The optical level is used to establish a horizontal line throughout the worksite. This can then be used along with measurements on the ground to determine the correct depth to dig the ballast out to, ready for the concrete sleepers. It is necessary to dig out the ballast, as the concrete sleepers are deeper than the old wooden ones.
The optical level is used to establish a horizontal line throughout the worksite. This can then be used along with measurements on the ground to determine the correct depth to dig the ballast out to, ready for the concrete sleepers. It is necessary to dig out the ballast, as the concrete sleepers are deeper than the old wooden ones.
Credit: Phil Hamerton, 22/02/2016