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.

I. Preparation of the Attack

=Front of Attack.= The tactical unit for an attack is a division. A division that is placed in the front line for this purpose is called an attacking division. To such a division is assigned the task of attacking and capturing a definite length of front of the hostile position. All the necessary means to carry out this mission are in the hands of the division commander.

The tactical unit for an _assault_, in this division, is the battalion. Each assaulting battalion is placed in front of that part of the hostile line against which it is to operate, which is called its front of attack. The length of this front is variable with the tactical situation. Also, this length in no way indicates to the enemy the strength of the attacking troops because they are disposed for the attack in depth. According to the size of the front of attack, the battalion commander will place two or three companies in the assaulting column, and two or one company as reinforcing support.

=Conditions of the Assault.= An assaulting battalion must be disposed in a certain manner, which is called the assaulting disposition. In establishing this disposition, we must consider the distance of the assault and the outline of the assaulting lines.

=Distance of the Assault.= The distance over which the troops make their assault across “No Man’s Land” must not be too great. This is to avoid as much as possible the enemy’s barrage and machine gun fire. For this reason, parallels of departure or jumping-off trenches, if necessary, may be constructed out in front of the first line for the assembling of the assaulting troops. On the other hand, your own first line should not be so near to the enemy’s position as to be in the zone of artillery dispersion when your own batteries are firing at the enemy’s first line. However, one is not always master of this distance, as it is a result of long fighting and occupation of the two positions. The proper concealment of these attack works, such as the parallels of departure, is an essential condition of success.

=The Trace of the Lines of Departure.= The trace of the lines of departure must be parallel to the first line of the enemy, not to your own, so that the assaulting troops will simply have to start in a perpendicular direction from the lines of departure to reach their objective. In other words, the assault is a simple frontal attack without maneuvers.

=Ground Preparation for the Assault.= It follows from the statements of the conditions of the assault and also of the tactical and material preparation of the attack, that the terrain from which these troops will start must be specially organized for this purpose. We have discussed the principles and details of the organization of the position for the defense, and it is clear that these must differ materially from those for the attack. An attack, like a defense, is made with the units disposed in depth. To launch an attack, certain of the defensive works that play but a passive rôle in the resistance, such as barbed wire entanglements, must be rearranged, modified, or partially eliminated. Other elements, such as routes, boyaux, and supply depots that facilitate the forward movement of reinforcements, are multiplied.

=Details of the Preparation of the Ground for the Attack.= All the details of the preparation of the ground for the attack are laid down in an order called the “Plan of Ground Disposition” issued by the general of the attacking division. This order is divided into two parts: the organization of the works, and their execution.

=Organization.= We know that the disposition of an assaulting unit is in the form of successive echelons, called waves. In order to protect these waves before the assault, it is necessary to construct for them trenches parallel to the enemy’s first line; and for this reason these are called parallels of departure. The trace of the first parallel fixes the directions of the others behind. For example, an assaulting battalion which is going to advance in four waves, might have two parallels of departure with two waves in each parallel. These parallels are narrow trenches like the defensive lines, but with a series of steps in the front side so that the men can go over the top easily. If there are no steps, trench ladders or footholds must be used.

Theoretically, one might think that the distance between these successive parallels should be the same as that between the attacking lines. But this is not practicable. Such practice would mark out boldly on the ground, for the enemy’s air observation, your intentions and your dispositions for the attack. Therefore, this method is strictly prohibited. Besides, it is not necessary, since the regulation distances between the lines and waves are not realized from the point of departure of the assault. The object of the assaulting companies is to cross “No Man’s Land” as quickly as possible to avoid the enemy’s defensive barrage and machine gun fire. Consequently, when the different lines of the first wave jump out of the same parallel of departure, they will dash across to the enemy’s first line with little regard to distances but with a fixed idea of reaching their first objective before the hostile garrison, and before the enemy’s barrage intervenes. They attain their regulation distance as soon as the zone of barrage is passed and when they have arrived at and crossed the first hostile line.

