Anglo American’s Grosvenor project has reached a tunnelling milestone after completing the people and equipment tunnel for a new underground mine near Moranbah in the Bowen Basin, Australia.
The tunnel boring machine’s (TBM’s) breakthrough came 29 days ahead of schedule with the team able to reduce the construction timeframe through knowledge from the conveyor tunnel that was constructed last year.
The conveyor tunnel was 980m long and was completed in five months. However, the people and equipment tunnel is 1,100m and took three months to complete.
Anglo American’s Grosvenor underground construction manager Adam Foulstone said: “From an industry perspective we have achieved the highest levels of collaboration and production through tunnelling which provided a safer environment than conventional tunnelling methods.
“On our best production day we installed 18 concrete rings, which was 25m, and our best week was 78 rings, or 110m.”
Anglo American is the first mining company to use a TBM to construct and underground mining tunnel in Queensland.
Once extracted from the drift, the TBM will go into storage for future use on other Anglo American projects as required.
The $1.9bn Grosvenor underground longwall mine will produce approximately 5M tonnes of coking coal for export. The mine is expected to be operational in 2016.