The first day of arriving at the mausoleum area was destined to be a sleepless night. Due to the tight time, the enemy might arrive at any time, so it was urgent to build a solid fortification. After determining their respective tasks, the entire army immediately devoted themselves to the construction of fortifications without any rest. With the concerted efforts of more than 30,000 people, a line of defense was built between Baihu Mountain and Ziyun Ridge overnight.

The defense line starts from the waist of Ziyunling in the south, extends northward along the mountain, then turns north to Baihu Mountain to close the entire mountain pass, and then turns west to connect to the Baihu Mountain position. The entire defense line is concave and is as long as eight miles long, but when you look closely at this fortification, it is not as tall as you imagined, nor is it made of bricks and stones, but is just made of local materials.

The straight city walls that are also very common are similar to a saw. There is a protruding part on each section of the city wall, like a horse's face, but not a four-sided platform, but a triangular bulge. There is another same city wall about twenty steps away from it, but it is slightly higher than the city wall in front, and the toothed protrusion is in the opposite direction.

Needless to ask, in everyone's eyes, such a strange city must have come from the little emperor's "strange ideas". This is true. Zhao Bing's inspiration came from the defensive facilities of the Western world hundreds of years later - the lever. However, the real lever is not what he created, but a star-shaped fully closed fortress. His current defense system is more like an expanded version of the lever, and he forced it to straighten it.

The earliest Western fortress walls were also very tall like the cities in Chinese history, and were reinforced with stone or bricks. Some towers or horse faces were also set up to obtain additional firepower output. If anything, some particularly solid cities had more than one city wall. However, with the emergence of gunpowder and the development of hot weapons, such fortresses are no longer suitable for wars. It can be said that artillery gave birth to bastions.

Many bastions are actually civil fortifications. With ordinary brick and stone walls, the front defense is not much stronger than ordinary city walls. In order to prevent damage from enemy artillery fire and to place large and medium-sized cannons on their sides, low and thick platform walls are necessary. Therefore, the slope of the outer wall of the bastion is only about one meter high. If the depth of the trench is reduced, the part above the surface is only six or seven feet high.

Compared with tall city walls, castles are more likely to be crossed. Without obstacles, ordinary people can even climb and cross with bare hands without the help of tools; while tall and steep castle walls, for most people, climbing is risking their lives or powerless to do anything about them.

However, at the beginning of the design, the star-shaped bastion did not specifically require the fortifications themselves to be able to properly hinder the siege's climbing, but could fully utilize the power of artillery as the target. It used firepower to prevent the siege from approaching, rather than relying on the wall itself. In essence, it was to turn the city block from a convex polygon into a concave polygon, and the star-shaped corners protruded outside the defense line, thereby increasing the shooting angle and length. In addition, from a towering city wall to a low trench, although the buildings that were higher than the ground after the city wall were exposed, it protected the safety of combatants above the city wall, thereby improving the overall defense ability.

There is another central dike between two prisms, that is, the connected city walls are shorter than in the past, so as to ensure that the rifle range can fully cover this area. The construction of a concave fort in front of the central dike is to prevent siege guns from directly firing the central dike, and at the same time, some musketeers can be arranged to strengthen the defense of the trenches. The purpose of building a Triangle Fort is similar. It is only slightly lower than the main fortress, but it can facilitate the artillery on the main fortress for exceeding the fire. At the same time, the artillery on the Triangle Fort also forms part of the crossfire.

In addition, the pathways hidden between the two platform walls and the garrison can be used as covers for counterattacks in the infantry. In order to prevent the enemy's longitudinal shooting, there are also many horizontal walls between the pathways, which can be bent as needed. The outermost inclined dike is the place where the crossfire is the most dense, and its inclination angle helps the defensive party to exert fire. In addition, the bastion should avoid using brick and stone buildings, and even if it has to be used, the outside should be covered with thick soil. Because the soil layer can absorb energy, the brick and stone are not only easy to damage but also easily cause jumps, which will cause serious casualties.

Such improvements make the bastion free of firepower dead ends, so that no matter where the attacking castle is attacked, the attacking party will expose the attacking party to more than one bastion surface. The defense party can use cross firepower to carry out multiple strikes, which means that any wall being attacked can have multiple firepower to defend. The designed multi-layer defense system has made the bastion form a layer of trench defense net, which can cover the enemy's firepower, turning the city defense into trench warfare. Therefore, it can exert great blocking ability.

