We nearing the start of pushing ore drives in our underground and they will be around 200-250m in length with 8m pillars - not much room for error. I am looking for some advice about laser setups that we could use to drive these ore drives and anyones experiences. Thanks

Steve McMurray
Senior Surveyor
Ernest Henry Mine

I normally install lasers 0.5m off the left wall and 1.5m above the floor, this allows the laser to hit the face when the jumbo is working, plus the operator can use the laser to mark up a grade line on the wall.

If you are worried about accuracy, always resect using 3 wall stations, have repition and redundancy in your fieldwork, use compnet to process your work to get class accuracy. After about 50m check the position of the laser dot at the face, reissue memos if any corrections are needed to bring the face back on line.

250m's is a pretty small straight line distance to mine u/g and not worth a lot of stress.