COMMON SURVEYS
Before construction of the tunnel began, a series of tests were conducted along the proposed tunnel route to determine the nature of the land beneath the power station. This information was crucial for tunnel excavators to know what they could potentially encounter during construction.
Triangulation survey
This type of survey is used to assess the space of a defined area. The survey involves measuring the angles in a triangle formed by three survey control points to pinpoint a location for engineering projects such as centre lines, terminal points and shafts for long tunnels like this one.