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.

See also

• Caltrop
• Cheval de frise
• Medieval fortification
• Trou de loup

Fortification | Medieval defenses

Abatiso