![OLD SARUM ditch](https://upload.wikimedia.org/wikipedia/commons/f/fc/OLD_SARUM_ditch.jpg)
In
military engineer
Military engineering is loosely defined as the art, science, and practice of designing and building military works and maintaining lines of military transport and military communications. Military engineers are also responsible for logistics ...
ing, a ditch is an obstacle designed to slow down or break up an attacking force, while a
trench
A trench is a type of excavation or in the ground that is generally deeper than it is wide (as opposed to a wider gully, or ditch), and narrow compared with its length (as opposed to a simple hole or pit).
In geology, trenches result from ero ...
is intended to provide cover to the defenders. In military fortifications the side of a ditch farthest from the enemy and closest to the next line of defence is known as the
scarp while the side of a ditch closest to the enemy is known as the
counterscarp
A scarp and a counterscarp are the inner and outer sides, respectively, of a ditch or moat used in fortifications. Attackers (if they have not bridged the ditch) must descend the counterscarp and ascend the scarp. In permanent fortifications th ...
.
Uses
In early fortifications, ditches were often used in combination with
ramparts to slow down the enemy whilst defensive fire could be brought to bear from the relative protection afforded by the rampart and possibly the
palisade.
In
medieval fortification
Medieval fortification refers to medieval military methods that cover the development of fortification construction and use in Europe, roughly from the fall of the Western Roman Empire to the Renaissance. During this millennium, fortifications ...
, a ditch was often constructed in front of a
defensive wall to hinder
mining
Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic ...
and
escalade
{{Unreferenced, date=May 2007
Escalade is the act of scaling defensive walls or ramparts with the aid of ladders. Escalade was a prominent feature of sieges in ancient and medieval warfare, and though it is no longer common in modern warfare ...
activities from an attacker. When filled with water, such a defensive ditch is called a
moat. However, moats may also be dry.
Later
star forts designed by military engineers like
Vauban, comprised elaborate networks of ditches and
parapet
A parapet is a barrier that is an extension of the wall at the edge of a roof, terrace, balcony, walkway or other structure. The word comes ultimately from the Italian ''parapetto'' (''parare'' 'to cover/defend' and ''petto'' 'chest/breast'). ...
s, carefully calculated so that the
soil
Soil, also commonly referred to as earth or dirt
Dirt is an unclean matter, especially when in contact with a person's clothes, skin, or possessions. In such cases, they are said to become dirty.
Common types of dirt include:
* Debri ...
for the raised
earthworks
Earthworks may refer to:
Construction
*Earthworks (archaeology), human-made constructions that modify the land contour
* Earthworks (engineering), civil engineering works created by moving or processing quantities of soil
*Earthworks (military), m ...
was provided, as nearly as possible, entirely by the excavations whilst also maximising defensive
firepower
Firepower is the military capability to direct force at an enemy. (It is not to be confused with the concept of rate of fire, which describes the cycling of the firing mechanism in a weapon system.) Firepower involves the whole range of potenti ...
.
Today ditches are obsolescent as an anti-personnel obstacle, but are still often used as anti-vehicle obstacles (see also
berm
A berm is a level space, shelf, or raised barrier (usually made of compacted soil) separating areas in a vertical way, especially partway up a long slope. It can serve as a terrace road, track, path, a fortification line, a border/ separation ...
).
A fence concealed in a ditch is called a
ha-ha
A ha-ha (french: hâ-hâ or ), also known as a sunk fence, blind fence, ditch and fence, deer wall, or foss, is a recessed landscape design element that creates a vertical barrier (particularly on one side) while preserving an uninterrupted view ...
.
Elements of a ditch in an artillery fortification (16th to 19th centuries)
![Fortification - ditch and rampart](https://upload.wikimedia.org/wikipedia/commons/1/15/Fortification_-_ditch_and_rampart.png)
* Scarp: the inner side of the ditch (closest to the fort) is called the scarp (or escarp) slope. This may be
revetted
A revetment in stream restoration, river engineering or coastal engineering is a facing of impact-resistant material (such as stone, concrete, sandbags, or wooden piles) applied to a bank or wall in order to absorb the energy of incoming water a ...
with masonry or brickwork, in which case, it is called the "scarp wall".
* Cordon: a course of protruding masonry along the top of a scarp wall, intended to make it harder for an enemy to stand a ladder against it.
*
Rampart
Rampart may refer to:
* Rampart (fortification), a defensive wall or bank around a castle, fort or settlement
Rampart may also refer to:
* "O'er the Ramparts We Watched" is a key line from "The Star-Spangled Banner", the national anthem of the ...
