Abstract: An apparatus for digging a trench including (a) a substantial vertical guide means (2); (b) mounting means (4) connected to the guide means (2) and movable substantially parallel to the guide means (2); (c) first drive means to move the mounting means (4) relative to the guide means (2); (d) a chain digger attachment (1) including an elongated frame (5) and a continuous digging chain (6) substantially surrounding the periphery of the frame (5), the attachment (1) being pivotally connected at or adjacent one of its ends to the mounting means (4); (e) second drive means (15) to rotate the continuous digging chain (6) about the frame (5); and (f) third drive means (24) to pivot the attachment (1) about the mounting means (4).