In order not to print the attack on the ground, so to speak, these different parallels of departure are not constructed in front of your position unless absolutely necessary. They are constructed when the distance across “No Man’s Land” is more than five hundred yards, when there is natural cover, such as woods to conceal them, and sometimes on reverse slopes. The different defensive lines of the sector make very convenient parallels of departure. The first waves of the assaulting company are placed in the firing and cover trenches of the first line. The reinforcing platoons are disposed in the transversal and intermediate and support lines. Behind these lines are constructed _places d’armes_ or assembling places for the reserve troops. These _places d’armes_ consist of a series of short transversal trenches leading off both sides of a central boyau.

If the first hostile line is too far from our own first line, on the night previous to the attack, hasty parallels of departure are constructed out in “No Man’s Land” for the leading wave of the assault. This is to give this leading element the best possible chance to arrive at the enemy’s first line uninterrupted by artillery fire and before the hostile garrison.

The work of preparing the ground for the disposition of the attacking troops also comprehends the following:

Several boyaux.

Command posts and observatories in advance of those of the defensive sector. Each chief must now be in the middle of his unit and not behind it.

Depots and medical aid stations. Each company has its own little ammunition depot near the post of the captain.

Ditches for telephone wires. Each battalion has telephone wires brought up in its main boyau as far as the first parallel. At this point, telephone material is stored so that the system can be carried into the enemy’s position with the least delay.

Small bridges are constructed for the passage of the parallels by the reserves.

It is not necessary that the shelter accommodations be numerous, especially in the first line, because the assaulting troops are brought in only a few days before the attack.

=The Execution of the Works.= The second part of the plan of ground disposition contains the details of the execution of the works for the preparation of the ground previous to the attack. This part consists of;

1. Emergency works (necessary to the assault).

Observatories and command posts.

The first two parallels of departure for each battalion. If none need be constructed, the defensive lines used for this purpose are designated.

Secondary boyaux between parallels, one for each company.

Entrance and evacuation boyaux.

Ammunition depots and water points.

Dressing stations.

If there is more time, the following are constructed:

The third and fourth parallels.

Telephone wires and material brought up.

Bridges for crossing the parallels.

2. Time of duration of the execution of the works.

This may vary from three to twelve days, or even more, depending upon circumstances.

3. Division of labor.

This depends upon the number of special working parties at your disposal. A whole division may be assigned for this work, but it is not the division that will make the attack.

4. Tools.

The tools required for this work are requisitioned from the headquarters of the attacking army.

5. Ammunition depots.

Cartridges, hand grenades, and signal rockets.

6. Ammunition depots.

Sandbags and logs.

7. Transportation of supplies.

Special means of transportation besides the usual ones, railroads, motor trucks, mules, horses, etc.

Artillery Preparation

During the time employed in preparing the ground for the attack, the artillery executes the preliminary bombardment. This comprehends three kinds of fire.

1. =Counter-Battery Fire.= A certain part of the artillery is detailed to destroy the hostile batteries or, if this is not possible, to neutralize them. This result is obtained by methodical fire on precise targets. Each battery or group of batteries is assigned certain emplacements to destroy. Counter-battery fire is long-winded work and is begun several days or even weeks before the attack. If the hostile batteries are not destroyed before the time of attack, they must be neutralized at this moment by violent shelling by all the batteries disposed for this purpose, with shrapnel and other special shells. This counter-battery action will hinder the hostile artillery from executing defensive fire, barrage, preventive fire, counter-preparation fire. It is carried out by special groups of heavy and light artillery under control of the general.

2. =Fire on Communication Routes, Depots, etc.= This fire, besides its destructive effect upon the enemy’s position, hinders the arrival of reinforcing troops, material, ammunition, and food. The shelling of distant roads, depots, and bivouacs is carried out by batteries of long-range guns. The fire on the nearest communications, such as interior supply routes, entrances of boyaux, kitchen emplacements, etc., is executed by light batteries of the divisional artillery.

3. =Destructive Fire.= Before the attack, the whole of the enemy’s position is submitted to methodical and violent artillery fire for the purpose of destroying:

Obstacles which may hinder the advance of the assaulting column: accessory defenses, such as barbed wire entanglements.

Elements of the defense, such as strong points, machine gun emplacements, observatories, depots, shelters, and dugouts.

