In the history of warfare in Europe, the defenders first relied on wooden fences or stone fortresses for defense, but the advent of trebuchets and primitive artillery made these two fortifications ornamental. Then the fortress came into being. All of a sudden, the shield outgrew the spear, leaving Europe with fortresses and small states.

How to solve the bastion when the artillery technology is not yet fully mature, European military scientists have persevered in exploring this. In the seventies of the seventieth century, Sébastien le Prestre de Vauban, a French marshal, a military engineer, and the founder of modern sappers, proposed a system of trench siege. It effectively solves the major problem of how to take down the fortress with complete defense force when the power of the attack artillery is limited.

To put it bluntly, this system is: digging trenches, and digging trenches out of the system, digging out art.

The specific excavation method is as follows: first dig a circle around the target to be attacked, and pile the excavated soil towards the side of the target - form a low wall to protect the sappers of the side. Then, on the basis of this circle of trenches, dig zigzag trenches, and after digging to a certain extent, dig a circle of trenches closer to the enemy's wall. Then start attacking the opponent's wall or the cannon on the wall (trebuchet) with your own cannon or trebuchet. If that doesn't work, repeat the steps above until you get closer to the opponent's wall.

In this process, due to the protection of the trenches, the enemy troops on the head of the city were basically unable to effectively inflict effective damage on the local sappers digging the trenches. In the same way, because of the protection of the trenches, the siege vehicles, trebuchets, artillery, etc., are basically safe to move in the trenches and gradually approach the local walls.

Moreover, as the trenches approach the enemy's walls, all of the enemy's defenses on the walls will be weakened more and more by the angle. No matter how strong your walls are, I have dug up to the root of your wall, what possibility do you have to struggle?

On the historical plane, in the middle of the 20th century, Taizu and Kaishen of this dynasty competed for the Central Plains. The Celestial Empire army faced many reinforced concrete systems of the Guo Party, and many times used super civil engineering to break down the enemy's defenses. This is actually a variant of the Vauban trench system. Therefore, the genes of the infrastructure madness of this dynasty have been revealed as early as when the foundation of the country was built.

"That's pretty much the way this trench system is, you see it all?"

"Rest assured, the student has fully understood."

At this time, Guan Yi's protégé Li Xiang and Li Zhanfei have been promoted to the position of Zhonglang General. Although the prefix of this Zhonglang general is an unprecedented "sapper", Li Xiang, who has fully matured at this time, no longer has the idea of desperately wanting to return to the Warrior series before. Because, he has become deeply obsessed with civil engineering.

"Well, for this system to be completed quickly, manpower is the foundation. You and your subordinates first surveyed the soil outside Luoyang City and calculated the amount of work. In the middle and late of this month, it should be enough to give you 90,000 prisoners for the teacher, right? ”

"Hehe, thank you. I've grown so big, and I haven't managed so many people. It's just that the mountain chief can really endure it, such a good method, and he has endured it until now. After a sentence, Li Xiang quickly said: "Rest assured, as long as there is enough food, the students dare to guarantee that these captives can do things very well." ”

"Humph! As a teacher, it is for a strong city like Luoyang that I have endured until now! After saying this, Guan Yi hugged Li Xiang and said in a low voice: "For the reliable news sent by the secret son of the division in the Eastern Wu court, Sun Hao, that idiot, is ready to launch an army of more than 100,000 from Nanyang County north to relieve the siege of Luoyang in August and September this year, after their autumn harvest. Well, although Wu Gou's combat effectiveness has never been taken into account by the teacher, but in the end it is 100,000 people, and it is very tiring to cut off their heads one by one......"

"The student understood. The students immediately lead people and start doing things. ”

My boss and teacher have already set a time for me to complete the project, so what else can I say? Get busy.

……

Beginning on March 20 of this year, more than 90,000 captives of the Jin State under the control of the Han army came to Luoyang one after another.

On April 1, Li Xiang, who completed the geological exploration and drawing design, with the help of many lieutenants and military marquis under his command. More than 90,000 prisoners of war were assigned to the section. Then the engineer Zhonglang gave an order, and more than 90,000 prisoners of war were launched in unison. Trenches began to be excavated at a distance of 500 meters from the outer walls of Luoyang.

In front of these prisoners of war, nearly 100,000 Han troops lined up to protect and monitor the working personnel.

Five hundred meters has exceeded the maximum range of trebuchets and bows and arrows at the head of Luoyang City. Therefore, in the face of this move of the Han army, the soldiers and civilians in Luoyang City could only watch in addition to watching, of course.

"What is Han Guo going to do?"

"Do you want to dig a tunnel?"

"But how could the excavation of the tunnel be so obvious, no, the vastness ......"

Don't say that Du Yu, Ma Long and others don't know anything, they have caused a lot of trouble to the traversers. It's a pity that this is a gap in the times, not a matter of individual ability.

Besides, now they have actually been deprived of their military power a long time ago, and they have become idlers who don't care.

Yes, in the end, it was the enemy soldiers who were coming to the city, so at this time, Sima Yan once again lifted the military power of all generals with different surnames. Instead, all of them were led by the people of the Sima family.

At present, the composition of the defense leadership in Luoyang City is as follows:

Commander-in-Chief of the City Defense: Emperor Sima Yan, personally led 20,000 princely guards.

Executive Commander-in-Chief: Generalissimo of the World's Soldiers and Horses, Director of Military Justice, Sima You, King of Qi (responsible for being a villain, such as punishing a prince who has failed to defend or something)

Deputy Commander-in-Chief: General of the Auxiliary State, Sima Jun, King of Ruyin, General of the Protector of the Country, Sima Gui, King of Taiyuan (each commander has 10,000 soldiers and horses as reserves)

The person in charge of the city gate: the nine Sima ...... led by Sima Lun, the king of Zhao Each led more than 14,000 soldiers and 5,000 or 6,000 people to form nine teams of 20,000 people, responsible for defending the nine gates of Luoyang.

In addition to these thirteen Simas, only two have real power:

First, the general Jia Chong. Mr. Jia Gonglu's duty was to mobilize all the people in the city to closely monitor all the officials and people in the city, and prevent these people from colluding with the outside enemy. Among them, the key monitoring object: Shangshu Ling Pei Xiu.

Second, Shang Shufu shot Yang Jue: responsible for the management and distribution of logistics materials.

This is normal and reasonable. It's just that it completely broke the hearts of a group of generals with foreign surnames. If this battle is lost, these guys will willingly surrender to Ji Han. If you win, well, if you win, you win. In the future, let the people of your Sima family do it.

Besides, in the hearts of Du Wei, Ma Long and others, they were in awe of Jiang Wei: because in the world, no one had ever won against Jiang Wei when the army was equal. But they have a way to make Jiang Wei return in vain.

As for Guan Yi, it is complete despair. Because this guy doesn't look at the war, he is stupid and has no aesthetic sense at all. However, counting the battles he commanded, it became more and more inclined to defeat Wei Jin in the way that Wei Jin did best: logistical crushing.

Du Pre, who was standing at the head of the city, looked at the prisoners of war digging trenches under the city for a long time, and made a color to Yanghu, who lowered his head and lowered his ears, only to hear Du Pre say in a low voice: "How do I think that the descendants of Emperor Xuan will eventually die in Emperor Xuan's art of war." ”