Abattis or Abatis (Fr.) --
arranged in the form of a hedge with trunks aligned and anchored
shallow ditch. Branches were sharpened and interlaced pointing
the enemy. Its purpose was to prevent surprise and to delay an
force within range of defensive weapons. Sometimes called a
Active Defense -- strategy of defending a
line by maneuver
Advanced Works -- fortifications in advance of
but still within firing range of the main works.
Angle -- where two faces of a fortification
Salient and Reentering Angles.
Apex -- foremost salient angle of a
that which protrudes farthest toward the enemy.
Approach -- a trench dug to get closer to the
called a sap in siege operations.
Artillery Strong Point -- a battery,
or bastion that served to anchor a larger system of
Artillery Works -- earthworks designed to
and to provide an effective field of fire.
Back-ditch or Interior Ditch
dug behind a parapet. See Ditch.
Banquette (Fr.) or Firing
Step -- a
shelf dug behind a parapet that allowed a defender to step up
ground to fire over the parapet, then step back down under cover
A banquette was only necessary when the parapet was higher than a
armpits. It was a common feature associated with prepared
curtains, and detached works, such as redoubts. If
survives, it is often blurred by soil eroding from the
Balk -- a narrow barrier of earth within the
an earthwork that was purposely left unexcavated. Balks
divisions between units in the line. A balk might also serve as
for a traverse made of logs.
Barbette (Fr.) -- artillery positioned to
fire over the
parapet rather than through an opening in it. See
A cannon firing en barbette had an unrestricted
of fire, but its gunners were more exposed to fire than one
embrasure. A barbette gun was raised to fire over the
means of a large carriage or by a gun platform built up to the
height. See Gun Platform.
Bastion (Fr.) -- an angular work that
from the main faces of a fortification. Its purpose was to
defilade by directing fire along the front of an adjacent
wall. Like a lunette, a bastion consisted of four parts: two
forming a salient angle oriented towards the enemy, and
flanks that directed fire sideways across the faces of
bastions. A curtain (or curtain wall) connected two or
Bastion Line -- a series of bastions joined
Bastioned Fort -- an enclosed earthwork with
in the angles to provide fire along the fronts of the connecting
Battery -- an artillery unit or a
to defend an artillery unit.
Berm or Berme (Fr.) --
or shelf left at grade to separate the scarp of the ditch
exterior slope of the parapet. When constructing
workers stood on the berm to relay earth from the ditch up onto
The berm was sometimes left to retard slumping of the parapet,
engineers felt that it assisted attackers in scaling the parapet
it pared down after construction. Soil eroding from the parapet
typically blur a berm's outline.
Blockhouse -- building constructed of heavy
the shape of a square, rectangle, or cross, to serve as a strong
for infantry or artillery. A ditch was often excavated around the
with the spoil thrown up against the wooden structure as a
against fire and gunfire. Often part of the first floor of a
was below ground, while the upper floor, pierced with loopholes
was built with an overhang so that defenders could fire down
base of the structure. Blockhouses were used to defend railroad
bridges, and depots, or served as a "keep" or place of final
a larger fortress or stockade. The excavations associated with
survive, although timbers were often scavenged for other uses.
brick or stone flooring and fireplaces.
Bombproof -- a log or plank room or bunker
with earth to protect troops from artillery fire. A surviving
appears as a large mound of earth, sometimes with an elongated
in the top where underlying timbers have collapsed or in the side
the entrance used to be. See Magazine.
Bottom of the Ditch -- flat space at the base
ditch that separated the scarp and
Boyau (Fr.) -- a communication trench,
a sap pushed
forward toward the enemy. Typically constructed in a zigzag
prevent exposure to direct fire from the front.
Breaching Battery -- a battery constructed
operations to enfilade a portion of the enemy's defenses or
down the enemy's walls or parapets.
Breastwork -- a linear earthwork that was
to cover the chest of a man standing behind it. A breastwork
be constructed of ad hoc materials, such as logs, stones,
cotton bales. The term is used very generically.
Bulwark -- See Rampart.