Each different kind of target calls for a certain number of rounds of a particular caliber. These calculations of the different numbers of rounds are the results of experience and are set down in tables for the information of the sector commander. The time, therefore, necessary for a proper preparation for the attack is a function of the number and strength of targets. The artillery preparation may last from one to twenty days, but it must continue until the elements of the hostile position are sufficiently destroyed to assure a successful attack.

Before an offensive, there is placed at the disposal of the attacking divisions, besides their regular divisional artillery, a special allotment of batteries. The different calibers of guns are used according to the nature of the target. The largest calibers are employed against the strongest elements of the organization: nests of resistance, strong points, and deep dugouts. Light artillery is used to obliterate trenches and boyaux and interior barbed wire entanglements. Trench mortars serve to destroy the elements of the first line and its accessory defenses.

=Plan of Artillery Action.= The details for the execution of these different artillery fires are laid down in the plan of action of the artillery of the army corps or of the division. This plan is a part of the plan of battle of the division. These details must be carried out punctually and with precision. The sector commanders are not interested directly in the execution of these fires, but they are in their results.

=Duties of the Infantry during the Artillery Preparation.= In connection with the artillery fire, the infantry in the position must observe the results of the bombardment and the leaders report their opinion upon its control.

=Observation.= The observation of the counter-battery fire, long-range fire on communication routes, and destructive fire on the interior of the position, falls upon the artillery’s ground observers and the aviation service. But the duty of observing the results of destructive fire on the enemy’s first line is carried out with the help of the infantry observers. Each regiment must observe the front upon which it is to make the attack. Special attention is paid to the destruction of barbed wire entanglements and machine gun emplacements. The interested infantry does not content itself with a passive observation, but must send out at night, or even in daylight, offensive reconnaissance parties. Their mission is to actually go into the enemy’s first line, to ascertain its condition, and to investigate the breaches in the hostile entanglements. The tactics of such a reconnaissance are the same as for a raid. The information gathered is sent to the division headquarters in the daily report of the intelligence officer or in special information reports.

=Control.= It is both the privilege and the duty of the infantry commanders to state in their daily reports their opinion on the artillery preparation. If they do not express their exact opinion on the progress of the bombardment, they are liable to pay for their carelessness at the time of the assault.

=Destruction of the Enemy’s Position.= The experiences of three years of trench warfare have given bitter proof that an attack against an insufficiently destroyed position will not only fail but will result in great losses. It is sheer folly to attempt an assault against undestroyed entanglements, or against a line in which the machine gun posts have not been demolished. One does not oppose materiel with men. In trench warfare, the conquest of the ground is made by the artillery; the infantry follow up this conquest to occupy and to hold the ground. The essential condition for the success of an attack depends upon the proper destruction of the elements of a position by the artillery.

=Plan of Battle.= The plan of battle depends upon, first, the strength of the enemy, obstacles to the attacking troops, lines of defense, nests of resistances, barbed wire, etc.; and secondly, the mission of the attacking unit and the means at its disposal.

=Strength of the Enemy.= The Information Service of a division has so many different methods of obtaining information and data of the enemy and his defenses that the assaulting troops can be constantly kept advised of the state of the hostile position. The regiment receives daily from the division headquarters an information bulletin, aëroplane pictures, and precise maps of the hostile lines. Upon these data the regimental commander bases his plan of battle. Comparisons of aëroplane pictures and maps are particularly useful. From all these data, the regimental intelligence officer makes pertinent extracts for the information of the battalion commander. Copies of the different maps are distributed by the battalion and company commanders to their officers and non-commissioned officers in order that they may have a better knowledge of the hostile position for the attack.

=Mission.= The general plan of battle is issued by the division commander. Based upon the terms of this order, the Colonel, Battalion Commander, and Captain issue detailed orders of their own plan of battle. The plan of battle of a small unit usually comprehends the following points:

Mission of the unit in the attack.

Front to be attacked, with definite limits.

Objectives, different lines to be taken, the last objective.

Disposition of the unit for the attack; formation, intervals.

Disposition of the unit in the parallels of departure before the attack.

The day (D) and hour (H) of attack.

Direction of the attack; compass angle.

Position of the leader.

