The last three kingdoms

Chapter 426 Digging Tunnels
On the second day, the main target of the Shu army moved to the East Gate.

The battle was still extremely fierce, but Liu Yin only used bed crossbows, trebuchets, and crossbowmen to carry out long-range attacks on Chang'an City, and did not send out siege troops.

The purpose of doing this, of course, is to reduce unnecessary casualties. In yesterday's siege operation, Liu Yin was purely trying to test the defense strength of the Wei army. Facts have proved that Sima Wang still has a good foot in the defense system of Chang'an City. If the capital is only obtained by force, it will be very difficult to take down Chang'an. Even if the old capital of the Shu army is lost, it may not be possible to capture it.

Siege operations, in the era of cold weapons, are undoubtedly the most difficult battles. The battle for a city often takes months or even years of fighting to see the outcome. If you want to break through a big city like Chang'an, you need time will be longer.

Of course, Liu Yin could not expect to take Chang'an easily by setting up a few ladders. The reason why he rushed to Haikou was that he would take Chang'an City within three days. Liu Yin naturally had his own clever plan, otherwise he would never I won't just talk about it.

Liu Yin's reliance is gunpowder. Although there are many people in the Shu army who have seen the power of gunpowder, they only regard it as an individual weapon. It can be thrown, thrown or buried, but it has never been used. Gunpowder in siege warfare, everyone naturally does not know its true power.

However, Liu Yin knew very well that it would be a breeze to pile up tons of gunpowder and detonate them at the same time to blow down a city wall.The defense of Chang'an City relies on the city wall the most. As long as you can blast a part of it, the entire Chang'an City will be opened. Without the protection of the city wall, it will not be so easy for the defenders in the city to defend Chang'an .

If you want to use gunpowder, you can't take it to the city and use it, otherwise it can only hurt its skin at most.Liu Yin knew very well that his gunpowder was only black gunpowder, not the powerful yellow-gunpowder. If he wanted to blow up the city wall, he would need a huge amount of gunpowder.The most reliable way is to dig a tunnel under the city wall of Chang'an, and bury tons of gunpowder directly under the city wall to achieve the desired effect.

Liu Yin chose the southern city wall of Chang'an as his target. On the first day of the attack, Liu Yin had already arranged for hundreds of engineers to dig tunnels outside Chang'an City.In order to hide the eyes and ears of Sima Wang, Liu Yin's tunnel entrance was chosen in his own barracks. A huge tent covered the tunnel entrance, and all the excavated soil was piled up in several connected tents. , will be cleaned out at night.

The height of the tunnel is about five feet, the width is about three feet, and only one person can pass through. Therefore, only one engineer is always digging on the working face. The working time of each engineer does not exceed the time of a stick of incense, so that it can be guaranteed that each engineer can work hard without sacrificing his physical strength.

The soil in and around Chang'an City is sandy, which should have been formed by the alluvial accumulation of the Wei River over millions of years. This kind of soil is best at digging tunnels, so the progress of the Shu army is very smooth. In just one day, they have already dug tunnels. To the edge of the moat.

The most difficult thing to dig a tunnel is the moat of Chang'an City. The moat is ten feet wide and three feet deep, which is very majestic. However, if you want to dig a tunnel under the city wall of Chang'an, you can't go around the moat.If the tunnel is dug too shallow, the moat is likely to be dug through. Digging through the moat is simply a nightmare.

In order to avoid such danger, Liu Yin personally presided over the excavation of the tunnel. Through careful measurement, the location of the moat was accurately determined. When the tunnel passed through the moat, it was dug into a big "U" shape. Dig deep, use wooden piles and planks for support and protection, after reaching the bottom of the city wall, lift it up, and dig the end of the tunnel under the city wall.

In this way, we can get twice the result with half the effort. As long as the city walls of Chang'an can be blown down, taking down Chang'an City is simply as easy as pie.

In order to keep from being discovered by the Wei army, Liu Yin deliberately listed the tunnel plan as a top secret plan. Not only the Wei army did not know about it, but even the irrelevant personnel of the Shu army did not know what to dig these tunnels for.

At the same time, in order to confuse Sima Wang, on the second day, the direction of the main attack was changed to the east. Naturally, the attraction of the Wei army was to the east.

The offensive and defensive sides launched a battle of bed crossbows and catapults. Arrows rained all over the sky, and the battle was fierce. Since no siege troops were sent, the casualties of the Shu army were very low.

However, Sima Wang, the old fox, still smelled something unusual. Although Liu Yin changed his attack direction, Sima Wang still focused his attention on the southern city wall.

The tactics of siege warfare are single, and there are few methods that can be used. Digging tunnels is one of them. There are many successful cases of tunnel digging in ancient times.Sima Wang obviously wanted to guard against Liu Yin's move.

Especially after the Shu army changed the direction of attack the next day, the treacherous Sima Wang was keen to find a clue, because if Liu Yin chose the south as the main attack target, he should launch continuous attacks in the south, so as to accelerate the attack. The destruction of the city wall was greatly deepened, but Liu Yin did the opposite, which made Sima Wang suspicious.

Sima Wang himself ascended the heights and gazed into the distance, and those special tents aroused his vigilance. These tents were all connected together, which seriously violated the principle of camping. The only reasonable explanation was that they had other purposes.

The biggest possibility is to dig a tunnel, and judging from the surrounding soil conditions, this guess is very likely to be true.

In line with the principle of preferring to believe what is there, and not to believe what is not, Sima Wang actively took precautions in the city of Chang'an.In his view, Liu Yin's purpose of digging tunnels was to bypass the solid city defenses, sneak some troops into the city, and then cooperate with the inside and outside to launch an attack, and Chang'an City would be in danger!

But now that he has seen through Liu Yin's method, Sima Wang cannot do nothing. The best way to detect whether there are enemy troops digging tunnels is to bury a few large urns underground in the city. will beep.

Sure enough, after a few large urns were buried, the direction and progress of the Shu army's tunnel digging were quickly detected.

Sima Wang secretly sneered, Liu Yin really couldn't make a secret move, but if he saw it through in advance, this move would naturally be useless. If he wanted to destroy this move, Sima Wang had many ways, it was so easy. pressure.

(End of this chapter)