Capital -- the imaginary line that bisects an
Casemate -- enclosed and roofed-over
The gun fired through an opening called an embrasure.
vaulted with stone were a basic component of permanent masonry
Casemates were constructed only rarely in the field with logs and
Cavalier -- See Keep.
Cheek -- side of an embrasure, often
by gabions or sandbags.
Caponière (Fr.) -- projection from the
of a curtain
wall that enabled infantry or artillery to fire into an exterior
Cheeks -- sides of an embrasure, often
with gabions, sandbags, or logs.
Chevaux-de-frises (Fr.) -- portable obstacles
logs with projecting sharpened stakes, joined together by chains;
"horses of Friesland" where the device was invented in the
Circumvallation -- siege lines built to
enclose, the enemy's defenses. See Countervallation.
Citadel -- See Keep.
Column of Fire -- a volume of fire directed
to the parapet. Entrenched soldiers tended to fire directly to
front when under attack, rather than side to side. To deliver
it was most needed, engineers changed the orientation and
of a fortification's faces and flanks. Each
parapet had a specific column of fire that swept the front or
with fire from an adjacent segment.
Command -- height of an earthwork above
Communication Trench -- a ditch and parapet
one part of an entrenchment with another to move troops and
These were sometimes simple shelter trenches, serving as arteries
reserves to some portion of the line. Called a covered
deep enough to conceal movement.
Continuous Line -- a line of fortifications
a solid front to the enemy. Parapets, or Curtains, connected all
artillery strong points on the line. See Lines at
Corbeil or Corbeille (Fr.)
-- a form
of gabion; a small wicker hamper wider at the top, placed
row along the parapet and filled with earth. The tapered shape
musketry loop-hole between corbeils.
Corduroy Road -- logs laid side-by-side in a
to make it passable in wet weather. The same technique was often
to gun platforms to support artillery pieces.
Counterbattery Fire -- artillery fire
directed at the
enemy's artillery in an attempt to silence or disable the guns.
of the threat of counterbattery fire, artillery positions were
built stronger and more massive than adjacent infantry
Countermining -- See Mine.
Counterscarp -- outer or exterior slope of a
Countervallation -- siege lines built in
with lines of circumvallation to protect the rear of the
force from assault by a relief force or from raids.
Covered or Covert Way -- in
fortifications, a walkway extending around the outside of the
ditch of the main line; in fieldworks, a ditch and parapet
protect and conceal the movement of troops and supplies to the
from camps or supply caches in the rear. A covered way was not
in the sense of being roofed over; it provided cover from
Cremaillière (Fr.) or Indented Line --
saw-toothed line of fortifications, designed to generate
all across the front of the line.
Crest -- See Superior
Crossing or Interlocking
Fire -- fire
that converged on the same target from two different points.
out a line of defense, engineers sought to generate interlocking
whenever possible. See Column of Fire.
Crownwork -- a detached earthwork open at the
formed of a central bastion and two flanking
two long flanks extending to the rear and inclining toward
Cunette (Fr.) -- a narrow drainage ditch
running along the bottom of a trench. Drainage was a continual
whenever an earthwork was occupied for any length of time.
have been observed to survive, typically within semi-permanent
siegeworks, and larger batteries.
Curtain or Curtain Wall -- a
line of parapet that connected two bastions or artillery
points, technically with an exterior ditch.
Dam -- often used in conjunction with
military earthworks to flood an
area for defensive purposes.
Déblai -- the earth removed from an excavation that provided the bulk of the material used to construct a rampart or parapet. See Spoil.
