As the Americans expected, the German destroyer Willy Frazel was equipped with passive sonar used to search for active vocal objects. A huge submarine like the Blue Cod stayed quietly, even if it was only one hundred yards away, it would be difficult for the Willy Frazel to find it unless the German crew found the dangerous attacker in other ways.

On the combat bridge of the German destroyer, a rough-looking lieutenant officer reported to Captain Major Kesen: "No discovery, sir, could it be that the flagship had a technical misjudgment?"

The German naval major in front of him had a full atrium, his facial features were upright, and he looked very aristocratic. He said calmly: "It was during the war, and when we were in the war, anything could happen. We must not numb ourselves and make the worst plans for everything."

"I understand, sir!" the lieutenant replied convincingly, "What should we do next?"

The major had already thought of a countermeasure and ordered without hesitation: "Drop a deep-water bomb in the area specified by the flagship."

The lieutenant officer had concerns about this method, and he questioned: "But... sir, if there were no enemies here, would the sound of the explosion of the deep-water bomb attract the enemies in the distance?"

The major said with a strong heart: "Where you can hear the explosion of a deep water bomb, you must have discovered this fleet through visual inspection or radio wave detection, so the idea that the dropping of a deep water bomb will attract the enemy is not true. On the contrary, it will make the enemy here feel that they have been discovered and make active evasive actions so that we can track its exact location. If there are indeed no enemies here, the explosion will also keep our crew members awake and be alert."

"Okay, as you said, what if you want to do, what if you want four or six?" the lieutenant suggested.

The major thought for a moment: "At the beginning, he threw six consecutively, and then one per minute."

The lieutenant's style of conduct seemed not enough to stand alone, but as an executor, it was reassuring. Soon after, a dull roar began to sound on the sea, sounding like rolling thunder from the horizon, or the legendary sea god beating its huge war drum.

The MC-Iib short-wave pulse radar developed by the Irish people is comparable to the top equipment of the same type of the United States and Germany. It can detect submarines in a floating state six kilometers away, submarine command towers are found about three kilometers, and metal objects the size of submarine periscopes are detected about one kilometer. The accuracy is close to the performance requirements of the fire control radar. Thanks to the accurate guidance of the "Ruger", the escort destroyer "Willie Fraser" throws deep-water bombs, which is only more than 200 meters away from the "Blue Cod" in a suspended state!

The modernized and modified 1922-grade destroyer can carry up to 36 barrel-type deep-water bombs and 240 hedgehog-type deep-water bombs. Within just a few minutes, the "Willie Fraser" dropped 10 barrel-type deep-water bombs in one breath. The change in the attack rhythm made the US officers and soldiers of the "Blue Cod" bear unprecedented psychological pressure, because according to normal ideas, their submarines must have been discovered by the enemy ship.

The commander of the German destroyer was scheming and Major Anderson, the captain of the "Blue Cod", was bold and careful. When all the crew were so nervous that they were sweating, he tried to infer the actual external situation from the changes in the sound. Although the impact of the deep bomb explosions made the people in the submarine feel panicked, they never caused substantial damage to the submarines, which meant that their explosion location was still outside a safe distance. So Major Anderson decided to take a bold move, and he signaled everyone to stay in place and not make any sound.

After the first few minutes, the explosion frequency dropped sharply, and the tight hoops placed on the head also decreased.

The correct judgment greatly improved Major Anderson's confidence. After about twenty minutes, the high-speed propellers of the enemy destroyers gradually weakened, and the slow propellers of ordinary ships gradually faded away. In this case, he decided to seize the opportunity to launch another attack.

The "Green Cod" quietly rose into the periscope. The night sky was filled with cumulus clouds, and the sea surface was faintly visible. The distance of the enemy fleet seemed to be much further than the previous torpedo attack. A few minutes later, the American crew completed the previously interrupted torpedo loading, and all torpedoes were set at a low speed of 30 knots, so that their theoretical range could reach more than ten kilometers.

The weapon commander calculated two torpedo shooting plans based on the illumination angle parameter table. Major Anderson chose the set of four torpedoes with a small scattering angle to shoot out at a 4-degree fan. After sailing for five or six kilometers, they will pass through the enemy fleet at intervals of about 100 meters, and the probability of all deviating from the target is about 80%. In other words, the "Green Cod" has a 20% chance of hitting at least one enemy ship.

As soon as the torpedo was launched, Major Anderson immediately ordered to put away the submarine periscope. In the tense and expectant waiting, time passed slowly. After more than six minutes, the sonar soldiers on the boat shouted excitedly: "The sound of explosions comes from afar! It should be our torpedo!"

The crew members heard the faint sound, and the sonar soldiers' judgment was undoubtedly the most authoritative. After he spoke, many of the sweaty crew members couldn't help but jump.

In order to determine the outcome, Major Anderson ordered the periscope to be raised, and at the same time, the crew were prepared for emergency diving to cope with the retaliatory attacks of enemy destroyers. In fact, at this time, the Irish heavy cruiser "Ruger" was eight kilometers away from the "Blue Cod". Even if the American submarine once again exposed the command tower to the water, the radar of the Irish warship could not accurately capture its reflected waves.

