Battery Harker and Battery Arnold share a continuous 750-foot-long parapet wall. Battery Harker on the right contains three 10-inch gun emplacements, and Battery Arnold on the left has three 12-inch gun emplacements. A protective earthwork, the parados, was built behind the gun emplacements to protect the fortification from enemy fire from the rear. Material for the parados was excavated from a moat created behind it, and wheeled scrapers carried the material from the bank to the top of the parados. The embankment is twenty feet wide across the top and runs the entire length of the parapet wall. Two latrines, or “earth closets,” with concrete walls were built into the parados for use by soldiers manning the battery area. In addition to the protection offered by the parados, the moat would slow a rear enemy assault on foot.