Dead Angle -- See Sector without
Defilade or Dead Ground -- a
ravine, gully, or depression within range
of an earthwork's weapons that could not be seen or fired into
Deliberate Entrenchments -- defenses
constructed in anticipation of need,
to defend a town, depot, or bridge, for example, typically
with a front or exterior ditch. If defending an important
occupied for a long period of time, deliberate earthworks might
to a semi-permanent condition. Magazines and bombproofs were
The parapets might be sodded with grass, revetments faced with
or stone, roads and ramps paved with flagstones, a well dug, and
complete drainage system installed. Frame barracks and
be constructed within or adjacent to the earthworks for the
Deliberate Fieldworks -- improvements made to
an existing line of rapid
entrenchments, typically the addition of detached works
Demi-bastion (Fr.) -- an angular work that
projected outward from the
corner of an enclosed or detached earthwork. A demi-bastion
of one face and one flank forming a salient angle.
flank directed fire across the front of an adjacent face or
Demilune (Fr.) -- a crescent shaped parapet
protecting a single cannon,
typically ditched in front. Also called an epaulement; in
a component of the bastion. The term was often used
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
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
generally redans, ravelins, lunettes, or redoubts. Other
swallow's tails, hornworks, crownworks, and priest
Direct Fire -- incoming fire striking
perpendicular to the parapet or
line of battle. Incoming fire could be direct, enfilading,
reversed, and ricochet.
Discontinuous Line -- See Line of
Ditch -- excavation providing soil to
construct a parapet. A ditch could
be in front of the parapet (front-ditch or
it (back-ditch or interior), or on both sides
Engineers preferred front-ditch construction whenever time and
as it created a stronger profile. Batteries, redans,
and redoubts were consistently constructed with a front-ditch.
construction was the fastest way to entrench, and therefore was
often for rapid infantry entrenchments. A double-ditch resulted
digging in front to widen an existing back-ditch parapet, from
a covered way behind a front-ditched line, or from capture
refacing. Some evidence of the ditch-a shallow
even if its parapet has eroded away. The scarp and
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
way behind a front-ditch parapet. An earthwork that was captured
turned (refaced) would have a double ditch. See
Drainage Ditch -- See Cunette.
Dugouts and Bunkers -- rectangular
excavations, usually 5-10 feet on a
side, associated with the principal defenses of an earthworks
These typically served a command or logistical function. On rare
in the field or during siege operations, dugouts might be roofed
roofed with logs and earth.
Earthworks -- any earthen structure excavated
for military purposes.
In simplest form, a defensive earthwork was composed of a parapet
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
of it, and a Zone of Contention (No Man's Land) separating
positions of the combatants. The entire fortified front, taking
combatants, might be a mile ore more deep with each zone
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
field of fire but the parapet protected the gunners. The sides,
of an embrasure often were reinforced by logs, planks, stones,
or gabions. Embrasures were common features of artillery
and often survive as an indentation in the otherwise uniform
Not all indentations are embrasures. Typically, there is other
of the presence of artillery-a gun platform and gun ramp, for
A single gun might have had multiple embrasures. See
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
destructive as incoming rounds might strike multiple targets and
fire could be brought to bear. Traverses were often constructed
a parapet to limit casualties caused by enfilade. Incoming fire
be direct, enfilading, oblique, plunging, reversed, or
Entanglement -- obstacles placed in front of
an earthwork to trip up and
delay attackers, sometimes used to refer to an abattis.
the Civil War, telegraph wire was strung from stump to stump at
to form a "wire entanglement." Most wire was retrieved or
or after the war, so little would be expected to survive
Entrenchment or Intrenchment
-- generic term for any form of earthen fortification.
In common usage, terms like breastwork, trench, entrenchment
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
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,
angle of repose for most soils. The interior slope was
to enable defenders to stand directly behind it. Nearly all
in original condition will display some difference in angle
exterior and interior slopes. See Interior and
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
stratum of soil in an excavated cross-section. See
Field of Fire -- area within weapons range
that can be seen and swept
by fire. Fields of fire were often improved by slashing
down) all of the trees or pulling down buildings in front of the
Fieldworks -- earthworks constructed by
armies while actively campaigning,
whether on the battlefield or in camp. Often hasty or
Fill -- logs, rails, stones, or other
available materials used to add
bulk to the parapet; typically gathered and placed along the
line before digging begins.
Fire -- organized and directed discharge of
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
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
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
Fossé (Fr.) -- an exterior ditch
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
prevent attackers from scaling the parapets. Sometimes called a
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
to have greater bulk and a stronger profile than rear-ditch
This was the engineers' preferred method and was consistently
to prepared fortifications, to detached works, and artillery
It is common to find a mix of front-, rear-, and double-ditch
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.
Gabion -- a large basket of interwoven vines
and saplings used to strengthen
or shape an earthwork. The gabion was set into position, then
with earth on site. When gabions deteriorated, the fill
shapeless mounds that can sometimes be identified in the
Glacis (Fr.) -- outer edge of the ditch, or,
by extension, the field
of fire of a fortification. In permanent fortifications, the
was shaped so that the ground rose gently as it approached the
protect and conceal the masonry revetment of the scarp.
time permitting, the glacis was sloped as a continuation of the
of the superior slope of the parapet. Some surviving
works have a shaped glacis, though it is fairly rare.
Gorge -- entrance to a detached work, or
simply the rear of the work, as in, a lunette is open "at the gorge." Leaving the rear of a work open allowed defenders in a secondary line to fire into it in case it were captured. A wooden stockade was sometimes built to close off the gorge.
Grade -- original ground level. Ditch
is below grade; parapet
is above grade.
Greater or Major Fieldworks
-- earthworks constructed with an exterior
Gun Pit -- an entrenched artillery position,
a platform, demilune
Gun Platform -- a flat, usually rectangular,
area behind a parapet on
which an artillery piece was positioned. The platform surface
floored with planks or split logs or corduroyed with logs
side by side. A platform might be excavated or elevated relative
depending on whether it was firing through an embrasure or
the parapet (en barbette). The size of the platform is
of the size of cannon it was intended to service (average 10 x 14
for a standard field piece). Sometimes, a platform was edged by
drainage ditch or flanked by traverses.
Gun Ramp -- a ramp constructed to move a
cannon into firing position on
its platform; the ramp may ascend or descend to the platform from
level. A gun ramp is a common surviving feature of artillery
Hasty Entrenchments -- See Rapid
Holes and Pits -- foxholes and other
personal defenses. Single-man
skirmish pits or picket holes (foxholes) were typically about
in diameter and 2-3 feet deep with the dirt thrown forward to
form a low
parapet. These holes were sometimes enlarged to hold two- or
firing teams. Pickets and skirmishers were deployed from 50-300
in advance of the main line of defense at intervals of 5-15
regularity of placement is one of the principal indicators used
field to differentiate a picket or skirmish line from random
by tree-throw. Interspersed along the skirmish line might be
which were short, discontinuous segments of parapet dug to cover
Fire pits or mess holes might be dug out of the ditch behind the
lines for cooking and sleeping. "Officer holes" sometimes appear
intervals from 5-10 yards behind the main lines, where file
non-commissioned officers, were stationed to keep the rank and
line. See Dugouts and Bunkers.
Hornwork -- detached earthwork formed of two
and two long flanks extending to the rear and inclining
the open gorge.
Hurdle -- revetment formed by
interlacing vines or saplings through
a series of posts set upright against the interior slope
Impoundment or Inundation --
flooded ground in front of or within a fortification
for defensive purposes.
Improving -- continuing to strengthen a
system of rapid entrenchments
over time. A simple rifle trench could be improved by widening
adding traverses, excavating dug outs or fire pits behind the
adding supply caches and a covered way to the rear. Soldiers
work on their entrenchments more or less continuously for as long
occupied them to make them safer, more comfortable, and more
Indented Line -- See Cremaillière
Infantry Works -- earthworks designed for
defense by infantrymen.
Interior Slope -- rear slope of the parapet,
usually nearly vertical to
enable the defender to stand against it to fire over the parapet;
faced by a revetment of logs, rails, planks, sod,
hurdles), stones, sandbags, or other available materials.
Internal Works -- structures built within a
larger earthwork, such as
magazines, bombproofs, and traverses.
Irregular Works -- See Regular and
Keep -- a blockhouse or redoubt built within
a larger fort for use as
a place of final refuge or last-resort defense. Also called a
Lesser or Minor Fieldworks -- earthworks
constructed with an interior
or rear-ditch. Because soldiers stood in the ditch to fire over
the total relief rarely exceeded five feet.
