Only fifteen units have so far been used worldwide for the DIBIT tunnel survey system. Digital Build in Tunnels (digital tunnel picture) surveying uses two electronic cameras mounted side by side on a tripod to produce a 3D surface picture of a 3m strip of tunnel allowing an extremely accurate surface map of the exact level of excavation.
Each section of tunnel requires the cameras to be rotated several times for the full scan. Data is stored in a site computer and then analysed with constantly developing software to produce a tunnel wall map.
DB consultant IRL of Austria has had major input into development of the system along with Graz University. DB wanted the system used because it gives a much more accurate record of the exact status of the tunnel excavation.
The contractor says however it was expensive to hire the four units it needed on site. And the system took a long period to learn well for the teams on site. But it does provide a very accurate measure of the excavation.
