.Nagoya, Mitsubishi Internal Combustion Engine Manufacturing Co., Ltd. Research Institute.

"11,000 meters, are you sure?" the old man in a white coat asked solemnly.

Next to him, a middle-aged man wearing white big tofu, who is about forty years old and wearing round-frame glasses nodded, "Yes, sir, at least 11,000 meters!"

"When will it be developed?" the old man asked again.

The man in glasses replied: "The engine takes 45 days. If you use an existing aircraft for testing, it can be completed before the end of February!"

"The time can't be shorter?" The old man seemed very anxious.

The man in glasses shook his head, "This is the fastest time!"

The old man lowered his head and thought for a while, "In this case, if this engine is installed on the Type 87 fighter, what is the maximum speed?"

The man in glasses seemed to have calculated this situation a long time ago, so he told him without thinking: "It should be more than 45 kilometers!"

Hearing this number, the old man frowned, "This is not enough. According to the military calculations, the other party's speed can be estimated to reach 500 kilometers per hour!"

"Sir, it will take at least half a year to design a ceiling speed that can exceed the other party's engine!" explained the man in glasses.

The old man lowered his head and thought for a while, "Well, do it! Don't worry about labor, materials and funds. In addition, I will report the situation to the military department tomorrow!"

The man with glasses lowered his head, "Please rest assured, sir, I will do my best!"

The old man nodded and patted the other person on the shoulder with his right hand, "I wish Zuo Teng Junma will succeed!"

After the old man left, the man in glasses transferred to his design room. Although the things they talked about were only on the drawings at this time, for the Japanese aviation troops who were facing huge challenges, this was their only hope to save face in a short period of time.

At this time, in this laboratory, in addition to the man with glasses, there were more than a dozen other researchers wearing white coats. Although it was already night, they were still busy.

"For the sake of the empire and for honor, I hope you will work harder!" said the man in glasses.

"Hi!" Everyone replied in unison with emotion that some of them were in their 40s, some were still in their early 20s, some had gone abroad to study, and some had graduated from universities in recent years. One of them was a young researcher named Jiro Otsuki. He was only 25 years old this year. He just graduated from the Aviation Industry Department of Imperial University of Tokyo a year ago, but he showed extraordinary talent in aircraft design. However, without further studies at the JUX and the American Codys, it is still unknown whether he could design a truly first-class fighter jet.

In addition, there is another seemingly unknown person in this research room. His name is Honda Tadayoshi, whose surname is Shi and his name is very ordinary, but his ancestors were the famous Tadaka Honda, a retainer of the Tokugawa family. The leading general. However, with the collapse of the Tokugawa shogunate, the descendants of the Honda family gradually fell into decline with the main family. It was still the "one-day coup" that 19 years ago that reminded people of this prominent family. However, the failure of that coup also became the masterpiece of the Tokugawa family in history. Most of the coup players in the mainland died. The remaining retainers either hid their names and ignored the world, or became Japanese spies specially trained by the German intelligence department.

Honda Tadao belongs to the latter.

Just one day later, the news that Japan had already been able to manufacture a new supercharged engine for fighter jets to fly at an altitude of 11,000 meters reached Berlin and to the German Emperor William III.

People understood that the time should not be delayed, so the extremely important imperial military conference was held in his palace. In addition to the Admiral Von Spe, Lieutenant General Karl Denitz, and Brigadier General Hermann Lange in the Far East, the most important generals of the German armies gathered again after the launch of Operation Barbarossa. They came here not to discuss anything, but to listen to the important imperial edicts of the German Emperor.

"After unremitting efforts of the government, intelligence departments and experts, the death of the former emperor William II was finally revealed. The French dominated all this behind the scenes, and the Japanese were the tools for the crime.

Now, France has received the punishment it deserves, but Japan is illegally invading one peace-loving country after another. Yesterday’s Australia, New Zealand, today’s China, who will be tomorrow? Guardians of the German Empire. It’s time to use a sword to punish the crime!”

Japan, the southern waters of Sagami Bay.

