George Leslie commissioned MHB consultants to undertake condition surveys of four water towers within the greater Glasgow area on behalf of Scottish Water. The assets vary in size, including the 2nd tallest in Britain, but are generally symmetrical water tanks elevated by columns above ground level.
The main challenges were mainly restricted timescales and collating condition related defects in an ordered way such that the contractor can locate and repair each defect and ultimately that Scottish Water can efficiently maintain their asset.
We wanted to use a total station so that points could be individually targeted and also to combine with the GPS to establish georeferenced control stations however the total station alone would have been too slow to complete the works in the very limited time available. We used state of the art Trimble survey equipment which combines laser scanning technology with traditional total station features. The result is a very versatile tool which allowed accurate control, low resolution fast scanning with important areas rescanned at higher resolution. Points could be annotated on site and each scan is photographed from the instrument in order that each point can be assigned colour and texture information.
Completing the majority of the sites in 1 day, along with the condition survey saved the client up-front costs and helped them with the access difficulties. It also allowed us to save time in the production of drawings by establishing a 3D model, which was developed within AutoCAD 3D Civils package.
With the model cleaned sections can be generated and laid out in a traditional 2D way in a drawing pack.