Four hundred and fifty meters!"

Rong Kangjian nodded to the non-commissioned officer who operated the submarine and turned to look at Du Xinghua.

"Keep the depth, heading 315, speed." Du Xinghua stood up, "release the navigator, display the laser scanning image on the main screen, pay close attention to the changes in temperature and sea current."

A "micro-unmanned submersible" shaped like a torpedo, dragging fiber-optic wires and copper-core wires drove into the deep sea from the launch tube on the right side of the "Porpoise" command chassis, sailing at a speed of 6 knots 350 meters in front of the submarine before it was reduced to. Several dark blue beams were shot out from the head of the submersible and repeatedly scanned the surrounding seabed terrain; the temperature sensor, pressure sensor and current sensor on the submersible are activated at the same time, and the surrounding hydrological information is continuously collected; the information is first encoded by the central processor on the submersible, and then transmitted back to the submarine through the fiber-optic wires.

After processing by the submarine's central computer, the complex electronic signals are converted into readable text and picture information.

Du Xinghua stared at the several screens on the fire control console without saying a word.

All the underwater passages of the Tula Strait were in his mind, but Du Xinghua could not guarantee that the submarine could pass through this "underwater corridor" that lasted tens of nautical miles without any danger.

Rong Kangjian walked over and glanced at the home screen.

The "navigator" is actually a small submersible propelled by electric power. Through copper-core wires, the submarine provides the required power for the propulsion system and detection system of the submersible. The "deep-sea laser detection" system equipped with the submersible is emitted by the blue laser with the strongest penetration ability and the least attenuation in seawater, and receives lasers reflected from undersea obstacles to determine the seabed terrain; various sensors are used to collect information such as water temperature, water pressure, and water flow to provide navigation data for the submarine. The biggest use of this set of equipment is to draw the seabed terrain and open up underwater channel. Because the "April" performed the task of opening underwater channel before, it was equipped with related equipment.

Compared with "echo detection equipment", the "navigator" that uses laser as a detection means is more advanced.

Because the laser does not emit noise, it will not "alarm" the Haitian sonar network. The biggest problem is that the light attenuates very quickly in seawater. Even the blue laser with the strongest penetration ability will transmit at most dozens of meters. The effect distance is far inferior to low-frequency sound waves.

Du Xinghua and Rong Kangjian both knew about this problem and knew that they might encounter dangers.

Because the detection range is quite limited, the submarine is likely to follow the navigator and walk into a "dead end". Compared to a navigator with a length of only a few meters, the radius of the submarine's circumference is generally more than 500 meters in length. Even if the boat is very skilled, it will take 300 meters to turn the space. In a narrow "underwater corridor", it is almost impossible to obtain enough turn space. At that time, the submarine must reverse and produce "unbearable" huge noise.

Turning is still a small problem. If the whereabouts are exposed and attacked, the submarine will be doomed.

"The captain. Arrives the first steering point in fifteen seconds."

"Keep the depth and speed. Navigate according to the navigation information." Du Xinghua breathed a sigh of relief and said to Rong Kangjian. "Let the officers and soldiers enter the combat post. If their whereabouts are exposed, we have to break through at full speed."

Rong Kangjian nodded and issued combat readiness orders to various departments.

“Five, four, three, two, one…”

"One-third left rudder, new direction 305, depth 450, speed 4."

The "April" tilted slightly, like a Tai Chi master, completing the steering maneuver very smoothly.

After the course was changed straight, a red light lit up in the command center.

Du Xinghua looked up and then looked at several officers and non-commissioned officers around him. Rong Kangjian operated on the fire control table and displayed the submarine's ground noise data on the small screen in the upper left corner. From then on, the "April" entered the detection range of the Japanese undersea sonar network.

84.

Du Xinghua glanced at his partner and said that the silent performance of the "Pulpun" was indeed not blown out.

When the "Swordfish" reduced the "Silent Sail" noise to below 90 Bei, "eclipsing" other submarines. The "Attabol" went to a higher level, and the noise was only 84 Bei!

84 bays and 89 dB are definitely two different concepts.

Under the same conditions, for every submarine self-noise decreases, the detection distance of the enemy's passive sonar will be shortened by one third, and the detection distance of the submarine's own passive sonar will be increased by 50%. Although under the promotion of various new technologies, the noise of submarines is getting smaller and smaller, such as the "biologically imitated sound-silence tiles", the noise of submarine's low-speed navigation has dropped below the background noise of the ocean, but there is always a limit to technological progress. Even the "Assinus" can only remain quiet at extremely low speeds, and when the speed is

After breaking through a certain limit, huge fluid noise will be generated. Another result of technological progress is that the means of detecting submarines are becoming more and more advanced. Although the main means of detecting submarines are still sonar, the performance of sonar becomes more and more advanced with the advancement of sensor technology and information processing technology. The United States developed the "adaptive main/~passive sonar detection technology" in 2020, which can detect submarines with noise intensity of about 90 baht under complex sea conditions. Relying on the sonar net, it can accurately measure the navigation status of the submarine.

