It took another two days for the earthen wall to be completely built. After the construction of the earthen wall, it is about 3 meters high and about 2 meters thick, and it is parallel to the south of Yokohara Fort, and the distance is only 200 meters. Just as the Thunderbolt army at Yokohara Fort was discussing the use of the earthen wall, the new annex army drove a large number of people and wood towards the earthen wall. This made Cao Ergou, who was standing at the head of the wall of Yokohara Fort, urgently order the cannon to be fired, he knew that those logs had only one purpose - to erect siege weapons. Although the walls of Yokohara Fort were strong, it could not withstand the bombardment of trebuchets all day long.

A few shells landed in the crowd in the open field, knocking down a large number of the new annexes and civilians who were marching towards the earthen wall, and the rest of the people scattered when they saw that the situation was not good. The shells landed half a mile farther than the earthen wall, and nearly a mile away from Yokohara Fort, and they obviously did not expect the artillery to hit so far. In fact, this time the artillery was still aimed at the new annex army that was walking behind, so the casualties of the people were only a fraction of the new annex army. This shelling really cast a psychological shadow on the new annex army, and the Thunderbolt artillery can actually hit so far and be so powerful, can this have a chance of winning? How can this battle be fought? It's just that what they said doesn't count, in the eyes of the Mongols, they are just cannon fodder.

Several more heads rose on the flagpole at the entrance of the newly attached barracks. Under the watchful eye of the Mongol cavalry, the new soldiers escorted the people to the earthen wall. However, unsurprisingly, it was subjected to heavy artillery bombardment, and then it broke and fled, and then the leading new annex army was beheaded by the Mongols. After repeating this several times, very little timber was sent to the earthen wall, but the number of new soldiers killed and injured by the explosion reached several hundred, and the number of migrant workers was also killed and wounded more than 100. The Mongols in the rear also saw that the Minfu was not the focus of the artillery attack, but the new annex army. At this time, the commander of the Mongolian army, Secret Huoli, also knew that if the threat of artillery was not resolved, the new annexed army would only die more and more, and its morale would collapse sooner or later. If all these cannon fodder are dead and escape, they must not let their cavalry attack the city. As for giving up the attack and adopting the method of persuasion? If it is said that there was still this possibility before the Thunderbolt army attacked Chengdu City, now not only the arrogant Mongols like the secret man Huoli will definitely not agree, but even Liu Heima, who advocates suppressing and appeasing at the same time, does not dare to agree. Now the consensus of the Mongols is that they must storm the mountains and slaughter all the people under the Thunderbolt army in order to vent their hatred of being attacked.

Looking at the dead and wounded all over the ground, Jiagulong, the general in charge of the siege of the Mongolian army, fell into contemplation in ancient times, and the deep-rooted concepts formed by years of siege experience have been broken by the bloody reality. Like Yelumaizhu, he was a Khitan and a rare siege expert among the Mongols. After Liu Heima raided Chengdu, it took only seven days to build a new Chengdu city on the ruins of the old city, which is his credit. After arriving at Yokohara Fort, he kept looking at it, trying to find out the weaknesses in the defense and how to crack the artillery, and he used the earthen wall fire cannon to prevent it. It's just that he didn't expect the range of artillery to be as far as a mile away. He had also heard that the Thunderbolt weapons were extremely powerful, but he didn't take them to heart, just the nonsense of the defeated army. As a perennial siege general, the most powerful fortification weapons he had ever seen were still trebuchets and ballistas. As for the artillery, whether it was the artillery of the Mongolian army or the artillery of the Song army, it was just a big momentum, and the flames and smoke that spewed out were terrifying, but the power was really inferior to the trebuchet.

