In the early morning, when the sun shines over the ridge and into the ravine, the earth boils again.

Guns!

The rumbling sound of artillery echoed in the mountains, and the shrill whistling of field artillery and the dull cry of mortar artillery echoed in the heavens and the earth.

The roar of the cannons made the valley boil again, and in the white smoke of gunpowder, the red dotted lines began to march towards the fortress at the top of the hill.

When the troops began to attack, Yu Shujie, as the commander of the front wing army, was churning with anger in his heart. His expression was even more anxious.

Four hours ago, before the sky was clear, Yu Shujie woke up on the marching bed, and when he opened his eyes, his first feeling was annoyance, not helplessness. Now, as he peered through the morning light at the small fortress on the top of the mountain, his anger grew more intense, and his breathing became more rapid.

"Hmmm......"

Like the officers and soldiers of the Ming army, Yu Shujie wore a straight military uniform, of course, because of the summer, so he did not wear a woolen military uniform, but a wear-resistant canvas military uniform, and a field telescope hung on his chest - this non-retractable monocular, because of its sturdiness and collision resistance, was welcomed by the army, and his left hand was on the handle of the saber.

This saber is a saber given by His Majesty the Emperor when Yu Shujie was promoted to a general in the third year of Xingqian, although this saber is not gorgeous, but it is also carefully made by famous craftsmen. He stood on a protruding slope in the middle of the valley with his saber in hand, his eyes fixed on the preface.

The sun slowly crossed the ridge, and a ray of sunlight shone obliquely on his thick body, and under the bath of the sun, he only felt a little stuffy, and the left hand holding the saber involuntarily broke out some sweat.

"It's been half a month......"

With this sentence in his mouth, Yu Shujie's breathing became a little short, and his eyes became more and more solemn.

Lieutenant Colonel Tian Liyuan was standing half a zhang away to his left, his eyes were also looking at the fortress, Ding Guoming was his orderly, just behind him, leading a black high-headed horse. If there is any reporter here now, he can observe him from a short distance, and then draw his profile with a pencil, and publish it in "Ming Pao", "Daming News", "Tianchao Weekly" or any other important newspaper or magazine, and then add the column title "Liupan Mountain pointed by General Yu's sword", of course, in such a news, he may be praised with all his words, but in fact, Yu Shujie's heart is extremely dissatisfied with himself!

As the commander of the front wing army, Yu Shujie knew that although the front wing army under his command had only more than 20,000 people, it only had 6 battalions of infantry, 2 battalions of cavalry and 2 battalions of artillery, which was only a forward force in the army of this western expedition. Now the situation on the battlefield is very obvious, and the Ming Dynasty has put the noose around the neck of the Manchus, waiting for the final strangulation.

However, the fortresses along the way made this final strangulation difficult.

Half a month!

Half a month of delay in front of a fortress, then how many fortresses are there next, is the war so indefinitely prolonged? Do you want to gnaw on bones like ants now, one after another?

"I should be able to wrap up ...... today"

Thinking of receiving the report before, Yu Shujie felt much better, and his breathing was a little easier.

"General."

Tian Liyuan turned his face and said to Shujie.

"As soon as the engineer brigade completed the blasting of the fortress, the thirty-fifth battalion began to attack."

Yu Shujie nodded.

He chose the thirty-fifth battalion, the most elite of the forward flank army, for this decisive attack. Sun Yicheng, the commander of the 35th Battalion, is not tall, but he is extremely capable, he is a veteran who has been in Jiangyin since Long, he knows this fellow countryman, he believes that Sun Yicheng can complete this task, and many soldiers of the 35th Battalion have experienced the baptism of battles all the way since Tongguan, and they are reliable.

As long as the sappers' blasting operation was completed, the 35th Battalion would definitely be able to knock down the fortress.

"If it weren't for the mountain......"

Thinking that in the past half month, the sappers had dug an explosion tunnel in the hard mountain, Yu Shujie felt a wave of anger hit him again.

It was the peculiar terrain of the mountains that slowed down the attack.

"In another hour, we can blast it!"

