Initially I was contracted to deliver workshop drawings of the bridge balustrades for this "Plastic" bridge using the dimensions from the architects drawings. Once the bridge bearers were installed the builder picked up on a few issues and lost confidence in the exact setting out of the bridge. I was then asked to survey the bridge to check to see if the balustrade would fit.
I went out yesterday and encountered a problem. The bridge is black and laser scanners don't like black. I got some advice and a simple work around using decorators masking tape was found so I new I had some usable reflections to work with.
I found that the scanner really really does not like black and am relieved that the masking tape trick worked as there were huge chunks of the structure missing.
A further 6 hrs work in the office using Trimble Realworks and Tekla Structures sorted it out and the answer is no, the balustrade won't fit unless we build in some tolerance somewhere.
I also have learned a further useful process that enables me to match the co-ordinates in my Tekla model to the Co-ordinates of targets in Trimble Realworks. This enables me to confidently merge my models with scans for further checking. Pictures of the scans and merged models are below.