In the view of the periscope, a large open flame ignited on the dark sea surface. Under the light of the fire, you can see the thick and thick smoke columns like a volcano eruption. This scene reminded Major Anderson of the early days when he witnessed a fire in a chemical factory, and the state of ignition of a large number of flammable materials was ignited.

Major Anderson was overjoyed: "Guys, we seem to have killed a German tanker. It is now like a lighthouse built on a cliff, and can be seen by ships dozens of kilometers away."

After saying that, the major gave the periscope to the weapon commander. After seeing it, the weapon commander gave it to the first mate, but the first mate did not give the viewing position to the fourth person, because while he was watching, he saw an enemy warship sailing towards this side with great momentum.

The warship that was sailing quickly was the "Willie Fraser" that had failed to perform anti-submarine reconnaissance missions. Before the explosion of its own tanker, the German destroyer was in the nearby waters. Because a crew member found a torpedo track on the sea, the destroyer commander immediately calculated the approximate location of the attacker based on the direction of the torpedo track, and found that he was likely to have passed by the enemy submarine before.

This time Major Anderson did not dare to be careless. He directed the "Green Cod" to dive deep into the water, and started the motor, adjusted the course, drove the submarine to sail north for a distance, and then turned off all power units and returned to the lurking state.

Having missed a target before, Major Kesen, the commander of the "Willie Fraser", would not stop easily this time. The angry German hound used sonar to lock the tracks of the American submarine, and then circled back and forth above its head, dropping more than 20 barrel-shaped deep bombs and more than 100 hedgehog deep bombs, stirring the entire sea area into a tumble.

The water surface displacement of the "Green Cod" is almost the same as that of the opponent. The weapon system consists of 6 533mm torpedo tubes, 1 102mm deck cannon and 4 7.62mm machine guns. When performing combat missions, it is usually equipped with 20 torpedoes and 100 shells. It has sufficient ammunition, but at this time it can only be passively beaten, and it may even be sunk by a deep water bomb weighing dozens of kilograms at any time. The principle of mutual generation and restraint of ships is indeed intriguing.

Taking advantage of the fact that the other party had no power to fight back in the water and could not call for rescue, the German destroyer launched an unscrupulous attack, with the stance of not giving up without using up all anti-submarine ammunition. This attack lasted for more than half an hour, and regardless of the outcome of the battle, it was impossible for the American submarine to pose any threat to the "Frederick Caesar" fleet during this period. Under the cover of the escort ship, the ships of the Allied Powers that became frightened birds gradually sailed away from this dangerous sea area, and the German minesweeper boats ordered to rescue the survivors of the tanker had basically completed the rescue work. Seeing that the crisis had passed, the scream of shells falling suddenly sounded on the sea, and then the sound of the explosion of medium-caliber shells. This sound immediately made many people sweat in a cold sweat.

Is it the enemy's cruiser that has arrived?

The Irish heavy cruiser "Ruger" has a special radar room. At this time, the small radar room gathered many technical officers and chief radar operators, and the officers on the bridge were anxiously waiting for news from the radar room. The ring ripples swept across the radar screen over and over again, reflecting the light spots representing the sea-surface ships. However, except for all members of the "Frederick-Caesar" regiment, there were no foreign objects on the sea surface 50 kilometers centered on the "Ruger". Even if the impact of weather and sea conditions on the effective detection distance of the radar can be considered, it can be guaranteed that there are no enemy surface ships within forty kilometers. So, where did the shells come from?

Although it had already received the enemy, the Willy-Fraser continued to remain radio silent. Its real-time communication with the Ruger could only pass through slow-efficient lighting signals: our ship was threatened by enemy artillery fire, and it was observed that the flames were in the northwest direction, and the distance was uncertain, so I requested guidance.

Every two minutes or so, flashing flames appear in the distant sea surface. Although it is slight, it actually exists. This makes the technical officers on the Irish heavy cruiser wonder: The radar is clearly functioning normally, so how can it miss the enemy warships that are firing within the detection range? Is it because the enemy has new technology to avoid radar detection?

Fortunately, there were officers on the ship who had a deeper study of the ships in various countries, and they made a reasonable speculation on the current strange situation: these mysterious shells were likely from enemy submarines equipped with large-caliber deck cannons!

Looking back on history, the first attempt to "submarines to resist cannons" were the British. They brought cruiser-class heavy artillery to submarines before World War I. In the wartime shipbuilding plan formulated in 1914, the British Navy decided to start construction of two super heavy artillery submarines (m1/m2) equipped with 305mm naval guns. This amazing plan failed to be aborted in the middle. After the war, the British government tried every means to reorganize the fleet. Submarines with low construction costs, high combat effectiveness and suitable for defense strategies were once placed in the best.

First, heavy artillery submarines suitable for maritime combat and coastal raids came into being. By the summer of 1933, the British Navy had three levels of heavy artillery submarines in service, equipped with 6-inch, 8-inch and 9.4-inch caliber deck guns. For their respective strategic needs, the United States, Germany and Italian navies also invested a certain amount of energy in the field of heavy artillery submarines. Most of the artillery carried by these submarines were 6-8-inch caliber, but the carriage methods were different, and there was a big gap in actual combat performance.
Chapter completed!