Due to the tight schedule, the construction of the tunnel began the next day.

In fact, even Qin Chuan himself stays at the theoretical level of many things, and if he wants to really understand it, he still has to explore it in practice or even actual combat...... After all, these are all exchanged for the blood and lives of volunteer soldiers on the battlefield, not that they will be able to use them or use them correctly if they know it.

But it should be said that because Qin Chuan knows the relevant knowledge, he can always find practical and simple ways to solve problems faster and better.

For example, the problem of drinking water storage...... Drinking water is a must, even more important than food, if you want to stay in the pit long enough and survive.

However, drinking water is very inconvenient to store in the tunnel, that is, it takes up space and makes the already narrow tunnel very crowded, and it is easy to be knocked over and lost due to the darkness.

The solution to this problem is actually very simple, dig a few pits in the tunnel, and then transport a few gasoline drums into it and bury them...... An excellent water tank is ready, and when the lid is closed, it does not even affect the movement of soldiers on it.

Another example is the issue of communication...... There was no signal in the tunnel, the radio could not be used, and it was not practical to pull the telephone line, because the telephone line could easily be found and cut by the enemy, and once it was cut, the soldiers in the tunnel could not come out to repair it...... Doing so is tantamount to throwing yourself into a trap.

The solution to this problem is to drive several steel bars into the tunnel from the outside as antennas...... Only a small section of the exterior needs to be removed, and it can be covered with stones and plants, and when a battle breaks out, there will be bullets, shells, and damaged cement and concrete fortifications, and who will pay attention to this small section of steel bar.

It really didn't work, Qin Chuan also told them an emergency method, such as a bad signal or because something else couldn't communicate, so he tied a wire to the grenade and threw it. Of course, this grenade does not pull it ablaze...... At first glance, you would think it's a stink bomb, and no one would be interested in picking it up and looking at it.

Colonel Slein and Major General Neumann were stunned when they heard these thoughts.

"If it weren't for your resume, I would have thought you'd fought a similar battle somewhere!" Colonel Slane said.

"Or, do you have a loved one who fought in the last war?" Major General Neumann asked.

Some German soldiers considered the First World War a disgrace, so they vaguely called it "the last war".

"Oh yes!" Qin Chuan replied: "My uncle lost a leg in the last war, and he always talked to us about his past, especially some things in the trenches, and some of my methods came from him!" ”

The First World War was fought in trench warfare, and in some ways trench warfare was somewhat similar to tunnel warfare, in that they also dug tunnels and hid underground...... So Qin Chuan is not wrong to say so.

However, they are only "somewhat similar", trench warfare is far less difficult than tunnel warfare, the reason is that the fortifications of trench warfare are mainly used to dodge artillery, and the enemy can come out of the underground bunker and live and move in the trench without firing the artillery.

In tunnel warfare, however, the enemy occupies the ground fortifications, and the soldiers can only hide underground and hold on, which is not at all a level in terms of physical and psychological pressure.

"No wonder!" Major General Neumann said to Qin Chuan with a complicated expression: "If you have the opportunity to go back, pay tribute to your uncle on my behalf, I also participated in that war, maybe we are still comrades-in-arms!" ”

"Okay, General!" Qin Chuan hurriedly replied: "But it is unlikely that you are comrades-in-arms, because he is a sapper!" ”

This is a lie by Major General Neumann of Qin Chuanshiki, who knew that Major General Neumann was an infantry major during World War I, so as to avoid showing his feet when asked about his number.

"Oh, it's a shame that I can't be your uncle's comrade-in-arms!" Major General Neumann patted Qin Chuan on the shoulder and said, "But I'm glad to be your comrade-in-arms, one day...... I wish I had a chance to meet your uncle and catch up! ”

Hearing this, Qin Chuan couldn't help but secretly complain, but he still responded: "Of course, General, this is my honor!" ”

Major General Neumann was a standard professional soldier, as can be seen from his seriousness and madness in the war effort...... For Europeans, it can be said that they can accept Qinchuan's suggestion of tunnel warfare, such as Major General Neumann, Rommel and Colonel Slein, who until now did not approve of this practice, because he believed that the result of this was to drive his own soldiers crazy before defeating the enemy.

"How could they possibly stand that darkness and helplessness!" Colonel Slein said, "Have you ever tried to stay in there?" I stayed for one night, but I couldn't stand it for just one night, and I knew I could go out at any time and there was no danger, if there were enemies standing outside, and they were throwing grenades or flamethrowers into it, or there was no food, no medicine, and the wounded were not treated...... God, this will turn into hell! ”

"Colonel!" Major General Neumann replied simply: "That's why we are better than them!" ”

Sometimes, pride or narcissism can be enough, but it's still necessary on the battlefield...... Because they think that Germans are better than other peoples, Germans who can't do it can do it.

On the other hand, if we don't have this sense of pride or national self-confidence, we will think in a different way: if the British and Americans can't do it, how can we do it?

Major General Neumann obviously belongs to the former, which also makes him very keen on Qin Chuan's defensive tactics, and it is not an exaggeration to say that he is obsessed, because he feels that this is a test of the spiritual will of the imperial soldiers, and it is also a time to prove that the Germanic nation is the best nation in the world, and of course he will not let go of this opportunity.

"The construction of the tunnel must be as simple as possible!" Qin Chuan continued: "On the one hand, because of the short time, and on the other hand, because we need to build a large area, we should use local materials as much as possible, that is, use wood to support the ...... in vulnerable parts."

"But if it can't withstand the enemy's bombardment, it will bury our soldiers alive!" Colonel Slane objected.

"There will be casualties on the battlefield at any time!" Major General Neumann agreed with Qin Chuan's words: "I agree with the lieutenant's statement, if we don't hide in the tunnel, our soldiers will be directly blown to pieces by the enemy's shells!" It is true that some people will be buried alive by hiding in the tunnels, but at least some will survive! ”

Qin Chuan didn't know who said it more reasonable, he only knew...... Colonel Slain was a little more emotional.