SA Mines and Energy Journal : November-December 2011
OCTOBER/NOVEMBER 2011 SA MINES & ENERGY JOURNAL 34 INNOVATION Establishing the accuracy of existing site drawings on a project can be very labour intensive, with the process usually involving multiple site visits to measure, sketch and photograph the existing facility. Pieces of information are often missed and there are often difficulties in obtaining measurements due to access or safety challenges and issues surrounding the accuracy of measurements taken. Fast, high-resolution laser scanning instruments are reducing the reliance on existing drawings for expansion projects, tie-ins and plant modifications. The process involves a specialised scanning team which is able to capture very detailed 3-dimensional information of a site in a fraction of the time compared to conventional survey and field measurement. These scanned measurements are taken at rates of up to 1 million points per second and gathered without contact from distances of over 100 metres, which enables large areas of complex plant to be captured rapidly and safely without working from heights or entering hazardous areas. The resulting data, referred to as a pointcloud, contains millions of 3D points, capable of producing a fully detailed 3D representation of an entire site. This information is then imported into 3D design software and used as a highly detailed background for 3D modelling and detailing of plant modifications. The accuracy and detail of the 3D pointcloud enables clash-free detail design from a single site visit. Once the pointcloud data is collected, 3D design is able to commence immediately, speeding up the design cycle and removing the need to invest time drafting and modelling existing conditions. The scan data can be accessed and viewed by all members of a project team, improving communication and ensuring that all parties are working from the same information. Prefabricated items can be scanned and checked for quality assurance against the original pointcloud and fit up then verified prior to installation and Laser Vision Executing Brown eld projects in operational plants presents challenges.New methodologies are delivering bene ts previously unachievable. By Mark Dayman.