Caeau Mine Shaft, North Wales

Category: Civils & Infrastructure
Tags: GPS Survey Sub-Surface Laser Scanning

Working in partnership with Geoterra we carried out a sub-surface laser scan survey of the Caeau Shaft at Milwr Tunnel in North Wales.  The project was required as the upper section of the old, sealed mine shaft required shoring up to prevent any future collapse and the client required 3D geospatial data to determine the shape and dimensional of the shaft in order to design and manufacture the stabilisation lining.

The Milwr Tunnel is a drainage tunnel which runs for around 10 miles before discharging into the River Dee Estuary in North Wales.  Originally built to drain the lead mines which lay beneath Halkyn Mountain, its is still in use today as a drainage tunnel.  The Caeau shaft is one of a network of several sealed mining shafts which require regular inspections to ensure any potential for collapse is detected and managed early enough to prevent any blockage to the main tunnel.

To negate the necessity of removing the large concrete shaft cap, a small hole was drilled to allow a small laser scanner to be lowered into the shaft to enable a laser scan of the internal space which reached depths of around 40 metres.  The Faro Focus 3D Laser Scanner was the survey tool of choice for this project due to its compact size.  In addition, the scanning was linked to GPS survey control to position the scanned data in its correct geo-referenced location, before producing a 3D CAD model, a TruView and a 3D laser point cloud for assisting the design of the structural lining.

Read more about all the services involved in this project : Sub-Surface Laser Scanning.

Project Details

  • Client: Geoterra

  • Location: Caeau Shaft, Milwr Tunnel, North Wales

  • Service: Sub-Surface Laser Scanning