Development work was carried out on the 6,500-foot level of First Nickel Inc.’s Lockerby Mine in early 2013, wrapping up in March of that year.
That work included blasting out a drift – the 65-2-1-West area – that did not proceed as planned. The entranceway was off-line, so corrective blasting was done to try and straighten it out, and wire mesh, split sets (long metal tubes that help to reinforce a ceiling) and shotcrete (sprayed-on cement) were used to strengthen the ceiling and walls in preparation for production drilling and blasting.
The wider-than-expected entrance created a structural integrity issue, as the arch that was in place to help distribute the stress from the backfilled-area one level above was not large and strong enough. Continue Reading →