When Yu Shujie urged the sappers to speed up, in a simple civil fortification less than 100 fathoms (meters) from the top of the mountain, the oil lamp illuminated the fortification, inside the fortification, a half-person height and width of only two feet in the cave from time to time from the sound of metal impact, in the past half a month, hundreds of sappers have been digging a tunnel in the belly of the mountain with hammers and steel drills day and night.

When they were digging tunnels in the mountains, the attacking troops were actually feints, although the attack seemed to be fierce, but in fact they were constantly attacking with small and medium-sized forces such as squadrons and brigades, so as to prevent the Qing army from discovering and suspecting the Ming army's construction attempts, even at night, they would bombard it at every turn, and from time to time they would shell it for a while, and the Qing army was exhausted, dizzy, and miserable. Under the cover of shelling, bombing, and feints, the Qing army was distracted, but the progress of the project was not fast, after all, they needed to dig a tunnel in the mountains.

Compared with the past, after ten years of technical improvement, now the engineering units of the Ming army have mastered the extremely advanced tunneling technology, accurate measurements make the tunnels they dig will not deviate, and the blasting charge is also extremely scientific, neither too much waste of gunpowder, nor too little to cause insufficient power, unable to destroy the city wall or fortress.

Although entering the tunnel operation, the construction difficulty has increased greatly, one is that the working face is narrow, and the other is that it cannot be operated upright, and the progress is greatly reduced. However, after half a month of non-stop construction, the tunnel was finally dug to the bottom of the Qing fortress, and after measuring the position and determining that the Qing fortress was above the tunnel, with an order, the soldiers immediately began to carry boxes of gunpowder into the tunnel, and soon as 5 tons of gunpowder were loaded into the tunnel medicine room.

The medicine room is located directly below the main fort, the tunnel turns to dig at 90 degrees, the excavation operation is very rough, in fact, as long as it can be loaded with explosives, after the explosives are filled in place, after taking some special fixing and protection measures for the detonator and the fuse, the sappers began to exit the tunnel, and then turned back to fill a large amount of soil, and tamped it with multi-layer sacks, and closed it tightly together with the turning part of the tunnel and most of the tunnel.

"The angle is set the deviation, and the level is set the height...... It's an extremely simple thing to do outside the tunnel, but once you're in the tunnel, it's not the same thing. The construction staff is not easy to grasp ......"

While the sappers were making final preparations for the blasting, Sun Yicheng, who was waiting for the attack at the second sortie point, listened to the captain of the engineer brigade explain that there were some problems encountered in the tunnel blasting operation.

In order to illustrate these things, Li Yinan, the captain of the engineering brigade, squatted on the ground, drawing a few lines on the ground with a tree branch, and at the same time drawing two figures on the palm of his hand towards Sun Yicheng.

One is a right-angled triangle, and after drawing this figure, he explained.

"Regardless of the altitude of the main peak, as long as the ground center of the two tunnel mouths is "zero height", "zero angle" and "zero distance" and the relative height of the main peak can be quickly calculated by using various instruments to measure or calculate, and the straight-line distance and azimuth ...... between the height of the medicine room and the mouth of the tunnel."

Sun Yicheng didn't know much about these professional terms, but it didn't prevent him from understanding the key graphically, and now he was like a student, where he was seriously studying this kind of blasting operation.

"What is this?"

He asked, gesturing to another figure.

"This is the explosives room."

Holding a branch and pointing to the schematic diagram of the medicine room on the ground, Li Yinan explained.

“…… A straight line to the end, then a ninety-degree turn, like a "T" shape. The intention of this is that if the medicine room is located in the middle of the tunnel, it must be turned 90 degrees, otherwise the power of the explosion will be lost along the tunnel. No matter how it is sealed, it is like paper, and it is useless at all. If you turn 90 degrees, it is equivalent to evenly distributing 50 percent of the longitudinal blasting force to the transverse, and most of the steering and pit are completely closed, and at the moment of explosion, a huge amount of energy is generated, just like a disemboweled bullet will not turn. Unleash the power of the explosion to the fullest, completely destroying the main castle above......"

When Li Yinan explained, his expression was a little proud, and he even said it deliberately.

"This method of blasting operation was studied by several instructors when I was studying engineering at the army school."

