LaRonde mine to have deepest shaft

In early March, MacIsaac Mining & Tunneling blasted the last bench in the No. 3 shaft at the LaRonde gold mine, owned by Agnico-Eagle Mines in northern Quebec. At 2,259 metres (7,380 ft.), it is now the deepest mine shaft in the Western Hemisphere.

MacIssac Mining notes that the No. 3 shaft is the 87th such project in its history, representing 48,150 metres (or 157,980 ft.) of shaft-sinking. The company was founded by the late John MacIsaac, who was recently inducted into the Canadian Mining Hall of Fame.

The shaft contract was awarded to the company in the summer of 1995, with initial preparation, mobilization and sinking setup completed by year-end. Shaft-sinking began in early 1996. The sinking was described as “remarkably trouble-free” with respect to ground control, even though the shaft is deeper than any other shaft in the notoriously poor ground belt. This is attributed to certain techniques that were adopted. For example, the monolithic concrete lining followed the face at an interval not exceeding 7 metres, and at no time were men exposed to more than 3 metres of open shaft walls. When work was completed, the crew had achieved 722 consecutive days without incurring a lost-time accident.

The shaft has a diameter of 6.25 metres. It also features 17 stations, two loading pockets, four lip pockets, and two mid-shaft chairs.

During sinking (above the bulkheads), about 10,000 metres of drifting and 3,000 metres of raising were completed. Hoisting of men, equipment, materials, services and muck was carried out via the No. 3 shaft (above the bulkhead), using a cage-skip combination.