Explosives Engineering Commons^™

Stemming Technique For Loading Angled Holes Charged With Anfo, Michael David Wilkins

Masters Theses

"Little research has been published on stemming blast holes, particularly what happens during the process. Previous work has concentrated on the performance of the inert material to find the best way to seal the hole and retain the explosive energy, at the exclusion of determining what happens during the loading and stemming process. Such studies were carried out by Konya and Worsey.

The major problem with stemming studies is that rock is an opaque material, and the actual mechanisms involved during the stemming process cannot be viewed. For this reason, tests were performed using clear tubes to simulate a blast …

Method Of Stemming A Blast Hole, Paul Nicholas Worsey

Mining Engineering Faculty Research & Creative Works

A method of stemming a blast hole loaded with an explosive charge. The blast hole has side walls, an outwardly opening mouth and a central axis extending longitudinally of the blast hole. The method comprises inserting a conduit having a discharge end inwardly through the mouth of the blast hole and positioning the discharge end of the conduit within the blast hole generally adjacent the explosive charge. Particulate stemming material is forced under pressure through the conduit for exit from its discharge end into the blast hole toward the explosive charge thereby to pack stemming material in the blast hole …

Blast Plug And Stemming Construction For Blast Holes, Paul Nicholas Worsey

Mining Engineering Faculty Research & Creative Works

A plug for use in stemming a blast hole having an explosive charge therein. The plug comprises a wedge member and a stabilizing structure on the wedge member. The wedge member tapers in an outward direction from a relatively wide base to a relatively narrow end and has a central axis extending endwise with respect to the wedge member. The stabilizing structure extends generally axially with respect to the wedge member from adjacent the base of the wedge member. The plug is to be positioned in the blast hole with the base of the wedge member facing inwardly toward the …

Dual Purpose Fuze, Paul Nicholas Worsey

Mining Engineering Faculty Research & Creative Works

A dual purpose fuze for a projectile which can activate a quantity of material selected from a group including high explosive, low explosive, propellant and pyrotechnic compounds. The fuze includes a charge holder having a socket therein facing the quantity of material to be activated. A fuze charge located in the socket has a depression in it so formed as to cause the fuze charge to explode in a jet directed outwardly from the socket of sufficiently high energy to activate a high explosive in a high explosive projectile, the fuze charge being sufficiently small to prevent rupture of containment …

Mine Warfare In The Russian And Soviet Navies, Jeffrey K. Bray

Graduate Program in International Studies Theses & Dissertations

This thesis examines the development of technology, tactics, strategy, and organization of mine warfare in the Russian and Soviet navies from 1807 to the present. The author reviews the trials and tribulations of the development of naval mines and their employment within these two navies. This development has been primarily driven by the needs of war and advances of technology. In spite of occasional setbacks, the Russian and Soviet mine warfare forces continued to provide support to the overall naval and central policies of their respective governments. This support has often been during times of high tension and limited resources. …

Mechanical Stemming Construction For Blast Holes And Method Of Use, Paul Nicholas Worsey

Mining Engineering Faculty Research & Creative Works

A stemming construction for a blast hole loaded with an explosive charge, comprising a tapering wedge member dispersed in the blast hole outwardly of the explosive charge with its narrower end facing outwardly toward the mouth of the blast hole, and particulate stemming material in the blast hole outwardly of the wedge member. Detonation of the explosive drives the wedge member into the stemming material to wedge the stemming material against the walls of the blast hole. The wedge member is preferably cone-shaped and can be provided with a stabilizing rod to prevent it from tilting.

Integrated Detonator Delay Circuits And Firing Console, Lawson J. Tyler, Paul Nicholas Worsey

Mining Engineering Faculty Research & Creative Works

A detonation system for use with supply of electrical energy has user operable firing console for selectably transmitting unit identification information, firing delay time information and selections from a command set including Output, Delay, Fire (Time), Abort, Power Up (Arm), Input, and Store. The console displays responses or information digested from responses by electrical delay detonators to the commands. The detonators have explosive, a capacitor for storing energy from the supply to set off the explosive, circuitry for charging the capacitor from the supply and transferring the energy from the capacitor to the explosive in response to first and second …

A Study On Fragmentation And Ground Vibration With Air Space In The Blasthole, Everett Ellsworth Bleakney Iii

Masters Theses

"The degree of fragmentation and the level of ground vibration from a bench blast employing standard full-column completely-coupled explosive charges are commonly controlled by varying one or more of the many dimensional variables of blast design. Blasting techniques such as decoupling and air-gapping, utilizing air space in the blasthole, have also been reported as having the potential to control rock fragmentation and ground vibration.

This investigation, using reduced-scale in situ bench blasts, examined the degree of fragmentation and the level of ground vibrations produced from the standard full-column completely-coupled, air-gapped, and decoupled methods of blasting to:

1. Compare the effectiveness …

An Investigation Of Combined Thermal Weakening And Mechanical Disintegration Of Hard Rock, George Bromley Clark, T. F. Lehnhoff, Vernon Dale Allen, Mahendrakumar Ramkrishna Patel

Mining Engineering Faculty Research & Creative Works

"The research under modified Contract No. H0220068 has been devoted to experimental thermal-mechanical fragmentation of Missouri red granite in place, and to supporting theoretical analyses. The results of the previous year's experimental work showed that thermal stresses are several times more effective in fragmenting hard rock when they are created within the rock rather than upon the surface. Also, large blocks {4-foot cubes) are not adequate to simulate the response of in situ rock.

Based upon laboratory tests an experimental round was designed analogous to an explosive blasting round with coiled wire heating elements placed in drill holes. Three displacement …

Ammonium Nitrate Blasting Agent (Anfo) For Land Clearing, G A. Greaves

Journal of the Department of Agriculture, Western Australia, Series 4

The introduction of "prilled" AN has revolutionised explosives practice and made possible safer and cheaper methods of blasting.

This article outlines the methods of handling and using ANFO blasting agent for land clearing.

New Regulations For Explosives, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

THE Explosives Regulations, 1963, are now in operation and the new rules will affect purchase and keeping of explosives by small users.

Blasting. Part 2. Explosives On The Farm, G A. Greaves

Journal of the Department of Agriculture, Western Australia, Series 4

EXPLOSIVES will function with maximum reliability and efficiency only when they are carefully stored under cool, dry conditions so as to avoid deterioration.

When preparing charges the user should follow a correct procedure and use the proper tools. Always treat explosives with respect and remember they are made to explode. When they hit they hit hard.

Blasting. Part 1. Explosives And The Farmer, G A. Greaves

Journal of the Department of Agriculture, Western Australia, Series 4

ABOUT 3,000 tons of commercial blasting explosives of various types are used every year in Western Australia of which approximately two thirds is utilised by mining industries and the remainder goes mainly to quarrying and public works.

The farmer and orchardist actually use only very small amounts but nevertheless explosives are a very useful working tool for the primary producer.