The shell fell directly through the top of the arc and fell in the middle of a group of Japanese. This shell uses a crude delayed detonation fuse with a delay of 5 seconds. At this time, almost all the Japanese soldiers recovered from their panic, thought it was a dud, and began to rejoice that they did not die.

The front-line observer lay in the grass, staring at the dark bunker. Watch as it suddenly explodes from within, blowing the entire top away. In one day, the pillbox withstood several artillery attacks and sapper blasts, but now, the pillbox was reimbursed with a single shot.

The rear of the Japanese army received a report that a pillbox had exploded, and the rear commander Ito was somewhat overwhelmed, speculating that the internal ammunition might have detonated. He ran to the top floor of the headquarters and looked in all directions with a telescope. His bunkers are evenly scattered around the city, with four main bunkers and the surrounding bunker group as support points in one direction, only one is lost, and the rest of the bunkers can still make up for the holes in the firepower and prevent the enemy from taking advantage of them, but if he loses two, the situation will be very delicate, and he waits anxiously to see what else will happen.

Zhou Youfu tasted the sweetness and felt that the thing given by Chu Tingchang was really a treasure. He ordered the sappers to use the extra rails and repair several sections of the branch line destroyed by the enemy in preparation for this cannon fire.

Due to the fact that the enemy pillboxes were scattered all over the place, not every target could be reached by this gun. However, it doesn't need to be extended too far, as these bunkers are built around the fortification, so you only need to add a few hundred meters of spurs. Due to the readiness of the roadbed and the accuracy of the sappers, soon the train was again sorted, and in order to cover his actions, the infantry also made several surprise attacks, capturing a number of minor, but possibly threatening enemy positions of the armored train.

These attacks completely confused the enemy's judgment, and Ito was scraping together reserves to block the passage behind the smashed pillboxes, but instead of attacking through this gap, the Chinese troops unhurriedly attacked some secondary positions in other directions, and there was no correlation between these attacks and the shelling, which was really incomprehensible to him.

According to the general military principle, it is correct to concentrate forces at the breakthrough point and continuously develop victories, but the enemy has gone the opposite way, fighting blindly with a hammer in the east and a mallet in the west.

While the Japanese were confused, the armored train slowly moved into a new position, and they approached the direct fire of the enemy's pillbox, and the enemy was unaware. Because of the accurate maps provided by the British prisoners of war, coupled with the artillery of Tao Mingzhang's strict training department, and excellent geodetic technology, the attack can be carried out exactly according to the map, without the need to fire flares to observe the target, of course, the scouts deployed in front are not nothing, their task is to observe/evaluate the effect of the attack.

The mortars around began to fire, of course, just to tickle the enemy pillbox group, the main fort here can carry 105 howitzer attacks, and the rest of the sub-forts can also resist the direct attack of 75 mm caliber mountain guns.

Due to the formation of enemy fortresses, the first shells did not attack the main fort. The artillerymen followed the map and found the cantonment hole on the side of the main fort, and since the captured British sappers were involved in the whole construction process, the map they provided was the same as that hung in Ito's office, and even some weaknesses were marked more clearly than on Ito's map.

The cave is deep underground, and a ton of aerial bombs cannot be exploded, but its weakness lies in the exit and vents, and the Japanese specially selected these professional engineers from the prisoners of war to participate in the construction, ostensibly a model of resource optimization, and this experience is also written into the annual summary report of the Southern Army, but now, they have to pay it back with interest.

300 kg shells fell from the sky and smashed directly on the exit, it was much better than the accuracy of the Americans*, and the accuracy was close to that of later generations of satellite guidance*.

The Japanese bunkers were built according to the latest 1942 regulations, with good internal lighting and ventilation, and the parts were reasonably spaced, and the exterior was connected to the outside by a tortuous and impermeable cement staircase. The exit is covered by elaborate camouflage and trees, and it is impossible to detect planes flying over even 100 meters in the air. * Fell right on the deadliest spot - three meters of soil above the passage. In an instant, the passage was covered with earth.

The soldiers on the train quickly reloaded, and they had to compress the time for the second shot from 10 minutes to 3 minutes, because the spare exits and vents were about to be blown up, and the enemy could not escape. Of course, both places are also accurately described on the drawings.

The Japanese troops in the cave felt a huge tremor in the ground, but they remained quiet, because the internal lighting and communication were not destroyed, and they were well-trained, unhurried, and waiting for orders from their superiors.

The second shell accurately destroyed exit No. 2. The reload time for the third shot was reduced to two and a half minutes. The target this time was the vents. The purpose is still not to destroy the hidden soldier hole below, but to block this passage with the thrown soil and suffocate the people below.

Again, the attack worked. The Japanese were unprepared, and after the vent was suddenly blocked, the diesel generators that were still in operation began to rapidly consume underground oxygen while emitting exhaust gases containing large amounts of carbon monoxide.

