BRIDGE-HEAD (Fr. in fortification, a work designed to cover the passage of a river by means of fortifica tions on one or both banks. In a wider sense it is used to mean the area occupied on the far side of a river by a protective de tachment in order to cover effectively the crossing of the main body. As the process of moving an army over bridges is slow and complicated, it is usually necessary to secure it from hostile in terruption, and the position constituting the bridge-head must therefore be sufficiently far advanced to keep the enemy's artillery out of range of the bridges. In addition, room is required for the troops to form up on the farther bank. In former days, with short-range weapons, a bridge-head was often little more than a screen for the bridge itself, but modern conditions have rendered necessary far greater extension of bridge defences.