Carborough Downs Conveyor Drift

This project involved the driveage of a 1100m long, 1:6.7 grade, 6.5m x 5m drift to enable the installation of the Mine's main conveyor system and act as a major intake airway for the underground workings. Initially the drift was to be commenced from a 50m deep box cut however due to surface constraints only a 19m deep box cut was able to be constructed. This created the challenge of driving the first 260m through the "weathered zone", which was very poor, soft ground that could not be excavated or stabilised using conventional drifting methods. This was successfully overcome by utilising specially modified excavators and a strata support system comprising steel arches and multi stage shotcreting methodology.

The stone portion of the drift was driven with a WDS AM105 roadheader fitted with onboard temporary support system and bolters which maximises operator protection as well as enabling rapid installation of strata support. The AM105 loaded directly onto a project specific WDS designed and built bridge conveyor, which in turn loaded onto a temporary floor mounted conveyor. This method minimised vehicle movement over the soft drift floor avoiding potentially high repair and maintenance costs.

This whole project was completed harm free.