While Chen Xin was preparing for the excavation plan, the military also slowed down its offensive. They gave up some caves and tunnels that had been built, instead defended the area that had been stabilized, and planned to collapse many passages, blocking all the roads that alien creatures broke through upwards, leaving only some of the holes for their own use.

After such adjustments, the military only needs a small number of troops to guard a few major channels left behind to block the path for alien creatures to attack upward.

And because of this adjustment of the attack to defense, most of the troops originally planned to attack the underground were temporarily idle.

The military did not really leave these troops idle. In addition to letting them continue to monitor the entire Dongting Lake area and preventing alien creatures from digging new channels to rush out of the ground, they were also preparing for the next clearance operation.

The military's offensive has not been very smooth before. On the one hand, it is due to the relationship between weapons, and on the other hand, it is because it is not suitable for combat in the underground tunnel environment.

Because of this reason, the military plans to conduct a training session on the existing troops during the three months of the excavation work, adjust the state and tactics of the troops so that they can exert stronger combat effectiveness in subsequent clearing operations, and at the same time they are more adaptable to the combat in underground caves and tunnels.

For this reason, the military specially reserved a small section of tunnels close to the surface that were not completely blocked, and opened them to the ground, rotated the idle troops into the tunnel, and fought with combat sub-body in the tunnel to study the tactics of fighting in tunnels and caves.

Because it is a specially reserved tunnel, the number of alien creatures in the tunnel is not as exaggerated as other tunnels, and the military also has greater room for trial and error and room for research on tactics.

By constantly putting various troops into the tunnel to fight, they were able to find more applicable tactics and conducting direct practical inspections, the military quickly developed a set of applicable tactics and quickly promoted them to all troops.

However, the military was not satisfied with this. On the one hand, they continued to let the troops explore tactical ways, while on the other hand, they came to Chen Xin, hoping that he could provide some more practical equipment for underground operations.

Chen Xin had expected the requirements made by the military, after all, the military put forward relevant requirements when discussing the offensive plan several times.

However, Chen Xin did not have any good ideas about the requirements put forward by the military.

Due to the environment in underground tunnels, various heavy vehicles cannot be accessed at all, and at most small vehicles such as Bobcat Assault Vehicles can be used.

Moreover, due to the narrow and complex terrain in the underground tunnel, heavy firepower such as various artillery can not be used at all. After all, one shot can only be fired for more than 100 meters and it will explode to the stone wall. If it is powerful, it will even cause the tunnel to collapse. No matter how hard the military is, it will not use heavy weapons in this situation.

Even the Titan's portable cannon was abandoned and used only a rotary machine gun.

However, even heavy machine guns are still in the question of bullets hitting the rock walls and causing jumps.

This has had a great impact on the advancement and combat of the troops, and has also made it difficult for the military to achieve more impressive results in previous operations.

This also puts Chen Xin in his conception of new weapons.

According to the requirements put forward by the military, Chen Xin could only think of tossing on small platforms such as the military's existing Bobcat Assault Vehicle, or designing new weapons for the Titan.

As a small multi-function vehicle platform that the military is now mainly equipped with the Army, the Bobcat Assault Vehicle has many things, such as light weight, small size, multiple functions, and strong adaptability. Before the disaster, the Army developed a series of modifications around the Bobcat Assault Vehicle, forming a car family.

Among these modifications, there are many 40mm assault guns and 120mm mortal howitzers are crazy.

You should know that the Bobcat Assault Vehicle is very small, with the body length of the 6*6 being only about three meters, and its weight is not even a ton.

However, even if the Bobcat assault vehicle can withstand a 120mm caliber cannon, it cannot achieve effective shooting in underground tunnel environments. The military has not been crazy enough to use this caliber cannon to fight tunnel warfare, so most of the time it is still equipped with heavy machine guns or small-caliber cannon models.

Even so, I still encountered many problems during use.

This also led to the urgent hope of the military to solve the problem of being unable to use large-power weapons in underground tunnels, and to put various heavy weapons into combat to achieve victory.

However, weapons with great power are all big blows. In order to pursue the killing effect, the 85mm grenade can produce about 900 effective fragments and can kill enemies within a range of 280 square meters. In the narrow tunnel, they are often shot by one shot, and both enemies and us are injured.

This also led to the fact that even though Chen Xin had a system, he really didn't think of any good ideas.

After all, the powerful weapons the military wants are all of this kind of virtue. The greater the power, the greater the damage area, which is really difficult to use in tunnels.

Previously, the military also mainly relied on heavy mechas and Titans to achieve certain results.

But this also caused terrible losses to Titans and heavy mechas. Logistics statistics concluded that the number of Titans and heavy mechas lost during the military's rework period was more than the previous defensive stage losses combined!

And what is more important is the driver's losses.

The heavy mecha in the tunnel is not bad, at least it is not that big, and there is still room for maneuvering and dodging. However, for the Titan, one can almost block a tunnel, and there is room for dodging only in some more spacious caves. This undoubtedly caused the Titan to bear a lot of attacks and caused the driver's casualties to rise sharply.

Faced with such a situation, Chen Xin himself urgently hopes to use heavy firepower in an environment like underground tunnels, so that the military can exert stronger combat effectiveness in the subsequent battles.

After all, even if the subsequent operations are carried out by excavation, the military still has to go deep into underground tunnels to fight. If there is no investment in new weapons, relying solely on tactical changes, it will be difficult to reduce casualties and equipment losses.

But this is not something that can be done easily. Even if Chen Xin can save a lot of research and development time, he has no clue or inspiration at this time and cannot think of how to solve this problem.

He grabbed his head in distress and curled the draft paper covered with various ideas in front of him into a ball and threw it towards the corner of the wall. Chen Xin was completely trapped: "The road to live-fire weapons is not working. Do you have to consider non-live-fire weapons?"
Chapter completed!