I. During the Preparation of the Hostile Attack
Revealing Symptoms of the Attack. The preparation of the hostile attack reveals itself by different preparations:
(1) The activity of the enemy:
His infantry will send out more numerous and aggressive patrols and reconnaissance parties.
His artillery will increase its daily destructive fire.
It will multiply its number of registering shots, establish barrage fires in the interior of your position, and begin to concentrate on communication routes.
His air service will take on unusual activities.
(2) Vigilant observation of roads and territory behind the enemy’s lines may reveal convoys carrying troops and supplies, the assembling of troops in woods, etc. (smoke from their kitchens), accumulation of materials in depots (often accompanied by explosions in artillery dumps).
(3) The observation service may discover new hostile works, such as the contraction of parallels of departure out in front of his first line. There may be also successive parallels behind the nearest jumping-off trench.
(4) Prisoners and deserters, who become more numerous because of the approaching offensive, may give valuable information concerning the coming attack.
The task of discovering the enemy’s preparation for an attack is incumbent upon all ranks, but above all, this duty devolves particularly upon the information service, balloon and air service, and artillery observers. In the sector, the intelligence officer must perfect his system of observation to the highest degree. The information in the daily reports is carefully sorted and tested.
Preventive Measures before the Attack. During this time, each chief of area takes all preventive measures possible against the coming attack. The attack is an expected event for which all must be prepared. The preparation simply consists in perfecting and carrying out of the original plan of defense.
Perfecting the Organization of the Position. New lines are created. The number of continuous lines between strong points and successive lines for defense in depth are increased.
Old lines, which are enfiladed by the enemy or which do not give flanking fire, are rectified or abandoned for new ones. The number of boyaux and communicating ditches are multiplied to facilitate the bringing up of reinforcements.
New accessories of defense are constructed and the old ones strengthened. This is especially done in the interior of the position with respect to parallel and perpendicular barbed wire belts to divide the position into compartments capable of all-round defense.
Additional false works are created, to waste the enemy’s artillery fire, The art of camouflage is extensively used during this phase. New shelter accommodations and dugouts are constructed for the better protection of the garrison during the preliminary bombardment.
Increase of the Control and Discipline of the Defense. The guard and observation services are reinforced. Sentinels, observers, and patrols are held to a stricter account of their duties.
Machine gun leaders are particular to perfect the disposition of their guns in depth of the position for interior fighting. The sector for each gun emplacement is carefully verified. Dugouts serving as shelters for guns during the bombardment are strengthened.
The support artillery must constantly verify the settings of their barrages. Numerous exercises are carried out for the call of the barrage with rockets, so as to keep the artillery constantly on the alert.
Liaison must be assured by other means than the telephone as this latter system usually breaks down under severe and continuous shelling. When the telephone is out of order, chains of runners must be resorted to. In the ordinary life of the trenches runners are not used. For this reason, when an attack is expected, new chains of runners must be established.
Supplies in the depots must be kept up to contemplated requirements. Besides the regular depots of the sector, numerous small ones are now established for the better distribution of extra ammunition and for the supply of reinforcing and counterattack troops. Supply parties are detailed to carry up ammunition during the battle.
Moral Preparation of the Troops. When an attack is expected, this fact must be told the garrison of each area, so that it can better prepare for it. The troops must not be left in ignorance, and upon the officers informing them devolves the responsibility of performing this task in such a manner as to raise the morale of their troops. The men must be maintained in the best of physical condition. Their food supply must be regular, of good quality, and sufficient. The tour of duty of the interior relief of the first line is shortened.
Duties during the Preliminary Bombardment. The most important and final act in preparation for the attack is a heavy and unusual bombardment of the position. Concentrated fire is brought to bear upon all visible points of the sector to demolish trenches, emplacements, dugouts, routes, and ammunition dumps, and to destroy the barbed wire entanglements. Certain batteries are detailed for counter-battery work. Barrages are established to prevent reinforcements from coming up and to cut communications with the rear. Against this bombardment, the defense has both a passive and an active rôle to play.
Maintenance of the Garrison during the Bombardment. The violence of preliminary bombardments is ever increasing and there seems to be no limit. High explosive shells of every caliber are used against the position. Any element of your system that is not properly concealed and can be located by the enemy is subjected to concentrated artillery fire until it is blown out of existence. Casualties inflicted upon the garrison are severe—in fact, it would seem from the violence of the artillery fire that few of the garrison could escape. However, when the assault develops, a machine gun may be found intact here and there in the position. One or two of these powerful weapons, by the use of flanking fire, may be enough to cause the failure of the enemy’s attack. It is possible to say that upon the use of M. G.’s depends the whole interior defense of the sector.
The maintenance of the garrison during the bombardment depends, of course, upon the number and depth of dugouts. The service of defense, however, requires many of the troops to execute their duties in the open trenches. The leaders must set the example in this respect by making their rounds, and taking their posts to observe the area from the observation posts. In other words, they must not stay in their dugouts.
The bombardment naturally causes a great deal of repair work to be done. This is executed at night or during lulls in the shelling. Only emergency works, however, are executed, such as repairing of accessory defenses, cleaning of trenches and rebuilding of shelters. When this work becomes too heavy for the garrison, reserve troops are brought up to assist.
Reply with Artillery Fire. The only means to decrease the effectiveness of the hostile bombardment is to reply with your own artillery. For this purpose, a certain part of your artillery is detailed for counter-battery work. The emplacements or approximate locations of the hostile guns are set down on maps. These are divided amongst the counter-battery artillery who attempt to silence or neutralize the same.
In a sector, the commander may ask for what is known as counter-preparation fire. This fire is similar to the preliminary bombardment of the enemy. It covers the entire position of the enemy and is just as methodical in its scope. All the artillery that is at the disposal of the general is used for this purpose, and consequently the call for this fire must be through the general.
Similar to the counter-preparation fire, but on a smaller scale, is what is known as preventive fire which may be called for from the support artillery. This fire covers the first and second lines and is used to prevent the enemy from assembling his troops in the first line for the assault. This fire has been found very efficient. It is called for by telephone and not automatically by rocket.