Chapter 490 Active Sonar

USS Nimitz, bridge command room.

Time passed by little by little, and everyone was hoping to find the Soviet submarine hidden on the seabed, but until now, nothing has been found!

"Our anti-submarine aircraft did not search for any suspicious underwater targets." Miller said: "There should be two possibilities. Either the Soviet submarine has left, or our Groton misjudged that there is no Soviet nuclear submarine underwater."

Miller believed in the advanced technology of the US Navy. Since they had been busy for so long and still hadn't found any underwater submarines, it could only mean that there were no Soviet submarines at all!

Putting down his cigar, Jonathan shook his head: "No, I think there is another possibility."

Another possibility? Miller looked at Jonathan, puzzled.

"This is the Soviet Union's newest nuclear submarine. Its silent performance is so good that our existing anti-submarine forces cannot detect it," said Lieutenant General Jonathan.

"How is this possible? Soviet submarines have always been very noisy, and they don't have advanced processing technology for their propellers," Miller said.

"If it was in the past, it would have been absolutely impossible, but now, it's different." Jonathan looked at Miller, their eyes met, and the look in their eyes could tell a lot.

Damn the island country! This country that the United States supported so much turned against it in the end, causing the United States to lose a lot! If the Soviet Union had the technology of the island country, it would be completely possible for it to improve its nuclear submarines!

"Last year, we noticed that the shape of the propellers of the Soviet Union's newly launched nuclear submarines had changed significantly. Through our agents, we obtained intelligence that the Soviet Union had mastered the processing technology for seven-blade large skew propellers," Jonathan continued.

For a submarine, the propeller at the tail is the biggest secret. It can be seen in various existing pictures that when the submarine is launched, the propeller at the tail is wrapped to prevent the leakage of the propeller parameters. For technologically advanced Western countries, as long as they see the shape of the propeller, they can guess the underwater sound characteristics.

Miller frowned: "If that's the case, then it might be our mistake."

If the underwater sound characteristics of a newly launched new submarine cannot be obtained, it will not be stored in the sonar system's database. When the sonar system is working, it may filter out this weak sound as a normal sound! Therefore, during the Cold War, when the US and Soviet submarines confronted each other, a very important point was to obtain the underwater sound signal characteristics of the other side!

"Maybe there are no Soviet submarines underwater, but if there are, they are a huge threat to us. The Soviet Oscar-class nuclear submarines are equipped with SS-N-19 anti-ship missiles, which are designed to attack our aircraft carrier formations. We must not take it lightly!" Lieutenant General Jonathan said: "I suggest that we immediately conduct a full-scale scan to ensure the safety of our fleet first!"

"Yes, order all anti-submarine aircraft to take off and drop active sonar buoys! All warships, turn on your sonars and conduct active searches!" Miller immediately gave orders to his aircraft carrier formation.

At the same time, the Kitty Hawk on the other side also conveyed the order.

The U.S. Navy has long since eliminated anti-submarine rockets and does not have the carpet bombing capability of the Soviet Union. However, it would be a mistake to say that they have no way to deal with extremely silent submarines.

Surface ships have sufficient means to deal with underwater threats, such as using the ship's own sonar and turning on active mode!

All warships, except small patrol boats, are equipped with sonar, which is usually installed at the front and is also commonly known as hull sonar or bulbous bow sonar. In fact, the bulbous bow is a special bow structure designed for modern ships to reduce wave-making resistance. There are a lot of turbulence here, which brings strong interference and affects the work of sonar, so it is not suitable for sonar domes. The real sonar dome is deeper than the keel and streamlined, with a smooth transition with the hull to reduce the impact of turbulence, and the sonar array is installed in this sonar dome that extends deeper than the keel.

Inside this shell is the cylindrical sonar array. This type of sonar has two modes: active and passive. In later generations, these two modes can be fully integrated into the same array, but now they are still separate.

Generally speaking, passive sonar is used to monitor underwater sounds, while active sonar is used to locate targets, track and control fire after discovering submarines, and bind launch data for torpedoes.

And now, following the order from the supreme commander, all sonars have been turned into active mode!

This seems a bit like being a rogue, or like a dead pig that is not afraid of boiling water. After all, the noise of surface warships is far greater than that of underwater nuclear submarines, at least 20 decibels higher. Therefore, surface ships can be easily discovered by underwater submarines, but it is not easy to discover underwater submarines. In this case, the passive method is not easy to use, so just use the active method!

With a flashlight, I won’t be able to find you!

At this time, the size of the warship will also play a key role, because the aperture of the bow integrated sonar cylindrical array of the warship varies greatly according to the size of the hull. The diameter of the integrated sonar array of small and medium-sized surface ships is only 1 to 2 meters, while the diameter of the integrated sonar array of large surface ships may reach more than 4 meters. For example, now, the sonar array diameter of the bow of the Nimitz is more than four meters! When using the active mode, the effective range of underwater submarines can exceed 20 kilometers!

The anti-submarine array was lined up in a row, as if combing the sea surface. All the warships turned on their active sonars, penetrating the sea water and scanning the silent world underwater. If there was anything there, they must find it!

At the same time, all anti-submarine aircraft, including anti-submarine helicopters, took off from various warships and dropped active sonar buoys according to their respective designated areas. It can be said that the area within a radius of 100 kilometers around them was all their search area!

"The Americans are a bunch of lunatics!" Nilgayev clenched his fists in K-146. Activating the active sonar so brazenly was simply a show of confidence!

If it is a war, I am not afraid of a head-on confrontation! The enemy's active sonar is like a flashlight. The one with the strongest light is a large warship. Even if I don't use anti-ship missiles, I can still kill it with a 650mm heavy torpedo!

Moreover, it was obvious that the American aircraft carrier also turned on the active sonar! Nilgayev couldn't restrain his impulse and wanted to fire a torpedo to hit him, but he did not receive the order to fire.

The Americans have a problem, let's see how we deal with it! Fortunately, we are on guard against this move by the Americans!

"Emergency dive to 150 meters."