Abstract: Apparatus for remotely controlled movement through linear and curved sections of a pipe, or other tubular conduit. The apparatus includes a pair of members spaced apart along a common, central axis. Each member carries a plurality of extensible and retractable pneumatic cylinders for movement of frictional engagement elements into and out of engagement with the interior wall of the pipe. One or more axial drive cylinders rigidly connect the spaced members for movement thereof toward and away from one another. The apparatus carries equipment for inspecting, measuring and/or performing other operations on the pipe, and is of simple and economical design, requiring no gimbal joints or other special linkages for movement in the intended manner.