It was not only the "Liu Changxun" that was attacked, but also more than one large attack submarine.

Almost at the same time, the "Zhou Kuande", about 50 kilometers northwest of the "Liu Changxun", was also torpedoed.

In total, 6 heavy torpedoes were fired at the hapless carrier.

Fatally, these 6 torpedoes came from two directions, front and rear.

The corvette in charge of cover blocked two torpedoes, and the other four torpedoes all hit the "Zhou Kuande".

Fortunately, only one torpedo detonated under the aircraft carrier's hull, and all three torpedoes fired from the bow side hit the aircraft carrier's hull.

Judging from the situation at that time, it is very likely that the submarine ambushed in front of the "Zhou Kuande" was affected by the escort warship, that is, the general-purpose destroyer that opened the way in front of the aircraft carrier, and adopted the attack mode of line guidance and active sonar, rather than the wake guidance attack mode. Probably because of the fear that the torpedo would miss the target, the fixed depth was slightly shallower than the draft of the aircraft carrier, which caused the torpedo to hit the aircraft carrier's hull directly.

Comparatively speaking, the damage caused by hitting the hull of the ship is much smaller.

The reason is also very simple, the aircraft carrier itself has an anti-torpedo compartment, and it is a small compartment structure, and the huge internal space can absorb and disperse most of the shock waves, thereby reducing the damage caused by the explosion. Conversely, if the torpedo is detonated under the hull, the energy released by the explosion will act directly on the hull of the aircraft carrier, such as the keel at the bottom, thus causing irreversible permanent damage to the main structure of the aircraft carrier.

If the power of the torpedo is large enough, for example, the Type 65 heavy torpedo developed by the Western Continent Group, with a mine head weighing 1 ton and a charge of 750 kg, can even blow up a 10,000-ton battleship in two, and in some extreme cases, it is not impossible to blow up the keel of the aircraft carrier.

Although the MK48's thunder head is much lighter, with a mass of about 250 kg and a smaller charge, the ability to damage the battleship is still not to be underestimated.

If all four torpedoes were detonated under the hull, the "Zhou Kuande" would definitely be more than lucky.

The key point is that when the "Chen Bingxun" class large aircraft carrier was designed, it was only required to remain unsinkable after being hit by three 533-mm heavy torpedoes, and it was aimed at the first generation of heavy torpedoes in service after the war, not new heavy torpedoes such as MK48.

Theoretically, the probability that the "Zhou Kuande" was sunk by 4 heavy torpedoes is more than 50%.

Although the torpedo hit the hull directly, the damage was less than expected, but it was hit by 4 torpedoes in a row, and no battleship could afford to suffer.

The situation of the "Zhou Kuande" can be said to be very serious, and it may be destroyed at any time.

The point is that the three torpedoes fired from the front all hit points in the forward part of the port side of the bow, and the three hit points are distributed within a range of less than 100 meters. As a result, about one-third of the port forward compartment was quickly flooded. In just a few minutes, the hull tilted forward by about 10 degrees, and the lateral tilt also exceeded 15 degrees. In order to keep the aircraft carrier balanced, that is, not to capsize the aircraft carrier, the captain has already ordered the right compartment to be filled with water. Because it is necessary to maintain longitudinal balance and avoid breaking the keel due to uneven force, water is injected into the right rear compartment. As a result, the two powertrains located in the water injection area had to be abandoned.

There are only 4 powertrains in the "Chen Bingxun" class!

To make matters worse, a torpedo fired from the rear blew up the No. 1 propulsion shaft on the outside of the port side of the aircraft carrier.

That is, after filling the right rear compartment with water, the "Zhou Kuande" lost three-quarters of its propulsion power, and only one set of propulsion systems remained functional.

Even if the servo could work normally, it would only be able to reach a maximum speed of 12 knots with a single propulsion shaft.

Because the left servo has also been impacted, it can't work normally, and the right servo needs to be fixed at an angle to keep sailing in a straight line, resulting in a lot of increased sailing resistance, so the actual speed that can be achieved is definitely not 12 knots, and it is very good to be able to run to 10 knots.

According to the information sent by the "Zhou Kuande," it is being repaired with all its might, and it will be a few hours at the earliest before it can be determined whether the aircraft carrier can be saved.

As long as it is attacked again, it will definitely be sunk.

Fortunately, after the "Zhou Kuande" was attacked, the escort warships discovered the sneak attack submarine and took action at the first time.

Actually, it's about the same on the side of "Liu Changxun".

By the time the "Zhou Kuande" sent the news, the anti-submarine helicopter had already found the submarine that had attacked the "Liu Changxun" and had called on other anti-submarine forces.

