Chapter 35: Grand Opening

  After Germany declared unrestricted submarine warfare in February 1917, the losses of Allied merchant ships increased from 300,000 tons in January to 400,000 tons in February, then jumped to 500,000 tons in March and reached 850,000 tons in April.

  On average, one in every four British merchant ships leaving the sea was sunk.

  To protect their own merchant ships and maintain the country's sea lanes, the British Admiralty began to adopt a convoy system, where dozens of merchant ships were formed into convoys escorted by destroyers or cruisers traveling between the US and Britain.

  On the vast ocean, a large fleet consisting of more than 30 ships is heading towards the British Isles. In this fleet, there are 20,000-ton oil tankers and tens of thousands of tons of large cargo ships, forming a nearly circular tight formation. Surrounding this circle are cruisers and destroyers with strong combat capabilities and high speeds, looking brand new and majestic. The big guns on these warships vigilantly gaze out at the sea, ready to respond with intense firepower to any unusual movement in the vicinity.

  Such a convoy formation looks invincible, but if you really want to pick out some flaws, the biggest drawback of this British fleet is that there are no aircraft carriers or airships accompanying the fleet.

  Zhang Haino had noticed this early on, and it was for this reason that he was able to command U171 to enter the attack position in a calm and unhurried manner by sailing on the surface before diving into the water - if even one British floatplane were flying with the convoy, his U171 would have had to start diving from a very far distance, which not only wasted time but also affected the submarine's subsequent tactical actions due to the consumption of battery power.

  "Angle!"

  “015！”

  "Target number one, distance 3300, bearing 15, speed 12!"

  This time, the lookout's position was taken over by Gunner Hackett, and Zhang Hainuo became the only person on the submarine who could observe the situation on the surface. At this moment, his periscope was aimed at a white cargo ship, its hull lines looked very sturdy, it must be able to carry a lot of goods, perhaps British urgently needed grain, minerals, or other more important supplies, Zhang Hainuo didn't need to figure out this point clearly.

  "Target 2, distance 3100, bearing 15, speed 15!"

  This time, Zhang Hainuo didn't need to report the angle to Hackett, because his periscope hadn't moved yet when another ship's shadow burst into his line of sight. It was a typical British fleet destroyer, with a displacement of around 1,000 tons, about one-third larger than Germany's large torpedo boats, and its hull looked particularly long and narrow. On the forecastle, there was a single-barreled naval gun, behind the sturdy bridge, the layout was relatively simple, with three smokestacks in a row along the centerline, a forward-facing single-barreled naval gun, two torpedo tubes, and an aft-facing single-barreled naval gun on the quarterdeck.

  As the combat advisor on the boat, also known as the captain's assistant, Cook carefully recorded the data reported by Zhang Hainuo. His responsibility was to record and calculate the shooting parameters of the submarine. Of course, all the data changed in the next second, which was also what he had to consider when calculating.

  Zhang Haino slowly turned the periscope clockwise, and this time he saw a warship that was larger than the previous destroyer. Its hull was about twice as long as the previous one, with a higher freeboard, and its firepower was stronger - there were two single-barreled guns on the forecastle, secondary guns and torpedoes in the middle of the ship, and two more single-barreled guns at the stern. From this distance, Zhang Haino estimated that its main gun was 152mm caliber, with a power level higher than those destroyers by a whole level. At the same time, Zhang Haino also noticed that there was a British-style divisional commander flag hanging on the mast of this cruiser - during his studies at the Kiel Naval Academy, there was a course that taught students to identify various ship flags. For other students, it was like teaching elementary school courses to middle school students, but for Zhang Haino, it was a very useful supplement!

  "Angle!"

  "Look at the dial on the periscope turret," Cooke said, "018!"

  "Target 3, distance 3000, bearing 180, speed 15!"

  Next, Zhang Hainuo did not continue to look for other targets and their related parameters, but instead ordered the periscope to be retracted.

  He remembered the instructor saying that during combat, they should minimize the time the periscope was exposed above the water surface to avoid being detected by the enemy.

  "Periscope! Torpedoes 1 and 2 set to depth 3 meters, angle of rotation 0! Torpedoes 3 and 4 set to depth 2 meters, angle of rotation 3! Torpedo 5 set to depth 2 meters, angle of rotation 0!"

  After issuing this series of commands, Zhang Hainuo stared at his watch with both eyes and asked Hackett "What is the estimated time for target 3 to reach position 5".

  "Start counting from 4 minutes and 20 seconds!"

  Zhang Hainuo no longer spoke, but silently waited. In the few days of entering the Atlantic, although not a single torpedo had been launched, he had figured out many things. An excellent submarine commander's excellence lies not in confronting enemy convoys head-on, but in fully utilizing the submarine's advantages to launch surprise attacks on enemy ships, achieving a fatal blow and then retreating quickly, keeping the enemy convoy in a passive state, rather than exposing his own weaknesses of being unable to counterattack when sailing at full speed and diving deep.

  Appearing at an unexpected time and place, Zhang Hainuo felt that this was the essence of Heisen's combat thinking. He couldn't just imitate Heisen's actions and tactics, but should use his own wisdom to analyze the battlefield and cleverly devise countermeasures.

  At this moment, Zhang Haino is no longer as confused as he was a few days ago in Beihai. He believes that the acoustic equipment installed on British warships has made some progress in positioning accuracy compared to before, but it is still in the passive search phase. Otherwise, U171's previous "feign death" would not have been so easily missed by the British!

  In a state of complete concentration and waiting, Zhang Hainuo's next 4 minutes passed almost in seconds, just as the second hand turned four circles and returned to its original position, he burst out like Hersen:

  "Raise periscope, torpedo room stand by for immediate launch!"

  After the periscope was lowered, Zhang Haino made some adjustments and aligned the angle to 5 degrees. A few seconds later, a white ship shadow entered his line of sight. Before he could say anything, it was too late, and he decisively ordered the launch of torpedoes No. 1 and No. 2.

  He paused for about two seconds and then shouted: "Launch torpedoes 3 and 4!"

  "Number one and number two torpedoes fired!... Number three and number four torpedoes fired!" came Edwin's voice from the other end of the speaking tube.

  At this time, Zhang Hainuo's heart had no excitement or excitement. He commanded extremely calmly:

  "Dive down to 40 meters!"

  63 seconds later, the first explosion came from the surface of the sea, 3 seconds later was the second one, and after another 2 seconds, the third explosion also came clearly. At this moment, Zhang Haino was wildly shouting in his heart:

  "Yes! I've finally opened for business!"