Abstract: Disclosed is a system for monitoring the speed at which a pipe string is lowered into or pulled out of a well bore during a well drilling operation. The system includes a unit which derives an electrical signal as a function of instantaneous pipe speed and a monitoring system which compares signals representative of instantaneous velocities with respect to predetermined velocity limits and provides physiological indications whenever such limits are transgressed. Also included are visual indicator means and recorder means, as well as a loop control system for automatic regulation of the speed.