During the march, Gongsun Xu constantly recalled the practice of trebuchets, he was not good at his studies in middle school, but he was very strong when he was naughty and played games.

When he was learning the principles of physical levers in middle school, his physics teacher taught them the principles of levers, and he quickly learned how to make small trebuchets.

When he made trebuchets, it was not because he was diligent and studious, but because he made a simple trebuchet that could hit people after class or other situations without being easy to detect.

Gongsun Xu still remembers that in that year, he kneaded the leftover rice into a ball and put it in a trebuchet made of chopsticks and small wooden sticks, and specially teased female classmates.

When a few rice balls went down, the girls' clothes were dirty, and they couldn't find who did it, but he made several girls cry.

Although he forgot a lot of details, he still had a general impression of making it when he was in junior high school.

Since the winch-type trebuchet could not be used during the march, Gongsun Xu thought of a counterweight trebuchet.

Although the counterweight trebuchet is simple to build, far less powerful and accurate than a winch trebuchet, it is much easier to make than a winch trebuchet.

Gongsun Xu did not make the trebuchet himself, but drew a sketch of the trebuchet and gave the sketch of the trebuchet to the soldiers who had worked as craftsmen under him.

For Gongsun Xu, making a trebuchet by himself will definitely not be better than making it by his craftsmen, in this case, it is better to give full authority to his craftsmen and let the craftsmen make trebuchets.

When Gongsun Xu was negotiating with Gongsun Zhan and Meng Yi, he recruited some skilled craftsmen from the two of them.

These skilled craftsmen were craftsmen who accompanied the army, and were sent by Meng Yi to Gongsun Xu to make ladders and some siege equipment.

At this time, Gongsun Xu directly called these craftsmen together and asked them to start researching and making a model of a trebuchet as quickly as possible.

The leader of these craftsmen is called Lu Shen, who is in his forties, because he has been making siege equipment with the army all the year round, and his skin color is not much different from that of the soldiers under Gongsun Xu.

Lu Shen also has some hair loss and little white head, he looks like an old woodcutter, if it weren't for the fact that he looks majestic, Gongsun Xu really didn't expect that this old man would be the first craftsman in Youzhou.

When the tun commander in charge of the craftsman battalion introduced Gongsun Xu, he specially pointed out that Lu Shen is said to have a little kinship with the family of Lu Ban, the originator of carpenters.

But what! This craftsman named Lu Shen does have quite extraordinary attainments, and most of the siege equipment in the Youzhou army were made by him.

This time, Gongsun Xu attacked Xiangping from afar, and Gongsun Zan and Meng Yi had no way to provide him with large-scale siege equipment, so he and Meng Yi transferred Lu Shen from the craftsman camp to Gongsun Xu.

In Gongsun Xu's military camp, Gongsun Xu gave Lu Shen enough respect and affirmation, not only recruited nearly 200 soldiers who had learned the craft to Lu Shen and the craftsmen of the craftsman battalion, but also offered them a super high price.

Gongsun Xu is a descendant of the world, and he has a lot of feelings about the statement that science and technology are the primary productive forces.

In any era, technology is the most important. At the end of the Han Dynasty, other people didn't know what a skilled craftsman represented, but Gongsun Xu knew it.

Asking Lu Shen out of Meng Yi and Gongsun Zhan's hands, Gongsun Xu didn't have any idea of letting Lu Shen return to Meng Yi and Gongsun Zhan.

Such a person is now, or in the future, is the talent that Gongsun Xu needs the most, and only when such a person stays, can he have a broader space for development.

Lu Shen has always had a kind of resistance to obeying orders under Gongsun Xu, a craftsman of his level has been paid enough attention in the late Han Dynasty, even if it is Gongsun Zhan's majestic white horse general, he has not chosen to serve, not to mention that there is a weak crown boy in front of him who has no hair.

In Lu Shen's heart, following a kid like Gongsun Xu to Xiangping City, there is no guarantee for even personal safety, and he can't tell when he will die of burning pot.

After arriving at Gongsun Xu's military camp, he saw that Gongsun Xu did not immediately ask them to rush to make siege equipment, and he even cast a disdainful look at Gongsun Xu.

Xiangping City is different from Xingcheng, it has undergone many years of construction, it is the strongest main city in the border fortress, if there is no good siege equipment, not to mention that Gongsun Xu now has 6,000 people, even if there are more than 10,000 people, it is impossible to shake the defense of Xiangping City.

When Gongsun Xu took out the sketch of the trebuchet and led several master craftsmen to make it, Lu Shen was even more disappointed in Gongsun Xu.

Marching and fighting, especially attacking cities, without his ladders and nest cars, what kind of city is it to attack!

The first cloud ladder to attack the city, the inventor of the cloud ladder is the legendary Lu Ban, the cloud ladder during the Warring States period, is composed of three parts: the bottom is loaded with wheels, which can be moved; The ladder body can be raised up and down, and it is carried by manpower during the siege of the city, and it is leaning on the city wall; The top of the ladder is equipped with hooks to hook the edge of the city to prevent it from being damaged by the defenders.

At the end of the Han Dynasty, the siege ladder had some changes, Lu Shen got three flavors, and the ladder made was the best in the whole Youzhou, and it was very practical to attack the city and plunder the village.

Lu Shen is more good at observing the enemy's vehicle---- nest car, there is a "watchtower" on the car, because the watchtower resembles a bird's nest, so it is called the nest car.

The body of this car is made of wood. There are four wheels at the bottom, the car is on the tree looking pole, the watchtower is set on the pole, the rod is equipped with a rotating shaft, and with six ropes, divided into three layers, the rod is fixed from six sides, and the bottom of the rope is wedged into the ground with a ring iron pickaxe.

In Lu Shen's hands, the nest car was greatly changed, in terms of the watchtower, he widened and heightened, and the bottom was made of thick logs as a base, so that the watchtower was wider, and more than a dozen archers could be placed on it to suppress the archers of the city's defense.

However, after Lu Shen's in-depth research, he was surprised to find that the drawings given to him by Major General Gongsun were actually a completely new thing that exceeded his knowledge.

Once this kind of thing can be successfully developed, it can even subvert hundreds of years of siege tools.

After Lu Shen and several of his master craftsmen worked overtime, the prototype of the trebuchet was made a day later. They experimented several times according to what Major General Gongsun said, and found that the effect was good, so Lu Shen sent his subordinates to invite Gongsun Xu and invited him to come and see their results.

When Gongsun Xu heard that the trebuchet had been successfully made, he immediately sent someone to invite Zhao Yun Hanyu, and asked Gongsun Da and Qi Ming to follow him to visit the trebuchet.