Stockton Drilling Services was recently called to the site of the New Royal Adelaide Hospital to help confirm the exact position, profile and orientation of a series of ducts installed as part of the project.
As part of the New Royal Adelaide Hospital (NRAH) construction, SA Power Networks (SAPN) needed to install a series of 160mm and 140mm link ducts between the new hospital and its Hindley and Whitmore substations. South Australian Direction Boring (SADB) was then engaged to install the trefoil configurations by horizontal directional drilling in lengths of approximately 700m to 1,000m.
After the ducts were installed and the hauling bays established along West Terrace and North Terrace, it was found that the hauling tensions of the 67mm OD power cables were much higher that initially calculated.
Stockton Drilling Services was contacted to see if their gyro survey tool could be used to confirm the exact position, profile and orientation of the ducts between the hauling bays. These exact measurements of bend radius could then be used to recalculate the hauling tensions required for the cable installation. Stockton mobilised within two days, and immediately commenced surveying the 13 sections.
Stockton used their DuctRunner gyro-surveying equipment, a patented gyroscope-based inertial measurement system designed for autonomous recording of positional data. The tools take an accurate X, Y, Z positional reading approximately every 10mm along the route. This data is then used to not only confirm the position, but also the grade and radius of the installed pipeline.
The survey data was made available to view on site immediately after completion of survey runs. X, Y, Z and bend radius plots of the survey line can be viewed on the site laptop and screen prints obtained. The complete survey files were then processed overnight and exported as CSV files containing X, Y, Z, bend radius, azimuth and pitch.
The 13 pipe sections were surveyed in just seven days. This new information then provided SADB with the knowledge required for them to undertake modifications of any tight or restrictive sections and for them to determine where additional lubrication points would be needed. This application of the gyro survey tooled ensured the successful installation of all the cables with the required timeframe.
