Abstract: An apparatus (20) for counterboring a pipe (25) includes an expander unit (24), a shaft (26) extending from the expander unit, a flywheel (30) rotatably and slidably mounted on the shaft, a frame (34) mounted on the flywheel to be movable in a radial direction, a tool mount (50) and a guide wheel mount (52) formed on the frame, the tool mount traveling with the flywheel into the interior of the pipe during counterboring and the guide wheel mount traveling outside of the pipe during counterboring, the guide wheel mount being connected to the tool mount by guide wheel arm (51) having a radial member (54) that is axially offset to the rear of the tool mount by a distance at least the length of the counterbore to be machined in the pipe, a cutting tool (56) adjustably mounted to the tool mount, a guide wheel (72) rotatably mounted on the guide wheel mount, an inward force applying member (116) and an outward force applying member (122) connected between the flywheel and the frame such that the frame can be moved

Abstract: Apparatus is disclosed for transporting heavy equipment such as welding current generators, a prime mover therefor, and associated devices or supplies, on and along a pipeline, the pipeline serving as a monorail. The apparatus, of elongated construction along the pipeline, is supported at one end and propelled along the line by power driven traction means engaging the top part of the pipeline. The opposite end of the apparatus is supported on a pair of laterally spaced swivel mounted wheels which engage the sides of the pipeline laterally away from and somewhat below the top of the line. The latter wheels give lateral support and stability to maintain the apparatus in a substantially upright position on the pipeline. Sensing means, such as a pendulum, mercury switch means, or equivalent, detect incipient tilting or motion towards instability and are used to steer the swivel mounted wheels, either directly or indirectly.