In the past, submarines did not stay underwater all year round. They spent most of their time sailing on water. They would only conduct diving attacks after they discovered the target.

Therefore, submarines are not adapted to the structure of elongated water droplets underwater. Most of them have the same structure as surface ships, suitable for navigation on the water.

They were also naturally equipped with powerful deck cannons.

After all, torpedoes are too precious, and many captains do not want to waste them, so they leave precious torpedoes for use at critical moments.

In the early days of the Atlantic battlefield, German submarines would warn the ship and wait for the crew to leave the ship before floating and attacking with deck cannons. If the opponent is armed, the submarine would injure it with torpedoes and then use artillery to clean up the mess.

During this period, their deck cannons were all large calibers, mostly 88mm and 105mm.

The German Navy has achieved many achievements using deck cannons. In addition to sinking millions of tons of merchant ships, it has also had other military achievements.

For example, the "u-242" even shot down a Soviet aircraft with an 88mm deck cannon, and the "u-134" also shot down the U.S. Coast Guard airship with an 88mm deck cannon.

The "u-130" destroyed the refinery and warehouse in Crussel with 105mm deck cannons in the Caribbean. The "u-711" destroyed the Soviet Pravochi radar station and the "Prague Pointsga" radar station with 88mm deck cannons.

However, with the continuous increase in the anti-submarine forces of the Allied Forces, the German submarine forces often faced threats. For them, as long as they were discovered, they meant being destroyed. Therefore, in the later stage, the German submarine forces almost lost the opportunity to operate deck guns, and accordingly, they canceled the deck guns and were no longer used.

Now, Germany has not faced such a threat. If you mount a deck cannon on a submarine according to the perspective of later generations, it would be quite funny and exaggerated, but when you think about it, it is an inevitable choice for the German Navy.

You should know that only nuclear submarines can attack Arctic routes. When there is only one nuclear submarine, it is impossible for it to cross the Arctic repeatedly and return to its own port for replenishment. One precious torpedo can consume one.

Then, using torpedo to attack key targets and using deck cannons to attack secondary targets is a good choice.

On the other hand, the task of the deck cannon has changed, and it is mainly used for air defense.

Letting submarines fight against aircraft is definitely a dead end. The advantage of submarines is concealment. However, in case of accidents, such as a problem with the reactor of nuclear submarines, or an oxygen-generating system failure, which leads to surface, there must be air defense measures, right?

Therefore, its deck cannon is not a large 88mm or 105mm deck cannon. It is not easy for such a large artillery to hide under the submarine's sound silence.

It is equipped with a rapid-fired 20mm Bofos gun, which can both face air and sea. Among German military equipment, it belongs to the role of panacea. For example, in addition to its own anti-aircraft gun, it has also been widely improved into tank guns, aviation guns, etc.

Now, on the submarine, it is also cleverly hidden in front of the command tower.

Another reason for this is that submarines in this era are almost all double-hulled.

The inside is a pressure-resistant shell, which is used to withstand the huge pressure of sea water. The inside of the pressure-resistant shell is the working environment of the personnel. If it is a single shell structure, the pressure-resistant shell is also an outer shell.

The structure of the double-shell is different. There is also a non-pressure-resistant shell outside the pressure-resistant shell, with a distance of more than one meter in the middle, which is filled with sea water. At the same time, various external equipment can also be deployed inside. The advantage of this is that it greatly increases the submarine's strike resistance.

For example, in later typhoons, there was more than two meters of sea water between the two shells. When the other torpedo came over and exploded outside, it could only damage the non-pressure-resistant shell outside, which was almost ineffective against the pressure-resistant shell inside.

At the same time, this is also convenient for activities in areas like the Arctic. If you encounter floating ice or something, you can stand it. At critical moments, you can even break the ice directly on the Arctic Ocean.

With Otto's order, the three sailors led by the second-level submarine official stepped on the wet deck and came to the front of the deck cannon.

The two men quickly flipped up the deck cannon, and the other two were responsible for dismantling the watertight shell box on the other side to complete the loading task. Otto looked at them from above and shouted loudly: "Disconnect the protective cover!"

During World War II, some German submarine soldiers would have serious accidents when using deck cannons, which was a blow-up, which was completely negligent.

The deck cannon must sail underwater with the submarine. Even if it is sealed, it will enter water. The seawater is corrosive. Therefore, the muzzle of the deck cannon is usually covered with a protective cover to act as a seal and open it when used, but when sailors operate it, they will always forget it!

Otto's reminder, the second-level official discovered the serious mistake he had made, so he quickly stepped forward and took off the cover from the muzzle, and then all preparations were made.

Open fire!

"Bangbang!" The 20mm deck cannon is absolutely not powerful enough. It is like using a pistol to deal with a tank with a cargo ship of tens of thousands of tons.

If it is a warship, it may be fired many cannons before sinking it, but now all the cargo ships are in front of it.

"Boom!" The armor-piercing incendiary bomb drilled into the abdomen of the cargo ship, and immediately exploded a large hole. The hull of the cargo ship could not withstand such an impact at all. It immediately broke a hole and the sea water poured in.

Okay, let's go next one!

Almost every cargo ship was only hit by three shells, and the cargo ship was opened with a big hole and slowly sank.

"Two cars, go back at full speed!" Suddenly, Otto shouted loudly.

The two propellers at the tail immediately rotated at high speed, dragging the 6,000-ton hull backwards. Just as they had just left for hundreds of meters, the cargo ship in front that had just been beaten exploded violently.

"Boom!" The weapons carried inside exploded violently. On the sea, with it as the center, within a radius of hundreds of meters, there were terrible fires!

If the submarine had not retreated just now, it would probably be damaged by the explosion and falling fragments at this time, and everyone breathed a sigh of relief.

Captain Otto's reaction was really too fast.

"Look, what is that?" a lookout hand shouted.

During the explosion, the cargo ship was torn apart. The cargo it transported was scattered on the sea surface. A large cylindrical thing floated in the distance. It looked very much like the equipment of an oil refinery?
Chapter completed!