The explosions above were sporadic, but the jolts they caused to U171 were far less intense than the ones experienced in the northern North Sea. After the ordeal of life and death they had gone through, Zhang Hainuo and his crew were much calmer facing such situations. The most exaggerated reaction came from Zhang Hainuo and Edwin. They each poured themselves a cup of coffee and leisurely sipped it, even though the shaking was enough to spill some of the coffee from their cups. They didn't mind at all, exchanging relaxed glances and expressions from time to time.
This time, the British attack lasted just over half an hour, probably because their passive listening devices (hydrophones and simple sonars) didn't detect any sound from the submarine, or perhaps because they didn't carry many depth charges to begin with. The explosions subsided.
About an hour later, the last buzzing also faded until it completely disappeared from people's ears. However, Zhang Hainuo didn't rush to the surface. Instead, he pondered over his achievements of the day. Clearly, three out of the four torpedoes hit British ships. The likelihood of the British detecting torpedoes traveling underwater at a depth of two to three meters and hitting them with gunfire within a minute is very low!
Zhang Hainuo's primary target was the cruiser, the flagship of the escort fleet. Sinking it, even if it didn't completely disrupt the command system of the escort fleet, would deal a heavy blow to the morale of the British sailors. His second target was a large cargo ship located at the front of the fleet. Choosing this target primarily considered the possibility that a missed torpedo could hit other cargo ships in its side or rear.
The best-case scenario, Zhang Hainuo thought, would be for the first two torpedoes to hit their planned targets, while the third would skip past them to hit a third target, perhaps another large cargo ship, or an unlucky destroyer. Whatever the case, as a novice, Zhang Hainuo was already very satisfied.
At least it proved that he had the ability to "survive" in this era.
After another hour and a half of patience, Zhang Hainuo finally ordered the submarine to surface. As usual, he first peered through the periscope to check the surroundings, then surfaced to half periscope depth, confirming that there were no seabirds around, before U171 timidly emerged from the water.
The situation on the surface somewhat surprised Zhang Hainuo. Black oil stains, white or brown fragments of wood, lifebuoys, and other floating debris could be seen everywhere, indicating that at least one ship had been sunk in this area!
"Ho, Hainuo, we've really done it this time! Look at this, it's at least a big one!" Edwin crawled out of the cabin, excited.
Below the conning tower, the other crew members emerged from various watertight compartment doors, one by one, onto the fore and aft decks of the submarine, silently observing the floating objects on the water's surface, momentarily forgetting to converse.
It was a peculiar calm, broken only after half a minute when Zhang Hainuo spoke in a relieved tone:
"Young lads! We've sunk an enemy ship!"
After a moment of silence, the air suddenly filled with excited cheers. Perhaps most of the people here had not expected victory to come in this way, especially just a few days ago when they were still lamenting and frustrated over their defeat.
Zhang Hainuo picked up the binoculars and carefully observed. There were no bodies of survivors or casualties on the surface, indicating that the British had cleaned up the battlefield before leaving. Therefore, U171 had no urgent need to stay here any longer. Zhang Hainuo promptly ordered the submarine to proceed at full speed to pursue the British convoy!
When the crew first heard this command, they were somewhat surprised. Pursuing a convoy with escort ships using just a submarine seemed a bit crazy. But their commander wasn't blinded by victory. It was still about three or four hours before nightfall. The British convoy was traveling at 12 knots (the speed of merchant convoys is not measured by the speed of individual ships, as they need to maintain a certain formation and spacing, and avoid collisions. The speed of slow convoys can be as low as about 7 knots), while U171's maximum surface speed reached 16 knots. This meant they had a chance to catch up with the convoy tonight. As is well known, submarines are sneaky during the day, but they become genuine "sea wolves" at night!
After restarting the submarine's engines, Zhang Hainuo ordered the communication officer to report the previous battle to the submarine command headquarters. Since Zhang Hainuo didn't personally witness the sinking of the enemy ship or find any tangible evidence of the sunken ship's identity, the only way to confirm the sinking was to cross-check their report with the information provided by the British regarding their ship losses. As long as the time, location, and general situation matched, the German Naval Command would confirm the submarine's success and reward the relevant personnel according to regulations.
Typically, sinking an enemy ship would earn both honors and monetary rewards, with the amount varying depending on the type and tonnage of the ship sunk. As far as Zhang Hainuo knew, these rewards were generally quite generous. For super aces like Hesen, the rewards could be several times their usual allowance.
About half an hour later, a confirmation telegram arrived from the submarine command headquarters in Wilhelmshaven, informing Zhang Hainuo that they had issued instructions to nearby submarines to converge on this area as soon as possible.
To Zhang Hainuo's somewhat unexpected surprise, the headquarters actually agreed to his request to temporarily command the nearby German submarines. In the next few hours, U93, U122, and U145 successively sent telegrams, indicating that they would arrive in the area before 3 a.m. The last telegram came from U89. Initially, Zhang Hainuo didn't know that this submarine was also operating nearby—mission arrangements were like the names of underground party members; once leaked, it could lead to deadly consequences. Therefore, even if the relationship between the captains was good, they would keep their submarine's position confidential until returning.
Being able to catch up with the British convoy at 10 p.m., Zhang Hainuo also had to thank the two newly replaced diesel engines during the overhaul. Their endurance, like mules, allowed U171 to maintain a high speed of around 16 knots for the past few hours. But luck was also a factor in finding a convoy in the vast ocean. If Simon hadn't noticed a very difficult-to-detect plume of smoke in the night sky to the right, U171 might have missed this delicious feast!
After re-locating the British convoy, Zhang Hainuo ordered a secret telegram to be sent to U89, U93, U122, and U145, except for U145, who wouldn't be able to arrive before 3 a.m. So, the attack was scheduled for 3 a.m., which meant they still had two to three hours of darkness to utilize after the assault!