Line of Battle -- a tactical, linear
formation of troops in which the
front ranks stood nearly shoulder to shoulder and the rear ranks
behind them in the intervals. Eighteenth- and nineteenth-century
deployed in such dense lines in order to concentrate their
a single direction. Since effective fire could be delivered only
front, the entire line of battle needed to shift position to
direction of fire. Military earthworks reflected these linear
Lines at Intervals -- a line of mutually
supporting detached works, typically
redans, lunettes, or redoubts that were not
by infantry parapets, also called a discontinuous line. In
at intervals allowed defenders greater mobility to conduct an
Listening Well -- a shaft sunk during siege
operations to detect an enemy's
attempt to tunnel under an entrenched position. See
Loop-hole -- a narrow slit through which a
weapon could fire.
Lunette (Fr.) -- a detached earthwork, open
to the rear, composed of two
faces forming a salient angle and two
and faces being of nearly equal length. Called a
when connected to another lunette by a curtain wall.
applied to a demilune or epaulement.
Magazine -- a secure, water-tight place to
store ordnance supplies; in
prepared works or fieldworks, a log or plank room or bunker
with a thick layer of earth to protect ammunition from accidental
or incoming artillery fire. Most artillery fortifications
any length of time had at least one magazine, depending on the
and types of guns. A surviving magazine typically appears as a
mound of earth, sometimes with a depression in the top where
timbers have collapsed or in the side where the entrance used to
The entrance was to the rear, opposite any incoming fire.
trenches or at least unobstructed paths for runners lead from the
to the gun platforms. From visible remains, it is difficult to
a mound was a magazine or a bombproof. A single mound
artillery fortification is likely to have been a magazine,
generally protected ordnance before men.
Maham Tower -- platform of logs, earth, and
during siege operations to allow besiegers to fire over
Main Line of Defense -- line along which the
principal strength and effort
of the defenders was concentrated.
Merlon -- section of parapet between two
Military Crest -- shoulder of a hill or ridge
rather than its actual crest.
The military crest is the highest contour of elevation from which
base of its slope can be seen without defilade. When
an area for surviving earthworks, it is often useful to search
Mine -- tunnel dug beneath an enemy
fortification, either to undermine
its foundations or to set off an explosion. Mine tunnels are
discovered today in association with siegeworks, usually when a
of it collapses. The best defense against enemy mining was
digging tunnels to intercept the enemy's mine.
Moat -- ditch in front of an earthwork that
was purposely filled with
Mutual Support -- two artillery or infantry
strong points, each within
the other's range and field of fire and able to assist the
if attacked. Engineers typically designed a fortification so
parts were mutually supporting.
No Man's Land -- See Zone of
Oblique Fire -- incoming fire that strikes
the parapet or line of battle
at an acute angle from left or right. Incoming fire could be
enfilading, oblique, plunging, reversed, or
Palisade (Fr.) -- a phalanx of sharpened logs
or fraise, anchored
in a shallow ditch and slanted to the front as an obstacle to
infantry. Also a wall of logs or stockade.
Pan Coupé (Fr.) -- a short straight
of parapet constructed across
the capital of a salient angle, having the effect of reducing the
sector without fire.
Parade or Parade Ground --
flat assembly area within a larger permanent
or semi-permanent fortification; often adjacent to barracks or
buildings; sometimes improved by leveling and draining.
Parallel -- a parapet thrown up to confront
defenses when conducting a
siege by regular approaches. The First Parallel
out of range of the enemy's guns. Saps were pushed
or a hundred yards to construct a Second Parallel, and so on,
the ditch of the enemy fortification. Imprecisely applied to
a curtain wall.
Parallel Fire -- fire directed across the
front of an entrenched line
or line of battle.
Parapet (It. parapetto, shield the
a linear mound of earth
built to defend against incoming fire. The thickness of a
determined by the armament that it was expected to withstand-for
5-7 feet; field artillery, 8-16 feet; for siege or naval guns, up
feet. The parapet consisted of an interior slope, usually
with logs, planks, rails, stones, sandbags, or fascines, so as to
vertical, the superior slope or crest, which
downward toward the enemy, and the exterior slope or outer
which took the brunt of enemy fire. The exterior slope typically
45 degrees, the natural angle of repose for most soils.
