Tactics and duties for trench fighting

by Georges Etienne Bertrand; Oscar N. Solbert

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: