Anglo American’s $1.95 billion Grosvenor project in Moranbah, Central Queensland, reached a key project milestone in October when its Robbins tunnel boring machine (TBM) operated for the first time.

Officially launched on site at Grosvenor, this is the first time a TBM has been used to construct a drift (or tunnel) on a Queensland coal mine, Anglo American said in a statement.

Anglo American’s head of underground excellence, Dieter Haage, officially launched the TBM and said this was an important milestone in the overall delivery of the Grosvenor project, which is located next to the company’s existing Moranbah North longwall mine.

“Targeting the same Goonyella Middle Seam as our Moranbah North operation, Grosvenor will be a world-class longwall mine and its delivery is a key part of our growth planned in Moranbah,” Haage said.

“It is exciting to reach this milestone today after almost one-and-a-half years of construction activity,” he said.

“The $40 million earth pressure balance machine will allow us to reach the coal seam early next year, bringing us that step closer to longwall production in late 2016,” he said.

Grosvenor project director, Glenn Tonkin, said the Anglo American team was excited to be pioneering this innovative tunneling method to build the 5 Mt/a (5.5 million stpy) Grosvenor Mine.

“Similar to the TBMs that have been used to construct the road tunnels in Brisbane, the TBM tunneling method will deliver advances in safety, higher quality drifts and faster project development,” Tonkin said.

The TBM will be used to build the two drifts on the project, one for the coal conveyor which will transport coal from the underground longwall to the stockpile area on the surface and another for people and equipment to access the underground once the mine is operational.

The TBM will pass beneath a steel archway roof that has been installed at the drift’s entrance and begin drilling into the ground to build the 7-m (23-ft) diameter tunnel, descending at an angle of one in eight until it reaches the depth of the coal seam approximately 160 m (525 ft) below.
As the TBM advances forward, pre-cast concrete ring segments will be used to line the inside of the drift.

Grosvenor site manager, Greg O’Donnell, said many contracting companies had worked hand in hand with Anglo American to deliver the project to this point.

“We currently have a team of about 700 people working at Grosvenor,” Mr O’Donnell said.

“I’d like to make special mention of Robbins for building and operating the TBM, Redpath Australia for assembling, commissioning and supporting the TBM mining, GHD for their assistance with the geotechnical engineering, Hutchinson Contractors for their civil work around this area and Hatch for providing general Engineering Procurement Construction Management (EPCM) support at site,” O’Donnell said.

Once in operation, Anglo American’s Grosvenor project will provide approximately 350 new jobs.