A mole, in the context of directional drilling, is a type of boring tool that creates a narrow hole in which small diameter flexible cables and pipes can be installed. The tool used is called an impact mole and is a basic form of trenchless technology. It is best suited for installations involving small diameters up to 10”, short distances up to 200’ and in compressible soils.
Also referred to as an impact mole.
Trenchlesspedia Explains Mole
The impact mole is positioned on a cradle using sighting levels. A compressor is activated that hammers the chisel tipped mole head through the desired length. When the bore hole has been completed, the cable or pipe is pulled back along with the mole as it is extracted.
Modern moles can be steered in a manner similar to that of a directional drill used for pilot bores. It has a slant-faced head rather than a chisel tip and is steered by the operator in the desired direction by rotating the head. A transmitter housing a sonde in the front of the mole allows walk over tracking of the moles location.