The Allies noticed Germany's infinite submarine warfare very early. German submarines were always active in the North Atlantic. The seawolf troops have been expanding from their initial scale to now. Over 1,000 tons or even 1,500 tons of ocean submarines have emerged one after another. Even though the British and American fleets were careful enough to send a large number of warships to escort, the sinking rate has been quite high. One loss of 10 times is almost as iron law. Because the submarine cannot be discovered, the German submarines even boldly came and ventured into the anchorage of the ship to attack. Taking advantage of the chaos, they attacked several merchant ships and left.

Although listeners resumed training with the support of the United Kingdom and the United States, the human ears not only have a small listening range, but also have a very high chance of being affected. As long as they are at night and in a chaotic environment, the chance of success is very high, which has caused a huge blow to Britain and the United States, and even canceled the original anchorage. As long as it is not a storm or other necessary conditions, there are few choices to anchor at night, even if it is marching.

Britain and the United States are looking for a reliable way to find submarines. Britain can only extend the basis of listeners, hoping to find better listeners from the middle. It seems that there are some effects. Several talented listeners can achieve a 30% accuracy rate, which is at least 4 times higher than the 7% accuracy rate of ordinary listeners. This improves the efficiency of this group. Unfortunately, there are only 3 such people, and it is impossible to listen for a long time. At most, you have to rest after giving your all your strength for 6 hours.

On the contrary, the United States has jumped out of the listener and chose other aspects. The United States has excellent scientific and technological conditions and industrial foundation. After absorbing the top technology in the UK, the United States' technological level is like entering a fast lane, and all aspects have improved rapidly.

Sonar, an underwater detection device, was originally the creative idea of ​​the British, but the British could not continue it. Instead, the United States saw this, went deeper, invested huge funds, and achieved considerable results.

In the early 1915, after the development of sonar was made in the United States, the United States began to install and debug the sonar system on destroyers, and the effect was slightly better than listening. This gave Americans hope that sonar is a machine, and as long as the reliability is guaranteed, it can continue to produce effects. Unlike the listener, when he is doing his best, the effect is OK, but it cannot last long, and the accuracy difference between peak periods and other periods is somewhat large.

The initial results are so outstanding. This has made the United States firmly believe that if it continues to research, the United States has much stronger scientific and technological standards than the United Kingdom and has rich human resources. As long as it increases investment, it will definitely gain.

Next, the United States increased its investment and gradually solved several key problems of sonar, and finally made practical sonar. After using it in the United States, it found that the effect was good and he was invested in the North Atlantic waterway. The sea wolf troops brought huge pressure to the Allies. Even if it was as strong as the United States, it could not bear it, let alone the United States. As soon as the primary products of sonar came out, even if they did not undergo strict and necessary testing to see if there were any side effects, they were installed.

In fact, the Americans are very good at roads. The power of submarines is mainly hidden. After all, for underwater ships, the huge sea and thick sea water are their greatest protection. With these, they can launch sneak attacks on ships. With the greatest effect, a 1,500-ton submarine can even sink more than 30,000 tons of battleships.

Of course, this is to the extent of theory. Battleships cannot act alone and are unlikely to be caught by submarines. As for setting up an ambush, the possibility is too small in naval battles. Submarines may have only one chance against battleships. The main ships with more than 25 knots are almost impossible to be attacked by submarines at high speeds.

Sonar is to eliminate the protection of submarines. In terms of accuracy, it is worse than ordinary listeners, but not as good as the most elite. However, 24 hours a day is very important. As long as sonar can detect submarines, it will be a disaster for submarines. With clear instructions, destroyers equipped with deep-water bomb projectors can easily sink the submarine. The submarine's shell does not have much protection, mainly sealing effect. Any deep-water bomb explodes at a close range, and the shock wave is enough to tear the shell of the submarine. Any underwater ship that sails underwater must float up, otherwise, it will become like a can, filled with water, and sink to the bottom of the water forever.

Submarines that were not able to be discovered before, became waves and the most important weapon for Germany to attack the Allies. They were mainly displayed on merchant ships in the sunken area. The hidden location and the sea were their greatest protection. With the help of sonar, the submarines could be discovered. To a certain extent, the entire North Atlantic Ocean became a forbidden area for submarines.