Tactical relation with the neighboring units during the advance.

Use of specialists; machine guns, trench cleaners, etc.

Support of artillery during the attack.

Unit liaison during the attack:

With neighboring units and leaders (runners, telephone, signaling, carrier pigeons).

With the support artillery (detachment of liaison, observatories, and rockets).

With air service (rockets, signaling, Bengal fires).

With balloon service (searchlights).

Equipment for the attack.

Supply of ammunition and water; advanced supply points.

Evacuation of the wounded; dressing stations, routes of evacuation, auto ambulance points. Also, routes of evacuation for prisoners and assembling points for same.

This plan of battle is so drawn up that it may be executed any later day that may be designated in the order for the attack.

=Preparation of the Men for the Attack.= The work of fitting their men physically, professionally, and morally for the task before them devolves upon the leaders of all ranks. By a system of relief, the men of the garrison get short periods of rest behind the sector to shake off the atmosphere of the trenches. Continuous instruction of both men and officers in the basic principles of fighting should be carried on at all times. The moral training of the men depends to a great extent upon the officers. The leaders, by example and encouraging words, should instill into their soldiers that fighting spirit which makes for success in battle.

II. The Assault

Formations for the Assault

=Disposition in Depth.= The assault has for its purpose the capture of the first hostile line, that is to say, the crossing of “No Man’s Land” and penetrating the enemy’s position. The assault is only the beginning of the combat. When the breach has been made in the enemy’s first line, the assaulting and reinforcing troops must continue the fighting in the interior for the conquest of the position. The direct object of the assault is to open the way for the attacking troops into the position. The attacking troops are disposed in depth in a series of echelons, so that during the advance each echelon is brought into the battle at the proper moment. This rule of formation in depth is followed without exception by every unit of whatever size.

The regiment forms with one or two assaulting battalions, and two or one battalion behind in reserve. The battalion has three or, better, only two assaulting companies and one or two companies with machine guns, in the second echelon as support. The company may have three, but more usually two, assaulting platoons with one or more reinforcing platoons in the second line.

=Waves.= The successive echelons have received the name “waves.” This designation is expressive but not clear, and causes mistakes.

First, waves may be formed by different dispositions: in deployed line or in line of small columns.

Secondly, the waves are not always composed of the same strength of troops or units, and consequently are not of the same disposition. The battalion commander will designate his first assaulting company as his first assaulting wave. Similarly, the company commander designates his assaulting platoons as the first wave; and the platoon leader, his first skirmish line as the first wave of the platoon.

Lastly, the real significance of the term “wave” lies in its application to the formation of the departure of the attack and during the first part of its advance into the interior of the hostile position. As soon as the assaulting echelons are held up by nests of resistance, they are obliged to halt while neighboring echelons on both flanks continue the advance. Also, reinforcing units will come up from behind to outflank such a nest. As soon as such a condition arises within the enemy’s position, the disposition of the troops in waves is lost and the fight is continued in the best formation possible under the circumstances.

Formation of an Assaulting Battalion

=Assaulting Companies.= In an assaulting company, a certain number of platoons are placed in the first or assaulting line, and the rest in the second line as reinforcing platoons.

The assaulting platoons deploy usually in two lines of skirmishers, the different specialists being assigned to places in these lines depending upon their functions in the attack. The line of assaulting platoons is known as the line of combat. A third line of grenadiers follows closely behind the assaulting platoon, and may be called a part of it. These grenadiers are furnished by the reinforcing platoons and are known as trench cleaners. Their function does not begin until the hostile line is reached, and it is to clear out the trenches of the first line of the enemy while the assaulting troops continue their advance in the open ground.

The reinforcing platoons are either deployed in lines of skirmishers or lines of small columns. These platoons constitute the line of reinforcement and follow the advance of the assaulting platoons at a distance of about forty to sixty yards. The machine guns detailed to the assaulting companies by the chief of battalion are placed with the reinforcing platoons and are usually carried on the flanks.

Considering the battalion as the assaulting unit and adopting the term “wave” to designate each platoon, we may say that the company of the first echelon of the assault is disposed in two waves. The position of the captain is in front of the second wave between the two reinforcing platoons. His liaison group remains with him.