Although the distance was a little farther, exceeding the range of anti-submarine missiles, the universal destroyer in this direction was not able to fire at the first time, but it was suppressed by 2 anti-submarine helicopters, and the Nuland submarine could only flee for its life, to be precise, it could not even escape.

Only about 15 minutes later, two anti-submarine patrol planes sent by the "Liu Changxun" were killed.

If you want to say, anti-submarine patrol aircraft are anti-submarine weapons, the nightmare of submarines!

Compared with anti-submarine helicopters, the biggest advantage of anti-submarine patrol aircraft is not only that they can fly faster, but also that they can carry more anti-submarine equipment and anti-submarine weapons.

Take the Imperial Navy's "Cruiser-4B", for example, which can carry 144 sonar buoys and 6 light anti-submarine torpedoes or 24 depth charges when fully loaded. In a single mission cycle, 12 targeted searches can be carried out, and 6 torpedo attacks can be launched. Because two anti-submarine patrol planes usually work together to search and attack, the combat effectiveness will be doubled.

Obviously, no submarine can withstand the repeated attacks of 2 anti-submarine patrol aircraft with 12 anti-submarine torpedoes!

As a matter of fact, before the anti-submarine patrol planes arrived, two anti-submarine helicopters dispatched by the destroyer had already launched an attack and threw four anti-submarine torpedoes one after another.

Subsequently, 2 anti-submarine patrol aircraft, using information provided by anti-submarine helicopters, dropped a dozen anti-submarine torpedoes in the direction where the enemy submarine could escape.

As long as it is possible to sink submarines, no one cares how many anti-submarine torpedoes are used.

Less than half an hour after the attack on the "Liu Changxun," the destroyer commanding anti-submarine warfare sent a message claiming that it had sunk the submarine.

It is indeed a large attack submarine of the "Los Angeles" class.

Shortly after the battle, the destroyer scooped up some of the wreckage of the submarine, including several life jackets, as well as broken balsa furniture.

However, it was only a few hours later that the destroyer used sonar to find the wreckage of the submarine that had sunk to the bottom of the sea, and confirmed that it was a large attack submarine with a length of more than 100 meters. Because the water depth in the warring sea area is more than 2,000 meters, there is absolutely no possibility of survival for the officers and men on the submarine.

On the side of the "Zhou Kuande", the anti-submarine battle lasted longer.

Although it was determined at the first time that there were at least two submarines that attacked the "Zhou Kuande," only one submarine was found within the first half hour.

The one that lay in ambush in front of the "Zhou Kuande".

It must be said that the captain of this submarine must be bold.

In any fleet, especially an aircraft carrier task force, the key area of anti-submarine defense is in front of the route.

The reason is also very simple, the speed of the fleet is faster, especially the aircraft carrier battle group in a combat state, the average speed is generally more than 20 knots, while the quiet speed of large attack submarines is less than 10 knots, not to mention that in order to save electricity, the time of high-speed navigation must be strictly controlled. Therefore, in battle, submarines often choose to ambush in front of the fleet route rather than sail with the fleet.

It is precisely in this way that the fleet will definitely focus on monitoring the front of the course.

Then, in actual combat, submarines will generally choose to ambush on both sides of the route, and launch a sneak attack from the side or rear after the fleet approaches.

Only in this way it will be possible to avoid anti-submarine warfare ships located in front of the fleet.

Obviously, unless it is a last resort, the submarine captain will not be stupid enough to go to the front of the aircraft carrier to die.

When the submarine opened fire, it was about 40 kilometers away from the "Zhou Kuande" and less than 20 kilometers away from the "Yangcheng" destroyer, which was opening the way in front of the "Zhou Kuande."

From this, it is not difficult to see that the boat has not had time to maneuver to a more advantageous position, and can only risk firing at the aircraft carrier under the nose of the destroyer.

As for the result, it is clearly unexpected.

Although it was not able to spot the enemy submarine at the first time, or it did not make an accurate judgment, after the "Zhou Kuande" was torpedoed, the "Yangcheng" immediately took action, activated the active sonar in the spherical nose bow, and discovered the enemy submarine in front.

The distance is so close, there is no need to dispatch anti-submarine helicopters at all!

After obtaining information about the submarine's position in a few minutes, the "Yangcheng" launched four anti-submarine missiles in a row. Probably fearing that the enemy submarine would be let go, 15 minutes later, the "Yangcheng" launched another round of attacks, firing four anti-submarine missiles at the sea area where the enemy submarine was located.

If anything, the Nuland submarine was unlucky enough.

"Yangcheng" is the 17th ship of the "Lucheng" class, which belongs to the second batch after the overhaul. Compared to the first batch, the most obvious change is the replacement of the multi-purpose launcher with eight sets of eight-pack vertical launch systems, which increases the bomb load and fire projection density.

