"Angle!"
"358!"
"Angle!"
"003!"
"Targets identified! Target 1—bearing 358, distance 1200! Target 2—bearing 003, distance 1400! All bow torpedoes ready for launch, set depth to 2 meters! Start engines, one-third speed ahead! Submarine turn left 2 degrees!"
Without taking his eyes off the periscope, Hessen issued a series of commands. In an era without radar and sonar on submarines, he was the only one who could see the surface situation. The others had to trust him completely and faithfully execute his orders.
Zhang Hainuo stood beside Hessen at the conning tower, seemingly the least busy among the crew. He didn't go to the torpedo room, which was related to his profession. Firstly, it was small and he might disrupt the torpedo loading process, and secondly, he was still relatively new to torpedoes, especially submarine torpedoes. He preferred to avoid on-site guidance.
"Torpedo 1 launched! Torpedo 2 launched!"
Every time torpedoes were ordered to be launched, Hessen seemed to explode with energy, as if the more powerful his voice, the more likely the torpedoes would hit the target. Immediately after, he briskly issued another command:
"Submarine turn right 5 degrees!"
This time, only 39 seconds after the launch of the two torpedoes, a loud explosion was heard nearby. It was certain that a torpedo had hit the target. However, when the second explosion didn't follow immediately, the crew felt a sense of disappointment.
About 50 seconds later, Hessen ordered the launch of torpedoes 3 and 4, then promptly closed the handle on the periscope.
"Retract the periscope! Dive to the seabed!"
Dive to the seabed?
This instruction wasn't part of the tactical commands Zhang Hainuo learned at naval school, but he had read about it in some articles and movies describing World War II. After all, large-scale submarine warfare had only begun about two years ago, and many examples, tactics, and experiences hadn't been compiled into textbooks yet. However, the absence from textbooks didn't mean the instruction was incorrect; many things were applied before they were documented!
0 minutes and 56 seconds later, two consecutive explosions were heard from the surface.
2 minutes and 40 seconds later, the submarine safely touched down on the seabed at a depth of 39 meters.
"Torpedo room, quickly load spare torpedoes. Everyone else, remain in place and minimize all activities!" Hessen glanced at his watch. "It's now 9:23 PM. We'll have to stay here for a few more hours!"
Although the battery could only power the submarine underwater for about an hour, the air inside could sustain the 27 crew members for at least 6 hours. By using the emergency chemical oxygen generators on board, this time could be extended by another one to two hours.
Zhang Hainuo calculated that from firing torpedoes at the freighter to diving, it had been about 2 hours and 40 minutes. In other words, U21 could stay submerged until well past midnight. Of course, Hessen could order the submarine to turn back now, but the unknown details of the anti-submarine nets and minefields near the shipping lane posed a significant threat from the remaining British destroyers.
This time, because no one spoke, Zhang Hainuo deeply felt the passage of time. The surface seemed quiet for a while, but soon the hum of engines and propellers resumed. Sometimes, it was possible to distinctly feel British ships nearby, and explosions of various sizes continued for over two hours. Some were from artillery—Hessen said that after being attacked by submarines, the British would use hydrophones on their ships, a very primitive listening device. If they couldn't locate the submarine, they would fire randomly into the water, seemingly to intimidate submarines below, but also to bolster their own morale. However, some explosions were caused by another type of weapon posing a greater threat to submarines. Hessen said that things like mines would explode only after reaching a certain depth. Zhang Hainuo thought, weren't those early versions of depth charges? However, without instruments like sonar to accurately locate submarines, using depth charges would likely be futile for the most part!
Gradually, the explosions grew more distant. After about two hours, it seemed that the British had had enough and the sea returned to calm. Hessen informed Zhang Hainuo that British warships usually wouldn't linger in the area too long. After rescuing survivors and attacking suspected targets, they would return home with ease.
Zhang Hainuo knew it was a typical bureaucratic decision. The British navy often made such seemingly foolish and laughable mistakes during World War I and even World War II. But from his current perspective, it was a good thing!
At 12:20 a.m., after surfacing to periscope depth and carefully observing the surrounding situation through the periscope, Hessen finally allowed the submarine to surface. After nearly six hours underwater, when Zhang Hainuo emerged from the hatch again, the fresh sea breeze made him realize how refreshing fresh air could be.
The sea surface was calm, with only the sound of the wind and waves hitting the hull. Various floating objects could be seen everywhere, such as debris, wooden crates or barrels, cans, clothes, and oil. In short, almost anything that could float on a ship was present here.
Hessen stood on the conning tower, carefully steering the submarine. During this time, the submarine didn't start its diesel engines but used batteries to propel it forward, minimizing the noise generated. By the time the battery was depleted, U21 was about 7 to 8 nautical miles away from the incident site, and that was when the two diesel engines started joyfully.
"Hainuo, you stay here and watch for a while. I'll go down first! Report any situation!"
Although it was an order, Hessen said it in a tone of negotiation, which made Zhang Hainuo feel comfortable.
"Okay, Roderick, rest well. I'll take care of these guys!"
Without any further ado, Hessen went down.
For Zhang Hainuo, everything had happened so quickly: the first boarding, the first victory, the first successful retreat, and now the first time acting as acting captain. It seemed like life had suddenly become smoother. He leaned over the intercom, cleared his throat, and said:
"Everyone, this is Hainuo von Finckenshtatstein. I'm taking over the entire boat!"
"Understood, the great hero from the Sächseltz!" The officers on duty in each compartment responded enthusiastically, and Hessen, who had already returned to the captain's cabin, heard the voice from his own headset. He smiled, shook his head, and then opened his thick logbook.
Under the domination of the night, the sea was empty. U21, like a lone fish, navigated on the vast expanse of the sea. Seven torpedoes were fired, sinking one freighter and one destroyer, hitting another destroyer, and possibly hitting one more. Although the results were not particularly spectacular, they were quite impressive. Now with only three torpedoes left on board and some distance from Hessen's planned target, it meant that U21 would continue to roam the Mediterranean for some time.
Zhang Hainuo thought for a long time and still felt that Hessen's decision to keep the submarine submerged was a very wise choice—one that the British could never have imagined!
However, there was still one thing he couldn't figure out: without detailed sea charts, especially the depth of the seabed around Malta, how did Hessen know that the depth at which they submerged wouldn't exceed the submarine's maximum diving limit?
After thinking for a long time without reaching a conclusion, Zhang Hainuo continued to stand on the high point of the submarine, using binoculars to observe the surrounding sea conditions. However, it seemed that all the Allied merchant ships had received the message about German submarine activity near Malta, as none appeared again.