=Supporting Companies.= The supporting companies of an assaulting battalion constitute the second echelon. These companies, also, are formed in two waves. These waves are formed like those of the reinforcing platoons of the assaulting company, either in deployed lines or in lines of small columns. Usually the battalion has two companies in the first line and two in the second line. In other words, the battalion carries out the assault in two echelons of two waves each, the distance between the two echelons being from 200 to 300 yards.

In rear of the support companies and following their advance, are the remaining machine guns of the battalion and the 37 mm. platoon.

The position of the battalion commander with his liaison group is directly in front of the second echelon and between his support companies.

=Disposition of Assaulting Battalion in the Departure Trenches.= We have seen that for an attack the ground is specially organized for this purpose and the attacking troops are disposed in _successive parallels_ or _places d’armes_. Usually this disposition is as follows:

The _two waves_ of the assaulting companies are placed in the first and second parallels which under ordinary circumstances will be the fire trench and cover trench of the first defensive line. _Consequently_, the different lines of each wave will occupy the same parallel, but at the moment of the assault the successive departures of the lines will permit them to automatically gain the necessary distances to separate them in the advance across “No Man’s Land.” _For example_, let us assume that there are four lines (this is the maximum) placed in one parallel. The men are numbered from 1 to 4 in successive groups of four each. Each No. 1 man belongs to the first line; each No, 2, to the second line, and so on. The distance between similar numbers in the parallels is about four paces, giving the proper skirmish intervals to the line. At the given signal of the leader of the line, the No. 1’s go over the top. The No. 2’s follow at the prescribed distance ordered or at another signal given by their leader. The other lines follow similarly, so that the assaulting troops have the regulation interval in line and a prescribed (not always regulation) distance in depth.

The two waves of the support companies are placed in a third parallel or _place d’armes_. This third parallel is usually an intermediate trench, or special work, executed for this purpose, located between the first and second defensive lines.

Machine guns and 37 mm. guns are located on the ground in relation to their places in the advance during the attack.

The battalions which are kept as reserves according to the plan of battle of the sector commander, are disposed in _places d’armes_ organized behind the parallels of departure. The colonel and his headquarters occupy a command post directly behind the assaulting battalion from where he can witness the launching of the assault and the crossing of “No Man’s Land.”

=Order of the Attack.= The attacking troops take the disposition that has just been explained some days before the attack. This disposition is laid down in a paragraph of the Plan of Battle. Each leader of an attacking unit, with a map of the ground on which his area is specially outlined, must study his disposition on the ground previous to the arrival of his troops. Besides this, the leaders must pay special attention to the hostile position, verifying the direction of the attack, and identifying the successive objectives and the nests of resistance that will be encountered.

When the general who is in charge of the attack judges that the artillery preparation is sufficient, that the supply systems for the attack are properly organized, that all is ready and, in short, that the psychological moment has arrived, he gives his order for the attack.

Based upon the divisional order for the attack, the colonels, battalion commanders, and captains issue their own orders. The difference between the plan of battle and the order for the attack lies in the fact that the latter fixes all the details of execution of the general operations laid down in the former. But also, the order for the attack contemplates the first measures to be taken as soon as the assault is carried out, especially the extension of the liaisons (telephone lines) and communications (boyaux) from the first parallel of departure up to the enemy’s position.

The order for the attack contains precise details of the following points:

Exact hour of the attack; or signal rocket for the same.

Details of the successive objectives; different resistances that will probably be encountered.

Time-table of the moving barrage and the rate of its advance.

Prolongation of the telephone lines; particular wires to be extended.

Prolongation of communications; boyaux to be built at night across “No Man’s Land”; units detailed for this purpose.

Supply of ammunition and water in the captured position; points of distribution.

=Departure of the Assault= [The hour (H)]. We have now arrived at the most important and critical moment of the battle, the hour (H) of launching of the assault. A few minutes before the hour (H) the men take the places assigned them in the parallels with strict orders to remain there. Bayonets are fixed on the rifles. Useless movements and noise of any kind are prohibited. Each man holds himself in readiness awaiting the signal of his immediate chief. Each chief of unit himself ascertains that his men are in readiness and in good condition for the assault. He sends all wounded back to shelter. The leader must impress his men with the confidence that he knows his duty, that he has foreseen and is prepared to meet all circumstances of the coming battle; The value of troops at this moment depends upon their leaders.