In the ancient plan of the Jiagu Dragon, suppressing the Thunderbolt artillery was the key to this siege. His idea was to transport materials to earthen walls and use the wall's obstruction to assemble them into siege weapons. For this reason, the height of the earthen wall and the distance from Yokohara Fort were carefully calculated, so that the trebuchet could be protected by the earthen wall, and the stones shot out from the curve could reach Yokohara Fort. It's just that how to get the materials and personnel to get to the earthen wall has become a problem at the moment. When the ancient Jiagu Dragon was distressed, a small colonel under his command solved this problem. This colonel was originally a tunnel soldier of the Jin army, and his suggestion was to dig a trench that led diagonally to the earthen wall from outside the range of the Perak army's artillery. By digging the trench wider and deeper, one can walk at the bottom of the trench and transport the material to the earthen wall. After listening carefully, Jiagu Longgu said that it was wonderful, and immediately ordered someone to execute it. This method is actually the civil engineering operation of later generations, and the method is a little stupid, but in addition to the large amount of work, the effect on dealing with firearms is really not bad. As for the manpower needed to dig the ditch, there is no shortage of Mongolian troops at all, not to mention the more than 10,000 people, even the thousands of new annexed troops are excellent labor.

Under the ancient order of Jiagu Long, thousands of people dug more than a dozen trenches at the same time, and the scene was very spectacular. This scene obviously fell into the eyes of Cao Ergou at the head of the city. At first he did not know the intentions of the Mongols, but it was only when a few days later that the trench was completed, and the soldiers of the newly annexed army advanced from the ditch to the earthen wall with materials. It's just that the ditch has been dug up, and no further bombardment will help. In fact, Cao Ergou also ordered people to shell the trench, but the effect was not satisfactory. The shells that fell on the ground could not hurt the people in the trench at all, and even the occasional shell that fell into the trench was blocked by the ditch wall, and only one or two unlucky ones suffered.

It took the Mongol army another three days to assemble dozens of trebuchets. These trebuchets can shoot stones the size of a human head, and they are also a great threat to Yokohara Castle. This kind of stone does not cause much damage to the iron and cement reinforced front walls of Yokohara Fort, but the relatively weakly defended fortress gate and the top of the castle wall are much more threatening. In order to prevent bows and arrows and rain from affecting the use of artillery, a roof and a breastwall were added to the walls of Yokohara Fort, which could not withstand the continuous blows of trebuchets. At present, the fortress guns of Yokohara Fort are all direct projectiles, and they cannot threaten the trebuchet behind the earthen wall, and the tiger squat cannon is required to deal with the target behind the earthen wall. Just when Cao Ergou was sending people back to Wanjiaping to get the tiger squat cannon, and was about to send people out of the fort to raid and destroy the trebuchet, the trebuchet opened fire. For a while, the stones that came with the sound of the wind smashed the head of the castle of Yokohara Fort, and from time to time there were screams of people being smashed, but fortunately, the stones that fell were only the size of fists, in addition to smashing a lot of utensils, only a few people were killed and injured. Tang Xiangwei, the commander of the sixth company who was familiar with siege equipment, explained to Cao Ergou that this trebuchet was actually a trebuchet commonly used by the Song army, and its main role was not to destroy the city wall, but to kill and injure people. Moreover, this distance has reached the limit of the trebuchet, if the stone is larger, the service life of the trebuchet will be greatly reduced, and it will be destroyed after a few launches. Judging from the stones that fell just now, the Mongolian army just wanted to suppress the artillery of the Thunderbolt army and provide fire support to the siege army.

Tang Xiangwei's words made Cao Ergou dispel the idea of going out of the fort to raid. Leaving the city at this moment, there will inevitably be hand-to-hand combat with the new annex army that protects the trebuchet. At this moment, there were hundreds of new annexes surrounding the city surrender plane, and Cao Ergou believed that he could defeat them with 300 men, but he would also pay a large number of casualties. Compared to the 5,000 men of the new annex army, the Thunderbolt army at Yokohara Fort only had 600 men, and even according to the exchange ratio of 1 to 5, the Thunderbolt army could not afford to suffer casualties. The Mongol cavalry was still eyeing the cavalry from a distance, and although the communication trenches leading to the earthen wall affected the cavalry's mobility, they could walk to the earthen wall and shoot with their bows and arrows, which would deal a fatal blow to the Thunderbolts who broke the trebuchet.