Two days after Xiahou Yuan failed to siege the city, Cao Cao finally arrived in Kunyang.

Before Cao Cao arrived, the bad news that Xiahou Dun's troops that had blocked the enemy along the way had certainly reached Cao Cao's ears.

So when Xiahou Yuan went out to welcome Cao Cao and Guo Jia, he saw that Cao Cao's expression was terrifying.

However, Cao Cao's words were still very generous:

"Miaocai, victory or defeat is common in military affairs. Yuan Rang's defeat, Gu had already investigated, and he could have resisted the temptation at the beginning. Zhuge Liang changed his methods several times and repeatedly lured the enemy, and Gu might not be able to resist it even if he asked himself.

Yuan Rang was shot and his eyes were broken, and he fought to retreat to death, which was also a price to pay. The most important thing now is to look forward and fight the battles ahead well, and discuss the rest in the future.”

When Xiahou Yuan heard this, his nose was a little sore. The lord had taken care of his brother and wanted to "start camp in the way, not be reckless". In the end, he sent half of his troops recklessly, but he was not punished for the time being.

However, by heart, Xiahou Dun's mistake in this battle was indeed smaller than that in history Ma Su's history in Jieting.

After all, Ma Su not only lost his troops, but also lost Jieting. The failure of the strategic goal is the key. Now Xiahou Dun only lost his troops, but the blockage is still blocking. Li Dian completed his succession better, and did not let Gao Shun's reinforcements rush out.

Therefore, it is indeed not suitable for heavy punishment during wartime.

Xiahou Yuan expressed his enthusiasm and encouragement: "Lord, take it for another day or two, and when the equipment is complete, attack with all your strength. The general has already tested it the end of the day before yesterday, and the enemy's garrison is very strange.

Their crossbows were extremely harmful, and they were like crossbowmen in the city who became sharpshooters, and the last general was puzzled. Therefore, they should first smash the city wall and make plans when they could rush forward."

Cao Cao nodded and approved: "If you are capable and you do not control it, you will be victorious. I am the first time I arrived today. The defense of Kunyang City has just seen it, but I really don't understand it. 'Let's see your wonderful talents'."

Cao Cao generously chose to delegate power at the tactical level.

...

Xiahou Yuan was inspired. Two days later, the leveraged catapult finally took shape. There were about dozens of them. Xiahou Yuan ordered to concentrate firepower to bombard the north wall.

In theory, Xiahou Yuan has many people, so he should attack and disperse the defensive forces from three sides. But now the first batch of catapults have been built, and there is not enough division, so he has to concentrate firepower, so he is deployed in this way.

After the start of the fight, Cao Cao also came to watch the battle in person, stood outside the range of the catapult to watch from afar, frowned and pointed: "Although the catapult is not enough to attack from three sides for the time being, at least he also divided his hands to understand the enemy's situation.

A hundred thousand troops were stationed in the city. Can we use so many people to repair stone casting cars? Can other soldiers who cannot do some skilled work put some effort into ramming the earth and building wooden buildings and looking out?”

When Cao Cao blamed him like this, Guo Jia next to him was also observing the enemy situation, and seemed to see some strange clues, so he did not dare to agree. He vaguely felt that Xiahou Yuan might have other difficulties.

Sure enough, Xiahou Yuan complained: "Lord, when I first came, I tried to make a pile of earthen platform and build a tall building. But after I built a small half of it, I barely raised it above the city wall, I realized that it was not useful at all."

Cao Cao said, "What happened?"

Xiahou Yuan pointed to the corner tower at the four corners of the city wall and said, "Originally, Xiuwang Tower was to see how many reserve troops the enemy had on the back of the city wall, and the virtual and real walls of the city walls were everywhere.

However, after Liu Bei's men built the strange corner towers at the four corners of the city wall, the corner tower was more than twice as high as the city wall, and it seemed to be a hollow building surrounded by dozens of feet in size.

In this way, we have to look at the tower, which has to be three times higher than usual, reaching seven or eight times higher than the city wall, so that we can see clearly in the city. Even so, there are still big blind spots where the corner tower covers, so that we can hide our troops from seeing it.

Moreover, since the corner tower is hollow, it should be able to hide soldiers. The hidden soldiers and invisible dead corners in the building can conceal the existence of at least two or three thousand people in each place. The exploration of the enemy's virtuality and reality in the building will lose its meaning. Therefore, the last general will only cultivate a small amount of time and no longer waste people."

