Tactics and duties for trench fighting

by Georges Etienne Bertrand; Oscar N. Solbert

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.