When digging fortifications, if the time is urgent, you can use some explosives to point the local blasting, and if there is no explosives, you can use the gunpowder of grenades to make your own soil explosives.

The ratio and quantity of these and the fixed-point blasting are very familiar to the sappers, and Lao Hei found the students of the sapper section last time to explain how to use them.

In order to be able to prevent more than 150 heavy artillery of the Japanese army, Lao Hei found an instructor from the artillery department, studied the destructive power of the projectile impact point, and obtained a set of data, and set the thickness of the top of the tunnel and the protective thickness of the mouth of the tunnel.

It is very important that each tunnel has at least 2 entrances and exits, otherwise it will be killed by the enemy who enters the trench, even if you can't get in, people will blow up the hole and seal the mouth, enough for you to eat a pot, so, even if you don't need to cunning rabbit three holes, you have to have two holes.

There are also tunnel tactics that are not defending for the sake of defending, passive defense, you have such a little trick, one day the enemy will understand clearly, the enemy is not a fool, and will also study countermeasures, so, if you don't want to die, you have to take the initiative to defend.

Lao Hei asked everyone to think about how much money they have, how many people and how much firepower, what kind of goods the enemy on the opposite side is, what good goods (firepower) they have in their hands, and what orders and requirements their superiors have.

Then this defensive position must meet the requirements of the tactics of this battle, such as the preparation of active defense while constructing.

In order to preserve themselves to the greatest extent and carry forward their firepower; The combination of long, medium, and near, high, medium, and low firepower, the multi-layer fire network of mutual support, and the convenience of sorties are carried out, supplemented by the setting of various types of obstacles in front of the position, forming a positional defense system based on tunnels and supported by trenches.

According to their own firepower, they construct various firepower points that form cross-support, and according to the information brought by the observation holes and messengers, the commander quickly calculates and issues instructions, uses communication trenches to transport troops and ammunition, and gives full play to the superior firepower in a short period of time to thwart the enemy's attack.

When the enemy's artillery is covered, only a few observation posts are left on the position, and the rest of the people try to enter the tunnels to conceal themselves as much as possible, so as to avoid foolishly putting all the personnel on the position, because the dense personnel will not give full play to the best firepower advantage, but will cause unnecessary casualties.

At the moment when the enemy's artillery fire was extended, there was no time to hesitate at this time, and it was necessary to immediately rush out of the tunnel shelter and enter their respective combat positions.

Because as soon as the enemy's artillery fire extended, the infantry attack would immediately attack, and many times, the enemy would move to the front of the position, and only wait for the artillery fire to extend, a distance of four or five hundred meters, and in a minute or two, he would rush into the trench.

It is very dangerous not to suppress the enemy at a distance of fifty meters, because at this distance, the enemy can already attack with grenadiers and even grenades.

Coupled with the cover of light and heavy machine gun fire in the rear, a charge, ten or so seconds, that is, the time when a magazine may have just been replaced, the enemy can rush into the trench.

Once the enemy entered the trench, the fortifications he had worked so hard to dig would be in vain, and the two sides would enter the trench battle on an equal footing.

However, if you are prepared, the trench battle is not terrible, and it can be won, after all, the number of enemies who rush into the trench is not large, and you must not be nervous at this time, in fact, the enemy is even more nervous, because he enters our lair, and he is surrounded by danger.

At this time, it is possible to immediately organize the firepower of the second and third lines of defensive positions in depth to suppress the enemy's follow-up troops, and then concentrate mobile forces to destroy or repel the enemy who has entered the trenches through the familiar communication trenches and taking advantage of their unstable foothold.

So, depth, depth, depth; Lao Hei has repeatedly emphasized depth, in-depth positions, in-depth personnel, and in-depth firepower, and the position cannot be just a single line.

At the very least, one more should be built in the back, and if the firepower of the troops allows, more than three can be constructed, parallel to each other, and the communication trenches can be used to achieve cross-connection.

If the strength of the troops is allowed, auxiliary positions can be preset or constructed around the main position, and cooperation and protection between positions can be carried out.

And Lao Hei proposed a spatial depth that opened everyone's minds, that is, the depth under the position, similar to the tunnel under the trench, which is equivalent to hollowing out a position, the same as an ant's nest.

In this way, even if the enemy occupies the surface position, everyone comes out of the ground, and with a counter-charge, the unsuspecting enemy can be eliminated or driven away.

And the meaning of the in-depth personnel is not to take out all the combatants at once, but to have reserves and supplementary units, and only when the key to determining victory or defeat or the last moment of danger can all troops be pulled out and used.

Depth firepower is also almost the same, whether it is an individual or a whole team, there must be a very clear budget for the use of ammunition, how much you have fought, and how much you have left, you must remember it clearly.

You can't just go up and crackle, and you can beat all the ammunition indiscriminately, and run out, and at the last moment of the real decisive battle, you can drink the northwest wind.

How much ammunition is left in the team and how long it can hold out, as a commander, it is the most basic quality to prepare, so for defensive warfare, ammunition can be saved, but it really can't be saved, and then think of other methods.

With in-depth positions, personnel, and firepower, there is no need to rush to fight for every inch of land with the enemy, and you can flexibly retreat and counterattack.

When the surface position is occupied by a strong enemy, it can preserve the living forces, retreat to the tunnel, concentrate on protecting the tunnel mouth, resolutely block the enemy from entering the tunnel, and at the same time attract the enemy's firepower and personnel, and cooperate with the counterattack of the second-line troops or friendly forces in the adjacent positions.

The in-depth position controls the enemy's follow-up troops with firepower, and sends small detachments to attack the enemy from underground, other exits in the tunnel, etc.

During the counterattack, the troops in the tunnel carried out multi-channel attacks from the flank and rear in cooperation with the in-depth counterattack troops, encircled and annihilated the enemy, cleared out the remnants of the enemy, and recovered the position.

If the position is important, or the troops are large and equipped with artillery, the infantry and artillery can work closely together to hold the position; When the enemy attacks, the artillery of our defending troops forms a defensive fire network at the front of the position, concentrates on attacking the enemy who is assembled, attacking, and reinforcing it, and suppresses its artillery in depth; Of course, these are things that the artillerymen learned.

When our infantry retreated to the trench to fight, the artillery covered the enemy occupying the surface position with artillery fire, supported the infantry to hold the trench, and entered the counterattack operation.

More daring active defense, there are counter-charge hard-hitting tactics, there are also flank roundabout outflanking and attacking the enemy, there are also tunnels dug under the enemy's offensive position, blasting or drilling out of the ground for a surprise attack, or trenches are bent to dig in front of the enemy's position, and the tactics of imminent operations.

Or several defensive positions cooperate with each other, pretend to lose the surface position of the middle position, and then organize firepower to carry out a joint attack on the enemy who enters the position, and the ambush forces in the tunnel under the middle position can rush out and blossom in the middle.

These were very advanced tactics back then, but it was a pity that the top of the army didn't pay attention to them, and the three dogs were fortunate enough to learn this, but their strength was too small in the entire army after all, and they couldn't control the battle situation at all.

What's more, after graduating, they are only junior officers, and many times they are just carrying out the orders of their superiors, and they basically have no opportunity to build and command such a large-scale defensive battle.

(End of chapter)