Whilst I was out in the city on a survey I was called by Geoff Sharpe of Hyforce Engineering. He was asking if I was in the vicinity of Roma street and if I was could I do a quick survey for him.
The job was to fabricate and install a walkway canopy for Queensland Rail. It was only a little job but Geoff was of the opinion that a scan was critical as there were so many services in the way that would potentially clash with our steel posts and purlins. This type of survey is tricky to do well if you measure manually. There is so much you can and will miss.
Again Risk Reduction is at the heart of the use of a laser scan for these types of projects.
I was just around the corner and agreed to pop in and try to do a quick survey to try to keep the costs down. To compound our problems the weather was rolling in and it was a bit wet. I had an umbrella and even in the slightly drizzly conditions the Faro X130 performed as well as always.
All together I did 8 scans and was on site for 2 hours. Another 2 hours in the office to process, Register and clean up the sans and I was ready to start modelling the steel work. Once you have got the scans imported into Tekla modelling is fast because you don't need to model existing structure from a scribbled survey or work out where things go. All together the survey cost my client $500 and $60 of this was the extortionate parking fee at Roma Street.
As I said before I was able to use the scan to ensure we did not clash with existing services. I could ensure our connections into the brick wall were on the center of a brick as I could see the courses clearly. I could also make sure we used as little packing as possible. I use a combination of modelling to the point cloud in Tekla Structures and clash checking in Trimble Realworks to get it right.
The point of this is that Laser scanning need not be expensive. The amount of data you collect and the reduction of your risk easily offset the cost of the survey. Yes scanners are very expensive and this goes a long way to explaining some of the reasons for high survey prices but because you pretty much nullify the risk of things not fitting the fabricator wins. As soon as you have to site alter anything your profit margin, such as it is, plummets. Small jobs seem also to be more vulnerable to errors and problems as they get less time spent on them, turn around needs to be faster and its assumed that as its a small job it doesn't matter or its easy. Laser scan surveys reduce the chance of bad fitting and clashes to nearly nil simply because they visually display ALL of the information to your drafty or design team in the same virtual space as your model.
The canopy was installed without incident and is now keeping the QR catering staff safe and dry. I have no idea where they park though :-(