Meanwhile, LT Owens had to solve a word problem: “If two helicopters with endurance X were detected at time Y, when will it be safe to return and recover José and Walter? Show your work. You will be tested on the material.”
Their intelligence pubs told them how much fuel the helicopters could carry, and they knew where the airstrip on the island was located. Commodore Mitchell, the only one on the boat with actual aviation experience, told her about how much fuel the helicopters would likely keep in reserve, which shortened their time aloft somewhat. Then factor in the travel time back, as well as the detection range of the sonar, if they were listening.
She reported to Weiss, “I compute turnaround at 1445, and ETA for rendezvous with Walter at 1530, assuming we tell the UUVs to wake up and close on our position at four knots.” Although speaking to Weiss, she did glance over to the commodore, who stood well off in a corner of the control room, pretending to study a tactical display.
Still watching Owens’s report, Cavanaugh quietly slid over next to Mitchell and asked, “What if they send another pair of helicopters to continue the search?”
“Then we’ll hear more pinging after the first two should have gone home,” Jerry responded. “But it’s unlikely. From the Russians’ point of view, all they had was the initial contact from that fixed acoustic sensor. They sent out a pair of aircraft to check it out, and found nothing. False alarms are a fact of life for any sonar system.”
“But what if the next pair are just listening?” Cavanaugh persisted.
“Remember the difference between active and passive ranges,” Jerry countered. “They’d have to be listening in exactly the right spot. There is a small risk in going back at all,” he admitted, “but we’re fighting the clock. I’m confident we’ll be able to recover the UUVs safely. The larger question is what we’re going to do about those ublyudok sensors.”
“Can you speak Russian?” Cavanaugh asked. As capable as Commodore Mitchell seemed to be, it wouldn’t surprise him.
“No, but I know how to start a fight,” Jerry answered.
Jerry studied the navigation display with Cavanaugh, Weiss, Segerson, Malkoff, and Ford. Joining them was Master Chief Paul Gibson, Carter’s chief of the boat or COB. The large flat-screen showed a composite chart of the waters off Bolshevik Island. The launch facility lay seven miles north-northwest of Cape Baranova, in five hundred and ninety feet of water. A circle showed its position, determined by the location of the ships Weiss had seen through the periscope on Carter’s first mission and from observations taken an hour earlier — a quick check to make sure the helicopters had left the area. The recorded video showed a cylinder being lowered into the water by the icebreaker.
“I’m pretty sure those are smaller than the ones we saw earlier, Skipper,” commented Segerson.
“Concur, XO.” Weiss nodded as he spoke. “Which means—”
“That they’re probably loading the launchers,” interrupted Jerry. “I’m willing to bet those are transport launch canisters for the Dragon torpedo.”
“And that means we’re running out of time,” Segerson concluded.
“Pretty much,” said Jerry.
“So, how do we get to the launcher complex?” asked Cavanaugh. “I’m not much good to you this far away.”
It was a good question. The UUVs’ surveys had counted at least twenty PMK-2 mines. If spaced at an optimal distance, it would take fifty to form a complete barrier twenty-seven miles wide. There was probably another line to the south, but that was irrelevant. They’d figured out how to deal with the mines, but they were just the first layer of the facility’s defenses. The second layer, comprised of MGK-608M fixed acoustic modules backed up with helos, was more of a challenge.
“I guarantee these were not here the last time we scouted the area,” Weiss stated.
“It makes sense that the Russians were still installing their defenses,” Jerry remarked philosophically. “I’ve encountered these acoustic sensors before, and just like last time, we found them by literally tripping over one. José’s image looks identical to the one I saw earlier. The system is called ‘Sever,’ and it can obviously detect a Seawolf-class boat.”
“What did you do about them the first time?” Ford asked.
“We ran like thieves, with most of the Northern Fleet after us,” Jerry answered, smiling.
Ford wasn’t deterred. “The UUVs were originally designed to find and destroy mines. This acoustic sensor is just like a bottom mine, except it listens instead of exploding. I recommend we put a mine-clearing charge on top of the cylindrical body and knock it out.”
Weiss and Jerry considered the suggestions, but only for a moment. Jerry waited for Carter’s skipper to speak first.
“No good, Ben, for two reasons. First, the modules on either side will transmit the sound of the explosion, but even worse, the network is almost certainly designed to show when a module has stopped working. Either way, we draw attention to ourselves.”
“And cutting the cable with a mine-clearing charge does the same thing,” Ford muttered. “That was going to be my second suggestion.”
Weiss observed, “What we have to do is get through the sensor net without alerting it in any way. But we couldn’t even get a UUV close to the sensor without being detected. How are we going to get anything close enough to do any good?” He didn’t sound optimistic.
Jerry smiled broadly. “No, there is something we can do.” He turned to Ford. “Has anyone ever measured the glide slope on the UUVs?”
“Like a plane?” Ford asked. When Jerry confirmed the meaning, the UUV officer answered, “Definitely not. I can tell you how far it will coast, given its speed when we stop the motors, but the UUVs are neutrally buoyant. And they’re shaped like a brick. There’s nothing to generate any lift like an airplane.”
“Okay,” Jerry replied, “so it’s not so much a glide as a controlled fall. If we put a UUV at the right depth off the bottom, and make it negatively buoyant, it will start to sink. We then point the nose down…”
“And you will get some forward speed,” Ford concluded.
Weiss nodded approvingly. “After we recover José and Walter, we’ll move some distance away from the island and test the idea. We will start a UUV moving, then shut down the motors and angle the nose down. We can measure the rate of depth change, then play with it until we find the best combination of angle and buoyancy.” Carter’s captain smiled. “So we launch the UUVs and they glide silently over the sensor’s position and then…” He stopped, unable to finish the sentence and scowled.
“If we can’t knock the sensors out,” LT Ford mused, “could we blind them by launching countermeasures? Use the UUVs to place several at different spots along the barrier and then drop one ourselves as we go through. We could even launch a mobile decoy while this is going on and point it north so they’re chasing the simulator while we head toward the island.”
“So instead of sneaking in, we just kick down the door?” Jerry asked.
“Doors and windows, all at once,” argued Ford. “Give them three, five, or even more major noise sources that blind portions of the net. Even if they assume we’ve crossed the barrier, they won’t know exactly where.”