The viewing building is originally viewed from the side back angle of the adjacent city wall, so the tall corner building can greatly restrain the viewing effect of the viewing building.

In this world, if you learn trigonometric functions better than Zhuge Liang, then it is probably only Li Su. Zhuge Liang himself set up a cross-view tower to explore the enemy's virtuality and reality for Liu Bei in the battle to break through Chang'an five years ago.

Nowadays, the knowledge of the Guandong princes is derived from Zhuge Liang's experience and secretly learning. Zhuge Liang's own tactics invented, and of course he is also thinking about how to restrain the countermeasures.

Cao Cao and Xiahou Yuan failed to copy it, and it was not unfair at all.

Regarding the engineering design of offensive and defensive cities, Zhuge Liang is invincible.

After the failed attempt to use the Watch Tower to spy on the distribution of defensive forces on each side of the enemy city, Cao's army chose to siege multiple faces and try to pull out flaws, which seemed meaningless.

Because even if you pull out a flaw, you don’t know where the flaw is, and you have no vision.

In this case, if one side has enough catapults, it will immediately put all its strength in this direction and smash the strong attack. It is not wrong.

Soon, Cao's army's huge rocks hit the city wall on the north side of Kunyang City like a meteor shower. Rammed earth fell down, and it looked quite good at first.

But after just a little smash, Cao Cao and Xiahou Yuan saw the problem. After the outermost layer of the walls of Kunyang collapsed, the color of the wall inside began to change, from earthy yellow to blue-white.

Cao Cao couldn't understand at first, but after a while, he saw that the blue and white positions were hit by stones many times, but they did not collapse at all, but they just loosened and moved. Only then did he confirm that there was actually a layer of granite temporarily reinforced part in the Kunyang City Wall.

Anyway, Zhuge Liang dug the canal and exploded the extra stones from Tongbai Mountain, and he had no use, so he wrapped a layer of them on the original city wall and added a thin layer of rammed earth outside.

The reason why there is soil outside the stone is to absorb kinetic energy and shock absorption. Otherwise, although the light stone will not be easily destroyed when it hits hard, it will easily loosen and fall off.

Even in later generations, even when the outer layer of the city wall was already stone, it was actually rammed earth and bricks and stones, with the core inside. The outer layer was made of bricks and stones to prevent the soil from falling off too easily.

However, the city walls with such structures are still relatively fragile when encountering heavy trenchers. The large stones that make the wall may not be smashed, but they are easily collapsed because there is no elastic buffer when directly contacted.

Moreover, the characteristic of stones is that once the middle collapses, those stacked on top will collapse. Unlike the middle of the rammed earth wall, the soil on it can be held on for a while with the tension supported by the left and right support, and carry a few more shells.

That's why Zhuge Liang insisted on wrapping a layer of thin soil outside the stone wall. Of course, there is another advantage to doing this, that is, when encountering enemy scouts before the war, they can do the best job of seducing the enemy to keep the secret.

To prevent Cao's army from not daring to fight after being scared, it is to seduce the enemy to invest too much and it is difficult to get rid of the tiger. This is the best way to do so.

Now, Cao Cao is obviously in an embarrassing situation of reluctance to give up on the cost of sunk.

Although the situation was bad, Cao's army had made all the stones. It was impossible for him to give up just because he saw that there were stones in the Kunyang city walls, which were too difficult to destroy. He had to bite the bullet and spend time to continue smashing.

It’s like if you knew the other person was extremely ugly before meeting the netizen, you wouldn’t go at all. But if you “have come”, for the sake of the air ticket, you won’t let someone leave directly.

"Don't hurry! Keep smashing! There are not enough catapults now, continue to build! Build a few more batches, and the guards will not be able to smash them faster than us. Sooner or later, they will not be able to repair them!"

Cao Cao was determined to be determined. He personally inspected the positions to boost morale and talked with the generals to relax. Kunyang City could at least besieged until the first month of next year. It would be considered a success before this. There is still time, so everyone should have confidence.

...

Unfortunately, it turns out that once a person begins to be reluctant to give up his early investment and persists, it is often the beginning of greater failure.

It’s like buying a junk stock at the bottom and picking up a flying knife, halfway up the mountain, and trying to wait for the trap to get rid of it. Often, it can’t be able to get rid of it for many years, and even the junk stock is almost delisted in the end.

In the following days, Cao's army continued to build catapults and continued to smash them. The scale of the catapults array became larger and larger, and it consumed countless manpower and material resources.

