Murray & Roberts Cementation secured the contract to deepen the existing ventilation shaft at Gold Fields’ South Deep mine to a depth of 2990 metres. The shaft is being extended to match the man and materials shaft adjacent to it, which is currently the deepest rock hoisting shaft in the world. The shaft diameter will be 9.10m.
This latest contract at South Deep adds to portfolio of projects Murray & Roberts Cementation is doing for the mine which includes the new mine development below 95 level.
Allan Widlake, business development director at Murray & Roberts Cementation, says that because the company is currently doing mine development work at the same depth to which the new shaft will be extended, Murray & Roberts Cementation can manage the full interface required between the mine development and the shaft deepening.
“The contract itself will be challenging as work will be done at an extreme depth and, more significantly from an operational and safety perspective, it is below an existing shaft,” Widlake says. “We have selected a methodology that will allow us safe access below the existing shaft and are using different methodologies to sink through the various levels.”
Widlake explains that the company will blind sink the lower portion from 2890m to the final depth while the upper sections from 100A level down to 2890m at 105 level will be raise drilled to create a central small diameter hole, then stripped out to the full width using conventional sinking techniques.
After the two sinking phases have been completed, Murray & Roberts Cementation will equip the lower section of the shaft. Widlake says that South Deep is currently equipping the shaft from surface down to 95 level, while Murray & Roberts Cementation will take over from 95 level.