Without hesitating, Mack ordered, 'Back full. Match sonar bearings and shoot, tube one, Master 37.'
With Cheyenne's, headway quickly killed by the backing bell, Mack ordered, 'Ahead one third.'
'Conn, sonar, unit one running hot, straight, and normal.'
If the Alfa continued on its present course and speed, the torpedo would reach it in seven and a half minutes.
The crew of the lead Alfa was excited. They had been chasing their quarry for some time now and were finally closing in for their first kill-against an American warship, no less. For all their excitement, though, they had no idea that there was an American Mk 48 headed their way.
A hundred feet above the surface, one of Jngraham's SH-60 LAMPS III helicopters detected Cheyenne's first torpedo within moments of its launch. The helos each had a single Mk 50 on board, which were smaller than Cheyenne's torpedoes. The Mk 50's hundred pound warhead was less than a sixth the weight of the explosive packed into Mack's Mk 48.
A quick communication flashed between the two helos, and moments later both pilots launched their Mk 50s- but not at the lead Alfa. Cheyenne wasn't likely to need their help with that one. Instead, they targeted the second Chinese submarine, Mack's Master 38.
Below the surface, Cheyenne was now comfortably within range of both submarines and was steering the Mk 48 into the lead Alfa, Master 37.
'Conn, sonar,' the sonar supervisor reported, 'Ingm-ham's SH-60s just dropped two torpedoes, sounds like Mk 50s, on the bearing to the second Alfa, Master 38.' There was a pause and then the fire-control coordinator added, 'It looks like they're going to hit, too, sir. BSY-1 shows they dropped them right on top of it.'
Neither of the Chinese submarines had any idea that they had been targeted by any American torpedoes. The lead Chinese Alfa never would.
The 650-pound warhead of Cheyenne's Mk 48 detonated directly aft of the Alfa's single screw and blew off the stern of the submarine. Running at four hundred feet, the crew on board the lead Alfa never had a chance. Those that didn't drown immediately as water rushed into the engine room were crushed by the pressure of the deep sea.
The second Alfa, still running at top speed, was unable to hear either Cheyenne or the two Mk 50s heading toward it, but its crew heard the explosion from the Mk 48 on the bearing of their sister ship. The second Aifa's captain slowed immediately to assess the situation-which was the worst thing he could have done. By stopping directly in the path of the American Mk 50s, he had sealed his own fate.
'Conn, sonar, two explosions, sir,' the sonar supervisor said to Mack. 'The Mk 50s just hit their mark.' A moment later he added, 'But she's not breaking up, sir,'
That didn't surprise Mack. The Alfa class SSNs had always been thought of as one of the hardest types of submarine to kill. Unlike most other submarines, the Alfa had a hull constructed not of steel, but entirely of titanium. This allowed it to dive extremely deep, probably 3,000 feet, and it also made her a very hard target to destroy. Alfas were almost as hard to sink as the double-hulled Typhoon.
The Alfa had gotten lucky, but she hadn't come away undamaged. The two American light weight torpedoes had hit the Alfa on its starboard side, damaging the starboard ballast tanks. To make matters worse, their reactor had automatically shut down when the control rods came unlatched as a result of the torpedo concussions. Without
