Information on these points cannot always be given by word of mouth. Written notes and plans should, therefore, be handed over to a platoon commander taking over for the first time.
In the meantime the incoming party should fix bayonets and all go temporarily on sentry at posts taken over. Occasional shots should be fired, so that the enemy’s suspicions may not be roused. The outgoing party then starts back, and when clear, the relieving party should be numbered off and sentries posted and dugouts allotted. When practicable sentries should be taken from the dugout closest to his post.
By day the number of sentries varies, but should not be less than one in six. The platoon sergeant is responsible for changing sentries, who are generally not on duty more than one hour at a time, unless under exceptional circumstances. When the maximum amount of labor must be obtained from the battalion holding the line, sentry duty is of any length that fits in with working arrangements.
Every man must see that he has a good clear position for all directions. Section commanders must satisfy themselves that men have done this and reported such. When these arrangements are completed, word must be quietly passed down for men not on sentry to stand clear, and they are all not in that position again until the “Stand to” hours, generally the hour nearest dusk and the hour before dawn.
After dark, unless the moon is bright, rifles should be kept in a firing position on the parapet, and all men not on duty should keep rifles with bayonets fixed while in the trench.
Observation. Continuous survey of the enemy’s lines through disguised steel loopholes should be made when the trenches are being held for any lengthy period, and such loopholes must always be sideways. Sites may be chosen by day, and made and disguised by night. Two steel loopholes about 3 yards apart enable a man with leveled rifle to wait by one while another with field glasses watches for target through the other.
An observer watching persistently through glasses in complete security should make himself so familiar with the look of the opposite trenches as to enable him to observe any alteration in the enemy’s wire entanglements, or notice immediately if a new sap has been run out from the enemy trenches under cover of night. He should watch points suspected of being machine gun implacements, and especially at night when the flashes can be detected. Observers should be told what marks, etc., to look for on men exposing themselves, and any result of these observations at once reported to the officer or N. C. O.
Inspection. A platoon commander should make frequent examination of trenches; at least once daily, go around with platoon sergeant and section commanders and decide on the necessary work to be done. Section commanders are responsible for carrying it out.
Before handing over a trench, a platoon commander should make a rigorous inspection to see that it is as clean as possible and that latrines are left in a satisfactory state. This includes the removal of old tins, paper, scraps of food, etc., which should be buried or burned, if possible. Empty cartridges should also always be kept cleared out, as they get imbedded in trench floors and hinder subsequent digging.