PREPARATION FOR THE BLAST
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Drill today |
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Drill 1937, Montgomeryville, PA. |
This is the drill that cuts 50-foot deep holes
into the rock. When 20 or more holes are drilled in a line across
the top of the ridge the holes are lined with plastic tubing.
This tubing prevents the holes from collapsing.
Special chemicals are carefully measured and
put in each hole along with an electronic detonating device. When
all is ready, everyone is ordered out of the quarry to a safe
location and the blast is set off.
