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Siege Terms

This page holds definitions of Civil War era siege terms which may not be easily recognizable to today’s reader. Learning the terms here should help with understanding many areas of Beyond the Crater.

Abatis – One of the oldest forms of defense for fortifications, the abatis is an arrangement of felled trees, with the branches facing outward from the defending position to impede the charging enemy.

Barbette – Usually found only in permanent or semi-permanent fortifications, a barbette was a raised wooden bed or platform that allowed an artillery piece to be fired over protective wall or parapet without exposing its gun crew to the enemy. During a long siege, the besieging army often set up elaborate but temporary fortifications for their artillery pieces, in which case a large mound of earth was often used as a substitute for a formal wooden barbette platform.

Breastworks – a barricade usually about breast high that shielded defenders from enemy fire.


Camouflet – To combat enemy miners tunneling under their siege works or trenches, Confederate and Federals sometimes used a simple explosive device called a camouflet. The explosive charge was planted in front of the defenses so that as enemy miners tunneled forward, the camouflet would rest in their path. When the enemy struck the device with a pick or shovel he would have to retreat hastily or the shaft would collapse on him. If planted skillfully, the camouflet would explode downward leaving the earth above intact so as not to reveal the mine’s location.
Probably as old as the history of siege warfare and gunpowder, these countermining devices were rare used during the Civil War but were tried by Confederates at Vicksburg. An 18th-century military dictionary stated that when miners struck camouflets, “stinking combustibles” would fly into their faces. Camouflet, from the Old French, means a whiff of smoke puffed into someone’s face.

Fascine – A bundle of sticks or twigs used to reinforce earthworks, trench walls, or lunettes, as fascine was a field substitute for a sandbag or cotton bale, the most preferred reinforcing materials. Usually buried in the earth interior of a wall, a fascine had a bristling top that would often protrude above hastily built field fortifications and the impression of being a defensive feature like an abatis.

Gabion – A cylindrical wicker basket several feet high, filled with dirt and stones, a gabion was used to reinforce fieldworks. Its use preceded the Civil War by centuries.

Lunette – A 2 or 3 sided field fort, its rear open to interior lines, was called a lunette. Lunettes were often named in honor of battery commanders or commanding brigadier generals.

Mortar – Mortars are among the oldest forms of artillery, and they had not changed much by the advent of the Civil War. Classified by bore size, 5.8-in., 8, 10, and 13 in., they threw a “bomb” or fused shell in a high arc over enemy walls and fortifications and sometimes lobbed shells over the heads of friendly troops as they charged the enemy. The coehorn mortar, among the smallest, had a 4.5-in. bore. Made of iron, mounted on heavy wood and iron beds, mortars were usually intended for siege and garrison work.

Parapet – In fortifications, a wall on top of a rampart that shielded riflemen or artillery crews from enemy fire.

Picket – An advance outpost or guard for a large force was called a picket. Ordered to form a scattered line far in advance of the main army’s encampment, but within supporting distance, a picket guard was made up of a lieutenant, 2 sergeants, 4 corporals, and 40 privates from each regiment. Picket duty constituted the most hazardous work of infantrymen in the field. Being the first to feel any major enemy movement, they were also the first liable to be killed, wounded, or captured. And he most likely targets of snipers. Picket duty, by regulation, was rotated regularly in a regiment.

Pioneers – Soldiers detailed to carry out duties similar to those of mdern combat engineers such as cutting roads, repairing bridges and works, and dismantling enemy artillery, fortifications, and railroads; the Pioneer Corps was a specialized unit in the Army of the Cumberland.

Point d’appui – A fortified or secure point that anchored or strengthened an army’s position was called a “point d’appui.” The sunken road and stone wall at Maryre’s Heights, Fredericksburg, Virginia are examples of this.

Rampart – In fortifications, a steeply sloped earthen embankment topped by a parapet.

Redan – In fortifications, a form of angled breastworks shaped like a V with its point facing the approach of the enemy.

Revetment – A support or reinforcing wall of earthworks or permanent fortifications was called a revetment. Sandbags, gabions, or fascines, revetted fieldworks; masonry revetments supported stone or brick forts.

Salient – A salient is an area of a defensive line or fortification that protrudes beyond the main works. In the Civil War, it extended closest to an enemy’s position and usually invited an attack. Generals erected salients primarily to cover dominating ground beyond their entrenchments.

Sap roller – A large wicker basket similar to a gabion, a sap roller was filled with stones and planks and rolled in front of lead sappers working on assault trenches in the face of the enemy. It deflected some of the small-arms fire and partially obscured a view of sappers at work.

Works – In military usage, standard terminology for fortifications.

Source: Shotgun’s Home of the American Civil War, Civil War Terms Page

{ 1 comment… add one }
  • John Horn June 4, 2017, 4:31 pm

    Some additional important terms are:
    Circumvallation–walling in the besieged; and
    Contravallation–walling out relieving forces.
    The Federal lines of circumvallation and contravallation were incomplete at Petersburg. The circumvallation went out to Fort Welch and then doubled back to the south as contravallation all the way to Blackwater Swamp.
    Had the Unionists fully invested Petersburg, the circumvallation and contravallation would have resembled Julius Caesar’s lines at Alesia.

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