Open an aircraft carrier to fight against Japan

Dongxiang Heihachiro said: "What? No mines?"

The captain of the minesweeper unit said: "Yes, but there are no mines!"

Dongxiang Heihachiro said: "You come to see me immediately." The captain walked into the command room after a while, and Dongxiang Heihachiro asked bluntly: "How can you be sure that there are no mines?"

The team leader said: "We sent a total of six mine-sweeping teams to search almost all the waterways of the port. There are no mines in the waterways."

Dongxiang Heihachiro frowned and said, "Is it possible without a mine? Could it be that the Chinese people tried their best to plant only one mine?"

The team leader pointed to the sand table in the command room and said: "General Dongxiang, the width of the port channel is 200 meters, and the length of our minesweeping is 50 meters. Our six groups are divided into two groups, each with three groups. The width is 150 meters, except for those shores where it is impossible to lay mines, it almost covers the entire channel, and it is absolutely impossible to miss the mines."

Dongxiang Heihachiro said: "Now go and scan the third time, do you understand?"

The sub-leader stood at attention and saluted, and said loudly: "The subordinates understand!" The sub-captain walked out after finishing speaking. Togo Heihachiro said to Akiyama Shinyuki: "Akiyama-kun, why do you think there are no mines in the waterway?"

Akiyama Shinyuki thought for a while and said: "Mr. Dongxiang, we have all worked on small warships before, so we should all know how to lay mines?"

Dongxiang Heihachiro said: "Of course I know that mines definitely need an anchor and a buoy. The anchor fixes the mine underwater, and the buoy keeps the mine floating at a certain depth. When the ship hits it, it will explode. In this way, the mine will definitely be found by the minesweeper. of."

Akiyama Shinichi said thoughtfully: "What if the mines of Lin Yuan's troops were placed elsewhere?"

Dongxiang Heihachiro asked: "Arranged elsewhere? Akiyama-kun, what do you mean by that?"

Akiyama Shinyuki said: "Just now the team leader said how deep are they?"

Dongxiang Heihachiro said: "20 meters, this depth has exceeded the draft of most ships. If the depth of the mine deployment is greater than this, the ship will definitely not be able to hit the mine."

Akiyama Shinyuki said: "What if the mines of Lin Yuan's troops don't need to be hit to explode at all?"

Togo Heihachiro asked, "What does this mean?"

Akiyama Shinyuki said: "During the development of our No. [-] torpedo, some experts pointed out that if we install a listening device on the head of the torpedo, and then install a control circuit behind the listening device, the torpedo can rely on The sound made by the enemy warship was used to track until it hit, but the technical difficulty was too great, and it was not realized in the end.”

Dongxiang Heihachiro asked, "What do you mean by these?"

Akiyama Shinyuki said: "What I mean by this is that the mines laid by Lin Yuan's troops are likely to use sound fuzes. With this kind of fuze, the ships do not need to touch the mines, and the mines will explode."

Dongxiang Heihachiro said: "Then that is to say: the mine depth of Lin Yuan's troops can be much smaller than 20 meters?"

Akiyama Shinyuki said: "That's right, if the mines of Lin Yuan's troops really have such technology, then they can put the mines directly on the bottom of the water, so that our mine-sweeping equipment will not be able to sweep them at all!"

Dongxiang Heihachiro frowned and thought, and Akiyama Shinyuki said: "Do you remember your question last night? Why didn't the mine explode for so many days, but it exploded when the large transport ship came over?"

Dongxiang Heihachiro nodded and said, "That's right, I do have this question."

Akiyama Shinyuki said: "Now it seems that this question is very easy to answer, that is: the mines used by Lin Yuan's troops are equipped with sound fuzes, and they will explode only when the sound from the ship exceeds a certain limit. I adjusted it last night. After reading the records of ships entering and leaving the port for the past two days, I found that except for the transport ship that was bombed last night, the other ships were small ships with a displacement of only a few hundred tons, and their sound was not strong enough to detonate a mine."

Dongxiang Heihachiro asked: "Will the sound from our submarine detonate the mine?"

Akiyama Shinyuki shook his head and said, "I don't know about this either, I'll only know after trying."

Togo Heihachiro shook his head and said, "We can't let the submarine try."

Akiyama Shinyuki said: "Of course not, we can think of some other ways."

Dongxiang Heihachiro asked, "What method?"

Akiyama Shinyuki said: "Since the mines of Lin Yuan's troops were detonated by sound, then we should find a way to make sound, wouldn't we be able to detonate the mines laid by Lin Yuan's troops?"

Dongxiang Heihachiro said: "This method is good, I don't know what we should do?"

Akiyama Shinyuki said: "We need to find something that can make a loud noise. What can make a loud noise?"

Togo Heihachiro said: "The essence of a huge sound is a change in pressure, so we only need to find something that can cause a huge change in pressure. The explosion of explosives can cause a huge change in pressure."

Shinyuki Akiyama nodded slightly, and said: "We can let the minesweeper team bring explosives, and then put the explosives underwater to detonate, and use this pressure change to detonate the mines."

Dongxiang Heihachiro nodded, and sent messengers to notify the minesweeper team leader, and the minesweeper team leader came soon, followed by Xiaoshan Shiji. Very unexpectedly, Akiyama Shinyuki asked: "Little tiger, why are you here?" "

Xiaoshan Shiji said: "I'm here to tell you that the idea of ​​using an explosion to detonate a sea mine is very unrealistic!"

Akiyama Shinyuki asked, "Why do you say that?"

Xiaoshan Shiji said: "You think that the mine is detonated by a huge sound. Although the sound and the sound of the ship's explosion sound loud, their frequency characteristics are completely different. The fuse of the mine must be detonated according to the frequency characteristic, so you use the sound of explosives to simulate the ship's sound. The sound is simply impossible."

Akiyama Zhenzhi frowned and said, "Don't you study the ocean? Why do you even understand acoustics?"

Xiaoshan Shiji said: "The propagation characteristics of sound in the ocean is the focus of my research. There is a special subject abroad - hydroacoustics!"

Akiyama Shinyuki nodded, and then asked: "Then how should we simulate the sound of a ship?"

Xiaoshan Shiji shook his head silently, and said: "Impossible, it can't be simulated. We have never studied the sound characteristics of ships at all, and we haven't even drawn the sound spectrum of a ship. Now we want to simulate it. How can it be simulated!"

Dongxiang Heihachiro asked: "Little tiger, since you don't know the characteristics of the sound of a ship, how do you know that the sound of a ship is different from the sound of an explosion?"

Xiaoshan Shiji said: "This is very easy. Think about it. The sound from the explosion is intermittent, but the sound from the ship is continuous. It is clear at a glance if you integrate it in the time domain!"