Bridge and Glacis

The bridge was the only designed entrance to enter or exit the fort. The bridge pivots in the middle and is weighted at one end, allowing for greater ease in closing it. The closed drawbridge served as the outer door, then there were two, large, heavy, timber doors, and behind that were two guards in a vaulted passageway called a sally port. The drawbridge is not crossing a moat. It is a dry ditch that provided a lane of fire for rifle and artillery from the bastions.  The glacis, or mounded earth, acts as a counterscarp to the curtain walls and it helps mask the fort from enemy view.