When he said this, Sun Yicheng looked at him in surprise.

"You invented it? How about it, can you get rid of this fortress this time? ”

Facing the battalion commander's inquiry, Li Yinan said confidently.

"Please rest assured that the person in charge of each tunnel is a person personally selected by me, and all the sappers have been strictly trained. Each squad leader with a shift should advance five fathoms without deviation, step excavation, and based on this distance, repair a horizontal step, such as a stairwell platform, and advance five meters on each step, and so on. Each platoon commander must ensure that there is no mistake in advancing ten fathoms. Using the dug tunnel as a reference, after I checked and confirmed, I continued to move forward. Now the medicine room is located directly below the fortress, 5 tons of gunpowder, not too much, no less, according to the soil quality, depth, explosion range size, explosive equivalent and other formulas, I repeatedly calculated, blowing up the Qing army's fortress required a total of 2.5 tons to 3 tons of gunpowder. ”

Looking at Sun Yicheng, Li Yinan added.

"That's a full double the standard that was stated, enough to raze the entire fortress to the ground."

"If that's the case, doesn't that mean that the fortress can be blown up at once, and then the brethren won't need to storm it at all?"

"Hmmm......"

Li Yinan replied casually.

"It's pretty much the same, but there will inevitably be some fish that slip through the net."

As the two spoke, the sound of guns echoed on the battlefield from time to time, and the feint troops were still covering the work of the engineers. After all, the feints will not stop until the sappers have completed their final preparations.

It was not until the sappers had completely exploded in the tunnel and began to evacuate the tunnel that the feint troops stopped their attack and withdrew backwards from the blasting range, and at nearly noon, they had all retreated to a safe position.

"Hoo ......"

Hiding in the trenches, Li Yilang's eyes were staring at the fortress of the Qing army, he and his comrades-in-arms were all looking at the fortress of the Qing army, they had already learned from the commander that their previous task was to cover the operation of the engineers, and now the engineers have completed the preparation of the blasting operation, as long as the fuse is pulled, it will not be long before this seemingly insurmountable fortress will be razed to the ground.

"They're back!"

Li Buting, who was hiding behind the perforation, looked at the retreating Ming army, looking at the appearance of those red figures retreating, and for some reason, a wave of ominous signs surged in his heart.

"Something must be wrong!"

Although he didn't know what was going on, Li Buting's heart still swelled with unease.

"Today's Minggou retreat is enough to be neat."

"Not really!"

"When did they just quit so simply?"

"Don't be unkind!"

When the Qing army in the fortress stared at the retreating Ming army suspiciously, there was full of doubts and speculation about the unusual actions of the Ming army.

Yu Shujie's eyes stared at the stone five-star fortress, the corners of his lips raised slightly, and he coldly ordered: "Detonate!" ”

As soon as his order was issued, there was a herald who used a signal tube to shoot a signal flare in the air, and seeing the fire dragon dragged out of the signal flare in the air, Sun Yicheng gave an order to the front, and the sappers near the tunnel immediately pulled the fuse "Zi", and the fuse burned up, burning towards the end of the tunnel in the bamboo tube.

Because the fuse is more than ten meters long, the waiting is anxious, and when the ignition sappers fled into the trenches, Sun Yicheng stared at the fortress anxiously, waiting for the moment when the fortress was razed to the ground.

One minute.

Two minutes.

Three-minute ......

After waiting for more than twenty minutes, with a loud and shocking sound, the seemingly solid mountain cracked like a piece of paper, and the earth shook the mountain and the fortress on the mountain, and the whole thing was lifted upside down.

The hill was overturned and leveled in its entirety. The fortress is completely news, and there are only a dozen people in the Qing army in the fortress who survived, and if they don't die, they will be blown up, and they are shocked and crazy. In the smoke of the explosion, a cannon barrel flew half a mile away along with the blown boulder, landed down the hill and even killed a horse - the only casualty in the final battle of the Liupan Mountain fortress.

After the earth shook, as the smoke slowly cleared, the soldiers in the trenches all stood up in shock, their eyes fixed on the leveled hill, and muttered to their lips.

"This, this...... What the is this...... Just blow them up later......"

。 Book Reading House