When arriving at the T-shaped port, only let the submarine engine maintain the necessary idle speed, try to use the inertia of the submarine to cross the dangerous area of two nautical miles, and the purpose of maintaining idle speed is mainly used to avoid sudden danger or to cope with emergencies can immediately increase the speed and can be avoided in time.

After the submarine came out of the T-shaped port, the engine was simply turned off, and the warm current was 100 percent used to propel the submarine forward, while the submarine remained at a suspension depth of about 80 meters.

Listening to Ma Yanshu's simple plan, Jiang Haitao nodded approvingly.

It can be said that the whole plan is to deceive the other side, and the most dangerous thing is not when it crosses the threat area, nor when it approaches the nuclear submarine "San Juan" out of the T-Junction, but when the 031 rushes towards the entrance of the T-Junction at an increasing speed.

The reason why Ma Yanshu and the others rushed to the entrance of the T-port at a higher and higher speed was to let the sonar crews on the "San Juan" submarine hear the same sound intensity of the No. 031 submarine as much as possible, and would not reduce the noise intensity by moving away, so that they would misunderstand that the No. 031 had not moved.

It can be said that only this deception is the most important, because once the other party knows that No. 031 is moving towards the T-port, the "San Juan" nuclear submarine will not stupidly wait on the perimeter of the trap, but will go over the "trap" and chase directly to the T-mouth, and wait for the No. 031 submarine to send its head to its muzzle.

Because as soon as the No. 031 submarine leaves, the so-called trap will no longer exist, and the nuclear submarine will naturally dare to run over it straight.

However, Ma Yanshu and Jiang Haitao also know that it is not enough to rely on the noise emitted by the engine to get higher and higher. The success rate of deception is too low.

The higher the speed of the engine. The speed of the submarine is correspondingly higher. The limited power in the submarine does not allow the engine to idle too much, not to mention that Ma Yanshu and Jiang Haitao hope that the submarine will have greater inertia when entering the most threatening area.

The reason why deception is difficult to succeed is that the sound is very Doppler effect. Anyone who has studied acoustic physics knows that the frequency of sound waves received as the source moves towards the observer becomes higher, and the frequency of the sound waves received when the source is far away from the observer.

Ma Yanshu's adoption of the farther distance and the louder the noise to misunderstand the sonar officers and men on the "San Juan" nuclear submarine can only be a temporary expedient measure, and there is no way to do it. If it were in peacetime, such a trick would never have succeeded, because the sonar crews on the nuclear submarine are experts and experts in this area.

But today there is a possibility of success. The reason is that there is a Zài acoustic cline here in the S valley, and as long as it is staggered and in the same position as the other party, the noise emitted by the No. 031 submarine will be refracted. And there are tall submarine mountains around the S valley, which will also reflect and refract the noise inside, and the noise will become inscrutable after the superposition of multiple reflected and refracted sounds, and it is impossible to distinguish clearly for a while, so it can only be analyzed with the help of a computer, or with the help of a very experienced person for a long time to compare and judge.

Another reason why Ma Yanshu is speeding up faster and higher is that he uses high speed to shorten the sailing time, and the earlier he arrives at the T-port, the sonar crew on the "San Juan" nuclear submarine will have less time for detection and less time for them to study and compare.

To show that submarine 031 is still in the valley. The submarine also deliberately turned on the active sonar before accelerating, and "illuminated" the surrounding terrain. Of course, it is also more convenient for No. 031 to escape.

The commander of the No. 031 submarine and the sonar officers and men were covered in cold sweat, and the commanders such as Ma Yanshu and Jiang Haitao were a little better, anyway, they were determined to make a bet, and they had to gamble on whether they could succeed or not. On the one hand, their ears had to listen very carefully to the movements of the "San Juan" nuclear submarine hiding in the distance, and on the other hand, they had to listen more carefully to the sound waves reflected from the surrounding seabed, so as to remind the submarine to avoid obstacles in time.

At this time, the active sonar cannot be turned on to irradiate the road ahead, and the distance can only be judged by the noise generated by the submarine itself and reflected back after encountering an obstacle on the seabed. This must not be sloppy or careless, and the slightest carelessness will destroy the boat and kill people. A lot of times they can't fully trust the computer and have to rely on people to analyze it.

With the full cooperation of everyone, the No. 031 submarine rushed through nearly ten nautical miles very smoothly, and the sonar room had not yet heard the movement from the "San Juan" nuclear submarine in the distance, and everyone couldn't help but sigh softly. Although there is no real escape yet, and there are still more dangerous sections to be completed, everyone at least sees hope for success.

At this time, Jiang Haitao suddenly picked up the microphone and connected to the line of the sonar room and ordered: "Aim the active sonar at the submarine mountain on the right side of the boat, at an angle of 135 degrees, and transmit it with maximum power!" Time for three seconds in a row! ”

"Yes!" The sonar officer replied loudly.

