Surrounding the fort was a shallow moat riveted with sharpened palmetto logs, as abatis, and the moat on the seaward side had planks with spikes positioned beneath the water. The armament of Fort Wagner on the night of July 18 consisted of one 10-inch seacoast mortar, two 32 lb. carronades, two 8-inch shell guns, two 32 lb. howitzers, a 42 lb. carronade, and an 8-inch seacoast mortar on the land face. Company A of the 1st South Carolina Artillery also had two guns positioned outside of Wagner's southern face by Vincent's creek to provide enfilading fire.