In the fighting method of submarines and surface ships, submarines are always out of disadvantage, for submarines, constantly improve their quiet performance, is the basis for their continued existence, when the underwater acoustic noise can be comparable to the ocean background noise, surface warships want to find underwater submarines, it will become extremely difficult. Pen × fun × Pavilion www. ｂｉｑｕｇｅ。 ｉｎｆｏ

It is from this point of view that in later generations, active sonar will gradually develop, and even active towed body sonar will appear, all to counter new submarines.

And the use of active sonar comes at a certain price. The war is very fair, how much to pay and how much to get benefits, turning on active sonar itself is a dangerous move to put oneself to death, after all, submarines are hiding in the dark, and turning on active sonar is easy to be discovered by submarines, on the battlefield, whoever turns on active sonar will be attacked first!

Therefore, if it is really a battle, the ships that turn on the active sonar are frigates of relatively low value, and if the active sonar is turned on, they are actually planning to work hard, and the 10,000-ton warships, or even tens of thousands of tons of aircraft carriers, will not come to take this risk. It's a fight to the death.

But now, it doesn't matter, until now, the United States and the Soviet Union have not really torn their faces and staged a third world war, and in this case, the two sides are still facing off in the style of the Cold War, with conventional rules, for example, for submarines that enter the range of their fleet, it is absolutely a beating of water dogs. And as long as the other party surfaces, the confrontation is over.

Turning on active sonar is like hitting countless flashlights, illuminating the underwater, and I don't believe I can't find you!

Americans are crazy! At the same time that the sonar crew found out that the American ship formation turned on the active sonar, Nirgaev also began to respond, diving!

Diving? Is it the way to deal with active sonar? Of course not! The detection distance of active sonar can even exceed 20 kilometers, and the depth of the dive, a few hundred meters is the limit.

But now, it is possible to use the dive against the detection of the Americans!

Urgent dive! With the order of Nilgeyev, the rudder surface of the horizontal rudder of the submarine began to turn sharply, and at the same time, all the submariners who were not at the post were quickly running from their positions to the torpedo compartment in the front!

The bow began to descend rapidly, and the huge submarine, with its hull tilted, continued to dive!

The hull stirred up the current, which could create an additional noise, but now, not much more!

At this moment, several sonar waves hit the hull of the huge 949-class submarine.

If it is an ordinary submarine, when it is hit by an active sonar wave, the hull will vibrate, and the cavity effect will amplify this sound, and the submariners inside can clearly hear this terrible sound, for them, the detection of active sonar means the arrival of the torpedo at the next moment.

But now, the active sonar wave hits the hull of the boat, first makes contact with the hull of the submarine, but before it touches it, it encounters something soft.

Silencing tiles!

The 150 mm thick silencing tile made of styrene-butadiene rubber is laid on the shell of the submarine, which has a complex acoustic structure, and when the active sonar wave comes, the silencing tile absorbs most of the sonar waves!

The Soviet Union has always used double-hull submarines, which are laid with silocencing tiles on the inner and outer shells of this submarine, the outer silocene tiles are mainly used to deal with active sonar, and the inner silencing tiles are mainly used to reduce noise for themselves!

Moreover, the sonar wave that came over this time was not the sonar wave from the perverted aircraft carrier, but just the sonar wave of an ordinary destroyer, and after absorption, the reflection back was quite small!

The personnel inside the submarine could barely hear the sonar waves in the outer layer, only the sonar crew quickly took off the headphones, covered his ears, and cursed in a low voice: "Damn Americans! ”

The principle of sonar is to amplify the sound signal, and this amplified active sonar signal at this time makes the sonar's ears extremely painful.

Dive, keep diving! As if training the golden bell jar and iron cloth shirt, the 949-class submarine hard-endured several sonar waves, and finally dived into the water at a depth of 150 meters.

"Balance the hull, calibrate the course, and move on." Nirgeyev said.

The sonar put back on the headphones, and the sound of the noisy active sonar was gone, except for the gurgling sound of the characteristic ocean background noise!

"We've managed to get into the density jump." The sonar officer reported.

Density Jump!

There is salt in the seawater, with the amount of salt, the density of the seawater is also different, generally speaking, this density is increased with the depth of the water layer suddenly increases, and the density of the seawater in the straight direction suddenly increases the water layer is called the density cline.

This is a dividing line, and there is a huge difference in the density of seawater between the surface and the depths. The low-density seawater will accumulate on the high-density seawater, which will be light at the top and heavy at the bottom, so that the seawater will be distributed in layers. Between the upper and lower layers, a barrier is naturally formed, called a density cline. This depth is different, in the ocean, it may be more than 1,000 meters, while in the offshore ocean, it may be more than 100 meters.

And these hydrological conditions need to be surveyed in advance to know. The major submarine powers all have oceanographic research vessels, and the use of the word "investigation" is actually to prepare for the operation of submarines.

The density cline is of great significance for submarine navigation. Because this thermocline causes the sound wave propagation to be refracted and refracted! That is to say, at this time, the sound waves of the active sonar emitted by those US warships on the surface of the water were all blocked back by the jump! The submarine can avoid detection by hiding under the cline!

Moreover, the thermocline is relatively stable, and the submarine knows that it can sit on it and flow with the seawater, saving fuel. Therefore, the density cline can be said to be a "liquid seafloor".

In addition to the density cline, the underwater can also use various complex hydrological environments such as thermocline, salt cline, acoustic cline, etc., and here now, the density cline is the most suitable.

An An'an is steady, under this water, then there is no fear of anything!

"Full speed ahead." Nirgeyev gave the order. Since it has entered the density cline, the active sonar waves detected above cannot come down, and the noise from its own submarines cannot be transmitted, so it is the most important thing to take advantage of this opportunity to leave here quickly, and the voyage just now has proved that the US aircraft carrier formation cannot effectively detect its own nuclear submarines, and if there is really a war, the 949 class will become a stealth killer! (To be continued.) )