Passive Defense -- strategy of holding an
entrenched position and awaiting
the enemy's attack.
Peneplein (Fr.) -- flat interior of an
enclosed earthwork, synonymous
in usage with terreplein.
Permanent Fortifications -- defenses
constructed to defend towns, garrisons,
depots or other fixed positions that were intended to last for a
time with minimal repair. A fort's ramparts could be constructed
of stone and brick or, if built largely of earth, would have
within and without to deter erosion.
Picket -- a guard or vidette.
Picket Holes or Skirmish
Pits -- See Holes and Pits.
Picket Line -- a row of guards, or videttes,
spread out in intervals and
formed in advance of the main line to provide warning of an
row of individual foxholes entrenched by the pickets. Picket
advanced anywhere from 50-300 yards in front of the main lines,
on the terrain and proximity of the enemy.
Platform -- See Gun Platform.
Plunging Fire -- fire directed from higher to
Postern -- See Sally Port.
Prepared or Provisional
Entrenchments -- See Deliberate Entrenchments.
Priest Cap -- a detached earthwork consisting
of two faces joined
in a reentrant and two long flanks extending toward
rear and inclining away from the open gorge. The design served
the fire of the two faces on a specific target to the front. The
of the re-entering angle determined the distance to the point of
Profile -- cross-section of an earthwork.
The higher and wider the parapet,
the wider and deeper the ditch, the "stronger" the profile. A
rear-ditched rifle trench had a "weak" profile.
Ramp -- an incline leading up to the
or allowing access to a gun platform.
Rampart -- a broad embankment of earth that
the functioning elements of a permanent or semi-permanent
The parapet and banquette were built at the front of the rampart;
moved troops from the interior of the work onto the
of the rampart. In early forts, a rampart was often improvised
double parallel revetments of logs and filling the intervening
stones and hard-packed earth. Ramparts typically were not a
of field fortifications but appeared occasionally in simpler form
artillery works. Sometimes called a bulwark.
Rapid Entrenchments -- fieldworks constructed
presence of the enemy, usually with a rear or interior ditch and
with ad hoc materials for fill and revetment, also called hasty
entrenchments. Although built "hastily, " these were rarely
as the modern use of the word might imply. Experienced soldiers
throw up a shelter trench sufficient to absorb small arms fire in
than an hour with only rudimentary tools.
Ravelin -- a detached earthwork open to the
two long faces forming a salient angle and two
See Detached Works.
Rear -- interior, away from the enemy.
Rear-ditch or Interior Ditch
in which soldiers stood to fire over the parapet; most commonly
rapid infantry entrenchments. Rear-ditch was the fastest way to
because each shovel of earth lowered the ditch and at the same
the parapet. See Ditch.
Redan (Fr.) -- a detached fortification with
forming a salient angle, often built as an outer work to
an advanced position. The work was open at the rear. A redan
was a common
form of all military eras. When bisected by a traverse down its
(along the capital line), it was called a flêche, or
When connected to adjacent strong points by curtain walls, it
Redan Line -- a series of redans
Redoubt -- an enclosed fortification designed
to be defended
from all sides. The trace of a redoubt could be square,
or occasionally circular. A redoubt could stand alone as a
work, serve as a place of refuge within a larger
be incorporated into a continuous line of entrenchments as an
or infantry strong point. Redoubts were a common feature
Reentering Angle or Reentrant -- angle in an
or line of earthworks that points toward the rear and away from
Systems of earthworks were purposely designed with both
Reface -- to "turn" or change the
facing of an
Relief -- distance from the crest of the
parapet to the
bottom of the ditch; relief is a component of the
Regular Approaches -- siege operations
conducted by building
saps, parallels, and breaching batteries, based largely on a
for the French armies by Sebastien le Prestre de Vauban
Regular and Irregular Works -- enclosed
Regular works were based on classic models-square or six-sided
and bastioned forts-and generally appeared balanced in proportion
symmetrical in trace. Irregular works were adapted to the
of the terrain and took a variety of shapes and traces. Although
"elegant" in terms of geometry, irregular works were often
stronger than the more rigid, classical prototypes.