But after instinctively agreeing, I realized that this order was too crazy, isn't this setting off fireworks in the night? You can see it as far as you stand.

"It's just looking for death, isn't it?" The sonar officer hesitated, picked up the microphone and prepared to question the captain's orders.

Not to mention that the sonar officer was shocked, even Ma Yanshu, who was directing the submarine to move quickly in danger, was also frightened and pale by this order, not to mention the deputy captain, political commissar and others.

The sonar officer did not hesitate for long, but turned to his subordinates and began to command, and when the sonar soldier adjusted the angle and set the parameters, he himself pressed the launch button of the active sonar.

"Tom! Tong! ......" The dull and loud sound was felt by all the officers and men in the submarine, and the submarine shook because of it, and some soldiers were even shocked to the ground by the sudden shaking.

The officers and soldiers were shocked, one by one, you look at me, I look at you, and everyone asked silently:

"What's going on?"

"What's going on?"

"Did you get the enemy?"

……

A column of water stirred up by the sound wave shot straight towards the mountain in the distance, and several unlucky big fish were affected by this huge sound wave, and their bodies flipped over like a kite with a broken string and "flew" straight up. The huge sound wave hits a solid mountain and reflects further back of the submarine until it encounters another mountain......

As soon as the launch of the active sonar ended, Jiang Haitao gave another order to the stern torpedo room: "Launch the No. 7 torpedo, set the median value of sound intensity, speed of 14 knots, depth of 200 meters, and close after 20 minutes." ”

It was impossible for the series of movements of the 031 not to alarm the nuclear submarine "San Juan", and soon the sonar crews in the sonar room received the noise of the 031 submarine.

The sonar soldier in charge of the listening hurriedly reported to his commander: "Report, the target is moving!" ”

However, when the commander of the sonar room asked for the specific number of movements, such as the direction and speed of the movement, the sonar soldier could not answer accurately for a while. The commander knew that the sonar soldier could not be blamed for this, and he immediately picked up the headset himself to join the monitor.

After listening for about three seconds, he sighed and said, "They didn't move far where they were. What is this for? Soon, because of the interference of the acoustic cline, all they heard in their ears was faint sounds.

After waiting for more than ten seconds, the noise of submarine 031 came again. I don't know if it was because the commander didn't listen carefully, or because he heard the sound after refracting back and forth, but his judgment was the same as that of the computer: the enemy target was still in its original position.

Only the sonar soldier who had been on duty always felt that the sound inside was a little different, the intensity of the sound seemed to have not changed, but the frequency had changed a little, that is, the other party was moving away from him.

However, he couldn't be sure, because the sounds he heard were sometimes directly from No. 031, some were from the reflection of mountains and rocks many times, and some were refracted by the acoustic thermocline, which was really varied, and the sound that made him feel strange was hidden in a mess of signals and could not be grasped.

The Commander was silent when he saw that he easily put down his headset, recognized the computer's judgment, and sent it to the control tower.

After about ten minutes, he could finally be absolutely sure that the enemy, that is, the Project 031 submarine, was far from his position, and he had to report to his commander again: "The enemy is moving away from us, at least more than ten nautical miles!" ”

The sonar commander was stunned, first looked at his subordinates with disbelief, and then picked up the headset, and at the same time manipulated the computer to analyze the number jù, and soon, the experienced also concluded that the enemy was leaving, and the computer also analyzed that the enemy had moved eight nautical miles.

Although there was an error between the judgment of a person and that of a computer, and the error was very large, the officer did not doubt the correctness of the person, because in this complex situation, the computer was not as accurate as the sonar soldier's judgment.

Therefore, he immediately summarized the relevant information and sent it to the conning tower: "The sonar room reports that the enemy submarine uses the acoustic cline as a cover movement, and the computer analyzes that it is at least eight nautical miles away from our side and is still moving. ”

"Bastard! The enemy is out of the eight nautical miles, how did they find out? When the captain saw this report, he couldn't help but be furious. At the same time, he walked to the chart, carefully looking for where the enemy might stay, and his eyes fell on the T-shaped mouth from time to time, and his face was cloudy, and he didn't know what he was thinking.

Just when he thought for a long time and was about to give another order, another message came from the sonar room: "The enemy submarine turned on the active sonar and continued to shine for three seconds. Computer analysis showed that the launch point was about two nautical miles from its original location. The relevant number is being verified. ”

Seeing this, not to mention that the captain was angry, even the chief of staff also scolded: "These bastards! Just said that the other party left the original position at least eight nautical miles, why is it only two nautical miles now? Could it be that their submarines can fly at any time? Relying on computers for everything, and putting all the blame on the computers, don't they themselves have the ability to make judgments? ”

(Thank you for your subscription support) (To be continued......)