Shaft liner innovation sets new standards

The robotic shaft liner has been designed to spray shotcrete linings in vertical or inclined shafts.
Operations manager Rory Burke said Macmahon clients would see a vast array of advantages in terms of safety and quality through the use of the shaft liner.
“By applying intelligent engineering solutions, the risk of hazards to operators working on the surface around open holes and moving hose lines has been reduced,” he said.
“The quality of the final shotcrete lining can be assessed in terms of thickness using the onboard scanning system. Infrared cameras monitor the spraying by relaying images to the operator and the shaft liner has been set up to largely operate independently on site, needing minimal cranage for setup.”
During the commissioning project at Barrick’s Fairyland mine in WA the benefits of the state-of-the-art robot were obvious. Design and construction of the shaft liner winch deck platform enabled the unit to be set up in close proximity to the collar of the hole without exposing personnel to the associated hazards.
Additionally, the intelligent design has significantly reduced the hazards associated with working around moving lines with the use of hose reels and guarding. The quality of the final lining was excellent and the rebound experience was in the order of 20 per cent, delivering considerable cost savings to the customer.
The project at Barrick required the lining of an 80m vertical, 3.5m diameter escapeway and vent shaft, according to project manager David Trembath.
“Although the ground is competent, the fact that the shaft would also be a travel-way meant that it would require some degree of surface support,” he said.
“To this end Macmahon Mining Services have developed a new shaft lining rig that offers an economic solution to what looked like an expensive problem.
“From the start to the end of the project I found MMS helpful and professional. Particularly impressive was the risk assessment process for the project.”
A Citect control system gives the operator minute control over all functions of the robot to produce a superior sprayed product with minimal rebound.
The shaft liner incorporates scanning technology to enable both pre- and post- scanning of the shaft surface area to gauge an accurate thickness measurement of the applied shotcrete.
These two controls alone can result in significant savings by reducing the volume required to complete the lining.
Recorded video footage of the shaft can be captured separately on DVD to allow close inspection of the condition of shaft walls and identification of any faults or overbreak.
Additionally, the shotcrete application is monitored and recorded on DVD to demonstrate spray consistency.
The shaft liner can line surface to underground raises or be taken underground to line internal raises. Macmahon can line shafts of the following specifications:
Diameter: 1.8m - 8.0m
Inclination: 90 degrees - 55 degrees
Max depth: 350m
Now commissioned, the shaft liner is completing various contracts throughout Australia. It has applications in underground mining and civil construction where vertical or inclined openings require surface support and no personnel access exists.
To learn more about Macmahon’s shaft lining capabilities tel: 0448 975 220 or email: mcalderwood@macmahon.com.au or shotcretingservices@macmahon.com.au
For more information visit: www.macmahon.com.au