In early winter in December, the snow began to fall in Hokkaido, but in the warm Tokyo Bay and Sagami Bay, the temperature at night was still around 5 degrees. On the night of a sparse star, two submarines floated side by side on this microwave-sized sea. In addition to the sound of waves hitting the hull and the occasional voice, everything around could be said to be silent.

The wind was not strong, and the black vulture cross naval flag on the two submarines was whirling silently. Although the weather was a little cold, standing on the deck of the ship in a windbreaker was still a very pleasant thing for the crew on the submarine. Although the German submarine in service had made great technological progress compared to 20 years ago, and the tonnage increased from the initial few hundred tons to one or two thousand tons, the number of personnel on each submarine also increased accordingly. From the outside, a submarine may be quite large, but a considerable part of the space in the boat is used to accommodate it.

Diesel engines, electric motors, batteries, weapons, sonar, telegraph machines and other equipment are very limited in space for crew members to live and rest. The problem of turbid air during stealth has been greatly improved but has not been completely solved (garbage, feces, diesel engines, etc.), and staying in the water for a long time is still easy to feel depressed. Therefore, the sunshine and fresh air on the deck are always what crew members yearn for most during their voyage. Of course, what they desire are fresh food, meat, eggs, fruits, vegetables, opposite sex, etc.

"Be careful of that cage chicken..."

A second lieutenant shouted in a low voice, but unfortunately it was too late, and the cage was still hit on the deck, which made the chickens inside clamor and scream.

"Shh..." The lieutenant placed his index finger in front of his lips, and then whispered to the uneasy chickens, "Do you want to be discovered by the Japanese and then caught and eaten?"

At this time, a bearded crewman quipped, "Hey, lieutenant, do you have a roast chicken for extra meals tonight?"

In terms of size, their submarine with the hull number u-915 is basically the same size as the u-043 on the right. The two submarines are connected by several steel cables. The baskets of chickens and baskets of vegetables and fruits are transported from the u-043 supply submarine through this steel cable. In addition.

An oil hose, thick as a thigh, is feeding precious oil into the submarine that has been floating on the sea for more than three weeks.

"We will continue to be on standby here depending on the situation!"

"I'm afraid yes, there is no news yet about when to start the action. Maybe we have to wait like this until the 10-week maritime duty cycle ends!"

"Oh, I'm starting to miss land!"

When the second-level private Hendrick Meyer came out of the submarine, he happened to hear the chief and deputy captain talking aside. Like the two officers and most of his colleagues on the boat, he was a little tired of life without fighting or entertainment, and just lurking silently in the sea every day. Sometimes he even complained about the experts who designed snorkels for submarines, which was the equipment that allowed the submarine to draw air from the sea at the depth of the periscope. This made it possible for Germany to use the current submarine to dive air in the sea.

Boats can hover or sneak in the water all day long, instead of floating up and breathing as before. Since entering the coast of Japan, they have been hiding out every day and night, avoiding Japanese patrol ships and merchant ships during the day, and only carefully surfaced at night for reconnaissance activities. This kind of work and rest time is very similar to nocturnal animals such as bats and mice. What is even more depressing is that they can only move in the Sagami Bay waters, which is full of temptations. Tokyo Bay is currently a "forbidden area".

(The earliest practical snorkel submarine in history was built by Germany during World War II, but in fact the Dutch invented this device in the 1930s, and the German army only obtained the technology from the Dutch after occupying the Netherlands)

The poor lieutenant who had no time to stretch his body, the second lieutenant who was talking to the chicken just now discovered him. "Hey, Meyer, do me a favor. Take these cages of chickens into the storage room!"

"Oh God..." Meier looked at the cage covered with chicken feathers and chicken poop in surprise. He liked to eat chicken, but didn't like to be occupied by this thing to breathe his precious time. As a poor deck gunner and orderly soldier, he had just cleaned up the two toilets inside the submarine.