: the actual wall of the fort which can be made of earth or masonry, is topped by a
parapet
A parapet is a barrier that is an extension of the wall at the edge of a roof, terrace, balcony, walkway or other structure. The word comes ultimately from the Italian ''parapetto'' (''parare'' 'to cover/defend' and ''petto'' 'chest/breast'). ...
for the defenders to fire over, and usually slopes away from the ditch (the "exterior slope").
*
Berm
A berm is a level space, shelf, or raised barrier (usually made of compacted soil) separating areas in a vertical way, especially partway up a long slope. It can serve as a terrace road, track, path, a fortification line, a border/ separation ...
: a ledge between the scarp wall and the exterior slope of the rampart, designed to increase the stability of the rampart and prevent any falling debris from compromising the ditch.
*
Faussebraye
A faussebraye ( it, falsa braga) is a defensive wall located outside the main walls of a fortification. It is of a lower height than the main walls, and is preceded by a ditch. In Greek and Byzantine
The Byzantine Empire, also referred ...
: a secondary parapet between the rampart and the inner edge of the ditch.
[Hogg, Ian V (1975) ''Fortress: A History of Military Defence'', Macdonald and Jane's, (pp. 54-56)]
*
Carnot wall
A Carnot wall is a type of loop-holed wall built in the ditch of a fort or redoubt. It takes its name from the French mathematician, politician, and military engineer, Lazare Carnot. Such walls were introduced into the design of fortifications from ...
: a
loophole
A loophole is an ambiguity or inadequacy in a system, such as a law or security, which can be used to circumvent or otherwise avoid the purpose, implied or explicitly stated, of the system.
Originally, the word meant an arrowslit, a narrow ver ...
d wall between the rampart and the inner edge of the ditch.
*
Chemin de ronde
A ''chemin de ronde'' (French, "round path"' or "patrol path"; ), also called an allure, alure or, more prosaically, a wall-walk, is a raised protected walkway behind a castle battlement.
In early fortifications, high castle walls were difficul ...
: a pathway running along the berm, behind the faussebraye or Carnot wall.
* Cunette: a narrow channel that runs along the floor of the ditch for drainage purposes.
* Bartardeau: a type of masonry
dam
A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use ...
across a ditch that is part wet and part dry.
[Lepage, Jean-Denis G G (2010)]
''Vauban and the French Military Under Louis XIV: An Illustrated History of Fortifications and Strategies''
MacFarland & Company Inc, (pp. 90-92)
* Counterscarp: the outer slope or wall of the ditch (furthest from the fort).
*
Sally port
A sally port is a secure, controlled entry way to an enclosure, e.g., a fortification or prison. The entrance is usually protected by some means, such as a fixed wall on the outside, parallel to the door, which must be circumvented to enter an ...
: a small door allowing the defenders to enter the ditch should it be occupied by the enemy.
*
Caponier
A caponier is a type of defensive structure in a fortification. Fire from this point could cover the ditch beyond the curtain wall to deter any attempt to storm the wall. The word originates from the French ', meaning "chicken coop" (a ''capon'' ...
: a masonry or brick structure extending into the ditch or traversing across it; it is pierced with loopholes to enable the defenders to fire along the floor of the ditch.
*
Counterscarp gallery: a passage constructed behind the counterscarp wall and pierced with loopholes, which enables the defenders to fire on attackers who have entered the ditch.
*
Glacis: an earth slope angled away from the ditch; the height and angle of the glacis was calculated to protect the rampart from direct fire but to allow the defenders to fire over it.
*
Covered way
In military architecture, a covertway or covered way (french: chemin couvert it, strada coperta) is a path on top of the counterscarp of a fortification. It is protected by an embankment which is made up by the crest of the glacis. It is able ...
: a path running between the outer edge of the ditch and the glacis, allowing defending troops to move around the exterior of the fort; it was usually provided with a
banquette
A banquette is a small footpath or elevated step along the inside of a rampart or parapet of a fortification. Musketeers atop it were able to view the counterscarp
A scarp and a counterscarp are the inner and outer sides, respectively, of a ...
or
fire step so that defenders could shoot over the crest of the glacis.
*
Place-of-arms
A place-of-arms ( it, piazza d'armi, french: place d'armes) is any place in a fortification where troops can gather. The term has a number of meanings, but it generally refers to an enlarged area of the covertway designed as an assembly point fo ...
: an open area of the covered way at an angle of the ditch, where defenders could assemble for a sally or
counter attack
A counterattack is a tactic employed in response to an attack, with the term originating in "war games". The general objective is to negate or thwart the advantage gained by the enemy during attack, while the specific objectives typically seek ...
.
See also
*
Border barrier
A border barrier is a separation barrier that runs along or near an international border. Such barriers are typically constructed for border control purposes such as curbing illegal immigration, human trafficking, and smuggling. Some such barr ...
References
{{Reflist
Fortification (obstacles)