Thunder Strikes Back

Chapter 93

The No. 411 submarine has been driving straight above a known trench, but did not dive into the trench rashly, because the navigation department is not sure about the depth marked on the chart and the accuracy of the inertial navigation. However, Marin's arrangement, Clearly there was an intention to make an emergency dive if necessary.His suspicions were finally confirmed. The submarine gradually got rid of the two old frigates behind it. The background noise on the bottom of the sea was returning to normal. The sonar department immediately discovered that there was indeed suspicious movement in the nearby sea area, but the source of the noise was still unclear for the time being. position and distance, but it can be roughly judged that it is approaching.The track analysis team on the boat is on standby at any time, maybe after the solidarity is strengthened, some clues can be caught.However, both Marin and political commissar Su Changjin are worried about another thing, that is, 411 has not obtained permission to fire, so No. 411 is obviously in a very disadvantageous position in the seabed confrontation.

"If anyone is actually following us, I think this person is an old hand, very good at using the water temperature layer here to hide tracks. You see, no leaks have been leaked so far. No complete track, maybe changing depth and course all the time. said Marin.Standing next to him was the deputy captain Sun Xiangdong. At this time, the political commissar couldn't bear the fatigue and went back to rest.

"It is possible, but it is also possible that there is a group of whales tens of nautical miles away. Sometimes it is difficult for the sonar department to distinguish their voices, especially when the whales are breathing up and down. They mistook them for medium-range submarines,"

"Judging from the speed of the ship, this possibility cannot be ruled out, but I have had a long talk with Sonar, and he said that he used his head to guarantee that it is not a marine animal. In addition, he thinks that the other party's strange whereabouts may not only be to hide himself , It is also because their passive sonar can search for us in the reflection area of ​​the seabed, and I think they should not be aimless." Marin said, his personality has caused him to always think of things as bad as possible.But the facts are also obvious. Since the opponent has more accurate charts, he can completely guess that he will go to a geographical shielding area, and the psychology of his peers is always the same.

"Captain, shall we check the inertial navigation data now?" The deputy captain proposed to float up a little so that an electronic mast could be extended to receive satellite navigation signals. Now it is 170 nautical miles away from the east coast of India, and there is no What kind of ship, he thought there should be no problem.

"Don't be careless now, it would be bad if there is a helicopter overhead. We have not left the radius of the shore-based anti-submarine helicopter."

Marin categorically rejected this suggestion, and Sun Xiangdong did not insist, because he had long been accustomed to being cautious and suspicious of the captain, and it might be beneficial to the safety of No. 411.

"Then, we can release the towed line array sonar, and the water depth is fine now."

"Okay, I'll leave this to you. We really need to increase the listening range. We can sail on a Z-shaped route."

"I think, I need to increase the speed a little bit. If I use the zigzag route, it will be more effective for playing the role of towing sonar."

"No, I don't think it should be too fast for the time being. The noise of the cooling pump is what I'm worried about. In addition, we can't get out of this deep ditch below. In case of a situation, the speed alone is not enough to cope."

"I don't think there is any need to think too much about India's submarine force, right? Just now their anti-submarine helicopters seemed very... frizzy. Without any threat, they dropped torpedoes almost at the edge of the range. The prediction error is astonishingly large.”

"Hmph, don't be too careless. I always feel that the nearby sea area is not as simple as you think. We are surrounded by murderous threats?"

"Four volts?" Sun Xiangdong was a little puzzled. It sounded like Marin's thoughts were really careful, but he'd better go to sleep now.

At a water depth of 110 meters, the towed sonar slowly left the top exit of the rear cross rudder of the No. 411 submarine.This is a 550-meter-long thick cable sonar, which can theoretically increase the detection range of this submarine several times.However, this kind of soft sonar is often unable to accurately measure the specific position of the target.

Marin sat on the command seat of the command module and dozed off. He hadn't slept for 30 hours. The personnel in the command module had changed shifts several times, but he hadn't left here.

