Blasting in the 21st Century
2020
Source: Stephanie Radu
Video Clip: (00:25): The limestone industry has long been active in the Thames River Valley. Early on, to loosen the rock, blasting was done with black powder and a light-and-run method. Black powder was replaced with rack-a-rock, a form of mining explosive patented in the 1870s. Rack-a-rock comprised an oxidizing agent (potassium chlorate) and a combustible liquid (nitrobenzene) combined at the job site. It arrived as sticks packed into a small box. Each stick was about a foot long and was wrapped in cotton. A fuse and cap would be attached.
One historian wrote, “The men treated these potent firecrackers with the utmost nonchalance. One man made a practice of clamping on the nitroglycerine caps with his teeth, and another broke the sticks over his knee when only a half cartridge was required.”
Today, blasting is taken on with much more care and precision. Watch as a blast takes place in a contemporary quarry pit and see the video transcription below.
The scene is set at the limestone quarries on a summer day.
An explosion happens and the wall of rock in the background of the video bursts.
A long beeping sound is heard.
A blast goes off with a loud explosion.
Sounds of crumbling rock are heard.