Although the toilet inside the submarine can also be used underwater, you must be very cautious and flush the toilet carefully, otherwise there will be a risk of sinking the submarine (there are cases in history), and the smell inside cannot be removed underwater. The "heavy task" of cleaning the toilet when the submarine floats on the submarine accidentally fell on Meier's head.

The superior's words were military orders. Although Meier was extremely reluctant, he took the chicken cage without any complaints, and then got back into the submarine cabin where the odor had not yet fully recovered. A few minutes later, when he finally completed the task and returned to the deck, the sea supply was over, but his leisure time had not come. The sonar soldiers found that there were ships sailing nearby, so the order to dive came soon, and Wall had to return to the bottom cabin in disappointment.

This is a VX-A mine-bracing submarine mainly focused on mines. Ding Jiao-toled torpedo tubes and a 40mm deck cannon can easily kill any Japanese cargo ship. It is enough to not lose the disadvantage when fighting against Japanese light patrol boats, but the premise must be that the commander issued a battle order.

Amid the giggles of chickens, the u-915 quickly dived to the depth of the periscope. Not long after, a Japanese cargo ship with a wide light slowly sailed past nearby. Sagami Bay is located in the south of Tokyo Bay and close to the outer sea. There are many merchant ships and warships passing here every day. The German captains found that these Japanese ships were very alert when sailing nearby. Merchant ships, cargo ships and warships did not control lights at all during night sailing, and eye-catching indicator lights were also on the navigation beacons and lighthouses.

Under the night, the lights clearly reflect the outline of the ship. This scene undoubtedly made the German captains who experienced the blockade of Britain and the United States feel itchy - this is really a good place to hunt on the sea!

About half an hour later, another two- or three hundred-ton offshore patrol boat passed by the nearby sea. The German captains were told that the Japanese Navy had developed several sonars with reasonable performance by combining self-development and imitation of German equipment. However, as far as we know, those sonars were only equipped with Japanese light cruisers and destroyers. Most of these ships with strong anti-submarine capabilities were deployed in the Japanese Sea and near the Tsushima Strait. Therefore, German submarines operating in Sagami Bay, especially in the high seas, were relatively easy to operate. Only breaking into the heavily guarded Tokyo Bay is the target that German captains were eager to challenge. However, unlike reconnaissance aircraft frequently entering Japanese airspace, if submarines were discovered in Tokyo Bay, the consequences would be serious. Therefore, the German Command required submarines operating along the coast of Japan not to leave the scheduled activity area privately before receiving the order.

The submarine was once again quietly suspended in the water, leaving only the periscope, snorkel and radio receiving antenna on the water surface. Private Meier had no choice but to clean up the garbage such as chicken feathers and vegetables between the cabin and the aisle. He always felt that his courage and ability should not be buried here. If he could choose, he would rather use the deck cannon to fight with the enemy in the rain of bullets. In fact, except for routine artillery training and exercises, he had no experience of using deck cannons in combat. As his age at the age of 20, he failed to catch up with the war against the United States in 1924 or Britain and Canada in 1925. After joining the German Navy submarine force for two years, he finally looked forward to another opportunity for war.

"Captain! Telegram! It's Telegram!"

The communications soldier suddenly jumped from his position with great excitement because the submarine engine was turned off. At this time, his voice could be heard in every corner of the submarine. Mayer was no exception. He turned his eyes to the command room as curiously as everyone else.

"Sergeant, you should maintain absolute calmness when operating in the enemy's sphere of influence!" The captain taught a serious lesson.

The poor communication soldier also realized his mistake, but his emotions had been suppressed for too long. Although the volume was lowered, the excitement was still beyond words, "Black blue sky, black blue sky!"

The captain burst into tears and exclaimed: "Oh, God, I finally waited!"

At 6 pm Berlin time on December 18, 1928, or 2 AM Tokyo time on December 19, a clear telegram was sent from Berlin. The "black blue sky" was transmitted to German bases and ships located in every corner of the world in a very short time. In order to ensure that every submarine could receive this signal, Germany's military bases in Qingdao and Haicunwei also deliberately issued long-wave radio signals for the next three hours.
Chapter completed!