Tactics and duties for trench fighting

by Georges Etienne Bertrand; Oscar N. Solbert

III. Fighting in the Interior of the Position

If the hostile assault on the first line is successful, the fight for the occupation of the position, which takes place in the interior, has only begun. Opposing his frontal progression through the position, the enemy will encounter, as we know, a series of defensive lines disposed in depth. Also, for instance, if a nest of resistance holds up the progress of a part of the assaulting troops, the successive overlapping waves will carry on along the flanks of this stronghold. If, then, the position is strongly divided into compartments, the fire of such defenses will take these overlapping troops in the flank and rout them. The defenders may also play an active rôle and the enemy is likely to encounter new troops sent up for the purpose of counterattack.

The division of the ground in support points, centers of resistance and sectors, has precisely for its object the localization of the enemy’s attacks. Each area must be organized to defend itself, independently of any other part of the position. Consequently, the officers must explain this condition to their men, so that they will have no concern if they see that the enemy has penetrated and is attacking them on the flank or rear. On the other hand, if several of these compartments hold their ground, the enemy may find himself surrounded in a certain area and cut off from the rear by barrage fire. Thus abandoned in a part of the position that he has momentarily taken, a vigorous counterattack will drive him out.

Defense of an Area. The defense of each area is made similarly to that of the first line, as these areas embrace the successive lines of the position. The areas range in importance from front to rear, the support point embracing the first line, the center of resistance the first two lines, and the sector all three lines of the position. The alarm of an attack is relayed by the area commanders, the captain to the battalion commander, who in turn communicates it to the colonel of the sector. Not only the attacked portion of the sector is affected by this alarm, but the whole sector, so to speak, takes up arms. Let us see what happens as a result of this.

All defenders of the area who have a special duty, immediately occupy their posts and remain there awaiting developments of the attack. For example, telephone men will remain at their instruments, runners will repair to their relay posts, observers occupy their observatories, and chiefs and headquarters officers remain at their command posts. And above all, the machine gun crews will man the guns disposed for interior fighting.

At the same time, the different troops held in reserve in the successive lines are used to hold their own line, to reinforce the line in front, or to make counterattacks. When the alarm is given, all supporting reserve troops take their places in their own lines. In each support point, the platoons held in reserve are sent forward as reinforcements to, or to make counterattacks against, the firing line. Similarly, in each center of resistance the companies held in reserve are employed as reinforcements or to recapture the first line. If, upon arriving at the first line, these troops receive no orders for particular duty, they replace the reserve platoons of the support point. Likewise, the sector reserve of the third line is sent forward to or, in case the enemy has taken it, against the second line. The static or passive organization of the defense lies in the series of lines of trenches disposed in depth, but the active rôle of the defender is carried out in these successive waves of defense moving forward in definite limits to meet the attack, not only to repulse it but to inflict as much loss as possible to the enemy. This transforms the defensive combat into more nearly a fight in the open ground, with the spirit of the offensive.

The Counterattack. It follows that the last and, very often, the most decisive means of defense of the sector is the counterattack. In each center of resistance, a counterattack has for its purpose the retaking of the first line when this is captured by the enemy. It is made by the battalion reserves located in the reserve line.

The sooner the counterattack is made after its necessity, the more effective it will be. It should arrive at the first line almost, one might say, at the same time that the enemy does. At any rate, the counterattack should strike the enemy by surprise while he is still in a state of disorganization. Consequently, in the plan of defense of the battalion, the counterattack must be foreseen and all its details must be laid down. All these details must be known and practiced by the troops who are to execute the counterattack, so that when the alarm is given the counterattack will start automatically without orders and be carried to a finish like a good piece of team-work.

The counterattack is launched on the initiative of the leader of these troops, without waiting for the orders of the battalion commander. The latter may not know the exact situation nor be so located in the area as to appreciate the opportunity of the counterattack.

Troops Detailed for the Counterattack. The company, or companies, held as reserve of the center of resistance, are divided into half-companies or platoons under the command of a single leader. Each one of these detachments is assigned to a support point and is put at the disposal of the captain commanding the same, to counterattack on his first line if captured by the enemy. In order to secure the proper liaison between these two units, the counterattack troops send a messenger to the command post of the support point which they are assigned to. When the hostile attack is executed and counterattack troops are needed, the captain sends this messenger back to call them up.

Routes or Directions for Counterattacks. Each detachment of counterattack troops has a fixed route for its attack laid down in the plan of defense. Usually a boyau that it employs or along which it travels, fixes the direction. For this reason, in the interior of the position gaps are left in the barbed wire entanglements to permit the passage of these troops in the counterattack. Portable chevaux-de-frise are employed to fill up these gaps when necessary.

Form of the Counterattack. The counterattack may be executed as a frontal or a flank attack. Frontal counterattacks are, perhaps, not as effective as the latter, but they are more easily executed, especially in the case where exact knowledge of the situation in the line in front is not known. This is the form of advance employed in the support point where the reinforcing platoons, starting forward to strengthen the line and finding it captured, change their tactics by leaping over the top and charging the line with grenades and bayonets.

A counterattack to the flank usually involves a little maneuvering. The most successful of these attacks are those executed in two detachments—for example, a party of grenadiers may attack the enemy occupying a part of the area either on one or both flanks. Its approach is usually through a trench or boyau. A second party of riflemen, at the same time, will make a frontal attack on the enemy over the top with bayonets. To completely surround the enemy, an artillery barrage is sometimes established to cut him off from the rear.

The battalion commander works out the plan of counterattack down to the most minute detail. But when the hostile attack is carried out, he is no longer the master of it. All the foreseen movements start at the proper time and are carried out in their workings like a piece of mechanism. The time of the start of the counterattack is in reality given by the enemy himself.

Repair of the Position. After a hostile attack has been repulsed, the chief of area must realize that similar attempts may be made without delay. The first and most important repair work that must be done is to construct a parapet along the firing line. There may be no trench left along this line, but a fire parapet of sandbags must be constructed immediately. At night reserve troops are brought up with tools and sandbags to put the line in the best state of defense possible.

CHAPTER VI
ATTACK OF A POSITION

Phases of the Attack. As we have already learned, the attack of a position by a unit comprises three phases:

The preparation of the attack.

The assault against the first hostile line.

The exploitation of the success by fighting in the interior of the position for its occupation.

These phases are the same as those in open ground warfare, but their importance, aspect, and order are not the same. Especially the preparation of a trench attack is such a preponderant phase of the attack that upon the manner of its execution depends the success of the attack. The exploitation of the success is a long and decisive operation. In trench warfare, the assault is only the beginning of the fighting for a position, and its purpose is to make a breach in the enemy’s first line. Through this breach, the reinforcing and reserve troops are pushed in behind the assaulting columns to deliver the real combat for the capture and occupation of the position.

Thus we see that the assault, which in open ground warfare is the final phase of the battle, is, on the contrary, in trench warfare the first move of the fight. In open warfare, the order of the battle is: the preparation, the approach march and infantry combat, and finally, the assault. An offensive in trench fighting consists of, first, the preparation; next, the assault against the first line; and last of all, the interior fighting for the position.

The cause of this reversion of the rôles of the attacking troops in a trench offensive operation lies in the strength and stability of the fortified front. It is impossible to maneuver against a continuous line which extends without a single breach. It is only possible to maneuver behind the first line or within the position after a breach has been made. If a part of the first line gives way before the pressure of the assailants, the leader of the attacking units pushes forward his troops through this breach without consideration of the strategical value of the part of the line broken.