Remblai -- the material used to construct a rampart or parapet, the bulk of this material provided from earth removed by excavation. See Spoil.
Retrenchment -- a secondary line of
to seal off a gap in the main line or to prevent a
Reversed Fire -- incoming fire that strikes
of a parapet or line of battle. Incoming fire could be direct,
oblique, plunging, reversed, and ricochet.
Revetment -- retaining wall constructed to
interior slope of a parapet. Made of logs, wood planks, fence
fascines, gabions, hurdles, sods, or stones, the revetment
protection from enemy fire, and, most importantly, kept the
nearly vertical. Stone revetments commonly survive. A few log
have been preserved due to high resin pine or cypress and porous
soils. After an entrenchment was abandoned, many log or rail
were scavenged for other uses, causing the interior slope to
quickly. An interior slope will appear more vertical if the
with the revetment still in place.
Ricochet Fire -- fire that strikes the ground
bounds into the air, used primarily by artillery firing a round,
shot. The glacis was shaped to deflect ricochet rounds up
over the parapet rather than into it.
Rifle Pits -- generically, any grouping of
entrenchments, usually discontinuous, with a rear-ditch and low
See Holes and Pits.
Rifle Trench -- a parapet for infantry,
up rapidly with a rear-ditch. Also called a shelter trench.
Salient -- a portion of a system of
earthworks that protruded
or bulged outward toward the enemy.
Salient Angle -- an angle in a work or line
that pointed toward the enemy. See Reentering Angle.
of earthworks were designed purposely with both reentering and
Sally Port -- opening left in the parapet as
to an enclosed earthwork. All enclosed earthworks had a sally
a postern when vaulted or roofed to form a tunnel.
Sandbags -- used to strengthen prepared
and siegeworks, often filled off-site and transported to the work
construction. A stratum of sand overlying a different base soil,
in an artillery work, might indicate the use of sandbags.
Sap -- a trench built to connect one parallel
next in order to advance siegeworks, sometimes built as a zigzag
or straight with internal traverses. See Regular
Sap Roller -- a large wickerwork cylinder
of a crew to absorb incoming fire as it worked on a
Sapper -- a pioneer or engineer engaged in
Scarp, Escarp, or Escarpment -- inner slope
of the ditch,
as opposed to counterscarp, the outer slope of a ditch.
and counterscarp are below grade and are visible components of
Sector Without Fire -- area in front of a
angle into which the defenders cannot fire. A sector without
was extremely vulnerable unless defended by fire directed from
part of the fortification.
Shelter Trench -- a simple rifle trench for
typically with a rear-ditch.
Siege Operations -- systematic entrenching to
an enemy's defenses, using classic engineering techniques. See
Siegeworks -- earthworks built to advance or
Skirmish Line -- soldiers deployed at
intervals in front
of the main line of battle to harass the enemy and delay any
a row of individual foxholes entrenched by the skirmishers.
lines were advanced anywhere from 50-300 yards in front of the
depending on the terrain and proximity of the enemy.
manned the skirmish line.
Skirmish Pits or Picket
Holes -- See
Holes and Pits.
Slashing -- cutting down all trees in front
of a line
to create a clear field of fire. Trees were felled in the same
with branches toward the enemy, serving as an obstacle to
trees might then be trimmed and arranged more formally into an
Slit Trench -- slang for a short trench,
similar to a
rifle pit, constructed for 3-5 men. Often found in a picket line
with foxholes or as shelter in the rear of a main line.
Spoil -- earth removed from an excavation,
termed in French the déblai. The spoil provided the bulk of the remblai, that is, the material used to construct a rampart or parapet.
Star Fort -- an enclosed work with
and reentering angles. A star fort might have from
to eight salient angles projecting toward the enemy. This was a
form until the middle of the Civil War, but many engineers
it to require more work than needed for a strong defense.
star forts survive from various time periods.
