Underground protection tube system for HV cables and pipes - uses pits dug at given distances apart and inserts tubes in horizontal channels linking pits

摘要

The underground protection tube is for running h.v. cables, pipes, etc. at a given depth below the surface. The construction involves excavating pits a given distance apart and linking them through horizontal underground channels. The cables can therefore be laid below existing cables, pipes and drainage pipes, etc. without exposing or damaging them. The cables (a) can be pulled through the horizontal channels by a traction system with a rope cable. The horizontal holes along the different sections must be aligned so that the cable can be pulled through with little or no friction. The leading end of the cable-form is protected by a nose cone and the traction rope guided up to the ground level by pulleys (c, d).