Abstract: A conveying system comprised of a rail and at least one transport hanger which can travel back and forth along the rail on rollers, the rollers having horizontal axes of rotation, the rail having horizontal conveyer support projections which are located at the bottom of the rail and along which the rollers are positioned for travel back and forth along the rail carrying the transport hanger with them, trolley wires which are insulated from one another being located on the rail to the side of the path of motion of the transport hanger, the rail having guideways for rollers of a trolley carriage at the side of the path of motion of the transport hanger for facilitating support and movement of the trolley carriage back and forth at the side of the transport hanger and independently thereof, the trolley carriage having sliding contacts for engagement of the trolley wires for powering a tool that may be carried by the trolley carriage.