There is no way, German submarines are still the first generation submarines, and their pursuits are mainly about size. They are equipped with more oil and have more ammunition loads. In terms of submarine sound processing, they are still at the initial stage. Ordinary listeners can distinguish them after training, let alone technically equipped sonars. After simple processing of sonars, they can hear the submarine movements in a range of 5 kilometers around them, and then, it is time for the submarine to be unlucky.

In late September 1915, the United States made a series of attempts and found that the effect was very good. Although there was no choice to attack, at least many submarines were found along the way, so the efficiency was definitely not low.

Through the introduction of the United States, the United Kingdom was also half-doubted and tried it personally. After discovering the effect of sonar, it immediately asked to install it. After working for several months, it finally had enough sonar. Starting from November 2, 1915, the United States and Britain jointly carried out a fisherman operation. At least 120 destroyers and light cruisers equipped with sonar were active on the North Atlantic route. After a month of fishing, it achieved excellent results. At least 107 German submarines were sunk, and the escort effect was extremely obvious. From the 12th to the end of the month, only 7 ships sank, and three of them were silent and had little to do with the submarine.

The effect of this original intention made Britain and the United States extremely happy. For Britain and the United States, the most terrifying thing on the North Atlantic route is the German submarines. German submarines can freely find targets. A certain percentage of sinking rate makes the British and American merchant fleets replace them in three years, not to mention the materials involved. Every loss cannot be borne. But now, with such an underwater eye, German submarines are really a waste. Any destroyer equipped with sonar and deep-water bombs can independently deal with a submarine.

After the United Kingdom and the United States achieved results on the North Atlantic route, they also wanted to copy them to the direction of the Pacific and Indian Oceans. There were also submarines active there. Although there were not many, they also caused losses to the Allies. However, the production volume of sonar was limited and it could only support the North Atlantic route for the time being.

Thanks to difficulties, otherwise Britain and the United States would have arranged sonar there but could not find the submarine, which would be a waste of time. On the routes of the Pacific and Indian Oceans, the active subjects are submarines from China, which are different from the primary submarines in Germany. These submarines have been treated and will not choose to use gasoline engines underwater. On the water, there are diesel engines, and underwater, batteries will be installed, and underwater is fully electric. On the propeller, fluid mechanics are also used, so the sound wave is reduced to less than 100 decibels at least.

The effect of a black hole with a submarine noise such as 90 decibels is still not as good as a black hole, 100 decibels. For this era, primary sonar is simply a nightmare. Even the discovery of the northwest sonar is not high, let alone primary products like the United States.

Surface ships are not of the same level as underwater ships. Underwater submarines are only required to hide them. Not only do they need to attack, but they also need to be discovered in time. Generally, there are noises of about 90 decibels at the bottom of the ocean in nature, which cannot be discovered by computers in later generations, let alone this era, there is no way out.

The continuous losses surprised Germany. The silence of a submarine represents the explanation of dozens of rigorously trained sailors. Unlike surface ships, there is no room for recovery. Unless the submarine chooses to float, those who can enter the submarine force are extremely loyal to Germany. The difference between underwater and above water causes the boredom underwater far from the water.

The Germans could not accept the losses of more than a dozen or more officers and soldiers in a ship, and even wanted to conduct an inquiry by China. Through the investigation, China finally confirmed that the Americans used sonar, which means that sonar appeared in this world faster than in history, and used it in the war.

When Germany asked about China's illness and seeking medical treatment, who knew, but got China's answer. After knowing the distance from the sonar, they stopped talking. For them, the submarine feast was gone. They risked their lives to attack fleets with warships, and they didn't even dare to get close. Germany also changed the method of submarine attack. When discovering ships, they needed to shut down to prevent being discovered. Before attacking, they would find out whether the other party had escorted, and only those who found that there was no escort would attack.

In this way, the losses of submarines were greatly reduced and the results of attacks were greatly reduced. However, the destructive power of the British and American fleets was almost zero. There is no way to ensure safety and pursue effects. This is impossible. (To be continued.)

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Chapter completed!