Southeast of the Okinawa Islands, Ryukyu Trench.

250 meters below the surface of the sea, a submarine about 80 meters long and 11 meters wide, with a dark body, like an elongated cigar smoke, with a streamlined command platform, retractable head horizontal rudders, and X-shaped tail rudders, the "Swordfish" submarine driven by pump-jet thrusters is slowly moving forward at a speed of six knots along the ocean current.

In the command center, Hua Jianfeng stared intently at the two bright spots on the fire control computer screen.

If the "Swordfish" commanded by Hua Jianfeng is a sharp sword, then the two nearby "Qinchao"-class AIP conventional submarines equipped with Stirling engines produced by the Swedish company Kaukum are ancient bronze swords dug out of the ground, and they should have entered the museum a long time ago.

"Captain, the No. 1 target boat has floated, do you want to follow?"

"Follow behind target boat No. 1 and keep a close eye on target boat No. 2." Hua Jianfeng walked behind the helmsman, "Control the course and speed, when the depth reaches fifty meters, activate the underwater camera, let's see what this new friend looks like." ”

The "Swordfish" quietly followed the Japanese submarine and floated towards the surface.

Two years ago, when he was transferred out of the "Gun Squid" nuclear submarine and served as the captain on the "Swordfish", Hua Jianfeng felt that he had been "mismatched", and he sulked for two months. Because the "Gun Squid" is the most advanced attack nuclear submarine of the Republic, the "Swordfish" is just a conventional submarine.

It's just that the "Swordfish" is not an ordinary conventional submarine.

"Longxiang New Energy Company" was the first to develop and produce not civilian composite batteries, but military composite batteries with a mass-to-energy ratio of 8 kilowatt-hours per kilogram. Later, the mass-to-energy ratio of the composite batteries used in the electric vehicles launched by Jiqing Company was only 2 kilowatt-hours per kilogram, and the performance was only 25 percent of that of the military type.

In the army, this high-performance composite battery has an alias: "Longxiang battery".

How significant is the geology-to-energy ratio of 8 kilowatt-hours per kilogram?

Diesel combustion has a geothermal value of 40,000 kilojoules per kilogram. Gasoline burns with a geothermal value of 44,000 kilojoules per kilogram. Each kilogram of "Longxiang battery" can store 28,800 kilojoules of electricity. 72% diesel land. 65.5 percent of gasoline land.

The geothermal efficiency of the direct injection internal combustion engine is about 50 percent. The energy conversion efficiency of superconducting motors is more than 70%. The geodynamic propulsion system composed of "Longxiang battery" and superconducting motor can completely replace the geodynamic propulsion system composed of diesel, internal combustion engine and ordinary battery. So that conventional submarines have a real "AIP". That is, "independent of air propulsion".

Equipped with a 400-ton "Longxiang battery" and a 7,500-kilowatt superconducting electric motor, the "Swordfish". After a full charge. Able to dive for 296 hours at a maximum speed of 27 knots. sailed eight thousand nautical miles in twelve days; If the submersible speed is reduced to six knots. You can dive for 72 days. Sail 10,000 nautical miles. There is no need to surface for ventilation during the entire patrol mission. Relatively. Even the conventional submarines of the 212 class equipped with fuel cells. You can only snorkel for a maximum of 21 days. If sailing at maximum underwater speed. can only last for a few hours.

The Swordfish can be charged at any port equipped with special charging equipment. If electricity is obtained from the civil grid. The charging time is twelve hours; If there is a dedicated high-power power generation equipment. It only takes two hours. Conventional submarines equipped with the AIP system must go to military ports with supporting logistical support capabilities to replenish liquid oxygen. or special fuel. It is difficult to obtain logistical support in commercial ports.

The geodynamic system composed of "Longxiang battery" and superconducting motor has another advantage.

Apart from an emergency diesel engine, the Swordfish had no conventional power equipment and no major source of noise. Combined with a pump-jet propulsion system, the noise level of the Swordfish was reduced to an unprecedented level. When sailing at a speed of six knots, its own noise is less than seventy decibels; Even if the speed is increased to 27 knots, it is only 98 decibels, which is far lower than any kind of conventional submarine, and even lower than the US Navy's "Virginia"-class nuclear submarines.

The outer surface of the "Swordfish" was laid with a 35-centimeter-thick silencing tile, which shortened the detection range of the enemy's active sonar by two-thirds. Coupled with very low self-noise, the Swordfish became the quietest submarine in the world.

It's just that the "Swordfish" is not perfect.

The "Longxiang battery" is extremely expensive, and the price of a 400-ton battery is more than that of an attack nuclear submarine, so its endurance is far inferior to that of a nuclear submarine. If a small fusion reactor were added to the Swordfish, it would have the ability to "have unlimited endurance".

Due to the limitation of the hull diameter, especially the diameter of the tail, the power of the superconducting motor cannot be further increased, which limits the maximum sailing speed of the "Swordfish", and the maximum diving speed of only 27 knots is not comparable to that of the most advanced attack nuclear submarine.

The length of the "Swordfish" is only 80 meters, the length of the middle cylindrical compartment is less than 55 meters, and the length of the passive sonar base array on the side side is only 50 meters, which is nearly 30 meters shorter than the passive sonar base array on the attack nuclear submarine.

