Fire-Step

So that soldiers in front-line trenches could fire through the parapet, a fire-step was dug into the forward side of the trench. The fire-step was 2 or 3 ft high. It was on this that the sentries stood. It was also used by the whole unit when standing-to (an anticipated enemy attack).

Cross-section of a front-line trench
Cross-section of a front-line trench