Managing the 20,000t of ice that forms in the pit in the bitter cold of winter is required due to the amount of water that flows into the pit each day. During warmer months, the water is collected and pumped into an extensive water management system, something that is not possible when it freezes in the winter.
The solution was developed following multiple brainstorming sessions and trials by the mine team during the past couple of years. The steel mesh is made up of wire and ropes woven into a hexagonal double twisted wire mesh that were hung along two pit benches.
Installing the mesh was both a feat of engineering and human ingenuity. A specialised contractor was hired for the job which involved teams of workers rappelling into the pit to bolt the mesh to the 20m-high pit walls.
Water runs down the steel mesh and freezes onto on the benches. This prevents water from running down over pit walls where it could freeze into potentially dangerous sheets. When ice on the benches builds up, the mine team can remove ice build-up by scaling, just like they would with loose rock. Scaling involves using a long bar to manually knock down the ice (or loose rock in the summer).
This article was originally published by De Beers.