Outside Linzi City, there is the camp of Donglai Army.
In the evening when the sky had just dimmed, two generals covered in mud came to Liu Yu.
"General, the tunnels in Nancheng and Dongcheng have been dug."
"Okay, arrange the manpower and keep an eye on the tunnel. Don't let the enemies in the city attack and destroy the tunnel entrance."
Although he knew that the defenders in the city would not go out to destroy the city, Liu Yu once again told them to carefully guard the tunnel they had finally dug.
In just three days, of course, the tunnel excavated cannot be very wide, nor can it dig a huge pit under Linzi City like the city wall was dug down.
The tunnel Liu Yu requested to be dug only needs to be able to reach the bottom of the city wall. It does not need to be very wide, as long as it can pass a cat's waist.
Because Liu Yu's tunnel attack did not intend to dig down the Linzi city wall at all, but intended to use the black gunpowder he had finally accumulated to blow up the Linzi city wall.
In fact, according to Liu Yu's original plan, after making the fire salt and having enough black huo yao, he planned to make a military weapon-artillery.
However, reality soon caused Liu Yu to temporarily abandon this plan. Iron and steelmaking in the Western Jin Dynasty were still in the early stages of ignorance. There was no temperature at all to melt enough iron materials, let alone cast iron artillery.
Of course, if you don't have iron cannons, you can still make copper cannons. After all, the characteristics of copper alloys allowed you to cast cannons that were durable enough until the 19th century.
However, copper-made artillery is also very difficult, not only because of problems with the casting process, but also because the copper alloy is not strong enough due to composition problems.
And because it’s too expensive, it can even be said to be very expensive.
In the Western Jin Dynasty, copper was money, and a thousand-jin copper cannon was like a mobile machine to show off wealth.
Liu Yu's strength in occupying a corner of Donglai County is still too weak. The current skills and abilities of the craftsmen in his hands are far from being able to implement Liu Yu's various ideas into reality.
With the cost of casting suitable copper artillery, it can be equipped with a considerable number of armored soldiers. The effect of these soldiers on the battlefield is far greater than that of a single copper artillery.
Therefore, during the expedition against Gou Xi, Liu Yu directly used the huo yao stored in his hand to blow up the city wall. Although in terms of the amount of huo yao used, this was a bit more expensive than artillery bombardment of the city wall, but the effect was probably better than that of bombarding the city wall with artillery. Artillery bombardment is even more effective.
Early the next morning, Liu Yu commanded two mysterious soldiers to carry out landfilling at the entrances of the tunnels in Nancheng and Dongcheng.
Several strong Donglai Army soldiers worked together to transport two large wooden boxes filled with black firewood from the entrance of the tunnel to the bottom of the Linzi city wall.
Then, a long fuse was pulled out. In order to ensure the success rate of igniting the fire, two fuses wrapped in black fire were left in each tunnel.
After placing the fire yao box and fuse, these soldiers filled the tunnel entrance with bricks, stones and wood blocks, sealing the box filled with black fire yao underground.
In this way, according to Liu Yu's idea, when the black fire comes, a huge shock wave will rush out from the relatively weak upper part, which should be enough to destroy the rammed city wall of Linzi City built in the Han Dynasty.
By the time all this was completed, it was already close to noon.
Under the curious gazes of many of his subordinates, Liu Yu ordered the soldiers to light up the smoke. This was a signal for Nancheng and Dongcheng to be lit at the same time.
Liu Yu, who was sitting in the south of the city, lit a fuse with his own hands. The fuse filled with black smoke burned rapidly, emitting a large amount of white smoke.
The surrounding generals and soldiers were full of curiosity and expectation. They could not imagine how Liu Yu could break through the enemy's wall with this method.
There are several generals with strong backgrounds in Qi County who have read many books about elixirs and immortality. They speculate that this stuff with white smoke coming out of it may be a type of fire with a strong yang energy. It can break through earthen walls.
However, according to the Five Elements in their impression, this fire virtue is Kemu De and cannot restrain earth virtue.
Everyone used their imagination to the maximum, and they couldn't figure out how Liu Yu's method could break through the city wall of Linzi.
People who were equally confused as Liu Yu's group of generals were Gou Chun and his sergeants at the top of Linzi City.
Gou Chun was condescending and had already discovered the enemies on the south and east sides of the city on the city wall. From early in the morning, he started transporting some strange wooden boxes into the tunnels at the entrances of the two tunnels, and then It’s masonry and earthwork again.
"That's not right. Although this cave attack requires transporting wood to support the tunnel, it is impossible to dig it so quickly to the point where it requires burning wood to trap the wall."
Gou Chun was greatly confused. These Donglai thieves had only been digging for three days. It was impossible for them to be so fast. For example, in order to counterattack the square hole attack on the city, the soldiers in the city also dug trenches along the city wall, and the depth of the trenches was It is impossible for the earthwork produced by the length to hollow out a section of the city wall.
"Did the soldiers listening to the urn at the corner of the city wall hear anything strange?!" Gou Chun was disturbed by the mysterious movements of the Donglai thieves. He asked the general next to him about the investigation status of the soldiers listening to the urn near the city wall.
"Don't worry, Ming Gong. The general has just gone to check. All the soldiers in the jar have their ears pricked up. There is nothing abnormal at all."
The general said respectfully.
In order to counter the enemy's tunnel attacks, a large urn was usually buried in the soil, and soldiers with sensitive ears could sit in it to listen for any sounds of enemy digging nearby.
Gou Chun nodded. Although the sensitivity of this listening urn is very suspicious, if someone digs, they should still be able to hear some slight noises.
Since there is no movement now, no one should be digging inside. In this case, the Donglai thieves outside the city are probably burning the pillars supporting the load of the city wall.
Gou Chun sneered, and couldn't help but secretly despise these Donglai thieves. These bumpkin from the remote mountains, I'm afraid they just dug a small hole under the city wall, thinking that they could collapse the city wall, so let them slowly Just wait, even if you wait until you die, this rammed earth wall will not collapse.
At this time, a thick line of black smoke suddenly rose from the Donglai bandits outside the city, like some kind of signal.
Gou Chun frowned and felt that although the thief was stupid, it was better for him to be careful and not to omit unnecessary measures.
He ordered his generals to send additional troops to the southeast and to be ready to guard the damaged areas in case the city wall collapsed.
Because the hole attack method will not make the rammed earth city wall disappear, but will cause the city wall to collapse and form a gentle slope in its original position. This gentle slope will often become a flesh-and-blood millstone for both the attacking and defending sides.
