Abstract: A utility power unit (10) for underground drilling and pipe laying operations comprises a stationary frame portion (12), a movable frame portion (14) capable of performing sliding movement relative to the stationary frame portion (12) and hydraulic cylinders (44) between the stationary and the movable frame portions (12, 14) for effecting the relative movement. The movable frame portion (14) includes an attachment (36) for removably attaching a tool connecting member (38) thereto and a further attachment (40) for removably attaching a rotary drive unit (52) thereto. The invention also provides a method of directional boring along an intended underground path (62) comprising the steps of providing a machine pit (60) at a location along the intended path (62) and drilling a bore along the intended path (62) by means of directional drilling apparatus (10) which includes a stem (30) provided with a drill (68) at a forward end thereof.

Abstract: A method of replacing an existing underground pipe (44) with a new pipe (48) comprises the steps of moving a pipe removing tool (70) along the existing pipe (44) to remove the existing pipe and dragging the new pipe (48) behind the tool (70) to replace the existing pipe while imparting vibratory motion to the tool (70) or continuously applying a dressing material ahead of the new pipe to act as lubricant or to fill in the annular space between the new pipe and the surrounding soil. According to another embodiment, the method comprises the steps of pushing out the old pipe (126) in one direction by means of a pipe removing tool (110) connected to a hydraulic unit (10) through a stem and replacing the old pipe (126) by means of a new pipe (48) by dragging the new pipe along behind the stem moving in the opposite direction during a return run.