Typically, 32 anti-submarine missiles, 16 anti-ship missiles and 16 medium- and long-range anti-aircraft missiles are loaded into 64 vertical launch tubes.

This is also quite understandable, after all, universal destroyers are the anti-submarine backbone of the fleet.

Subsequently, anti-submarine helicopters dispatched by the "Yangcheng" discovered the wreckage of the enemy submarine, to be precise, the remnants of the surface of the sea.

It's just that anti-submarine operations in the other direction did not go so smoothly.

The main thing is that behind the "Zhou Kuande", there was originally only one ocean-going frigate, that is, the "Lujiang", which blocked two torpedoes for the "Zhou Kuande". The ship belongs to the "Yichang" class, the performance is not advanced, the displacement is just over 3,000 tons, and it sank after a mine.

That is, after the "Zhou Kuande" hit the mine, there were no escort battleships in its rear!

What is even worse is that the "Zhou Kuande" did not send an anti-submarine patrol plane before it hit the mines, and did not even let the anti-submarine helicopter take off.

As a result, only after about 25 minutes did 2 anti-submarine helicopters from the air defense cruiser arrive.

After missing the "critical 15 minutes", it is not so easy to find the escaped submarine.

Here, the most basic submarine tactics are involved.

To put it simply, any submarine will try to retain as much power as possible before launching an attack to ensure that it can escape at full speed after the attack.

If anything, this is where the value of large attack submarines lies.

Because of the larger tonnage and the ability to carry more batteries, it can travel longer at the fastest speed, so as to get out of the dangerous sea area before the enemy's anti-submarine forces arrive.

Of course, thanks to a more powerful propulsion system, large attack submarines can basically have a diving speed of more than 30 knots.

Theoretically, a formation of 2 anti-submarine helicopters can cover up to 10 nautical miles in a single search, and it is usually not reached.

As a result, as long as the submarine can get 10 nautical miles before the anti-submarine helicopter can hit it, the probability of escape is more than 80 percent.

This is also a big basis for determining the performance indicators of large attack submarines!

Even in combat mode, it usually takes 20 minutes for an anti-submarine helicopter to take off in an emergency and it takes 50 kilometers to fly away, so the maximum diving speed of a large attack submarine needs to reach at least 30 knots to ensure that it can sail 10 nautical miles before the anti-submarine helicopter arrives.

Because of various unexpected factors, such as the time required to search for submarines, the reaction time left for anti-submarine helicopters is only 15 minutes.

In fact, this is also the key reason why the Imperial Navy attaches great importance to anti-submarine patrol aircraft.

Even a 10-ton anti-submarine helicopter has a combat radius of more than 150 kilometers, so it is often unable to pursue a large attack submarine that escapes quickly. In contrast, anti-submarine patrol aircraft not only fly faster, but also have a combat radius of more than 500 kilometers.

If it is necessary to pursue submarines, it is definitely anti-submarine patrol aircraft that can be relied on.

In many cases, the main mode of anti-submarine warfare is to pursue enemy submarines, rather than searching for submarines whose whereabouts have not yet been revealed.

The point is, the search for submarines is extremely difficult.

It was not until 45 minutes later that two "Cruiser-4Bs" dispatched by "Liu Changxun" rushed over, and then two "Cruiser-4Bs" from "He Yongxing" arrived.

Within a few hours of that, several anti-submarine patrol planes and more than a dozen anti-submarine helicopters arrived.

It's just that the Nuland submarine was not found until the fleet turned to withdraw.

Strangely, no unknown radio signals were intercepted!

Generally speaking, submarines will send out battle reports at the latest after a successful sneak attack, and large attack submarines generally use communication buoys. The key is that the communication buoy can set working hours, say, to delay by a few hours, so that the submarine has enough time to evacuate.

Obviously, the Nuland submarine did not use communication buoys, which is really strange.

It was not until after the end of the war that the Imperial Navy learned that the submarine had also been placed on the "missing" list by the Nuland Navy. It took more than 20 years before it was found by a private expedition team. The sinking site was a trench about 30 kilometers northwest of the sea area where the "Zhou Kuande" was attacked. There were no signs of external attack on the wreckage of the submarine, and it is likely that during an emergency dive, the maximum depth was exceeded, causing the pressure hull to shatter. Because it adopts a large compartment structure, the boat does not even have a chance to save itself.

It's just that the submarine was not sacrificed in vain.

The three torpedoes fired by the boat not only sank the "Lucheng" frigate, but also severely damaged the "Zhou Kuande," and it was the damage caused by this torpedo that caused the "Zhou Kuande" to retire ahead of schedule. However, the most important thing is to attract a large number of anti-submarine forces.