Whether with classic tunnel boring machines or with the shield tunnelling method: correct grade and direction are essential. Here GEO drifting lasers are pointing the way. And they can do so much more!

In order to always keep the accurate reference axis, the machines’ position and direction of advance are continuously monitored and kept on course via various position sensors and at least one two-dimensional laser receiver.

In this well-established procedure, the prerequisite for successful control is a reliable laser beam projection. Once in place and having the desired grade and direction, it provides the tunnelling machine with a precise means of orientation.

For this application, GEO drifting lasers have been the global industry leader for more than 30 years. While the desired grade can be adjusted to an accuracy of 0,001 %, the horizontal direction of our premium model, the VL-80, is preset and, if necessary, corrected by a second laser beam, including a special ‘locking receiver’.

With this specially designed positioning device, the alignment of the target axis in terms of height and lateral position does not pose a problem.

This technology is available exclusively from GEO.

The optics designed for this laser enable secure control up to a distance of 500 m. To this purpose, the laser’s performance can be adjusted at five levels, depending on the requirement at hand.

Leading manufacturers of tunnel boring machines worldwide rely on our laser technology.