Chapter 24: H-Formation Tactics

  Hesston ordered the periscope raised again just ten minutes after U-21 had dived.

  In ten minutes, the U-21 had traveled 1.4 nautical miles at full speed underwater; the steamer was moving toward the harbor a distance of less than 2.5 nautical miles from it, and the tug coming out of the harbor had approached to within nearly two nautical miles of the steamer.

  This looks like a simple yet complex math problem, relying on his sensitivity to numbers and strong mental arithmetic skills, Zhang Haino knew that U-21 had basically entered the attacking position. If he were the commander, he would order the submarine to stop advancing and wait quietly for the freighter to enter the best shooting range, then launch torpedoes, dive, and withdraw.

  Koxing didn't do that!

  "Angle!"

  “289！”

  "Target No. 1, bearing 289, range 6100!"

  After reporting these data, Hessen turned the periscope clockwise for nearly half a circle.

  "Angle!"

  “073！”

  "Target 2, bearing 073, range 9500!"

  Then Heson and Periscope both turned around in place before giving the order:

  "Take in the periscope and proceed at one-third speed ahead!"

  Zhang Hainuo felt strange in his heart, if he continued to sail forward, the angle between the submarine and the freighter would become larger and larger. When the submarine launched a torpedo attack, it would try to make the target close to its 0-degree angle or 180-degree angle, unless Hersen wanted the submarine to pass through the opponent's course and launch an attack from the other side, or...

  No, no way! Zhang Hainuo immediately overturned this "or" in his heart. Anyone with a little military knowledge knows that the hit rate of launching torpedoes on both sides of the bow is the highest, because the target cross-sectional area is the largest, and conversely, the cross-sectional area of the bow and stern is the smallest. From this perspective, the hit rate of torpedo attacks will also decrease significantly. Unless the distance is close enough!

  A few minutes later, Zhang Hainuo felt that the impossible thing was happening step by step. When Hersen observed through the periscope again, the angle of target 1 had changed to 273, which means it was in the left bow position of the submarine, while the angle of the patrol boat was 85, almost in the right bow position.

  "Turn 90 degrees at one-third speed!"

  Hersen's order meant that the submarine would turn 90 degrees to its own right, i.e. with its bow pointing towards the ferry and the port, and its stern towards the freighter.

  What is this guy thinking?

  After completing the turn, U-21 would be sandwiched between the freighter and the tugboat. Did he want to sink both ships with two torpedoes, one from the front and one from the back?

  No, no way! Zhang Hainuo refuted his own speculation once again, because nobody would use a torpedo to attack such a small barge of only tens of tons, and its draft was so shallow that most torpedoes would pass underneath it.

  After the submarine completed its turn, Heson ordered it to shut down its engines at the earliest opportunity.

  The cabin of the submarine quickly fell silent, a faint humming noise similar to that of a bee came from outside, Zhang Haino guessed it must be from the direction of the cargo ship at the stern.

  After raising the periscope again, Hinson's No. 1 target bearing changed from 273 to 181, at a distance of 1,500 yards; the No. 2 target bearing changed to 359, at a greater distance of 4,300 yards!

  "Torpedo set to depth 1, gyro angle 1, aft torpedo ready for launch!"

  "Torpedo room aft reports ready!"

  The stern torpedo tube was loaded with a minimum depth charge, zero rotation angle, and could be launched at any time. After boarding the boat, Zhang Haino also learned about He Sen's peculiar habit from other crew members and felt very puzzled. In order to avoid mistakenly injuring their own ships, some submarine torpedo tubes were equipped with insured torpedoes set to maximum depth, but He Sen had the stern torpedo room do the opposite, while the four forward torpedo tubes were set according to convention.

  Time was ticking away second by second, and with each passing second, the distance between them and the freighter narrowed by 10 yards. The atmosphere inside the submarine's cabin suddenly became oppressively heavy, so heavy that it was almost suffocating.

  Hesen remained fixedly staring at the observation port of the periscope, until the second hand on his watch had almost made a complete circle, when his voice suddenly burst out:

  "Torpedo number 5, fire!"

  The 5 x 450mm torpedo tubes on the U-Boat III are arranged in a forward four and aft one configuration, with the fifth torpedo being the one waiting to be launched from the stern tube!

  Zhang Hainuo did not know whether the crew on that cargo ship had discovered the torpedo under the water, perhaps their captain was calmly commanding the ship to evade, or perhaps those sailors would shout and jump into the water ahead of time to escape, but the distance of less than 500 yards left their ship with almost no chance of avoiding it, unless this torpedo missed its target!

  On the other side of the periscope, Hersing did not intend to witness the ship being torpedoed with his own eyes. For him, such scenes had perhaps been seen too many times!

  "Dive down to 15 meters!"

  20 seconds later, a loud noise came from the water's surface. The explosion point was apparently very close to here and could be felt on the submarine with a very obvious vibration. At this time, the crew members' hanging hearts finally put down, and everyone applauded to celebrate, including Zhang Haino.

  This is also his first taste of victory after coming to this era!

  Hesen, the ace boatman known as "Sea Madman" by his peers, was still calm and collected at this moment.

  Yes, Zhang Haino thought, this battle is far from over. Did the sailors on that paddle steamer see the trajectory of U-21's torpedo? Will they discover U-21's periscope? After a successful attack, why didn't he quickly retreat? What does this guy Hersing want to do?

  Zhang Haino was still a bit confused, but he suddenly thought that it was precisely because submarines usually launch torpedoes from the side of ships, and the British destroyers coming out of the port behind would definitely think that the German submarine attacking the freighter was on the side of the ship and withdrawing in the direction away from the port - as long as U21 remained quietly submerged here, it would not be easy to be discovered by the British destroyer.

  On the inky blackness of the sea, the low profile and limited lighting of the trawler made it difficult for the sailors on board to observe the torpedoes fired at the freighter several thousand yards away. It was precisely because of this that Hensen did not worry about the trawler discovering the location of U-21, but rather, the British sailors' visual error might lead them to mistakenly believe that the freighter had struck a mine and sunk!

  Was Hinson's intention to make the British make a wrong judgment and then pursue in the wrong direction, so that U-21 could safely evade the attack of those British destroyers by launching an attack from the bow of the freighter with the only torpedo at the stern?

  Looking at Hesen's face which was colder than ever, Zhang Hainuo had a feeling that this guy was not just trying to hide from the attack of the British expulsion ship!