Because of the limited space in the bow, even if the torpedo compartment is moved back and four torpedo tubes are installed on the ribs of the submarine, it can only be equipped with a spherical active/passive sonar with a diameter of six meters, so the performance of the "Swordfish" active sonar is not as good as that of the "Gun Squid".

Finally, due to the limitation of the internal space of the hull, the "Swordfish" could only carry 22 torpedoes and missiles, which was indeed very inferior to the reserve ammunition of the 38 torpedoes and missiles of the "Gun Squid."

For a conventional submarine with an underwater displacement of only 3,350 tons, the performance of the "Swordfish" is already very outstanding, not only is no conventional submarine comparable to it, but even the French Navy's "Barracuda"-class attack nuclear submarine is not necessarily much stronger than the "Swordfish."

After seeing the "Swordfish", Hua Jianfeng immediately changed his previous opinion.

He was even more pleasantly surprised by the fact that the Navy of the Republic built only one "Swordfish". The main thing is the cost of 18.4 billion, which discourages the navy. If it had not undertaken the heavy task of "testing," the Navy would have been willing to spend the same price to purchase two "Gun Squid." Serving as the captain of the "Swordfish" is not "flowing", but "ascending".

For the next two years, Hua Jianfeng has been calling the "Swordfish" home.

As the "assembly chief", Hua Jianfeng participated in the construction of the "Swordfish", and put forward several very valuable suggestions to the engineers during this period.

Through related work, Hua Jianfeng has a deeper understanding of this submarine.

In addition to having a strong "heart", as well as a sufficiently large "lung", the "Swordfish" also has a well-developed "brain".

The highly automated operating system and the jobs saved by eliminating conventional power equipment have reduced the number of officers and men of the "Swordfish" to 34 people, and only eight people are usually needed to control the entire submarine. The highly integrated detection, search and fire control system, coupled with a central computer running 250 million times per second, gave the Swordfish the sharpest response speed. In an engaged state, the Swordfish was able to track eight targets while controlling four torpedoes to attack two of the most threatening targets.

A good horse with a good saddle, a warrior with a sword.

"Swordfish" was armed with the most advanced weapons, in particular, heavy torpedoes.

The new electric torpedo uses a composite battery as a power source, and the firing range reaches 35 kilometers in 70-knot high-speed mode; In low-speed mode of 45 knots, the firing range can reach 65 kilometers. A torpedo head filled with 250 kilograms of high-energy explosives is enough for one torpedo to damage a destroyer, or two torpedoes to damage a cruiser, and three torpedoes to incapacitate an aircraft carrier.

Everything made Hua Jianfeng very happy, and he felt that the "Swordfish" was more like a super submarine in science fiction.

Half a year ago, after the "Swordfish" was officially put into service, Hua Jianfeng and 33 other officers and men had a new mission. Within five months, the "Swordfish" participated in three joint military exercises, and its performance was fully affirmed.

A month ago, Hua Jianfeng once again led a boat to sea.

Their mission was to track down the Japanese Navy's second improved, AIP-equipped submarine that was training in the waters off the Okinawa Islands.

Until now, the "Swordfish" has tracked those two Japanese submarines for eleven days.

Three days ago, after completing its last mission, the Swordfish "greeted" the Japanese submarine with an active attack sonar. As a result, more than 20 "Sea Hawks" of the Japan Maritime Self-Defense Force, eight P-3C "Orion" anti-submarine patrol aircraft, and hundreds of sonar buoys were recruited. "Swordfish" did not leave, still following behind the Japanese submarine, taking the opportunity to find out the anti-submarine tactics of the Japanese submarine.

Two days ago, another submarine of the "Tide" class arrived.

If the fight starts, Hua Jianfeng is confident that he will kill two "pro-tides" at the same time.

"Captain, it's fifty meters."

Hua Jianfeng came back to his senses. "Turn on the exterior lights, enter from behind the enemy boats, and let's take a closer look at the appearance of the little devil's new submarine."

A blurry figure appeared on the screen of the fire control computer.

Nearly 80 meters long and 10 meters wide, the Japanese submarine was like a huge whale, quietly floating in the sea at a distance of 25 meters from the surface. The Japanese submarine was testing the newly equipped non-penetrating optoelectronic mast, as well as satellite communication equipment, and did not find the "Swordfish" that appeared behind it at all.

"It's like a sea manatee. Scratching through the bottom with the command platform, dozens of little devils are finished. ”

"I can't bear it." Hua Jianfeng smiled faintly, "Go around from the left, reduce the speed to the second section, and see if the little devil can hear the sound we make." ”

The "Swordfish" slowly turned and reached the left side of the Japanese submarine.

"Captain!" The sonar chief suddenly shouted, "There is contact." ”

Hua Jianfeng frowned slightly. "Discovered?"

"It's not. At ten o'clock, the distance was far away and faint. ”

"The Yankees' nuclear submarines," Le Jiacheng walked over, "maybe the 'Los Angeles' of the Seventh Fleet." ”

"It should be 'The Waves,' or 'Virginia.'" The sonar chief corrected the co-captain's statement, "There is no matching characteristic noise data, and it is certainly not 'Los Angeles.'" ”

At this moment, a command that the ink was not dry spat out of the laser printer.

"Urgent dive." Hua Jianfeng quickly finished reading the order he had just received, and handed it to Le Jiacheng. "We've done our job, it's long past time to return."

After reading the order, Le Jiacheng secretly sighed and nodded to the helmsman who looked back at him.

A return order from the General Staff, the "Swordfish" should go home