U7 has sunk!
The sinking did not occur in the English Channel, nor in the North Sea or any part of the Atlantic Ocean, but right at its berth!
Upon his return to Wilhelmshaven, Zhang Hainuo learned that on Christmas Eve, while the crew of the submarine were all attending festivities in the town, several British or French spies managed to deceive the guards near the dock and plant bombs on the submarines. Five submarines were sunk in total, including U7, U39, U100, U109, and U171.
What saddened Zhang Hainuo the most was the sinking of U171 by a bomb placed by the saboteurs. It was the first submarine he commanded, and most of his achievements were accomplished while commanding it. He considered it his most beloved vessel.
However, what comforted Zhang Hainuo was that aside from a few patrolmen, no one else was injured in the incident. His current crew, including Edwin and his former subordinates, were all unharmed. He believed that rebuilding an elite submarine team wouldn't be too difficult as long as they were all together.
Over the next two weeks, Zhang Hainuo and the unfortunate crew members not only assisted the navy in salvaging the submarines but also endured thorough questioning by the Naval Provost Corps. Fortunately, one of the spies was captured shortly afterward, confirming that the submariners were innocent. However, despite this, Zhang Hainuo and his crew still received reprimands for failing to protect their submarines adequately.
Among the five submarines, U7, the smallest in tonnage, was the first to be salvaged. Expert analysis revealed that the saboteurs used a relatively small yet precisely placed bomb in the most critical location—the oil tank of the submarine. Consequently, the submarine was not only sunk quickly but also had its vital equipment and pipelines destroyed by the fire before sinking. After further evaluation, U7, U100, and U171 were declared irreparable, while the other two submarines were towed to dry docks for extensive repairs.
Although their submarine was destroyed, and all personal belongings were lost, Zhang Hainuo noticed that his crew members didn't seem too despondent, and some even appeared relieved. Zhang Hainuo quickly realized that most of them either had their allowances sent home regularly or had already spent them. Furthermore, there wasn't anything valuable on board the submarine. Moreover, this small and old relic of a submarine had already caused them enough trouble. They were eager to move on to a more comfortable, less bumpy, more heavily armed, and more survivable new submarine.
In fact, Zhang Hainuo shared similar thoughts. He knew that if he continued to command a submarine like U7 in operations in the English Channel, he would sooner or later suffer the same fate as his predecessor, who died of a heart attack.
As three of the submarines were declared "dead," the navy had to redeploy Zhang Hainuo and his crew. However, since there were no available submarines at the moment, they were temporarily assigned to the newly established 6th Submarine Squadron. When Zhang Hainuo and his crew reported to the squadron, only one submarine had been received from the shipyard, and over 200 crew members were undergoing training. Along with the three damaged submarines' old crew, they were enough to form ten submarine teams based on the specifications of the former UB-type submarines. However, the superiors only organized them into six teams, each comprising 48 personnel. Due to his rank and achievements, Zhang Hainuo was appointed as the commander of the 2nd team.
Considering the differences in quality and experience between the old and new crew members, the superiors decided to rearrange the teams, with the old submariners forming the core and the new recruits forming the majority. Although Zhang Hainuo was reluctant to part with the seasoned veterans from U7, he managed to retain Edwin, Simon, and several other former crew members in his team, feeling that his gains outweighed the losses.
Furthermore, the formation of 48-person teams allowed Zhang Hainuo to estimate the size of the new submarine. He believed that it must be a submarine with a submerged displacement of over 1000 tons. Indeed, the new submarine turned out to be larger than he had imagined.
For the first month at the training base, since the new submarine had not yet been completed, Zhang Hainuo spent his days conducting physical training with his team, providing them with insights into operational tactics based on his and other officers' experiences, and using his knack for games to bond the team. Soon, it was noted that the atmosphere within Zhang Hainuo's 2nd team was more cohesive compared to others.
During this time, Zhang Hainuo also made certain adjustments to the team structure based on his understanding of the crew members. Edwin remained as the torpedo officer, Simon as the chief officer, and Giselle as the best engineering non-commissioned officer. The other crew members were assigned to departments according to their skills and interests. When their new submarine finally arrived from the shipyard, they had become a well-coordinated submarine crew, something that Zhang Hainuo was very proud of as their commander.
A month and six days later, although the new submarine had not yet completed its final assembly, detailed information about it was finally distributed to Zhang Hainuo and his team. It was then that Zhang Hainuo learned that he would be commanding the U139, the most advanced and long-range cruiser submarine in the German Empire to date. With a submerged displacement of 1500 tons, it was more than twice the size of the UBIII type submarines. Equipped with six 500mm torpedo tubes, it was the most powerful submarine of its time. Additionally, it could carry 8 spare torpedoes, three deck guns—two 100mm guns and one 37mm gun—along with two 8mm machine guns. The formidable surface firepower truly amazed everyone!
Moreover, this class of submarine could carry up to 110 tons of fuel, allowing it to travel over 10,000 nautical miles!
Although Zhang Hainuo only had the specifications and schematics of the submarine at this point, the grief of losing his previous vessel had vanished without a trace. Even in the later stages of World War II, a submarine like the U139 would still be highly sought after. While its speed might not be superior to other submarines, its weaponry and endurance were outstanding. Zhang Hainuo even believed that he could use a U139 to dismantle a British convoy—sinking all the escort vessels with torpedoes, and then surfacing to use deck guns to sink the remaining merchant ships one by one. Of course, the premise of this idea was that he wouldn't be sunk himself. Unfortunately, the U139, apart from having a greater diving depth than ordinary submarines, did not have a substantial increase in defensive capabilities, nor was it equipped with advanced sonar or similar listening devices!
After familiarizing himself with the submarines' on-paper performance, Zhang Hainuo began to ponder their true purpose—spending more than twice the funds to construct submarines with such an ultra-long range was obviously not for operating in the vicinity of Britain. This reminded Zhang Hainuo of the German submarine attacks on mainland United States in the later stages of World War II. Could it be that the German commanders in World War I had similar intentions?
PS:
1. During World War I, Germany had over a dozen types of submarine models, some named after the first submarine of the class, such as U1, U5, U23, while others were named based on submarine type with Roman numerals or letters, such as UBI, UBIII, and UD, where UB represented coastal submarines and UD represented foreign-trade types.
2. U139 was the pinnacle of submarine construction during the German Empire in World War I, known as a cruiser submarine by the British and Americans. After the war, it was acquired by Britain and the United States, and was extensively studied, exerting a significant influence on submarine development. During World War II, Germany, the United States, Japan, and Italy all manufactured cruiser submarines that were stronger and more modern than the U139.
3. Indeed, towards the end of World War I, the German Navy dispatched several U139 submarines to operate near the coast of the United States, but their effectiveness and impact were not as significant as the German submarines in World War II, and the reasons remain unknown.