Now Zhang Junyue no longer had much mind to observe and evaluate the damage caused by the catapults and crossbow arrows to the shield carts and the masters behind them, and he was more concerned about the catapults and heavy ballistae of the Huaiyou Army that began to stay at a distance between 250 and 300 steps.

Catapults and ballistae are not new, and both are the most commonly used equipment for both attackers and defenders.

But the drawbacks of these two devices are also obvious.

There are three biggest problems with catapults.

First, the range is limited.

The range of the ordinary and simple catapult is only eighty steps, even if it is a large feudal lord's excellent production, it is only about a hundred steps, and almost no catapult has a range of more than one hundred and twenty steps, of course, if the defender relies on the height advantage of the city wall, the distance can be appropriately increased, but it is only one or twenty steps.

Second, it requires a lot of manpower to operate.

Of course, manpower is not a problem, but an ordinary catapult needs one or twenty people to pull the rope to trigger the power to throw stones, and the stones are only one or twenty pounds in weight, if the power is expanded, the manpower required is even more, and this also brings a problem, such a large-scale concentration of personnel, and because of the operation, it is almost impossible to wear armor, so once it is hit by the enemy's long-range weapons, the loss will be great.

Third, it is inconvenient to move and easy to damage.

The reason why it is said that it is inconvenient to move and easy to be damaged is not only that this kind of equipment is difficult to move and easy to disassemble, but also that this kind of thing is easy to be attacked by the place because of its conspicuous location, and at the same time, it is more troublesome that this equipment itself is extremely worn out in the process of operation, and the general ordinary catapult fires 60 to 80 stone bullets, which are basically scrapped, and the huge stress and wear of the support arm will lead to falling apart and destroying.

Again, there are a lot of problems with ballistas.

First, the launch speed is extremely slow.

The ballista is basically through the winch to stretch the crossbow, and then to complete the assembly of the crossbow arrow, and then launch, each process consumes a lot of energy, and the process is fine, there can be no mistakes, and once the launch is carried out and then assembled, the time required for assembly is quite long, it is not easy.

Second, the use environment of the ballista is limited.

The Ballista is not very convenient for the attacker due to its parallel firing, and it is necessary to increase the elevation angle to attack the defender (the wall), and this increase will affect the attack range of the Ballista.

Third, the maintenance and repair of ballistas is difficult.

Compared with the catapult, the ballista is more troublesome is that the winch of the twisted spring, the machine bracket in this era are precision parts, basically handmade, once damaged, it means that this huge instrument is scrapped, because they are all handmade by craftsmen, it is basically difficult to replace, and due to moisture, moth-eaten, wear and tear and other factors, it is easy to damage, plus the price is extremely high, so the use rate is not high.

Because of these factors, the use of catapults and crossbows is very limited.

Like ant thieves and water bandits, they will basically not be equipped with catapults and crossbows, because it is too inconvenient to carry and travel, not to mention, and the manufacturing process is complex, difficult to maintain, and expensive, so they basically give up, even if it is a general small feudal valve, the degree of adoption is also limited, only like a medium-sized feudal valve, it will be equipped with a larger scale of use.

But today's abrupt performance of the Huaiyou Army gave Zhang Junyue a not very good premonition, as if the equipment and equipment strength of the Huaiyou Army far exceeded everything that the previous scouts had learned, and this power may even bring unpredictable variables to the entire campaign.

Under the watchful eye of the Pinglu army on the city wall, the increasing number of trebuchets and heavy crossbows began to prepare themselves in an orderly manner.

The distance between three hundred and twenty steps and three hundred and fifty steps was enough to ensure their safety from being attacked by the ballista at the head of Qingzhou City.

It was the first time for Yang Lu to participate in such a war, since last night, he had not slept well, no matter how he calmed himself down and forced himself to sleep, but he had no way to sleep well.

At the end of the night, he slept for an hour at most, and then got up early in the morning and began to supervise and inspect the equipment and equipment of the troops to begin preparations.

As Yang Xun's second son, even if he is not as easy as his brother Yang Gu to enter the government hall or the Privy Council, but at least it is still easy to mix up an official and a half-position in the local area, and his father's face in Luhao Erzhou is still big enough, and his father even wrote a letter to ask him if he had any thoughts about going to Chuzhou, which was newly under the jurisdiction of Huaiyou, to serve as a secretary and join the army, but he still refused.

He had no interest in becoming a magistrate at all, and now this position was the most suitable for him.

