Heihachiro Togo said, "What? No mines? ”

The leader of the minesweeper detachment said: "Yes, there are no mines!" ”

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

The detachment leader said: "We sent a total of six mine-sweeping teams to search almost all the port waterways, and there were no mines in the waterways at all. ”

Heihachiro Togo frowned and said, "Is it possible without mines?" Could it be that the people of China only laid a mine with all their efforts? ”

The detachment leader pointed to the sand table in the command room and said: "General Dongxiang, the width of the harbor channel is 200 meters, the length of our mine-sweeping net is 50 meters, and our six groups are divided into two batches, each batch of three groups, and the width of the net is 150 meters. ”

Heihachiro Togo said, "Now you guys go and sweep it a third time, understand?" ”

The detachment leader stood up and saluted, and said loudly: "My subordinates understand! After the captain finished speaking, he walked out of the road, and Togo Heihachiro said to Akiyama Shinyuki: "Akiyama-kun, how can you say that there are no mines in the waterway?" ”

Akiyama Mayuki thought for a while and said, "Togo-kun, we've all worked on small warships before, so we all know how to lay mines, right?" ”

Heihachiro Togo said: "Of course, the mine definitely needs an anchor and a pontoon, the anchor fixes the mine under the water, and the pontoon makes the mine float at a certain depth, and the ship will explode when it hits, so that the mine will definitely be discovered by the minesweeper." ”

Akiyama Mayuki said thoughtfully: "What if the mines of Lin Yuan's troops were laid somewhere else? ”

Heihachiro Togo asked, "Somewhere else?" Akiyama-kun, what do you mean by that? ”

Akiyama Mayuki said: "Just now the captain said that the depth of their net is how many meters? ”

Heihachiro Togo said: "Twenty meters, this depth has exceeded the draft of most ships, and if the depth of the mines is larger than this, the ships will definitely not be able to hit the mines." ”

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

Heihachiro Togo asked, "What does this mean?" ”

Akiyama Shinyuki said: "In the process of developing our No. 1 torpedo, some experts pointed out that if we installed a listening device on the head of the torpedo and then installed a control circuit behind the listening device, the torpedo could be tracked by the sound of the enemy's warship until it hit, but the technical difficulty was too great, and it was not realized in the end. ”

Heihachiro Togo asked, "What do you mean by that?" ”

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

Heihachiro Togo said: "So that means that the depth of the mines of Lin Yuan's troops can be much smaller than twenty meters? ”

Akiyama Shinyuki said: "That's right, if Lin Yuan's troops really have such a technique, then they can completely put the mines directly under the water, so that our minesweepers can't sweep them at all!" ”

Heihachiro Togo frowned and thought, Akiyama Shinyuki said, "Do you remember your question last night? Why did the mine not explode for so many days, but it exploded when a large transport ship came? ”

Heihachiro Togo 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 fuses, and they will only explode if the sound emitted by the ships exceeds a certain limit, I checked the records of the ships entering and leaving the port last night, and found that except for the transport ship that was bombed last night, the other ships are small boats, with a displacement of only a few hundred tons, and their sound is not enough to detonate mines. ”

Heihachiro Togo asked, "Will the sound from our submarine detonate a mine?" ”

Akiyama Mayuki shook his head and said, "I don't know this either, only after trying it, I will know it." ”

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

Akiyama said, "Of course not, we can think of some other way." ”

Heihachiro Togo asked, "What way?" ”

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

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

Akiyama said, "We need to look for something that can make a loud noise, what can make a loud noise?" ”

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

Akiyama Mayuki nodded lightly and said, "We can ask the minesweeper detachment to bring explosives, and then put the explosives under the water to detonate them, and use this pressure change to detonate the mines." ”

Togo Heihachiro nodded, and sent a herald to inform the leader of the minesweeper detachment, and the captain of the minesweeper detachment came in a short time, followed by Koyama Ishiji, Togo Heihachiro and Akiyama Shinyuki were very surprised when they saw Koyama Ishiso coming, Akiyama Shinyuki asked: 'Koyama-kun, why are you here?' "I'm here to tell you that the idea of detonating a mine with an explosion is very unrealistic!" ”

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

Xiaoshan Shiji said: "You think that the mine is detonated by a huge sound, this is just the appearance, in fact, the sound has many frequencies, and the human ear can hear only a small part of it, so although the sound of explosives explosion and the sound of ship explosion sound 'very loud', but their frequency characteristics are completely different, the fuse of the mine must be detonated according to the frequency characteristics, so it is impossible for you to use the sound of explosives to simulate the sound of the ship." ”

Akiyama Shinyuki frowned and said, "Aren't you studying the ocean?" How do you even understand acoustics? ”

"The propagation characteristics of sound in the ocean are the focus of my research, and there is a special discipline in foreign countries - hydroacoustics!" ”

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

Xiaoshan Shiji shook his head silently and said: "It's impossible, we can't simulate it, we haven't studied the sound characteristics of ships at all, and we haven't even drawn the sound spectrum of a ship, and now we want to simulate it, how can we simulate it!" ”

Heihachiro Togo asked, "Koyama-kun, since you don't know what the characteristics of the sound of the ship are in the road, how do you know that the sound of the ship is different from the sound of the explosion?" ”

Xiaoshan Shiji said: "This is very easy, you think, the sound of the explosion is intermittent, and the sound of the ship is continuous, and it is clear at a glance when you integrate it in the time domain!" ”