Sally port, parapet wall and ditch visible at Fort Stedman , Petersburg National Battlefield, photoby Jon Buono.
A-C | D-F
| G-P | Q-Z
Military Earthworks Terms
Dam - often used in conjunction with military earthworks to flood an
area for defensive purposes.
Déblai - See Spoil.
Dead Angle - See Sector without Fire.
Defilade or Dead Ground - a ravine, gully, or depression within range
of an earthwork's weapons that could not be seen or fired into from the
Deliberate Entrenchments - defenses constructed in anticipation of need,
to defend a town, depot, or bridge, for example, typically constructed
with a front or exterior ditch. If defending an important position and
occupied for a long period of time, deliberate earthworks might be improved
to a semi-permanent condition. Magazines and bombproofs were built.
The parapets might be sodded with grass, revetments faced with sawn planks
or stone, roads and ramps paved with flagstones, a well dug, and a more
complete drainage system installed. Frame barracks and storehouses might
be constructed within or adjacent to the earthworks for the garrison.
Deliberate Fieldworks - improvements made to an existing line of rapid
entrenchments, typically the addition of detached works for artillery.
Demi-bastion (Fr.) - an angular work that projected outward from the
corner of an enclosed or detached earthwork. A demi-bastion consisted
of one face and one flank forming a salient angle. The
flank directed fire across the front of an adjacent face or curtain.
Demilune (Fr.) - a crescent shaped parapet protecting a single cannon,
typically ditched in front. Also called an epaulement; in permanent fortifications,
a component of the bastion. The term was often used interchangeably with
lunette, but this is imprecise.
Dentate - zigzag or saw-toothed parapet designed to direct fire obliquely
left and right across the front, designed to create interlocking fields
of fire. See Cremaillière Line.
Detached Works - fortifications constructed in advance of the main line
to delay an enemy's approach or built as components of a line of intervals,
generally redans, ravelins, lunettes, or redoubts. Other variations included
swallow's tails, hornworks, crownworks, and priest caps.
Direct Fire - incoming fire striking perpendicular to the parapet or
line of battle. Incoming fire could be direct, enfilading, plunging,
reversed, and ricochet.
Discontinuous Line - See Line of Intervals.
Ditch - excavation providing soil to construct a parapet. A ditch could
be in front of the parapet (front-ditch or exterior), behind
it (back-ditch or interior), or on both sides (double-ditch).
Engineers preferred front-ditch construction whenever time and labor permitted,
as it created a stronger profile. Batteries, redans, lunettes,
and redoubts were consistently constructed with a front-ditch. Back-ditch
construction was the fastest way to entrench, and therefore was used most
often for rapid infantry entrenchments. A double-ditch resulted from
digging in front to widen an existing back-ditch parapet, from constructing
a covered way behind a front-ditched line, or from capture and
refacing. Some evidence of the ditch-a shallow trough-often survives
even if its parapet has eroded away. The scarp and counterscarp
are the inner and outer slopes of the ditch.
Double-ditch - parapet with both an interior and exterior ditch. Double-ditching
was used to widen an existing back-ditch parapet or to provide a covered
way behind a front-ditch parapet. An earthwork that was captured and
turned (refaced) would have a double ditch. See Ditch.
Drainage Ditch - See Cunette.
Dugouts and Bunkers - rectangular excavations, usually 5-10 feet on a
side, associated with the principal defenses of an earthworks complex.
These typically served a command or logistical function. On rare occasions
in the field or during siege operations, dugouts might be roofed or partially
roofed with logs and earth.
Earthworks - any earthen structure excavated for military purposes.
In simplest form, a defensive earthwork was composed of a parapet or mound
of earth and a ditch from which the earth was excavated.
Earthworks Complex - consists of the Main Line of Defense, a Zone
of Occupation behind the main line, a Zone of Fire in front
of it, and a Zone of Contention (No Man's Land) separating advanced
positions of the combatants. The entire fortified front, taking in both
combatants, might be a mile ore more deep with each zone identified by
a specific grouping of features and artifacts.
Embrasure (Fr.) - a wedge-shaped opening cut to allow artillery to fire
through the parapet. A cannon firing en embrasure had a restricted (45-degree)
field of fire but the parapet protected the gunners. The sides, or cheeks,
of an embrasure often were reinforced by logs, planks, stones, sandbags,
or gabions. Embrasures were common features of artillery fortifications
and often survive as an indentation in the otherwise uniform parapet crest.
Not all indentations are embrasures. Typically, there is other evidence
of the presence of artillery-a gun platform and gun ramp, for example.
A single gun might have had multiple embrasures. See Barbette.
Enceinte (Fr.) - "body of the place," area of a fort or redoubt enclosed
by the parapet.
