In military engineering, a ditch is an obstacle designed to slow down or break up an attacking force, while a

trench A trench is a type of digging, excavation or depression in the ground that is generally deeper than it is wide (as opposed to a swale (landform), swale or a bar ditch), and narrow compared with its length (as opposed to a simple hole or trapping ...

is intended to provide cover to the defenders. In military fortifications, the side of a ditch furthest 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.

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 A palisade, sometimes called a stakewall or a paling, is typically a row of closely placed, high vertical standing tree trunks or wooden or iron stakes used as a fence for enclosure or as a defensive wall. Palisades can form a stockade. Etymo ...

. In medieval fortifications, a ditch was often constructed in front of a defensive wall to hinder

mining Mining is the Resource extraction, extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agriculture, agricultural processes, or feasib ...

and escalade activities from an attacker. When filled with water, such a defensive ditch is called a

moat A moat is a deep, broad ditch dug around a castle, fortification, building, or town, historically to provide it with a preliminary line of defence. Moats can be dry or filled with water. In some places, moats evolved into more extensive water d ...

. However, moats may also be dry.

Star fort A bastion fort or ''trace italienne'' (a phrase derived from non-standard French, meaning 'Italian outline') is a fortification in a style developed during the early modern period in response to the ascendancy of gunpowder weapons such as c ...

s designed by military engineers like Vauban, comprised elaborate networks of ditches and

parapet A parapet is a barrier that is an upward extension of a 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/brea ...

s, carefully calculated so that the

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

for the raised earthworks was provided, as nearly as possible, entirely by the excavations whilst also maximising defensive firepower. 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 Soil compaction, 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 b ...

). A fence concealed in a ditch is called a

ha-ha A ha-ha ( 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 of the lan ...

Elements of a ditch in an artillery fortification (16th to 19th centuries)

* Scarp: the inner side of the ditch (closest to the fort) is called the scarp (or escarp) slope. This may be revetted 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: * LAPD Rampart Division, a division of the Los Angeles Police Department ** Rampart scandal, a blanket ter ...

: the actual wall of the fort which can be made of earth or masonry, is topped by a parapet 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 Soil compaction, 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 b ...

: 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 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 loopholed wall between the rampart and the inner edge of the ditch. * Chemin de ronde: 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 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 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 (fortification), curtain wall to deter any attempt to storm the wall. The word originates from the French ', meaning ...

: 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, and to allow the defenders to shoot over it. * Covered way: 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 or fire step so that defenders could shoot over the crest of the glacis. * Place-of-arms: an open area of the covered way at an angle of the ditch, where defenders could assemble for a sally or counter attack.

References

{{Reflist Fortification (obstacles) Earth structures

Uses

Elements of a ditch in an artillery fortification (16th to 19th centuries)

See also

References