Because it was a dark attack, it was not discovered by the Qin army until the fleet approached the cofferdam, but it was obviously too late at this time, and the twenty large warships of the Dai army all fired ceramic missiles at the cofferdam with their side sides. The bed crossbows on the medium-sized warships also started one after another, firing crossbow guns.

Some of the missiles fell on the cofferdam, some crossed the cofferdam, and fell behind the cofferdam, igniting a fire, illuminating the night, and the raft also took advantage of the firelight, rowing in the direction of the cofferdam, and the crossbowmen on the raft opened their bows and fired arrows at the defenders.

The Qin soldiers guarding the cofferdam were beaten and killed countless times, and they immediately dispersed. And the rafts of the defenders have docked, the soldiers on the raft are not guns and halberds, but shovels, pickaxes, hoes and shovels and other things, after boarding the cofferdam, immediately shovels and pickaxes are raised, hoes and shovels are waved together, and they are digging and shoveling the cofferdam. Many soldiers simply grabbed the sandbags with their hands and threw them away. And the crossbowmen guarded the cofferdam with crossbows.

Originally, the height of the cofferdam was only two or three feet higher than the water surface, and it was mainly made of sandbags, which could withstand such excavation, and in a short time, the cofferdam was dug five or six gaps, although the gap was not large, but once the water found the gap, it did not immediately flow down the gap and flood the plains outside the cofferdam.

At this time, the Qin army in a nearby fortress rushed to the rescue, but it happened to encounter the water rushing down, although the gap was not big, but the water was condescending, very fierce, so the Qin army was suddenly swept away by the current, and the whole army was suddenly in chaos, and many soldiers were swept away by the current. The crossbowmen of the Dai army opened their bows and arrows at the cofferdam, shooting at the Qin soldiers who were staggered by the current.

The soldiers on the cofferdam are still working hard to dig the cofferdam, expand the existing gaps, and dig out three or four new gaps, and the water flow is more rapid, and after a while, the dozens of zhang square near the cofferdam has become an ocean.

However, at this time, other Qin troops also rushed to the rescue, and they naturally did not dare to go below the cofferdam, but killed the Dai army from both ends of the cofferdam. But the Dai army did not fight with the Qin army, and when they saw the reinforcements of the Qin army coming, they immediately returned to their rafts and drove away from the cofferdam, but on the cofferdam of dozens of zhang, more than ten gaps of size were left, and the water flowed continuously.

Seeing the retreat of the Dai army, the Qin army had no intention of pursuing the Dai army, and hurriedly blocked the gap, because at a distance of more than ten miles, there was a fortress camp of the Qin army, and if the water potential was not blocked, it might flood the camp, and once it caused a large-scale burst, then the consequences would be even more unimaginable. Therefore, if the army retreats, it is important to retreat, or to close the gap.

Originally, Wang Jian had fallen asleep in his big tent, but after hearing the news, he couldn't help but break out in a cold sweat, so Wang Jian couldn't care about sleeping anymore, hurriedly got up and dressed in armor, and ordered the mobilization of troops, and the gap in the cofferdam must be blocked.

But just after Wang Jian's order was handed down, another Qin soldier hurried into the big tent and said, "Report to the general, the cofferdam in the south has been attacked by the Dai army fleet, and the water is released. ”

It turned out that although the fleet of the Dai army had retreated, Ding Ce saw that there was still some time before the sky was high at this time, and most of the attention of the Qin army was also attracted, so he did not order to return to Shuizhai, but led the fleet to the south and launched another attack on the cofferdam.

The process is almost exactly similar to that in the East, with the Dai army first dispersing the defenders on the cofferdam with pottery missiles and crossbow guns, then the raft is docked, and the soldiers go out with shovels, picks, hoes and shovels to dig the cofferdam out of the water.

After hearing this, Wang Jian couldn't help but be taken aback, it seems that the defenders are not attacking all the way, maybe they are hit by the sound of the plateau, and his main direction of attack is the south instead of the north? If the Dai army destroys the cofferdam on a large scale, not only will the Qin army's plan to flood Daliang completely failed, but all the Qin army camps stationed outside the cofferdam may be flooded, and these hundreds of thousands of Qin army civilian servants may be buried outside Daliang City.

However, at this time, Wang Jian's experience of more than 40 years of military career finally experienced, and he completely calmed down, and immediately ordered, all the soldiers of the whole army got up, and immediately entered the state of alert, all the cofferdams should be strengthened and not relaxed, and at the same time ordered Xin Sheng to immediately lead the naval army to attack, of course, not to attack the girder, but to guard around the cofferdam and interfere with the army. Another 20,000 troops were sent to reinforce the cofferdam in the south.

