A distance of more than ten meters was reached in a flash. The Japanese tank soldiers and machine gunners had no time to open fire. Chu Ming and more than a dozen wounded soldiers rushed up roaringly.

"Boom...Boom..." The explosions of grenades rang one after another, and two of the Japanese Type 4295 light tank vehicles were destroyed on the spot. This was due to the poor power of the grenades equipped by the Sichuan Army, otherwise none of the four tanks would have been spared.

After a huge explosion, the Japanese infantrymen who followed the tanks also stood up one after another, holding guns, rushed up with their commanders, screaming and screaming.

At this time, the bearded man sitting in the trenches and not charging with Chu Ming and the others was smoking a cigarette he had turned out from a dead platoon leader.

Groups of Japanese soldiers rushed up one after another, howling in their mouths, the bearded man's speech that was completely incomprehensible. Just as more than a dozen Japanese jumped into the trench first, the bearded man smiled and pulled the grenade in his arms.

The grenade squeaked with blue smoke. After a sharp-eared Japanese soldier discovered the bearded man and the grenade in his arms, he screamed in horror: "Baga, grenade..."

However, before he finished speaking, he was overwhelmed by the explosion that exploded. With a loud "boom", the power of more than a dozen grenades exploded together was still extremely powerful.

The dozen Japanese who rushed into the trench were all blown away, and the fire rose up and rushed into the sky with thick smoke.

……………………………

In Taicang City, the first batch of gunpowder collected by Mr. Zhao has arrived. In addition, there are a large number of ceramic clay pots and other items. Zhang Xinghan immediately dispatched 500 soldiers who could make landmines from the engineering company and each battalion to participate in the thundermaking.

Outside the city, Zhang Xinghan and his guards were inspecting the progress of the positions outside the city. Suddenly, Luo Tianyou walked over quickly with a hurried look on his face.

When he arrived, Luo Tianyou quickly stood up and saluted: "The team is not good."

"What's wrong?" Zhang Xinghan asked immediately when he saw Luo Tianyou's face was in a hurry and didn't know what had happened.

"Bizhi led his men to dig the tunnel, but he couldn't dig it less than two meters deep just now." Luo Tianyou said with a embarrassed look on his face.

"Why can't you dig?" Zhang Xinghan asked in confusion.

"The geology here is really not suitable for digging tunnels. The soil is soft and moist. I am afraid that it will be digging deeper. If there is no need for Japanese bombing, the tunnels will collapse by themselves!" Luo Tianyou said with a heavy face.

"This is how." Zhang Xinghan couldn't help frowning and pondering when he heard this. He really didn't expect that the south of the Yangtze River is not as good as the north China. Most of the north China are mountainous and hilly areas, with hard soil and very suitable for digging tunnels. Taicang is located along the Yangtze River, and the ground is mostly paddy fields and lakes. As Luo Tianyou said, the soil is wet and soft.

The tunnel was shallow and could not become a hole at all. If it was dug deep, the hollowed-out soft soil would probably not be able to bear the pressure and collapse. Even if it could barely support it, if the Japanese attacked the ground, they would definitely bombard and bomb the Zhongrui regiment's position. In this way, the tunnel that was barely supported would definitely collapse because they could not withstand the pressure from the ground.

If this is true, the consequences will be extremely terrible. Once the tunnel collapses, the soldiers entering the tunnel will become turtles in the jar.

"Is there any good way?" Zhang Xinghan pondered for a moment and looked up and asked.

Luo Tianyou shook his head with a difficult face. Obviously, he had no good idea, otherwise he would not have come to find Zhang Xinghan.

For a moment, Zhang Xinghan could not think of any good solution. If there were no crisscrossing tunnels, even if the officers and soldiers of the Zhongrui regiment were brave and good at fighting and were not afraid of death, facing the Japanese who were several times more powerful than them, with aircraft, cannons and tanks, even if the entire army was wiped out, they would not be able to stop the Japanese's attack.

At that time, the national army's retreat route on the battlefield of Songhu will be cut off, and a great defeat will still occur, and the losses of 100,000 officers and soldiers and the outbreak of the Nanjing Massacre will inevitably be avoided.

"Let's go, go back to the regiment headquarters first." Zhang Xinghan said to Luo Tianyou with a heavy face.

"Yes!" Luo Tianyou responded and then followed Zhang Xinghan toward Taicang City.

Along the way, Zhang Xinghan thought of countless ways. The reason why he built undersea tunnels and undersea tunnels in later generations was that with the development and progress of science and technology, he had a large number of engineering materials such as steel and concrete and cement as support.

Although Zhang Xinghan only excavated authentic tunnels, not building undersea tunnels and undersea tunnels, and did not require any superb technology, he also did not have steel, concrete and cement that could reinforce authentic tunnels.

Let alone steel, even Chairman Jiang dares not say that he can produce a large amount of steel. At this time, China's steel production has not been high. Iron can barely meet the existing industry, but high-quality steel can only rely on imports.

Cement, which is now the grey, although China already had cement plants at this time, its cement production was extremely small. In small counties like Taicang, there might not be a cement building in the whole city.

Soon, the group returned to the Zhongrui Tuantuan headquarters located in the city. Zhang Xinghan first took out a cigarette and handed it to Luo Tianyou, then lit one for himself, took a deep breath, and fell into deep thought with his frown.

Recalling later generations, a kind of farming crop such as sweet potatoes used to store the fields in the plains was dug in rural areas, Zhang Xinghan's mind was filled with an inspiration.

There are many such cellars that are excavated in places with soft soil. Generally, local people will use solid logs as support. Although the tunnels they excavated are much deeper than those of the cellars, the weight of the wooden piles is much greater.

As long as there is a strong enough log in the tunnel, it can support the pressure from the ground.

Moreover, if the tunnel is dug deep, it may be able to dig a hard soil layer, so that the solidity of the tunnel can be greatly improved.

Because Zhang Xinghan remembers that when he was a child, someone built houses in the countryside. Some newly built houses were digging deep underground for four or five trees or even more in order to lay the foundation, so as to dig hard land.

After making up his attention, Zhang Xinghan immediately looked up at Luo Tianyou, who was also thinking hard, and said, "Lao Luo, I have thought of a way. We can do this. Dig the tunnel as deep as possible. If you can dig hard land within ten meters, you can dig the tunnel along the hard land, and then use solid logs as support for the tunnel. Also, tell the soldiers to try to strengthen the tunnel walls, so that the tunnel should be safe.

The deeper the digging, the more it can withstand the Japanese bombardment and heavy artillery bombardment. Zhang Xinghan naturally understood this principle.

"Okay, now we can only try this method." Luo Tianyou nodded immediately, then turned around and left.
Chapter completed!