Underground Transmission Lines Mean?
Underground transmission lines are electrical or telecommunications cables that are installed beneath the ground. Large natural gas pipelines are also called transmission lines, but the term underground transmission lines is normally used to distinguish underground from overhead cabling.
Trenchless construction is often used to install transmission lines for all kinds of utilities.
Trenchlesspedia Explains Underground Transmission Lines
There are both advantages and disadvantages to placing cables in underground tunnels rather than mounting them on enormous transmission towers. It costs more money to install cables underground, and repairs can take much longer. But underground cables are not subject to severe weather events, including hurricanes and freezing temperatures. It is also less likely for underground cables to be vandalized or stolen.
Underground transmission lines are used as an alternative to overhead cables, which may be considered unattractive. Some communities rally support for underground lines because overhead cables may detract from the landscape or pose a risk of electrocution.
A 2015 whitepaper from the North American Society for Trenchless Technology (NASTT) says that large-scale changes in the US electrical generation industry are leading to increased use of trenchless techniques for installation. Materials such as fused PVC are used in horizontal directional drilling and sliplining operations to support underground high voltage power cable installations.