=Support Artillery.= During the time just preceding the hour (H) all the artillery which does not execute counter-battery fire is employed to protect the assault. A part of this artillery is given to each of the assaulting battalions as support artillery. Liaison and observation detachments are sent by this artillery to the infantry battalions to which they are attached. These detachments have the same composition and rôle as explained in the defense of a position.

The artillery support holds under its fire that part of the hostile line assigned to its infantry battalion. A violent fire is especially directed against the enemy’s first line, the objective of the assault. Protected by this fire, the assaulting battalion moves forward. For a few moments after the launching of the first waves over the top, this fire remains on the enemy’s first line. The protective barrage is then lifted and is established on the hostile second line, where it also remains for a certain time, according to the barrage time-table, and so on.

=Departure of the First Echelon= (Assaulting Companies). At the precise moment or signal the first wave of an assaulting company jumps out of its parallel of departure, the different lines of which it is composed being formed as previously explained. In a similar manner, as soon as the first wave is launched, the second wave goes over the top of its parallel. All the different lines of the different assaulting companies advance straight to the front towards their first objective. The rate of advance, although not a run, is as rapid as the circumstances of the torn up ground of “No Man’s Land” will permit, at the same time maintenance of the formations being paramount. Success depends upon the proper location of the specialists in the formations of the waves, and this order must not be lost in the confusion that results from too much speed.

The result is that all the lines of the assaulting companies start almost at the same time from the two parallels of departure, and with shorter distances between the lines than that called for by regulation. This formation is not a drawback, but, on the contrary, works to better advantage. The first and most important thing to avoid at this time is the defensive barrage of the watchful enemy. This is established as soon as he is aware of the assault. If the reinforcing line follows closely behind the line of combat, it has a better chance of passing the danger zone before the enemy’s barrage is established. A company caught under the enemy’s barrage will lose, on an average, fifty per cent. of its effectives. Also, the assaulting companies must arrive in the first hostile line as quickly as possible behind their own barrage. The assaulting platoons, who set the pace, should arrive there almost “as soon as the barrage lifts.” Troops that arrive at this opportune moment will surprise the enemy in his shelters or in the act of taking his place on the firing line. It is better to risk losing a few lives by your own barrage than to give the enemy time to man his first line.

Finally, the regulation distances between the different lines and waves will be attained during the progress after passing the enemy’s first line.

=Departure of the Second Echelon= (Supporting Companies). When the first echelon, or assaulting companies, have crossed “No Man’s Land,” the battalion commander usually launches the second echelon, or supporting companies. By this time, the battalion commander will have an impression of the assault, and the distance which separates the two echelons is at this moment the one usually required (200 to 300 yards). In order to avoid the enemy’s barrage and to profit by any lull in his fire, the battalion commander chooses the exact moment for the departure of the second echelon.

=Advance of the Reserves.= As soon as all the waves of the assaulting battalion have penetrated the enemy’s position, the reserve battalions of the regiment leave their _places d’armes_ and move forward through boyaux to the first parallels of departure. In this position they await the order of the colonel to advance into the enemy’s position to join the combat for its conquest. The colonel awaits the first report from his assaulting battalion before giving the order for the advance of the reserves.

III. Fighting in the Interior of the

Position and Exploitation

=Principle of the Fighting.= The fundamental principle of the fighting in the interior of the position is that each attacking unit from the division down to the battalion receives a definite objective. This objective is usually an area containing the lines of the hostile position with precise flanking limits. The farthest line in the objective area must be gained by the units at all costs. Beyond this last objective, strong reconnaissance parties and patrols are sent to keep contact with the enemy.

Usually the attacking regiments, which carry out the struggle in the interior of the position, are assigned the mission to capture the third or covering line of the artillery. The continuation of the struggle beyond this line and the capturing of the enemy’s guns is what is called “the tactical exploitation of the success.” The troops that carry out this operation are the reserves of the division held out for this particular purpose. The plan of battle does not include orders for this action.

