Conventional power submarines use diesel engines in the surface state or snorkel state, which can have an endurance of thousands of nautical miles, but when they are underwater, they can only use batteries, so the underwater navigation time is very short. If sailing at full speed, it can consume all the electricity in one hour, and if it is sailing at low speed, it will last for tens of hours.

Therefore, the combat performance of conventional submarines is not strong. Once the power is exhausted, it has to float to the snorkel state, and once the snorkel is exposed, it will be discovered and vulnerable to attack.

But nuclear submarines are different.

Relying on the energy provided by nuclear reactors, nuclear submarines have almost unlimited endurance. During the entire service period, nuclear fuel can be replaced at most once, so it can sail underwater for a long time.

As for the oxygen that the submarines need underwater, it is not difficult for nuclear submarines. It can be obtained by electrolysis of water, which is quite easy.

The endurance of nuclear submarines depends entirely on the submarine's own endurance.

The high performance of nuclear submarines comes from nuclear reactors. Nuclear raw materials are fissioned to generate heat. This heat is taken away by the water flowing through the reactor core, just like boiling water in a boiler. This water is taken outside to form a circuit. , Through heat exchange, the water in the secondary circuit is heated, and the water in the secondary circuit becomes steam, which drives the steam turbine.

Structurally, it is the same as a warship, except that the boiler burns nuclear materials.

In this way, two circuits are also taken. For safety reasons, the primary and secondary circuits are isolated to avoid the threat of radioactivity.

When the nuclear reactor is in operation, the primary circuit needs a water pump to continuously circulate the cooling water, otherwise the heat of the reactor cannot be taken away in time, and problems will occur. This water pump is an important source of noise on the submarine.

Even if the submarine does not start and the propeller does not rotate, the pump must be in working condition. Unless the reactor is shut down, the submarine will not have any energy.

This noise is easy to detect. Therefore, later generations of submarines have begun to study natural circulation reactors. They don't need this pump, and rely on the density of water to circulate themselves. Of course, this requires a very high level of technology.

Now, this underwater submarine is exactly the Victor class of Bear Country.

The Victor class, also known as class 671, belongs to the second-generation attack nuclear submarine of the bear country. It is mainly responsible for attacking enemy surface ships, destroying enemy sea lines of communication, attacking merchant ships and laying mines, as well as anti-submarine and **** tasks.

After the first nuclear submarine entered service in 1967, dozens of ships have been built.

Compared with other nuclear submarines, it is not big and has a displacement of less than 5,000 tons. Such a small nuclear submarine has good maneuverability and can move more flexibly in shallow waters. Therefore, this time, it is secret. Land came to the military port of Han to observe.

Although it was during the daytime to go up to the periscope for in-depth observation, it was not afraid of anything. Relying on the backward anti-submarine level of the Han country, it could not be found at all. The Han people couldn't help it if they left so swaggeringly.

It can only come during the day, but how to take pictures at night?

On the submarine's control tower, the captain Ivanov carefully observed the opposing military port through the periscope. At the same time, a camera linked to the periscope was snapping photos.

It's really boring. If the Han Chinese submarine came out, followed the opponent for thousands of nautical miles, and then frightened the opponent, it would be fun!

Now, the Cold War is still going on. What the bear country's submarine soldiers like most is to fight against the Eagle country's submarine underwater. From time to time, there will be a terrible crazy Ivan action, which is a fun.

On his side, there are sonar soldiers, sonar soldiers are listening to the movement outside, although there are ships around, there is no need to worry about finding yourself, they are just listening.

Suddenly, a sonar soldier frowned: "Five nautical miles away, a target has changed course and is coming towards us."

As a sonar soldier, you must have a pair of keen ears. This famous sonar soldier is even more outstanding. He heard the ship change its direction, and then listened carefully for a few seconds, and he couldn't help but say: "The target is Type R submarine."

The Type 033 submarine of the Han State is a replica of the Xiong State R-type submarine. The sonar soldiers on the submarine can be easily distinguished. It is definitely not Xiong State’s own R-type submarine, which is Han State.

Ivanov's eyes left the periscope and said: "Attention, put away the periscope, dive to a depth of 30 meters, double cars, and go three times."

Now that the other party has discovered it, the mission here is over and leave here.

Following his order, the sailors inside the submarine all started to operate from their posts. The engineers pushed the operating rods one by one, and the propellers at the tail turned, chucking the water, and the submarine began to accelerate.

The horizontal rudder of the bow began to move, and the submarine slowly sank its head and dived into deeper water.

After all, it’s near the port. It didn’t take long for the boat to dive, and the hull was level again. This action is very smooth. If it’s an emergency dive, it will be more exciting. Those who have nothing to do will run to the front. Go to the bow of the boat, increase the gravity of the bow, and let the submarine tilt down as quickly as possible.

"Right rudder." Ivanov gave the next order, turn around and return!

When the propeller at the tail started, the noise became louder. On the Type 033 submarine that followed, the sonar soldier shouted anxiously: "The target has started, the speed has increased, and it is turning!"

The goal is to slip away!

The captain yelled: "Quick, full speed, give me full speed!"

Once the opponent speeds up, I will not be able to catch up. The nuclear submarine can easily reach 30 knots when it is underwater, while my submarine can only reach 13 knots if it is not accelerated by the opponent. If it catches up in the initial stage, the opponent will escape.

At this time, the captain realized that he had made a mistake and did not report to his superiors!

However, he didn't have time to report. After all, when he first discovered it, he couldn't report it immediately. He had to identify and confirm that it was the enemy before he could report it.

Now, if you don't stop the opponent, you can only watch the opponent slip away!

Following his command, the propeller at the tail turned at a high speed, and all the batteries were generating power. The 2700 horsepower motor drove the propeller to rotate at a high speed to catch up!