Enclosed Work - an earthwork designed to be defended from all sides.
Enfilade or Enfilading Fire - fire from the flank that swept along the
length of a parapet or line of battle. Enfilading fire could be particularly
destructive as incoming rounds might strike multiple targets and no return
fire could be brought to bear. Traverses were often constructed behind
a parapet to limit casualties caused by enfilade. Incoming fire could
be direct, enfilading, oblique, plunging, reversed, or ricochet.
Entanglement - obstacles placed in front of an earthwork to trip up and
delay attackers, sometimes used to refer to an abattis. During
the Civil War, telegraph wire was strung from stump to stump at shin level
to form a "wire entanglement." Most wire was retrieved or scavenged during
or after the war, so little would be expected to survive archeologically.
Entrenchment or Intrenchment - generic term for any form of earthen fortification.
In common usage, terms like breastwork, trench, entrenchment (intrenchment),
curtain, and fieldworks were applied with little precision.
Epaulement (Fr.) - See Demilune.
Escarp, Escarpment (Fr.), or Scarp - rear or inner slope of a ditch.
In a front-ditch earthwork, a continuation below grade of the exterior
slope of the parapet. See Counterscarp.
Exterior Ditch - See Front-ditch.
Exterior Slope - outer side of the parapet that faced the enemy and intercepted
incoming fire. The exterior slope typically inclined 45 degrees, the natural
angle of repose for most soils. The interior slope was more vertical
to enable defenders to stand directly behind it. Nearly all extant earthworks
in original condition will display some difference in angle between the
exterior and interior slopes. See Interior and Superior
Face - a straight segment of parapet making up a larger earthwork that
delivered direct or oblique fire to the front.
Facing - covering or treatment of a slope with sod, sandbags, stone,
or other materials. See Revetment.
Fascine - tightly bound bundle of saplings used to reinforce a parapet
or in revetment. Evidence of the use of fascines might appear as a darker
stratum of soil in an excavated cross-section. See Revetment.
Field of Fire - area within weapons range that can be seen and swept
by fire. Fields of fire were often improved by slashing (cutting
down) all of the trees or pulling down buildings in front of the line.
Fieldworks - earthworks constructed by armies while actively campaigning,
whether on the battlefield or in camp. Often hasty or rapid
Fill - logs, rails, stones, or other available materials used to add
bulk to the parapet; typically gathered and placed along the intended
line before digging begins.
Fire - organized and directed discharge of weapons.
Fire Pits or Mess Holes - See Holes and Pits.
Flank - left or right end of a line of battle or position; side; a segment
of parapet thrown back to protect the side of a position or to allow defenders
to deliver fire across the front of an adjacent face.
Flanking Fire - fire directed from one segment of parapet to sweep the
front of an adjacent segment.
Flêche (Fr.) - a small redan with a central, bisecting traverse
giving it the appearance of an arrow.
Fort - an enclosed fortification defended by artillery; a complex, multi-component
earthwork; a wooden stockade with corner blockhouses, often with ditching
or other earthen components; generically, a military base.
Fortification - earthen works or other structures erected to defend a
place or position.
Fortress - a system of defenses designed to work together as a whole
to defend a fixed position. Often a permanent fortification.
Fossé (Fr.) - an exterior ditch fronting a rampart or curtain.
Foxhole - an individual shelter hole. See Holes and Pits.
Fraise (Fr.) - row of pointed logs set close together and inclined toward
the enemy, often erected in the exterior ditch of a redoubt to
prevent attackers from scaling the parapets. Sometimes called a palisade.
Front - exterior, toward the enemy.
Fronting - orientation of an earthwork vis-à-vis the enemy.
Front-ditch or Exterior Ditch - ditch on the outside of a parapet designed
as an additional obstacle to assault. A front-ditch allowed the parapet
to have greater bulk and a stronger profile than rear-ditch construction.
This was the engineers' preferred method and was consistently applied
to prepared fortifications, to detached works, and artillery fieldworks.
It is common to find a mix of front-, rear-, and double-ditch entrenchments
in a single continuous line. See Ditch.
Fully Stocked Forest Stand - This refers to a full overstory canopy capable of replenishing the forest floor. Foresters typically use basal area to measure stocking in a forest. A rule of thumb is that the lower limit of full stocking is around 60 square feet of basal area per acre. In pine and pine-hardwood forests, it is 80 square feet per acre. Basal area (BA) = 0. 005454d 2 BA is basal area in square feet and d = tree diameter in inches. Summing the basal area from all trees over an acre provides basal area per acre which is a measure of stocking. Basal area for mature deciduous forests in the eastern United States generally range from 100 to 150 square feet per acre.
A-C | D-F
| G-P | Q-Z