| They were built as a system of separate fortresses, abatis lines, and on forested terrain, tree blowdowns. |
| There were still labourers out there, struggling to manoeuvre an abatis into position. |
| Union soldiers completed digging a series of ditches that zigzagged forward and reached the abatis. |
| It was a combination of towers, palisades, ditches, abatis, and caltrops to slow the attacking Gauls. |
| To improve their position the Americans felled trees and improvised an abatis. |
| The Canadians' defences were herring-boned lines of trenches, backed up by abatises. |