Since he was a child, he has been addicted to strange tricks and obscenities, and he likes to do the most is to design and make various handmade devices, and later became interested in the way of magic, and many of the Gaine spells have promoted and enlightened his design and production, and then after mastering some of the basic principles of magic, he returned to the original, and regained his fascination with the design and production of various mechanical devices, the persuasion of his father and brother, and the eyes of outsiders, did not affect his hobby interest.

It wasn't until Haozhou entered Huaiyou, Jiang Feng introduced him to the Daozang Material Office, and he was like being introduced to a grand view garden, only to find that there were so many people here who had the same interests and hobbies as him, communicating with each other and learning from each other, and doing what he was most eager to do.

This is his happy land, he can even stay here for ten days and half a month without going home, for a doubtful point and a problem, he can forget to sleep and sleep all night and study for three days.

And all of this can be verified today, and that's when it's the happiest.

Yang Lu participated in the improvement of the catapult.

The improvement of the catapult is mainly from two aspects, one is to increase the range, and the other is to improve the durability of key parts.

The increase in range is mainly solved by improving the quality of the torsion spring parts, and the production of this special metal part is quite complicated, and without the technical support of the Ruijin Hall and the Lihuo Room of the Daozang Institute, it is difficult to break through in the refining of this obviously mixed metal in the first place.

Yang Lu had almost seen the process of this mixture, which was said to be a mixture of Ugin, cold iron, and Mithril, in the hearth.

This kind of stretching is general, but once the torsion spring made by special twisting method has more than five times the torque of the ordinary torsion spring, and once he conducts it to the throwing arm of the catapult through special parts, it can make the throwing arm throw larger stones with faster strength and more ferocious force, and the distance thrown is far beyond the distance that ordinary catapults can reach.

The torsion spring alone is not enough, the torsion spring as thick as a finger is not at all that ordinary people can twist, even if it is through the winch to achieve the superposition and accumulation of power, it is still very difficult, which requires the improvement of the design, through the extension of the arm distance, the decomposition of the force of multiple gear parts.

All in all, Yang Lu was sincerely convinced, and he was still a little reserved and proud when he first entered the Daozang Material Office, but when he slowly came into contact with more, he realized that his little wisdom was at most a little clever, or a little talented, but under the convergence and collision of the wisdom of hundreds of people, the talented geniuses were beyond reach, not to mention that these people were all leaders in this way.

The alloy smelted from Ugin, Mithril and cold iron is also used in the twisted spring of the crossbow, which is also the most important part of the crossbow, and this twisted spring is also mixed with the same strong power and has certain magical properties, and its power is even more extraordinary.

It's just that Jiaojin has always been rare, and if Jiang Feng and his party hadn't obtained a complete Jiaojin in Lei Ze Tujiao, and then used it to transform the heavy ballista, it would not have been possible to achieve such an effect.

But even if there is a complete barrup, it is only enough for six heavy ballistas, and like other heavy ballistas, all of them can only be solved by special twisted springs.

The personnel of the equipment unit are divided into two categories, one is the operator, the other is the support personnel, and in peacetime, these two types of personnel are often together, the operators have their own procedures during training, and the support personnel are only after the problem situation to carry out maintenance and support.

However, in wartime, the two sides need to work together at the same time, and the support personnel need to observe and find problems at any time, and at the same time, once problems arise, they must deal with them immediately, including preparing sufficient spare parts and replacement processes.

Yang Lu carefully observed the operation and assembly of the heavy ballista.

Compared to trebuchets, this heavy ballista is more complex, not only has a range than a catapult, but also far exceeds the accuracy of a catapult.

According to the earliest design of the material officer, the heavy ballista was changed from the earliest single-row horizontal column to a three-dimensional separator, which is equivalent to a longitudinal placement in a wrong format, so that each ballista can be used to the greatest extent, and the original seven crossbow arrows can be installed in each ballista, and now the crossbow arrows installed after longitudinal placement can reach three times the twenty-one crossbow arrows, and because of the special aiming frame and angle fine-tuning turntable, the shooting area can be observed through the observation post, and then precision shooting can be carried out to achieve the best shooting effect.

It can be said that the current heavy ballista and catapult have basically achieved excellent coordination of precision shooting and area strike, which is the biggest reliance of Huaiyou in the siege of the city.

If it weren't for these two pieces of equipment that had been continuously improved and evolved, Jiang Feng would not have dared to take the risk of attacking Qingzhou City, or Jiang Feng would not have been allowed to take such a risk if the defense system of Qingzhou City might bring huge losses to the Huaiyou Army.

You must know that according to the current normalized proportion of offensive and defensive losses, if you want to take Qingzhou City, I am afraid that Huaiyou will have to pay at least more than 30,000 losses, which is still without calculating the loss of the master, which is unacceptable to Jiang Feng now.