My German Empire

Mooring a German fleet in Waha Hua, a correspondent report to Haierman Command. "Commander, our destroyer found suspicious signal at 50 kilometers northeast, suspected of an enemy submarine."

"These idiots, is it dead?" Haierman commander smiled and told him. "Sinking them!" Who can I appear here in addition to US military submarines here?

The secondary officer of the side is open. "It seems that the US military submarine supporting Wahu may give them fresh water purification equipment. But just try our latest sonar system."

In 1912, the luxury huge rounds collided with the icebergs, and the outbreak of the First World War in 1914, which greatly promoted the development and development of civilian and military sources. The first anti-submarine admission is in the First World War, but the performance of this water echo positioning system is unreliable due to theoretical and technical imperfection, and threatens to deal with German U-type submarines. There is no contribution yet.

The studies have not terminated because of the end of the battle, until 1935, Germany, Britain, and the United States have also developed several more practical sources. In 1938, the sonar equipment began to produce in the United States. In World War II, almost all military ships have been equipped with a sonar system and played a very important role in the sea battle. At that time, there were more than a thousand submarines in the war, most of them were discovered by sonar. of.

"Reporting, the enemy's destroyer is being approaching at high speed!" In the underwater US military submarine, the submarine sounds quietly listened to a few seconds after a few seconds. I have just found a German destroyer in the distance, although I dive in time, can be obviously discovered by the other side.

"Dive to 30 meters, the speed is lowered to 3! Reduce the noise!" With the impersonal command, the submarine closed some unnecessary equipment to reduce the noise that the submarine was issued in the sea. However, these noise can be said to be uncomfortable, the sound of the submarine engine and the propeller emitted is the main noise source, unless all power systems are turned off, otherwise discovered that their probability is still very large.

They can't close all power systems. If the enemy ship on the water does not leave, their situation will be more dangerous.

On the sea, a German destroyer has been close to this sea area, and the ship has issued a command. "Open the initiative! Put this mouse out!"

Sona technology can be divided into passive and active sonar. Simply talk about only the ear, listening to the various sounds underwater, can only estimate the approximate orientation of the goal. And the active sound is more mouth, shouting with the mouth, receives the echthics with the ear, and determines the target distance. These two have their own advantages and disadvantages, active sonar test points, but easy to expose (the water surface ship opens the active sona is equal to the submarine in the water: "Hey! Buddy, I am here, my position is here, Have you listened to it? ". Violation of the passive hidden point, but not allowed, the submarine collision of the later generation, showing passive nna still has problems.

The noise sent by the underwater submarine is low, and the passive sound is unable to distinguish the submarine and the noise of the sea. The active sonar can, because the active sound is positioned against a particular echo. In general, as long as the submarine does not cover the bed (sank to the seabed), the active sonar can effectively position the submarine.

The German destroyer turns on the active sound and starts to transmit the frequency band sound wave to the surrounding sea.

Ultrasonic is divided into three bands of low frequency, intermediate frequency and high frequency, where the intermediate frequency of anti-interference ability is best detected using an intermediate frequency ultrasonic wave, which can be effectively imaging the submarine that is hidden in seawater. Ultrasonic waves of low frequency bands and high frequency sections are long, but the accuracy is poor, or the accuracy is high but the distance is close, it is not as appropriate for the intermediate frequency. It has a good distance and good precision.

But unfortunately, this band is also a physiological band of most marine creatures (such as dolphins, whales and other large marine animals, relying on medium-band sound wave echo positioning for navigation and predation activities, etc.), although in the late Second World War II, some national equipment Na, but later found that the use of the sonar has led to a large number of phases of marine organisms that rely on echo positioning patrols, internal bleeding or even dilutive, some dolphins or whales are stranded to the strange sea, and even rushing on the beach (that is, the collective of people think suicide). Therefore, the United Nations has formulated relevant measures in order to protect these marine organisms. Therefore, under the pressure of global public opinion, the military will abandon the use of China-Frequency, even some countries even high-frequency Gradually canceled.

Unfortunately, now you will die, no one will care about those marine animals.

Table tennis! Table tennis! Table tennis!

The intensive sound waves hit the US military submarine, and the sonards screamed with the headset.

The cavity effect enlarges this sound, and the sailors in the submarine clearly hear this terrible sound.

"Continue dive to 50 meters deep!" Although the Thomas boat is unclear what the German does this means, it can be obviously not friendly and determines what is done.

Soon, the submarine has dive 50 meters deep, but the terrible ping! Table tennis! Sound is more dense.

Because the sonards took the headphones, they did not hear a German destroyer on the water, and had dropped several deep water bombs.

boom! The sudden explosion makes the sailors in the submarine.

The first deep-water bomb exploded at the left side of the submarine, there is no substantial damage to the submarine, but the other deep water bomb exploded in the submarine boat, huge shock waves blow the submarine front. Out of a big hole, the sea is straight.

"Equipment first sea water! Emergency float!" I heard the impairment of the boat, and the Thomas boat immediately reached the ups and floats. This level of impairment is fatal for a submarine. If you continue hard, then they can only go to God; and he doesn't want to see the old man in the old man so early.

The sailors of the submarine can be described as practicing, and the commander of the yachboard has been executed immediately. With the operation of the sailors, the compressed air poured into the ballast water tank of the hull, and the sea water headed out. When the boat was first, the weight was reduced, but the tail was filled in, and the submarine ship was naturally It's up, the whole submarine is fast!

At this time, the third deep water bomb was almost exploded by the shell of this submarine. It is also skillful, if it is an ordinary deep water bomb, will only explode in the set depth. The deep water bomb of the German is a near-fried letter. As a result, the deep water bomb whose deep water bomb is rubbed out, and the huned submarine has been born under the terrible impact of this terrible impact. Two trip, slowly sinking a deeper seabed.