The Sky Safari maintenance team had concerns over wear of the running wheels on each of the 9 cable way towers. This was perceived to be the case due a misalignment of each tower from the centre line of the cable way. KFW were engaged to determine a solution to provide centre line marking on each tower for future realignment. Our task was made all the more difficult as the cable way base and top mechanical terminals together with each of the 9 towers are not intervisible.
We utilised a combination of static GPS and micro baseline total station survey to determine the centre line. GPS control points were established adjacent to each tower, the cable way terminals and were based on MGA co-ordinates by connecting to a network of surrounding SCIMS permanent marks. The mechanical terminal bull wheel axes were determined by angle observations and co-ordinated with GPS control points with azimuth control being observed to city skyline trig stations.
Through this approach we were able to obtain RMS values for our control of ±5mm. Subsequently we provided centre line position points for each tower at matching accuracy.
The exercise demonstrated the ability of Static GPS to provide assured results which were achieved in an efficient manner.
Client: Taronga Zoo Sky Safari Maintenance Team
Contact: Ed Wilke