It is a principle that grazing rifle fire upon a defensive enemy is more effective than plunging fire, but any entrenched position higher than your own held by an enemy gives them a tremendous advantage. Regardless of what opinion may be held as to the maximum depth of a field of fire required to meet or repel attacks, whether in masse or open order, it should be obvious that the greater the depth of the field of fire and the more extensive the view of the enemy’s operations, the better it will be for the defending forces.

Protection from and localization of artillery fire must be provided by the internal construction of the trench rather than by a position that protects but also restricts the field of fire. There are frequently found in front of a firing line small areas of ground which are not covered by direct fire from your trench. A flanking fire frequently can cover these areas, but in spite of this, they must be watched constantly by means of listening posts or concealed observation posts, which may be hidden by the banks of rivers, hedges, ruined houses, or whatever natural existing concealment renders observation possible.

At night, it is a safe principle to support listening posts by automatic rifles, trip wires with noise making arrangements attached to them as common sense under the circumstances dictates. Great care and caution must always be taken to prevent the discovery of these listening posts by the enemy, and when discovered, alternative posts should be made or greater care taken for the protection of the men occupying these posts, such as overhead protection by mesh wire against bombing, and the upkeep of a small supply of bombs and close-range weapons in the post. The important trenches on the front having been located with a view of protecting the immediate front and with due regard to their relation, tactically, to the other trenches already located, the connecting trenches obviously must be subservient to the more important ones. Every endeavor must be made to avoid enfilade fires in the flanks, to give and to receive mutual support, and in particular to support those flanks which are not protected otherwise.

It is an essential consideration in the location of all these trenches that lateral communications can be established, and that supplies, supports, reserves, ammunition, etc., together with the means of retiring if necessary be taken into account. The distance from the water supplies and the possibility of concealing approaches is a further governing factor, although in many cases an ideal condition cannot be realized.

Then there is the counter attack, in case the fire trench should be taken, and the kind of soil which is so essential to its relation to bad weather and water seepage—these also require thought and study.

These things are main considerations to be kept in mind after a line has been settled on, whether during attack or whether siting trenches under common circumstances. It is not expected and is not necessary, when trying to obtain a position during attack, to keep all of these conditions in mind, but it is essential that when the attack has been finished and things return to slightly more normal circumstances, that these things be given instant consideration and proper action taken.

Were such a thing as concealment possible, it should be the first thing of importance to be kept in mind. Listening posts, machine gun positions, reserve dugouts, company, battalion and regimental headquarters, and similar things, at some distance behind or on fire lines, may be concealed, but fire-trenches are sure to be observed sooner or later (mostly sooner) by aeroplane and other means of observation, and it is best that one should admit the impracticability of concealment at once and take the proper protective measures. If opportunity for concealment offers itself, as it may do, according to the lay of the land, it should be taken always. It should always be kept in mind that one should try to place himself in the position of having the enemy’s point of view, both from his trenches and his aerial observations.

Advantage should be taken and even care given along trenches to the extensive cultivation of the weeds, grasses, etc., that may grow rapidly in the excavated soil.

It is, and always will be, a matter of much argument that trenches should not be dug near hedges, ditches, roads or rows of trees, on account of easy ranging mark given to the enemy artillery. In a country where such things are scarce, the idea may have a leg to stand on, but certainly to the Western Front it does not apply. It does not take artillery a moment to approximate by ranging shot, check by deduction or addition the range of trenches in any area, even if lying along a hedge or road. The ditch or hedge in some cases will provide the starting of a trench and offer fair amount of cover from fire to the troops working. A ditch immediately in front or behind the trench greatly helps to solve the many and varied difficulties of drainage, and when in front of a trench, can be made into a formidable obstacle, generally by throwing in varied lengths of barbed wire. Trenches under the cover of a hedge are very often safe from aerial observation, and even when located, sniping and observation can be carried on from them if the contours of the ground are favorable. It is always possible to do a certain amount of repairing and moving of troops only when unobserved from the enemy’s trenches. If advantage is not taken of these natural protections, such as hedges and trees, then they must be destroyed.

It is obvious that a great deal of labor can be lost and work thrown away if a policy is not adopted and continued. Battalions relieving one another up and down the line may waste a tremendous amount of labor unless the relieved officer’s policy is explained. If each commanding officer of a relieving battalion is permitted to air his own theories, duplication of work and lack of continuity will exist. Therefore, it is essential that the officers relieving the trench be thoroughly informed of work going on. With this object in view some of the officers of the relieving battalion should do a tour of duty (about 24 hours) before their troops take over the trench. An Officer and Non-Commissioned Officer are detailed from each relieving company for this duty. In the trench this officer is instructed by the senior officer present, and the non-commissioned officer by the ranking non-commissioned officer, in the policy to be continued. The commanding officer of the occupying company should have a sketch map of his sector of trench which he turns over to the relieving officer. This map should show the work under construction; proposed work; wire defenses; and if possible, the enemies machine gun emplacements, observation posts, snipers and work in progress. The notes accompanying the map should give the general conditions concerning the work—depth to which it is safe to dig, nature of soil, conditions regarding drainage, and all information in regard to the enemies’ activities during the period of occupancy. In addition, the relieving officer has the trench diary showing all the information covering every minute detail of the happenings during that company’s stay in the trenches. This diary is a continuous record of that particular sector and remains with the occupying company until it is relieved and then passes into the possession of the relieving half company, and so on, forming a continuous running record of the policy applying to the upkeep and methods employed therein. This diary, unless it is buried to avoid falling into the hands of the enemy, will continue until the end of the war. So every half company inherits one from his predecessor in the line upon its assuming the obligations previously assumed by its fore-runner, thus preventing a duplication of work and assuring continuity of endeavor.