The switch is thrown on the DuPont Condenser Discharge Blasting Machine and all 900 holes are fired at once. This machine, which builds up enough voltage to set off as many as 1200 holes at one time, removed the need for power lines or portable...
Typed caption on photo: "Water-tight cans of explosives being pushed into the cage at the collar of a 570-foot vertical mine shaft on Maud Island, about 120 miles northwest of Vancouver, B.C. The explosive was used to blow the top off Ripple Rock,...
Typed caption: "Long a menace to navigation, Ripple Rock used to lie in Seymour Narrows, above, 120 miles northwest of Vancouver, British Columbia. If the peaks of the rock had been visible they would have appeared directly above the freighter's...
Lammot du Pont's specifications for blasting powder made from sodium nitrate rather than potassium nitrate. This powder was called soda powder or soda blasting powder. Also included is a letter from George Harding suggesting changes to the...
Well broken rock was the objective, and the result was what drillers call maximum fragmentation with minimum back break. Along the turnpike the crack and rumbling of blasting has given way to the drone of traffic.
Dynamite is brought up to the face after round has been drilled. DuPont's Special Gelatin 40% strength is widely used in all types of underground blasting.
Typed caption on photo: "Deep into Ripple Rock, drillers drove a 'Coyote' tunnel which was packed with 2,750,000 pounds of high explosives supplied by DuPont of Canada (1956) Limited. Ripple Rock was located just below the surface in Seymour...
