Case Study - Utility Tunnels, UK

Scope of Works Apex Engineering Service’ client commissioned us to survey the entire underground tunnel structure – including the tracing, labelling and mapping of all high voltage utility cables – within a limited time-frame. Our access to the underground facility was limited to a 15-day window of opportunity. Within that time, we were required to survey the full extent of the tunnelling, including marking up/labelling all cables from entry to exit points. Methodology We employed Leica HDS 6000 laser scanners, which have a scan duration of one minute, 36 seconds per setup, and a total of 266 scans were needed to complete the survey. Our use of high definition laser scanners meant we were able to complete the site survey works within 10 days, a full five days ahead of schedule. The completed deliverables were issued to our client within just one month of our leaving site. Deliverables We produced a complete set of drawings for the full extent of the underground system on an Ordnance Survey grid. The drawings included a comprehensive map of all utility cables from entrance to exit; levels and clearance heights to all tunnel entries and exits; cross sections at every intersection; and evenly-spaced sections between junctions. A total of 117 cross-sections were drawn up and labelled, including long sections at essential runs. Watch the movie: We also provided our client with a copy of the Tru-view files, which deliver a 3D interactive photo environment of each scanning location. By using the key plan, our client could visually inspect and interrogate any point on the tunnel where the scanner was set-up. This enabled personnel, who had never set foot on the site, to view and interrogate the tunnels remotely from their desktop without the risk or expense involved in a site visit.