The Kunyang defenders continued to guard as hard as rocks. After fighting every night, they sent people to carry buckets of thick mud and pour it on the place where the rammed earth was smashed and peeled off outside the stone wall. In this way, if they were hit at the same position tomorrow, they could buffer it to prevent the stones from being smashed down.

It was almost the end of November, and the Cao army sieges intensively siege and bombarded with various means for more than ten days, and the trenchers increased from dozens of units to more than two hundred units. Finally, the defenders could not withstand it and could not repair it. Many wall stones were cracked and fell, and the gap at the city wall became larger and larger.

However, the defenders in the city were not beaten for nothing but fight back. Although the divine arm crossbow could not suppress the catapult position, the catapults of the defenders on the city could suppress the catapults outside the city. The defenders also deployed catapults to bombard. Although the number was far less than that of the attacking parties, they were better because of the convenience of observation and easier to clear at a fixed point.

During the days of bombing, Cao's soldiers were killed and injured, and dozens of catapults were smashed. If the catapult had not been small and the city walls had large targets, this exchange would have been even more amazing.

After Cao's army was exhausted from his temper, Guan Yu finally took out another spare tire ace.

On November 28, on the twelfth day after the Cao army began bombardment, many thick straw ropes suddenly appeared on the top of Kunyang City when Cao army concentrated on bombardment.

It is just that it is made of ordinary long straw, straw, etc., which are easily rubbed with unpopular flexible plant fibers. It is much cheaper than hemp ropes because they don’t need to be weaved. However, these straw ropes are made of solid materials, very thick and dull, almost one foot thick, and look like straw bales connected together.

The outside of the thick straw rope was soaked with wet mud, and then it was hung from the city wall, especially to protect weak places where the stones had been smashed by the trencher and the stones were almost gone.

Cao Cao and Xiahou Yuan thought what was wrong at first? But after continuing to smash it with a catapult, they found that this thing was really evil.

First of all, these mud and thick straw ropes are not hung directly against the stone wall, but are also a fork-like strut strut one or two feet away from the wall and then hung in the air.

The straw rope is not subject to force, and when hit by the flying stone of the catapult, it will naturally retreat and buffer, or slip or deflect to both sides. However, this obstacle will remove a considerable part of the impact force of the stone bullet. More importantly, even if the bricks behind are smashed, it will not fall off easily if there is something outside blocking it.

This thing actually has no technical content, and Zhuge Liang is not cheating either. He just thinks about it based on simple physical principles. The core idea is buffering and not to confront head-on.

Similar to adding a layer of grille armor or piled up sandbags outside the main armor.

Moreover, there are indeed similar things in history, such as "History of the Song Dynasty. The Eleventh Chronicle of the Sung Dynasty. The Armor of the Armor" talks about the progress of military science and technology in the Song Dynasty. The last paragraph mentions something called "protecting the air fence", which is the last military science and technology innovation in the late Song Dynasty, used to deal with Hui Hui artillery.

This thing is indeed useful, but it was invented in the ninth year of Xianchun (1273), and this year happened to be the capture of Xiangyang City by Kublai Khan. It was equivalent to the urgent remedy that the Song people thought of after the breaking of Xiangyang City, and they were unable to make up for the truth.

At this moment, when Cao Cao encounters such a killing weapon, what can he do?

It can only be said that whenever Master Li Su takes out something and is prepared for large-scale imitation and plagiarism, they will definitely keep the restrained moves in advance. If there is no restrained move, they will continue to think about it over the years and fight with each other.

Cao Cao is not wronged.

On the first day, Cao Cao didn't believe in this evil and continued to bombard the crazy bombardment. After a morning of bombing, he only smashed a few pieces of stones in the city wall, and many of the cheap straw ropes were broken by him.

But what makes people desperate is that the bargain is too easy to replenish. It is broken, and the city wall will soon take out the reserve stock and make up another one at the gap.

After two or three days of this, the time finally entered the beginning of December. Cao's army was completely depressed. Although not many people died, the whole country realized that there was no hope for this technical confrontation between the offense and defense city.

"If this continues, your morale will be exhausted if you continue to waste it. Before the soldiers can react and the idea of ​​fear of war spreads, you will finally fight for a full-scale attack!"

Cao Cao realized this problem and attracted Xiahou Yuan to discuss with him, demanding that a comprehensive three-dimensional attack be organized tomorrow and pile up all the equipment he had built these days.