The reason why Zhao Bing chose the bastion to build a defense system was not only because it could fully exert the power of the firearms, but also because of the unscrupulous reason. It is important to know that the Yuan army suffered enough to attack the city when they headed south. Therefore, after pacifying Jiangnan, Kublai Khan ordered the demolition of the city walls in Jiangnan. However, during the battle, the Song army, which was mainly infantry, needed to station in a certain place for a long time, or needed to stick to key points, it was impossible to do everything. They lined up every day to wait for the enemy to attack, so they would be exhausted without waiting for the battle to die, so they needed to build defensive fortifications.

You should know that even a small castle cannot be completed in a short time, especially a city that can garrison troops. The project volume is not only too large, but also not much meaning. Therefore, the defense power of the front wall of the same thickness may not be higher than that of those with tall walls, but this defense system is convenient for local materials and rapid formation. The city wall can cover the opponent with multiple layers of firepower networks, and it is enough to defeat several times or even dozens of times of enemies with a very small number of people.

Of course, there is no perfect matter in the world, and the prisms also have flaws. Fortresses with complex geometric star-shaped fortresses are designed in the offensive and defensive battle. Through design and planning, firepower covers each other, and can usually respond to the enemy's attacks well. However, the so-called cross-fire without dead ends is also built on the fortress shape design itself. Compared with city walls or city towers, the ability to deal with artillery bombardment has been improved, but it does not mean that it is damaged after being attacked.

By concentrating attacks on one direction, or making up the determination to destroy or blast one of the corners after protracted artillery and earthwork, the entire cross-fire design will have dead corners. After the loss of firepower, the low platform wall and inclined embankment allow the enemy to easily cross. The wide platform wall gives the defending gun a good launching platform, which means that after the siege is on the table, it can expand more troops compared to the narrow city wall at the same time.

Usually, the city guards who are at a disadvantage in quantity, combat power or firepower need to rely on fortifications to balance the gap between the enemy and us, the more troops the enemy can deploy on the attack surface at the same time, the more obvious the disadvantages of the defending side will be. Therefore, if the star fortress loses the shape of a corner, the only choice of surrender or being surrendered.

It is precisely because there is nothing absolute in the world that Zhao Bing cannot guarantee that this defense system will not be broken, but he is 90% sure to ensure it is not lost. His information comes from the success of the star fortress, which is based on the success of gunpowder weapons. The attacking party usually has to pay major casualties to achieve the premise of both offensive and defensive use of gunpowder weapons, or relatively mature front-mounted black gunpowder smoothbore muskets and cannons.

But now it is precisely because our side has entered the age of hot weapons. The Yuan army has just seen the path and is mainly cold weapons and equipment. However, in the age of cold weapons, crossbows cannot do things that can only be done by artillery. Therefore, if you want to achieve the status and achievements of the firearm era in the age of cold weapons, the Yuan army is as powerful as a crossbow, which is simply impossible...

Although the leverage has become one of the subjects for building a city as early as the New Army Training Camp, it has been gradually promoted to the entire army and has become a must-training subject. It has been practiced many times during the exercises, but it is the first time that it has really been put into actual combat and has made significant adjustments. Therefore, even though the defense line in front of him has been formed, Zhao Bing still dared not be careless. He inspected the entire defense line again, found the weak points, and urged them to improve it as soon as possible.

"The Sun governor is now rainy, and there are many rivers in the south of the Yangtze River, the groundwater level is very shallow, and the terrain in the valley is high in the west and low in the east. Your garrison hole is so low that you will have to take a bath once it rains!" Zhao Bing went down into the traffic trench and drilled into a garrison hole to check the Sun Jin Road, the commander of the Third Brigade.

"Yes, Your Majesty! I will immediately rectify and deepen the drainage canal!" Sun Jin replied attentively.

"In addition, the soil here is not very good. The support should be strengthened. The traffic trench must be strengthened. The traffic trench must be stabilized with fences as soon as possible to prevent collapse. If the hole collapses, the traffic trench may have gaps when it collapses!" Zhao Bing said after he stepped out of the hole.

"Yes, my subordinates will send troops to protect immediately!" Sun Jin hesitated and replied.

