Abstract: A pneumatically operated pipe crawler for transporting inspection equipment along the interior of a pipe comprises an elongate cylindrical tube of flexible resilient material, such as latex rubber, the tube being partitioned by longitudinally spaced plugs which are hermetically sealed to the wall of the tube thus defining three longitudinally separated chambers. The inspection equipment is mounted at the leading end of the crawler. To advance the crawler along the pipe, air or other gas is supplied to the chambers and exhausted therefrom in repeated cyclic sequence for sequentially expanding the chamber wall portions into clamping relation with the pipe, each wall portion recovering to its axial length upon deflation of the chamber, thereby to propel the tube step by step along the pipe.