Even if the city wall has not collapsed for the time being, it is impossible to care about it. In the past years, when there were no catapults, the siege war was not defeated! It is not that it would be impossible to attack the city wall if it could not be smashed! At most, the casualties were a little heavier!

Xiahou Yuan also knew that the lord's decision was right, and he was unwilling to give up without fighting, so he made every effort to prepare. Moreover, after attacking these days, although there was no wall breaking, the peripheral obstacles were basically cleared, and pits and traps were eliminated and filled in. It was indeed possible to fight.

On the second day of December, Cao's army launched the most violent general attack in the past twenty days.

Hundreds of ladder trucks, rushing cars, and digging city wooden donkeys were in line, and nearly 200 remaining catapults were also splashing stones wildly.

Tens of thousands of Cao's crossbowmen have their own huge Teng Shields and temporarily deployed to the frontier wooden array houses to shoot against the defenders at the city. However, even with these defensive facilities, their situation cannot be said to be safe. Because the defenders have many slashing shots that throw gravel, they will specifically cover these simple fortifications that can cover arrows.

Teng Shield and wooden boards will still be destroyed by stones.

For a moment, the sound of killing in the north of Kunyang City shook the sky again, and the tide of Cao's ants attacked fiercely. As usual, the Han army asked the crossbowmen to advance behind Yangmapo to use crossbows and arrows to output. The hit rate was extremely high, and countless Cao's lives were harvested.

But this time, Cao's army fought to the death and suffered huge casualties, but forced all the Han army's crossbowmen to retreat. They still fought bravely again to attack the city gate for the Han army's crossbowmen to retreat. They were still blocked by several thousand jin gates, and were all destroyed after bloody fighting in the gate and the inner wall city. They watched the Han army close the city gate behind the gate and blocked the door with a knife truck.

During the whole process, Cao's army did not learn from the lessons, nor did they consider using their body to hold the Qianjin Gate and prevent it from falling. Today, there was a special officer of Cao's army who brought a wooden, long weapons and long shields to try to block the Qianjin Gate.

But the Han army is not a vegetarian. The Han army only exposed one thousand jin gate that time. Today, Cao army realized that the enemy's full strength had not been tested last time, and there was more than one gate!

What's even more vicious is that today the Han army stocked up huge amounts of boiling water and boiling gold juice above the door hole, and poured it into the bottom of the door hole. In the end, there were even some tincture oil, torches, gunpowder pots, and sulfur poisonous smoke cartridges. No matter what, it was stress-free to kill all the people at the entrance of the city gate.

Cao's army failed to seize the gate, so he had to hit the city wildly, while climbing the city, and destroying the crossbows deployed behind Yangmapo, which had no time to bring back to the city.

There was no cover on the back of Yangmapo and no shooting spots. During the whole process, the Han army frantically exported from the top of the city, and Cao's corpse quickly filled the one-way trenches behind Yangmapo.

Cao's ladder truck and the city-digging wooden donkey actually went uphill and then slowly downhill, reaching the base of the city wall. The slope they drove down from the back of the Yangma Slope was the wreckage of the crossbow and the body of Cao's army.

When the bloody battle reached this level, Guan Yu finally stopped hiding it. He personally climbed the city tower, directed the battle directly, and made someone fight his flag.

Cao's army first climbed the city, and there was a gap in defense. Guan Yu also personally brought the reserve team to urge the supervision, waving the blue dragon sword and chopped up dozens of Cao's soldiers who had not yet established a foothold next to the female wall.

Guan Yu knew very well that a battle of this scale would not be short of his own killing of these 100 people, and he stood on the city wall and killed the unstable enemy, and he would not have any sense of accomplishment to win without martial arts.

What Guan Yu cares about is to attack the morale of the Cao army as quickly as possible, spreading the bad news that "Cao army was trapped, Guan Yu personally guarded the city, and there were tens of thousands of elite soldiers of Liu Bei army in the city", which made as many Cao soldiers know about it, and thus frightened.

"Han General Pass".

Cao Cao also gritted his teeth and supervised the battle and watched from a distance below the city. When he saw Guan Yu's banner appear, he was shocked: "Didn't Guan Yu's banner always confront Yuan Shao in Hanoi County and Shangdang County?

Although I haven't heard the news of Benchu's death yet, it should be just the news of Yuan Shang blocking. There is such a big opportunity in Hebei, how could Liu Bei send Guan Yu to Kunyang?"
Chapter completed!