With others

In submarine warfare, detection and counter-detection methods have been competing for development.

"Captain!"

Du Xinghua was shocked and looked at the sonar.

"Anti-submarine patrol aircraft, northeast, is shortening a distance of 100 kilometers away."

"Attacking us?" Rong Kangjian asked immediately.

"No, the approaching speed is not fast, and it did not fly towards us."

Rong Kangjian frowned slightly and glanced at Du Xinghua.

"It should be a normal patrol." Du Xinghua was very calm, "Pay attention closely, there is no need to worry."

Sonar nodded long and said nothing more.

After the outbreak of the Peninsula War, the Japanese Navy strengthened the patrol efforts of several important waterways in the Ryukyu Islands. Fortunately, the Japanese Navy did not know that the Republic's submarines "opened up" the Tugala Strait channel. The patrol plane should be flying to the Osuzu Strait, because the Osuzu Strait north of the Togala Strait is the most ideal maritime channel to enter the Western Pacific. During the Cold War in the United States and the Soviet Union in the last century, the Osula Strait was one of the seven important straits that the United States must control in the Western Pacific. It is precisely because for decades, the Republic's Navy's submarines rarely entered the Western Pacific from the Osuzu Strait.

The "Adolphus" continues to follow the route that has been detected as a deep-sea ghost.

Using the hydrological information sent back by the navigator, the central computer on the submarine automatically calculates the best navigation route and fine-tunes the submarine's ballast water tank, rudder and horizontal rudder to ensure that the submarine always sails on the scheduled course.

As time passed by minute by minute, Du Xinghua and Rong gradually relaxed their spirits.

After completing the fifth turn, the "April" completed half of the voyage.

Compared with several other "underwater corridors", the biggest feature of the Tugala Strait channel is its winding route. There are 11 turning points on the route about 55 nautical miles, and half of the waterways are in the canyons of the undersea mountains. The main purpose of choosing this winding route is to try to keep the submarine in the deep sea and avoid the sonar nets laid on the surrounding seabed.

Although the navigator can provide real-time navigation information for submarines, snorkeling at a depth of multiple meters is not much different from crossing a maze with eyes closed.

Even the slightest mistake will cause the submarine to hit the sea cliff tens of meters away on both sides of the route. Even if the submarine sails very slowly, it will not be crushed to pieces, and the whereabouts will be exposed due to the huge noise generated by the impact.

When we are about to reach the sixth steering point, the situation changes.

Without sonar reminder, the data displayed on the fire control screen is enough to illustrate the situation. To the northwest of the channel, an unknown submarine "ambushed" in a shallow basin formed by an eruption of a submarine volcano on the island of Guyeongliangbu, about 25 nautical miles away from the "Atelporcs". Judging from the size of the submarine warfare, this distance is very close. The submarine must have encountered a little trouble while sitting in the sinking ground, and made a huge noise that was enough for the "Atelporcs".

"Japanese submarine?"

Du Xinghua shook his head and said, "The diving depth is 240 meters, which is not very similar to the conventional submarines in Japan. Compare and analyze the data in the database to see if there is any gain."

The comparison and analysis results came out soon, and no similar results were found.

Rong Kangjian frowned. "Maybe it is a new Japanese submarine, or an attack nuclear submarine."

"It should be an attack nuclear submarine, but not a Japanese submarine." Du Xinghua believed in his intuition very much. "There is no intelligence that Japan has built an attack nuclear submarine, and the lurking location is very unusual. At least we have never found Japanese submarines moving in shallow water basins of the Tugala Islands."

"Is it an American submarine?"

"It's either an American submarine or a Russian submarine." Du Xinghua smiled coldly and said, "It's not a Japanese submarine anyway, and it's even less likely a submarine from the Bangzi Country. Has the characteristic noise been recorded?"

“It has been recorded.”

"Take it back and leave it to the Military Intelligence Bureau for processing." Du Xinghua pondered for a while and said, "There is no need to pay attention to it, let's continue to move forward."

Passing by the uninvited guest, the "Adoppog" continued to advance along the "underwater corridor".

Du Xinghua and Rong Kangjian both knew that it was likely to be an attack nuclear submarine of the US Navy, and it was likely to be the legendary "8111" class, which is the "Virginia" class.

The basic models of the "Virginia" class are built in total 35~ (hull numbers range from ssn774 to ssn810), and starting from ssn8111, a large number of advanced equipment has been added. According to the information provided by the Military Intelligence Bureau, the "8111" class is likely to use composite batteries as auxiliary power and propelled with superconducting motors, and the silent performance is better. In addition, the "8111" class uses higher-strength hy-12 high-strength steel, with the maximum diving depth increased to 560 meters and the maximum speed increased to 36 knots.

Very advanced and very difficult to deal with submarines.

Du Xinghua didn't want to "create things out of the way" and did not cause trouble for "unidentified submarines" in trouble.

damn it**

It’s the last few days of the end of the month, and the first six monthly tickets for classification are guaranteed. Please support me, brothers! (To be continued,)

First release
Chapter completed!