CANADA - Redpath Raiseboring has announced that it has completed the longest raisebore in the Northern Hemisphere and all of the Americas. The record-breaking feat took place on 25 May at Kirkland Lake Cold's Macassa Mine at North Bay, Ontario, Canada. At 1,010m long, the bore formed part of a pair of 3.66m-diameter ventilation shafts (one on top of the other) extending from the surface down to mine level 5617 (1,712m). Accomplished in two stages, two Redpath-designed machines drilled concurrently, one underground, the other on the surface to complete individual ventilation raises of 660m and 1,010m respectively.
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