Stockade -- generically, a log fort; when
used as an
adjunct to earthworks, a vertical wall of logs tied or nailed
to protect the flank or gorge of a battery,
redoubt. Loopholes were cut in the logs to allow for rifle
exterior of the stockade wall might be ditched with the earth
against the logs. Archeological excavation might reveal evidence
postholes or remains of the post in the ground.
Strong Point -- a dominating position,
usually high ground,
defended by entrenched artillery or a concentration of
artillery work within a continuous line of entrenchments.
Superior Slope -- crest of the parapet on
weapons to fire. The interior slope was nearly
so that a man could stand comfortably against it. The superior
inclined slightly toward the enemy. The exterior slope,
intercepted most incoming fire, inclined more abruptly. See
Supply Cache -- a rectangular excavation,
feet on a side and three feet deep, found in rear of the Main
Defense. See Earthworks Complex. These served as
for boxes of food or ammunition and are found in sheltered
to a road or a covered way. On rare occasions in the field or
siege operations, a supply cached might be roofed or partially
with logs and earth.
Swallow's Tail -- a detached earthwork
two faces joined in a reentrant and two long flanks
toward the rear and inclining toward the open gorge.
Tenaille (Fr.) Line -- a series of adjacent
of equal or differing sizes, joined at the flanks with no
Terreplein (Fr.) -- ground level, grade;
a level area inside an enclosed fortification; in permanent
the flat surface of the rampart behind the parapet.
Tête-de-pont (Fr.) -- an entrenched
bridgehead with both flanks anchored on a river, designed to hold
a river crossing.
Throw Up Works -- to entrench. Earthworks
as being "thrown up."
Trace -- outline of a fortification as drawn
on a plan
or "traced" upon the ground. In terms of engineering, the trace
earthwork was its most important characteristic. To be
trace should take advantage of the military strengths of the
mitigate its weaknesses; its design should accomplish its purpose
overall plan of defense; its length should be adjusted to the
soldiers designated to hold the position.
Traverse -- a short segment of parapet used
incoming enfilade fire from sweeping the length of a line,
the rear wall of an enclosed work from a plunging fire
front, to cover a sally port, or to provide extra protection for
or supply cache. Traverses were sometimes built of or reinforced
and were usually constructed perpendicular to incoming fire,
perpendicular to the defensive parapet. In rapid entrenchments,
might be constructed entirely of logs.
Trench -- usually short for entrenchment,
to the ditch of an entrenchment or to an auxiliary entrenchment
of a rampart.
Trous de loup (Fr.) -- rows of pitfalls, 4-6
dug in checkerboard fashion in front of an earthwork to obstruct
attacking force. Each cone-shaped pitfall concealed a sharpened
Turned Works -- an entrenchment captured by
and refaced, resulting in ditching on both sides of the
Work -- any discrete component of a system of
applied most often to detached defenses, to forts, or artillery
Zigzag Trench -- See Boyau.
Zone of Contention -- No Man's Land, the area
the deployed skirmishers of the combatants, often defined by the
of the opposing skirmish lines. Because skirmishers tended to
or withdraw according to nuances of the terrain and localized
the width of this zone fluctuated. See Earthworks
Zone of Fire or Kill Zone --
the Main Line of Defense and the advanced skirmish or
typically no wider than the effective ranges of standard infantry
In this zone, soldiers cut down trees to clear a field of fire
erected obstacles, such as an abattis or entanglements, to
down and break up an attack. Nothing would remain from such
unless it was the shallow ditch that anchored the abattis. One
find larger dugouts that held reserve pickets that could be fed
the skirmish line as needed. See Earthworks Complex.
Zone of Occupation -- area behind the Main
Line of Defense.
This zone might extend 200 yards or more behind the front,
the terrain. In this zone were activities of logistics and
which sometimes left evidence in the form of support trenches,
supply caches, bunkers for officers and non-combatants, or
through which troops and supplies could move unseen from the rear
front line. In some cases, artillery positions were constructed
over the front lines at distant targets. See Earthworks