After a long time, a new signal was slowly caught by the towed sonar. The sonar listener couldn't tell what it was, so he amplified the suspicious sound signal, and then filtered and gained it. He thought it was the cooling of a nuclear submarine. The repeated noise from the circuit, and then beckoned to Sun Xiangdong who was on duty.Sun Xiangdong took it upon himself to ask the helmsman to turn a few times in order to further judge the location of the sound. Due to the lack of speed, the turning of the submarine was very slow. However, the electronic and manual calculation of the moving target completed the positioning almost at the same time, and there was not much difference between the two. There is a submarine hidden in the area about 10 nautical miles behind the submarine, and it seems that Marin really guessed it.The speed of this submarine is slightly higher than that of No. 411, and the depth is roughly the same as that of No. 411. Judging from the sound characteristics, it is still difficult to determine the nature of the submarine. Sometimes the propellers of conventional submarines also make sounds similar to cooling pumps, but since Being able to track 411 for such a long time, it is expected to be a nuclear submarine that does not need to float up to the depth of the snorkel.Sun Xiangdong hesitated for a while, whether to wake up the captain, or continue to deal with it on his own, and finally he walked over to wake Marin up.Without wasting much time, Marin immediately understood the situation, not only because of his quick thinking, but also because he generally guessed all the possibilities aside.

"Only 10 nautical miles? So close."

"Not like the sharks you're most worried about, we're having a hard time spotting sharks or Los Angeles at this distance, I see..."

"You think it's an Annihilator?"

"That's right, that's what we judged. Since we found him first, as long as we turn around and use the bow sonar to intercept again, we can fire very accurately. I'm not bragging, I'm 8% sure to use a torpedo Hit it," said the mate.

"Playing the piano randomly, do you still have discipline in your mind? Can you say such things?" Marin said bluntly, there is no combat part of this mission.

"Then what to do, it will catch up soon, if we speed up to leave now, we may expose ourselves."

"Prepare to dive, hide in the shielded area below, and wait for it to make a mistake."

"But the accumulated error of our inertial navigation is already very large, and the depth on the sea chart is also very inaccurate. If you dive rashly, I'm afraid..."

"Try your luck. In our line of business, you have to take a little risk."

10 nautical miles away, inside the Indian Annihilator, Colonel Manush stood energetically behind the periscope and waited for a new report. According to his calculations 10 hours ago, he should be very close to the submarine now.He was sure to find and sink his opponent in this area.

"Torpedo chief, open the cover of the No. 2 and No. 3 torpedo tubes."

"clear."

"Gentlemen, I can already feel that the opportunity is very close to us, and it is almost within reach. Keep the speed and search around slowly."

"Sir, I found a strange sound signal." A professional non-commissioned officer whispered.

Manush walked over quickly, and on the voiceprint map, there was indeed a weak high-frequency signal appearing repeatedly, about 2 Hz.

"They're measuring the water depth under the keel? Can you find the location now?"

"The sound signal is too weak, and the approximate bearing is 305. How about the distance? I don't know." The sergeant replied. In fact, the part of the electronic calculation showed that the distance was only one nautical mile away, but the sergeant knew that this unreasonable number must be wrong. The system's judgment of the wave position of the weaker sound is always far less than the actual distance.

"Don't worry, we can change the depth a little bit." Manush suddenly regretted opening the torpedo cover rashly just now. This action may have been rushed.The enemy boat turned on the water depth detection, indicating that she was about to hide in that trench. Does this mean that he has already noticed it?It seems that there is only one thing to do and two things to stop.Manush grabbed the intercom: "Torpedo No. 2 is ready to launch!"

Of course, No. 411 has noticed that the sound of the Arihant opening the torpedo tube cover was only delayed by about 10 seconds, and it was heard by No. 411. This reminded Marin, the commander of the Indian submarine, that there was about to be a dead fish. Contrary to his previous hesitation, he made a decisive decision to turn on the water depth detector under the keel to measure the water depth below and provide measurement data for No. 411's timely dive and hiding.This is a compromise method. He is sure that such high-frequency sound waves will be detected by the enemy's passive sonar, but he also knows that the enemy cannot find himself with this low-power sound source alone.

"Dive quickly, lean forward 15 degrees, and dive to 160 meters. The heading remains unchanged, and the speed increases to 9 knots." Marin issued an order.He was sure that the play of probing each other and Zhou Xuan was over, and now it was time to play the final card. He was sure that one of the advantages of hiding below was the towed sonar still left above the trench.It can provide an asymmetrical reconnaissance advantage, but the price is that the 411 boat has a very high chance of hitting the rocks on both sides of the trench due to navigation accuracy problems.

"Azimuth 170, high-speed propellant, maybe a torpedo, distance 80 chains." The towed sonar found that the enemy had launched a torpedo, and it seemed that the Indian commander 10 nautical miles away was really determined to go to war.

(End of this chapter)