Underground warning system for underground conduits or pipes

摘要

PCT No. PCT/AU97/00470 Sec. 371 Date Mar. 2, 1999 Sec. 102(e) Date Mar. 2, 1999 PCT Filed Jul. 22, 1997 PCT Pub. No. WO98/03764 PCT Pub. Date Jan. 29, 1998The invention provides a warning to the excavation above a pipe, conduit or cable laid underground by a service utility by the directional drilling method by providing a coloured area of drilling mud and/or soil about the pipe, conduit or cable. A colouring material is added to the drill fluid during the direct drilling operation which then colours the drill mud and/or soil about the pipe, conduit or cable.