ODDS’N’SODS — Not with a bang but a wimper

In the mid-1980s, the Kidd Creek zinc-copper mine in Timmins, Ont., began a blast-monitoring program in conjunction with Canadian Industries Limited (CIL) and Porcupine Powder.

I was the Kidd Creek representative responsible for co-ordinating the mine’s preparedness for each phase of the program, and one day I asked the foreman of the longhole blasters to ready the next site. The test itself was to involve in-hole and vibration monitoring of sequential blasts in 77/8-inch-diameter holes charged in decks, with sand stemming between each deck.

The longhole blasting crew spent 12 or more overtime shifts at the site, during which time they prepared a dry location for the instruments, piled sand beside each ring of holes, unplugged collars and plugged toes. The area was then fenced off to prevent unauthorized access.

On the day of the planned test, I accompanied a CIL scientist from McMasterville, Que., his assistant and a crew of longhole blasters to the test site.

When the monitoring equipment had been set up at a safe location, the vibration monitors were fastened to the walls of the drift. The next step was to lay out cables for the in-hole sensors, measure and load the holes, and place probes into them at appropriate intervals.

While trying to measure the first hole after lunch, however, we discovered that the holes had been filled with sand. No other sites were available for the test and the blast, and so the entire project was scrapped. The representatives from the explosives companies went home with nothing to show for their time and effort other than a trip to Timmins.

I later learned that an underground crew attempting to recover a raise-borer head had removed the fences and drove into the test site from behind.

Unknowingly, they filled the holes in behind them as they went.

— The author, a mining engineer, resides in South Porcupine, Ont.

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