=Details of the Interior Fighting.= Let us follow an attacking regiment in its progress in the interior of a hostile position, and consider the use of the different echelons of which it is composed: assaulting companies, reinforcing companies, and reserves.

=Assaulting Companies.= The advance of the assaulting platoons regulates the advance of all the successive elements. These platoons, after crossing the first hostile line, continue their movement without hesitation. The rate of advance is, of course, variable with the difficulties of the ground and the strength of the hostile organization. For this reason it cannot be very rapid. The pace of the leading elements of the assaulting column is foreseen in the plan of battle (depends upon the strength of the enemy’s position), and this becomes the rate of advance of the moving barrage. If no unforeseen and serious resistance is encountered, the assaulting platoons will be able to keep up with their protective barrage. Sometimes, however, they may halt for a moment in their progress under cover of some shelter to regain their alignment.

As a part of the assaulting platoon comes the trench-cleaner detachment. The trench cleaners are armed with hand grenades and trench knives. Their function is to enter the hostile trenches taken and, profiting by the surprise effect of the attack, to vanquish the last resistance and to make prisoners of the defenders still in the dugouts. They pay special attention to picketing all entrances, exits, and shafts of dugouts so that detachments of the enemy cannot come out and fire into the rear of the waves that have already crossed. If the different lines of the hostile platoon are very far apart, the number of trench cleaners is increased, a detachment dropping off in each line.

As long as the assaulting platoons do not meet resistance, the reinforcing platoons follow the former at the regulation distance to avoid mixing of the different waves of the attack. If, however, the assaulting platoons suffer severe losses, and are unable to continue the progress, the reinforcing platoon, either by order of the captain or upon the initiative of its leader, moves up and reinforces the combat line. Its function then becomes the same as that of the assaulting platoon.

Again, if a gap should occur in the combat line, due to losses or extension of the front, the reinforcing platoon moves in that direction and fills the gap. In general, the tactics of the reinforcing platoon are always to assure continuity of progress by outflanking resistances that have stopped the advance of the platoon in front.

The machine guns attached to an assaulting unit follow and protect the flanks. When halted they fire on retreating hostile troops and on special points of resistance. Their special use, however, is against counterattacks.

=Reinforcing Companies.= The reinforcing companies, with the machine gun reserve and 37 mm. gun of the assaulting battalion, after they have penetrated the hostile position, follow the progress of the assaulting waves at the prescribed distance. They advance in line of small columns but make use of any cover that the ground affords to minimize losses from hostile fire. During this advance, their mission is to rally all the elements of the assaulting companies and push them forward; and also to watch out for the flanks, pushing out to protect them on their own initiative if necessary. But when the line of combat is held up by resistance the supporting companies are maneuvered by order of the battalion commander. Naturally, the whole line of combat will not progress uniformly. Certain assaulting platoons will be held up by nests of resistance, while others in the intervals will carry on with less interruption. Reinforcing platoons and support companies are maneuvered to outflank such nests of resistance and to fill the resulting gaps in the combat line.

Let us take a concrete example of an assaulting company followed by a supporting company held up by a nest of resistance (a ravine, reverse slope, or woods strongly organized with machine guns) and follow the movements of the reinforcing platoons and supporting company. (Examine the diagram showing maneuvers against a nest of resistance in connection with the following explanation.) The first figure shows the formation of the four platoons of an assaulting company advancing in the interior of a position followed by a supporting company. The 1st and 2nd are the assaulting platoons, and the 3rd and 4th the reinforcing platoons. The supporting company follows in double column of platoons. The second figure shows the 1st assaulting platoon held up by a nest of resistance with the 3rd or reinforcing platoon moved up on the right flank. Platoons =2= and =4= of the same company carry on, and this movement results in a gap in the line of combat between the 2nd and 3rd platoons. The third figure shows the 1st and 2nd platoons of the supporting company moved up in this gap, and the 3rd and 4th platoons acting as reserves. The nest of resistance is thus attacked from the front and flank and the continuity of the combat line maintained. When a nest of resistance is encountered the attacking troops must not accumulate in front, as this will multiply the losses. The line of combat will attack the front of a nest of resistance while the successive reinforcing and supporting waves maneuver against its flanks. The battalion commander will use all the weapons at his disposal as machine guns, 37 mm. guns, and rifle grenades to reduce the nest of resistance. If this method fails he will have to call on the artillery for help, but this necessitates a modification of the artillery barrage time-table.