As soon as a few orders were issued, I saw Zheng Guo hurriedly walk into Wang Jian's big tent and said, "General, what's going on?" ”

Wang Jian smiled bitterly and said: "The plateau is really powerful, it actually launched an attack at this time, and dug cofferdams in the southeast and southeast, and now I have sent people to intercept the gap." ”

Zheng Guo couldn't help but be surprised when he heard this, he was the best hydraulic engineer of this era, not only good at digging canals, but also proficient in river management, flood control and other technologies. Of course, I know the danger of a river embankment breach, because if the breach is too large, it is very difficult to think of blocking it. Therefore, Zheng Guo immediately said: "General, I will personally go to the gap to take a look." ”

Wang Jian nodded, because the scene must be a technician like Zheng Guo to preside over the overall situation, so he also hoped that Zheng Guo would rush to the scene to guide, and said: "Now there are two gaps, and the water order can only go to one place, does it matter if the other place matters?" ”

Zheng Guodao: "It's okay, I can send my younger brother to another execution point, and I can also take it for a while." ”

Wang Jian relieved his heart and said, "Then there is a labor order." As he spoke, he picked up a talisman from his desk, handed it to Zheng Guo, and said, "Shui Ling, please hold my warrant, you can command and dispatch all the troops on the scene." Then he dispatched a personal guard to protect Zheng Guo.

Fortunately, the gap dug by the Dai army was not large, and the Qin army was overwhelming, and there was a hydraulic engineer like Zheng Guo who was proficient in hydrology to command on the spot, so after fighting in the middle of the night, the Qin army finally blocked all the gaps. However, outside the cofferdams on both sides of the southeast, the water has reached a radius of several miles, and the water depth has reached three or four feet, so it is only a few dozen steps away from a camp in the east.

After Wang Jian received the report, he also breathed a sigh of relief, and at the same time he was lucky, fortunately, the plateau was just a small fight last night, if the plateau went all out, the Qin army would be really dangerous.

In fact, the plateau is not unwilling to attack with all its might, but it is indeed beyond its strength, because now there are only more than 60,000 troops in Daliang City, which is not enough to fully compete with the Qin army, in fact, although the army attacked two cofferdams in a row, but each time it can be used to destroy the cofferdam for a short time, it is only more than 20 minutes, and the reinforcements of the Qin army are coming. In addition, the camps of the Qin army are now extremely widely distributed, and it is impossible to flood all the camps of the Qin army if only one side of the cofferdam is opened.

Although he was busy in the middle of the night, Wang Jian still gathered the generals to discuss countermeasures.

In fact, Wang Jian didn't sleep for half a night, and he had already thought of several countermeasures: first, the existing Qin army besieging Daliang was divided into four groups, stationed in the four sides of Daliang City, based on the forts built on the periphery of Daliang, each fortress was stationed with 5,000 soldiers, and a certain number of trebuchets were prepared, and they were responsible for the continuous inspection and protection of the cofferdam day and night, while the other armies were moved to the high ground, and regularly sent troops to patrol.

Once the fleet of the modern army is assaulted, the soldiers are not allowed to stand on the cofferdam to meet the representative army, but first hide below the cofferdam, use the cofferdam to block the long-range attack of the representative army, and wait until the soldiers of the representative army have landed on the shore, and then re-board the cofferdam to meet the battle, so that the long-range weapons on the representative army's warship will lose their effect. The main purpose of the Qin army was to drag the Dai army, prevent the Dai army from destroying the cofferdam, and wait for their own reinforcements to come to support.

And the navy can no longer be idle, and every day a number of small fleets must be arranged to patrol around the cofferdam without interruption, in case the army launches another surprise attack.

After hearing this, the generals also thought that these measures of Wang Jian were feasible and should be implemented immediately.

In addition, there are large areas of stagnant water on the southeast side of the cofferdam, which has a great impact on the actions of the Qin army, and it is necessary to clean up the stagnant water.

But Zheng Guo built a small ditch to Wang Jian, which did not need to be too wide, three or four feet, and ordinary people could directly cross it, and the depth was only four or five feet, so that all the stagnant water could be diverted downstream of the chasm. After the stagnant water is drained, a ditch like this is dug around the cofferdam, so that if there is a breach in the cofferdam in the future, the stagnant water can be easily drained away. With the current manpower of the Qin army, as long as the route of the ditch is demarcated, it will take two or three days at most to successfully dig the ditch.

After Wang Jian heard this, he also agreed very much, Zheng Guo deserved to be the best water worker in the world, and the method he proposed was indeed a one-and-done policy, and now the Qin army has more than 300,000 civilian servants, even if they don't work every day, the Qin army still has to provide them with food and drink, it is better to find something useful for them to do.

Seeing that Wang Jianzhi accepted his own construction, Zheng Guo mentioned to Wang Jianyi again, and after the ditch was dug, the civilian servants all went to continue to increase the height and reinforcement of the cofferdam, and they could increase it as high as they could, so that it would be more difficult for the army to destroy the cofferdam, and it would be more time for the Qin army to come to the rescue. And even if the army digs the cofferdam again, it can directly take sand bags from both sides of the breach to fill the gap.

Wang Jian also had no objection, accepted all the construction proposals proposed by Zheng Guo, and ordered Zheng Guo to take full responsibility for the construction.