||The abatis is a defensive feature consisting of felled trees lying
parallel to each other with sharpened branches pointing in the
direction of the attackers approach.
||The advanced ditch is a defensive feature at the base of a glacis opposite
the covert way. The purpose of the advanced ditch is to
obstruct attacking infantry.
||The angle formed by the adjacent flanks of two bastions or by a flank and
||The step of earth inside the parapet, sufficiently high to enable the
defenders standing upon it to fire over the crest of the
parapet, yet be protected.
work consisting of two faces and two flanks, all of the angles
being salient. A curtain connects two bastions. Viewed from
the interior of the fort the bastion is divided at the salient
creating a right face/flank and a left face/flank.
l'épreuve des bombes
||A structure sufficiently thick and strong to be impenetrable by bombs.
||The interior slope of a parapet
||A covered passage across the ditch of a fortified place designed to
shelter communication with the outer-works or to afford a
flanking fire to the ditch in which it stands.
||Interior gun chamber behind a fort wall. The gun is fired through a
protected opening in the wall (casement). Casemates protect
the guns and gunners and allow a fort's guns to be arranged in
||The highest or covering course of a wall.
||A projecting course along the junction of a parapet and scarp forming a
junction for the change in building materials and an obstacle
to scaling the wall.
||Solid pillars of masonry within the body of the revetment. Counterforts
are perpendicular to the revetment and are designed to support
the weight of the rampart fill.
||The vertical or nearly vertical side of the ditch nearest the besiegers
and opposite the scarp. It is generally faced or revetted in
permanent works to inhibit the descent into the ditch.
|covert way (covered way)
||A space running along the top of the counterscarp protected by an
embankment whose outer slope forms the glacis. It serves as a
protected walkway and assembly area for the defending
||A trench in the bottom of a dry ditch which functions to drain water and
obstruct the enemy.
||That part of the rampart or wall between two bastions or two gates.
||The excavation around the works from which the earth for parapet and
rampart is obtained. Ditches may be wet (moat) or dry, with
the latter the preferred in 18th & 19th century forts.
When the excavation is on the side farthest from the enemy, it
is called a trench.
||An opening in the parapet. Parapet embrasures are smallest at the interior
opening and wider towards the exterior. This widening is
called the splay.
||Gunfire directed at the enemy which exposes the
entire length of the enemy position to gunfire from one
location. Enfilade fire is effective because more of the
position is exposed to the gunfire.
||The angle formed by the face and flank of a bastion. The shoulder of the
|face (of the bastion)
||The faces are the two parts of the bastion that form the salient angle.
(of the bastion)
||The parts of the bastion that join the faces to the
ramparts. The line of fire from a flank would run parallel to
the wall that it abuts and defends.
||A slope of earth, usually turfed, that inclines from the covered way
towards the country. Its object is to bring assailants into a
conspicuous line of fire as they approach the fort.
||The space between the ravelin and the fort.
||A storehouse for munitions.
||Gun fire directed at a position from an angle
approaching 45 degrees. The positioning of guns to fire at an
oblique angle is considered disadvantageous.
||A fence constructed of a row of closely placed wooden
||The interior ground surface of a fort which serves as a drill and assembly
||The interior wall of the rampart, which encircles the
||Breastworks, walls, and bulwarks of earth, wood,
brick, iron, stone, etc., located on the exterior edge of the
rampart of the fort.
||A secondary gate through the rampart wall for access
||An oblique or sloping interior road to mount the terreplein of the
||The broad embankment or mass of earth surrounding a
fortified place. A rampart forms the body of the place. The
exterior wall is called a scarp (escarp) and the interior wall
is generally the parade wall.
||A work constructed beyond the main ditch, opposite a
curtain, composed of two faces and forming a salient angle. It
has its own ditch and usually a counterscarp. Alternately
called a demi-lune.
||A small fort of varying shape, usually of a temporary
||A retaining wall of masonry built for the purpose of
holding back the earth of which the works are composed, e.g.,
for the scarp and counterscarp.
||The projecting angle formed by the two faces of the
||A gate or passage by which the garrison of a fort may
attack besiegers. The term is applied to the postern leading
under the rampart into the ditch, but its modern application
is a cut through the glacis to the covert way. When not in
use, sally ports are closed by massive gates of timber and
||The faces of the fort on the inside of the ditch.
|shoulder (angle of the bastion)
||The angle formed by one face and one flank of the
||An enclosed field work in the shape of the heraldic representation of a
five pointed star.
||A small trench protected by a low embankment located
within the ditch and bordering the scarp walls of the fort.
||The broad surface of the rampart, below the level of the parapet and the
||Mound(s) of earth or a masonry wall which separate
gun emplacements, building entrances, and other positions from
enfilading fire. The traverse is designed to confine the
effects of a bomb fired into the fort.