After the diesel engine stopped due to insufficient oxygen supply, the internal lighting suddenly failed, and the people below panicked, but the concentration of carbon dioxide and carbon monoxide was already very high, and choking smoke filled the entire bomb shelter. The army lost command and began to run towards the exit, trying to dig away the blocked mud with their hands, but the mud in the collapse kept filling up and could not be cut at all. The struggling men ran frantically and trampled on their own, causing a large number of dead and wounded.

The train guns then turned to the main pillbox, and by this time the nearby enemy had already noticed it and began to fire flares into the air. When the flare fell, the Japanese saw a train stopped not far away, and the commander couldn't believe his eyes, the railroad tracks in that place were personally supervised by him.

The squad leader stationed in the bunker began to make phone calls. But it was too late. Shells fell from the sky, opening skylights over their heads. After 5 seconds, the shell exploded, and the huge amount of * explosion in such a small space (including the ammunition stored by the Japanese army) would never leave a living hole, and the huge cement block thrown down easily destroyed the nearby anti-aircraft gun position.

Major General Sagara Ito, who was stationed in Legoku, saw through the telescope that a mushroom cloud was rising from the firelight, and he judged that it was another time when the ammunition depot was detonated, and how did the enemy smash these pillboxes one after another? Even if you push the bulky 155 guns in front of the position, you won't be able to smash them so quickly.

The armored vehicles slowly retreated, and the Japanese retaliated with fire, mainly mortars, but not accurately. Before dawn, Zhou Youfu still needed to shoot this cannon once. He needed to uproot the three deadliest points on the periphery, and these bunkers were covering each other with the help of horns.

Sure enough, the Japanese army was prepared, and flares began to be fired non-stop around the pillboxes, thinking that it was the work of the Chinese engineer death squad to sneak attack, but this misjudgment caused trouble for the armored train, after all, its range was very short and easy to expose.

Zhou Youfu concentrated his artillery on attacking the enemy's pillbox, and quickly suppressed the enemy's fire on the surface position, and the enemy did not dare to fire flares indiscriminately.

Seeing the stitches, the train went out again obscenely and quietly slipped into the position. This time, it didn't dare to stay too long, and directly attacked the core main fort of the bunker group, and it was solved in one shot.

Japan's standardized bunkers are destined to end no different. When Captain Ito saw the third fireball in the telescope, he was so angry that he fainted, and the soldiers next to him hurriedly dragged him down for first aid.

At dawn, Zhou Youfu changed into an armored train equipped with 75mm mountain guns, and Lie Cheng drove through the middle of three enemy pillboxes to launch a strong attack to uproot the remaining fortifications.

The sappers braved a hail of bullets to lay the tracks for the train to move forward step by step, fortunately with the huge wreckage around it as cover. The enemy, having lost its main defensive barrier and direct firepower, could only continue to fire mortars at the approximate area of the rising steam in order to thwart the attack, but the damage to the fortified armored trains was minimal, and the main casualties came from the engineers who built the railway. But the armoured vehicles were already slowly advancing, and this difficult advance was also to prepare for the suppression operation at night, so that the mortars, which had a range of only 1.2 kilometers, could get closer to the other pillboxes. Lao Zhou gradually ran into his own offensive methods on Chu Tingchang's plan. The Japanese plan to hold on to the fortress for two months and kill and wound 20,000 people, and he has to let the devils see who has the final say.

The commander fell into a coma, causing the Japanese to temporarily lose their supreme decision, and the troops below became impatient, and some units began to leave the fortified bunkers in an attempt to recapture their positions by charge. This was exactly what happened to Zhou Youfu, and his artillery group was waiting for the enemy to leave the solid bunker and make a fool. At the same time, U.S. planes arrived and began to bomb the city indiscriminately, and the U.S. military also received information from British prisoners of war, and they used the temple in the city as a benchmark to see the glittering golden dome of the stupa at an altitude of 4,000 meters, and as a reference, they could easily find the corresponding target area.

The B17 bombers that arrived from India were equipped with a new type of bombing commander. This kind of commander provides a stable aiming/tracking platform through a gyroscope, and calculates the ground speed more accurately through the integration computer, which increases the accuracy of bombing by orders of magnitude, of course, provided that the aircraft is not interfered with by ground anti-aircraft gun fire and maintains a long period of level flight.

The low-altitude bombs of the B25 bombers, which arrived in advance, well diverted the attention of the Japanese anti-aircraft guns. This allowed the B17 bomber to practice this complex bomb delivery for the first time.

The B17 pilots used the Norton Command Instrument to take over flight control and achieve the most primitive Spitfire cross-linking, which will be another leap forward in human warfare technology. * Falling from the sky and falling densely around the Japanese artillery positions and ammunition depots in the city, inflicting a rare heavy casualty on the Japanese army. In the past, the Japanese were more afraid of low-altitude bombing, and the error of high-altitude bombing was often more than one kilometer, so they were not too nervous. But in this bombing, all favorable factors were concentrated on the side of the Allies, including precision fire control, accurate intelligence, cloudless skies, and extremely low wind speeds.