"Why are there any difficulties?" Zhao Bing looked at him with a puzzled look and asked again.

"Your Majesty... there are no difficulties, I will do it as soon as possible!" Sun Jin replied attentively.

"The war is imminent. It is not a time to speak loudly with a slight belly. If you have any difficulties, don't be a mother-in-law!" Zhao Bing said with a frown.

"Your Majesty, then I'm disrespectful!" Sun Jin said with a respectful respect, "Your Majesty, this is a mausoleum area, and woodcutting is strictly prohibited. We can only search outside the valley. This trip not only delays time, but also requires a lot of manpower to transport it, so the speed is naturally much slower!"

"Well, that's true!" Zhao Bing nodded along the ladder and climbed the wall. He knew that this was an unavoidable real difficulty. Building fortifications would inevitably require a large amount of wood as support, and other protective measures such as manufacturing war sheds. However, it was impossible to occupy the already precious space on the ship to transport it, so he could only use the local materials. Although there were trees all over the mountains, they could not be harvested, which was really disheartening.

"Commander Zhang, do you see that the vision here is not very good?" Zhao Bing stood on the cannon position on the platform wall and looked forward with a telescope at Zhang Pingdao, the commander of the Guard's direct artillery regiment.

"Your Majesty, yes. The trees ahead not only block the observer's view, but also the dense trees hinder the artillery's firing boundary, making it difficult to exert their power!" Zhang Ping nodded.

"This is not possible. Without the support of artillery, it is difficult to support the entire defense line with muskets alone. Mongolian soldiers will jump onto the platform wall without riding horses. You can immediately send someone to cut off the trees that affect the observation and clear out the shooting circle!" Zhao Bing pondered for a moment and said to Zhang Ping.

"Yes, my subordinates will immediately execute!" Zhang Ping saluted.

"You are still watching the fun here!" Zhao Bing turned his face and looked at Sun Jin with a sad face, "I'm so angry with you fools. You see them chopping down trees as firewood, why don't you send someone to drag them back!"

"I am so stupid, your Majesty is considerate..." Sun Jin also understood at this time and immediately understood the meaning of the little emperor. What he said was a killing two birds with one stone.

"I didn't say that you would cut down trees casually, but just ordered you to clear the shooting world!" Zhao Bing immediately interrupted him and waved his hands repeatedly.

"Your Majesty, this is not good? Those old men not only want to nag and advise, but also cut down the tomb-protecting trees. The late emperors will not blame them!" Chen Dun reminded at this time.

"Tsk, living people are important, dead people are important? In other words, they have already given them face. I can still understand this. Besides, I am wiping my butts for my ancestors, otherwise the old nest would have to be dug by those thieves. They would have too late to bless me, so why bother to blame me?" Zhao Bing said disdainfully in the direction of the cemetery.

"Hehe, what would happen if Your Majesty's words reached Mr. Deng's ears?" Chen Dun nodded after hearing this and said with a smile. Yesterday, it was His Majesty who asked someone to hang up the thief who was caught, but the old men scolded him, saying that his behavior was inappropriate and righteous, especially that he should not treat the dying people like this. However, His Majesty had to take the blame without saying a word, and he still felt indignant.

"Haha, do you think Mr. Deng believes in you or me? Don't forget that someone's reputation has never been very good when he was in the General Manager's Mansion!" Zhao Bing smiled, and walked forward with a few words in Chen Dun's ear.

"I...my..." Chen Dun was choked and tried to think of how to refute it for a long time, and couldn't help but feel angry.

"Your Majesty has a good idea. Don't tease the situation randomly, otherwise don't blame us brothers for turning against each other!" When Chen Dun was in a fit of anger, Sun Jin and Zhang Ping suddenly held his arm on the left and right, and said seriously.

"I still want to turn against you!" Chen Dun struggled for a few times but didn't break away. He gritted his teeth and stared, "I think if I hadn't led you into the General Manager's Mansion back then, would you have the same face as if you were now?"

"It's true that you led us to the General's Mansion back then, but later I realized that it was deceived and coerced by you. Where is the General's Mansion? If it weren't for your kindness, we would have been beaten to death on the spot!" Sun Jin poked Chen Dun's ribs with his fingers.
Chapter completed!