Longwall operators hold key to innovation: Longwall 2010

INNOVATION at longwall mines should be driven by operators and middle management upwards to senior management and in collaboration with OEMs to make real improvements in operations, delegates at Longwall 2010 heard yesterday in the Hunter Valley.

Lou Caruana

A number of case studies that displayed adaptability and ingenuity at an operations level were then presented during day two of the conference, which followed a “recovery” breakfast of bacon and egg rolls after the official conference dinner on Monday night.

Smaller companies that had fewer layers of management bureaucracy were proving to be well suited to changing working environments, Jim Middleton of Jack Doolan Capital said.

Centennial Coal’s Mandalong colliery’s services electrical engineer Bruce Davies spoke about how development improvements were introduced to the mine’s Sandvik ABM-25 miners.

The uneven shape of the floor being produced by the continuous miners at Mandalong was a significant safety and operational issue at the mine.

The Autocut project successfully automated the cutting cycle of the ABM- 25s through “closing the loop” – a process of monitoring and continuous refinement of the Autocut system, Davies said.

“I contacted Sandvik, and Duncan Edwards got involved from Sandvik,” he said.

“We went down and simply had a look – what they were doing, what sort of results they were getting, and how to talk to them.

“It became obvious to us that it wasn’t totally the machine set-up, which everyone was blaming.

“Talking to the workforce it was obvious they were trying their hardest.”

Mandalong engaged Sandvik to assist its site engineers to implement the Autocut feature on one of its ABM-25s.

The mine found Autocut helped reduce the number of slip/trip/fall injuries due to the improved floor horizon.

It also improved the quality of the travelling roads for worker transport and shuttle car movements, and improved the workplace for belt moves.

One of the most significant advantages of the Autocut system is the consistent improvement in productivity.

Since installing Autocut in two ABM-25s, Mandalong has twice broken weekly development records, and in February this year smashed its monthly development record.

In an interactive session between BIS Industrial Logistics general manager Mark Doyle and BIS Coal Services director Joe Thomas, the process was outlined where the supplier developed and invested in new products – such as a mobile elevated work platform – to solve minesite problems.

“We are committed to providing practical solutions to our customers,” Thomas said.

Mining Consultancy Services managing director Chris Wilkinson outlined a process-based production management system using electronic machine monitoring and ruggedised PDA technology, and offered case studies of systems developed by MCS for South African mines.

Moranbah North’s technical services manager Steve Winter outlined the developments of Moranbah North’s 1750-tonne longwall and its overwhelming acceptance and enthusiasm by the mine’s longwall crew.

To overcome major yielding issues and to cope with the deep and geologically problematic Goonyella middle sea, the mine owner Anglo American Metallurgical Coal put in an order to Joy Mining Machinery for super chocks for the Queensland mine.

The specification was for the supply of approximately 143 face supports and eight gate end supports set at 2.05-metre centres to work an extraction height of 3.5-4.5 m for a 305m-long coal block.

The supports were to provide roof load density pre-cut of 148 tonnes per square metre with a 5% set to yield ratio.

A lower advance and set cycle time of 14.5 seconds was specified and the supports had to be capable of being operated from the front and rear walkways.

Total transportation height, including transporter, was limited to 2.7m and support weight to 62t.

To achieve this specification, Joy proposed a 2 x 1750t support with 480 millimetre bore double-telescopic constant yield legs and 300mm bore stabilising ram with an open height of 5m and closed height of 2.4m.

Anglo accepted the proposal and the supports were also to be equipped with a 200mm bore advancing ram, a 170mm bore base left ram, 130mm bore base pusher ram, integral two-stage flipper and hydraulic shielding to both of the supports.