abatis n : line of defense consisting of a barrier of felled or live trees with branches (sharpened or with barbed wire entwined) toward the enemy [syn: abattis]
- A means of defense formed by felled trees, the ends of whose branches are sharpened and directed outwards, or against the enemy.
means of defense
Abatis, abattis, or abbattis (a French word meaning a heap of material thrown) is a term in field fortification for an obstacle formed of the branches of trees laid in a row, with the tops directed towards the enemy. The trees are usually interlaced or tied with wire. Abatis are used alone or in combination with wire entanglements and other obstacles.
Although used since at least Roman Imperial times, abatis is rarely seen nowadays, having been largely replaced by wire obstacles. However, it may be used as a replacement or supplement when barbed wire is in short supply. A form of giant abatis, using whole trees instead of branches, can be used as an improvised anti-tank obstacle.
An important weakness of abatis, in contrast to barbed wire, is that it can be destroyed by fire. Also, if laced together with rope instead of wire, the rope can be very quickly destroyed by such fires, after which the abatis can be quickly pulled apart by grappling hooks thrown from a safe distance.
An important advantage is that an improvised abatis can be quickly formed in forested areas. This can be done by simply cutting down a row of trees so that they fall with their tops toward the enemy. An alternative is to place explosives so as to blow the trees down.
Though rarely used by modern conventional military units, abatises are still officially maintained in United States Army and Marine Corps training. Current training instructs engineers or other constructors of such obstacles to fell trees, leaving a 1 or 2 meter stump, in such a manner as the trees fall interlocked pointing at a 45 degree angle towards the direction of approach of the enemy. Furthermore, it is recommended that the trees remain connected to the stumps and the length of roadway covered be at least 75 meters. US military maps record an abatis by use of an inverted "V" with a short line extending from it to the right.
- Pamplin Historical Park & The National Museum of the Civil War Soldier includes large and authentic reproduction of abatis used in the U.S. Civil War.
abatis in German: Verhau
abatis in Spanish: Abatis
abatis in Esperanto: Abatiso
abatis in Croatian: Abatis
abatis in Romanian: Abatiză
advanced work, balistraria, bank, banquette, barbed-wire entanglement, barbican, barricade, barrier, bartizan, bastion, battlement, breastwork, bulwark, casemate, cheval-de-frise, circumvallation, contravallation, counterscarp, curtain, demibastion, dike, drawbridge, earthwork, enclosure, entanglement, escarp, escarpment, fence, fieldwork, fortalice, fortification, glacis, loophole, lunette, machicolation, mantelet, merlon, mound, outwork, palisade, parados, parapet, portcullis, postern gate, rampart, ravelin, redan, redoubt, sally port, scarp, sconce, stockade, tenaille, vallation, vallum, work