=Rôle of the Artillery during the Attack.= During the attack the artillery carries out the following different fires:

Counter-battery fire.

Protective fire on the flanks of the attack.

Accompaniment or barrage fire.

The first two fires are executed by a part of the artillery directly under the chief of artillery of the division, who in turn is under the control of the general.

The third kind of fire is executed by the support artillery, detailed to the different assaulting battalions as in the defensive organization. The action of this artillery directly interests each infantry chief of area, to whom are sent liaison detachments and observers (an officer, N. C. O.’s, and artillery orderlies). This third kind of fire is the only one that we will consider in detail.

=Principle of the Accompaniment Fire.= During the progress of the attack the support artillery establishes a moving barrage in front of the advancing infantry. This barrage travels by bounds. It remains for a certain time on each defensive line and at intervals between them so as to thoroughly sweep the intervening ground. The time-table, or rate of this moving barrage, is laid down in the plan of action of the artillery. The infantry leaders of course are acquainted with this time-table.

=Other Means of Controlling the Barrage.= The moving barrage may also be advanced successively by order of the commanding general according to information received from the leading elements of the assaulting battalion, from the artillery or aëroplane observers.

Calls may be made directly from the line of combat by rockets, or other means of liaison. With reference to the barrage there are two uses of rockets; one is for calling the barrage in the defensive, and the other is calling for an advance of the barrage during the attack. It may be remarked that it is impossible to call for a decrease in range of the barrage as this, of course, would be dangerous to your own troops. It is better to decrease the rate of advance of the barrage rather than to have it move too quickly and risk abandoning the infantry.

Lastly, the preceding means for controlling the barrage can be employed in conjunction. That is to say, a time-table for the barrage is adhered to during the first part of the advance when the positions of the hostile lines are well known, while during the last part, when the infantry’s progress is not so regular and the ground is not so well known, each advance of the barrage may be called for by rocket, as each resistance met with is disposed of. If an assaulting battalion meets a resistance which it cannot reduce by its own means, it must call upon the support artillery for help. To do this, the artillery must halt its barrage and for an interval the time-table is not in effect. Such an emergency calls for a special action on the part of the support artillery, and also for the intervention of any other artillery at the disposal of the general. This particular action of the artillery may be called for automatically by rocket or by the other means of liaison. The rôle of the officer and N. C. O. of the artillery liaison detachment is to give the artillery the precise technical information necessary in such a case to establish its fire on a nest of resistance. This action of halting the barrage and giving the artillery a new objective is exceptional and delicate to execute. As soon as the resistance is reduced, the time-table is resumed.

=Liaisons During the Attack.= The proper co-ordination of all the foreseen developments of the attack lies in a good system of liaison. There must be leadership liaison for the transmission of orders and reports, and infantry-artillery liaison for the proper co-operation of the two arms. The means of liaison in the offensive are the same as those considered in the defensive organization. The principle of their use is the same but made more difficult by the progress of the different attacking echelons. It is the duty of all leaders to foresee the establishment of liaison for the engagement in their plan of battle, and also for the prolongation of these means with the advance of the attacking troops.

The means of liaison are:

Telephone lines (for leadership in artillery. They are lengthened from the parallel of departure to the interior of the enemy’s position.)

Signal communication (established from the enemy’s position to a central point in the rear).

Rockets (precise signification of each kind laid down in orders).

Carried pigeons (headquarters that are to carry these laid down in orders).

Detachment of special runners (essential to be established between all units).

=Aviation.= During the advance, a particular system of liaison is established with the air service. Each division has at its disposal a certain number of accompanying planes that fly low and follow the assaulting battalions. Their duty is to establish communication between the leading elements of the advancing infantry, and the artillery, and the commanding general. The infantry signal to these airplanes by means of rockets and Bengal fires, and the planes in turn communicate with the artillery and the commanding general by means of wireless.