Abstract: A transmission system for handling materials moving underground comprising a plastic pipe having metallic material of relatively high electrical or electronic conductivity and sensitivity secured to the pipe body. When the pipe is installed in the ground, the metallic material will be automatically buried in association with the pipe body. Detecting means suitable for sensing the presence of the conductive material can then be employed for locating the pipe whereby digging operations or other activities can be engaged in without the danger of damaging the pipe.