Subsidence Management Plan - Quetools

2 MINE PLANNING2.1 MINING METHODSThe proposed mining method represents a continuation of the current systememployed at Glennies Creek Colliery, namely continuous miner developmentsupporting longwall extraction.Roadway development in gateroads and main headings will be carried outusing continuous miners. These continuous miners are either wide head(single pass) or narrow head (double pass) machines, with integrated roof andrib bolting rigs. Shuttle cars are employed to transport the coal from thecontinuous miners to the conveyor system.Secondary extraction will be by retreating longwall methods. The longwallequipment is capable of operating in the height range of 1.8m to 3.1m and ofnegotiating the expected geological conditions, including any sandstonechannels. With an average seam thickness of 2.3m, the full seam will beextracted.Longwall extraction is the preferred method of mining as it provides thegreatest production and economic efficiencies when compared to otheroptions. It is the only method that can provide acceptable economic returnsfor extraction of the area based on coal quality, required production levels,current economics and forecasted economic parameters.2.2 MINE LAYOUTThe longwall panels are oriented in a north-east/south-west direction, withmain headings being developed in a north-westerly direction. The longwallpanel widths are 246m (rib to rib) to maximise resource recovery and reducethe amount of development drivage required over the life of the mine relativeto longwall tonnes extracted.The mine layout perimeter is constrained by areas of the Middle Liddell seamwhich are steeply dipping.2.3 CONSIDERATION OF SUBSIDENCE IMPACTSThe location and orientation of Longwalls 10 to 17 represents the mostpractical, efficient and cost effective progression of the longwall miningsystem at Glennies Creek Colliery. It is expected that any potential subsidenceimpacts on the identified surface and sub-surface features within theApplication Area can be adequately managed through measures set out in thisSMP.ENVIRONMENTAL RESOURCES MANAGEMENT AUSTRALIA 0038321/FINAL/3 JANUARY 20072