Miners' Circular, Issues 58-61

Front Cover
Bureau of Mines, 1947 - Mineral industries
 

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Contents

Shot firer placing Airdox shell in borehole
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Shot firer retrieving Airdox shell after blast
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Details of Hydrabuster hydraulic blasting device
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A Needle used in firing black blasting powder with a miners squib B hole charged with black blasting powder and primed with a fuse
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Pellet powder primed with electric squib and with fuse
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Preparing fuse for lighting
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Properly and improperly cut fuse placed in a blasting cap
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Crimpers and blasting cap crimped on a fuse
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Shunted electric detonators
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A Permissible singleshot blasting units drycell battery refill type B permissible singleshot blasting units drycell battery package type
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Permissible singleshot blasting units storagebattery type
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Permissible singleshot blasting units magneto type
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Permissible 10shot blasting units
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Making clay dummies for stemming shots
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Introduction
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A Measuring depth of drill hole before inserting explosive charge B results of blasting a boulder in which the borehole had been properly drilled and...
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A Miner scraping cuttings from borehole B charging borehole with wooden tamping bar
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Shot firer hangs blasting cable on timbers and gets in clear before firing
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A blownout shot of black blasting powder exploding bituminouscoal dust in an explosion gallery
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Standard brick magazine
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Standard sandfilled or weak concretefilled magazine
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Magazine of simple construction for storing small quantities of explosives capacity 4000 to 4500 pounds
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Method of installing sand trays and ceilings in various types of magazines
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Method of constructing a sandtray ceiling
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Details of an easily constructed magazine door
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Magazine ventilation
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Linings for steel magazines
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Explosivesstorage magazine and barricade 30 31
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Bibliography
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Page iii - Interior, to make diligent investigation of the methods of mining, especially in relation to the safety of miners, and the appliances best adapted to prevent accidents, the possible improvement of conditions under which mining operations are carried on, the treatment of ores and other mineral substances, the use of explosives and electricity, the prevention of accidents, and other inquiries and technologic investigations pertinent to said industries...
Page iii - Interior, to make diligent investigations of the methods of mining, especially in relation to the safety of miners, and the appliances best adapted to prevent accidents, the possible improvement of conditions under which mining operations are carried on, the treatment of ores and other mineral substances, the use of explosives and electricity, the prevention of accidents, and other inquiries and technologic investigations pertinent to said industries...
Page 15 - (b) Charges exceeding one and one-half pounds, but not exceeding three pounds, shall be used only if boreholes are 6 feet or more in depth, and explosives are charged in a continuous train, with no cartridges deliberately deformed or crushed, with all cartridges in contact with each other, and with the end cartridges touching the back of the hole and the stemming, respectively, and class A or class B permissible explosives are used.
Page iii - ... said industries, and from time to time make such public reports of the work, investigations, and information obtained as the Secretary of said department may direct, with the recommendations of such bureau. The first annual report of the Director of the Bureau of Mines issued in 1911 states: The Bureau of Mines was established by an act of Congress (36 Stat. 369) approved May 16, 1910, and effective July 1, 1910. The demand for special recognition and aid from the Federal Government for the mining...
Page 43 - ... material. The roofs of magazines so located that it is impossible to fire bullets directly through the roof from the ground need not be bulletproof, but where it is possible to fire bullets directly through them, roofs shall be made bullet-resistant by material construction, or by a ceiling that forms a tray containing not less than a 4-inch thickness of sand, or by other methods.
Page 38 - Metallic frames, casings, and other electric equipment that can become "alive" through failure of insulation or by contact with energized parts shall be grounded.
Page 42 - Pilled construction, such as concrete blocks with the cells filled with screened sand, weak concrete, cement mortar or other effective bullet-resistant filler; or exterior and interior wooden walls not less than 6 inches apart with the space between filled with screened sand, weak concrete, cement mortar or other effective bullet-resistant filler, and the exterior walls covered with sheet iron not lighter than No. 26 gauge, or other fireresistant material...
Page 45 - Each door shall be equipped with two mortise locks; or with two padlocks fastened in separate hasps and staples; or with a combination of...
Page 70 - ... 4. The charge shall be detonated with a permissible shot-firing unit 5. Cardox shall not be shot off the solid, over heavy rock binders or shale, or in a "tight
Page 60 - ... 1. The bodies and covers of special cars and the containers shall be constructed of nonconductive material. 2. If explosives and detonators are hauled in the same explosives car or in the same special container, they shall be separated by at least a 4-inch substantially fastened hardwood partition or the equivalent. 3.

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