IC 8392 Horizontal Boring Technology: A State-Of-The-Art Study

This report on the state of the art of horizontal boring technology for underground power transmission installations was prepared by the Bureau of Mines at the request of the Department of the Interior. This paper describes the different machines and methods used in augering, impacting, pushing, drilling, and machine tunneling horizontal holes through soil and rock. A review of the borehole survey and guidance tools and techniques applicable to these methods is also given. Nonboring methods used for emplacement of power distribution and transmission lines are briefly discussed. The paper ends with a brief technical forecast, an analytical summary of the state of the art, and recommendations based on power industry needs. Horizontal boring techniques for power distribution lines installation are adequate to meet the requirements of the power industry, particularly where such burial involves relatively short distances in soil or soft rock. For burying power transmission lines, particularly in the harder rocks and over relatively long distances, horizontal boring methods are not as well advanced. Research and development as well as economic incentives to equipment manufacturers could substantially improve the state of the art. Obstacle detection and guidance systems for directing boreholes to specified targets need major improvements to meet the requirements of the power industry for underground burial of distribution and transmission lines