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Coal strip mine operators in Western Canada often mine steeply-dipping multiple coal seams in mountainous terrain. The ability to fragment the rock waste layers above and below these seams with minimum disruption of the seams in large blasts normally involves decked charges in large rotary boreholes. Mining these seams may take two or more separate blasts to break the waste wedges above and below the coal, but these wedges can be blasted in a single shot for better mining efficiency.

Jan 1, 1985

By Inc. The HDH Group

The Alternative Risk Market is defined as the segment of the insurance market that is made up of self insurance, risk purchasing groups, risk retention groups and captives. It is commonly referred to as the alternative to the traditional market, even though more the majority of companies today are insured through the alternative risk market than the traditional market.

Jan 1, 2007

By Richard B. O'Meara

"The demand by a customer to an Explosives supplier to fulfill a specialised productrequirement was met by a level headed decision to try to satisfy that demand. This paperwill describe the fundamental steps required in order to develop and produce a newexplosives device, while under certain resource constraints, such that the needs of thecustomer and the supplier are met safely and effectively."

Jan 1, 1993

By Minoru Kawamura, Yukio Kato, Yoshikazu Hirosaki, Satoru Suzuki

A wireless blasting system for tunnel construction which consists of a loop antenna, oscillator and blaster, has been developed. The basic technology of this method had been studied in the 1970s to develop a wireless initiation system for undersea blasting and has been successfully used as a Remote Controlled (RCB) system in the Honshu/ Shikoku Bridge construction project in Japan.

Jan 1, 1998

By Chen Aiping, Wei Banyun, Chen Canchang

"The gaseous explosives consisting of combustible gas and combustion-supporting gas wereused in the opening end of a steel pipe and the ignition was in the closed end of the pipeusing continuous air feed within the permissible length limit of industrial equipment, theexperimental results show the mechanisms of forced transition from combustion todetonation and what is the effective equipment for the transition."

Jan 1, 1993

By Ronald L. Sanders

The prevailing view of the coal mining industry by government officials is: "Tell everyone you're coming - Don't let anyone know you're there - And remove all evidence you have ever been there". Now the irony is that the government inspectors are just enforcing the law. The coal mine operators seem more interested in genuine reclamation than the inspectors.

Jan 1, 1979

By Todd B. Harrington, Dennis M. Lydon, Walter B. Sudweeks

Heavy ANFO products made by mixing ANFO (or AN prills) with a relatively small amount of emulsion (typically 15-30 percent) have become very popular in recent years. They are less expensive than straight, sensitized emulsion and maintain the good shooting characteristics of ANFO but have higher bulk strengths. Their use, however, is generally limited to larger diameter, dry boreholes. Smaller diameter, wet-hole quarries have not been able to widely utilize this low cost bulk product.

Jan 1, 1989

By R E. Otterness, M S. Stagg

The U. S. Bureau of Mines conducted 22 full-scale blasts to determine the effects of delay and explosive type on fragmentation. The shots were conducted over a period of 7 years in three limestone quarries and one granite quarry. Hole diameters, bench heights, and number of holes varied from 6.4- to 14-cm, 6.7- to 14-m, and 4- to 24-holes, respectively. Explosive performance and actual firing times were measured and screening was used to assess the fragmentation.

Jan 1, 1995

By Norman Disley, David B. Counter, Lionel Hebert

Misfires in underground and surface production blasts can be costly. Costs can arise from loss of resource, production interruptions, having to redrill or otherwise refire the blast (a hazardous process at best), due to added secondary blasting or breakage, and/or from increased LHD maintenance costs attributable to poor fragmentation.

Jan 1, 1996

By Jack Elorenta

A recent forum of mine operators revealed a continuing strong interest in alternative methods of freeing rock. A Rand Corporation report lists a continuous mechanical machine that would replace drilling and blasting as a priority for mine operators. Meanwhile, mounting evidence documents a dramatic cost benefit in processing where increased blast energy is available. The reasons for this dichotomy may be due to a number of factors.

Jan 1, 2002

By E Emery Jr Gray

The City of Richmond, in an effort to improve sewage treatment facilities, designed an invert syphon to cross the James River at Fulton Bottom. The design criteria called for installation of two 36-inch pipe' lines at an elevation of -35 with the mean water level being at elevation 00. This paper discusses the actual method of construction used to blast the river bottom. Choice of excavation equipment, nature of the river, as well as the geological structure, were taken into consideration.

Jan 1, 1979

By Unknown

Contact Local Law Enforcement Authorities. Contacting the local law enforcement authorities is essential to the quick recovery of explosives taken in a crime. Contact Local ATF Office. The local ATF office will work with the local law enforcement authorities investigating the theft. They can also assist in the preparation of the Theft/Loss Report for submission to the U.S. Bomb Data Center.

Jan 1, 2009

By Mauro Fornaro, Marilena Cardu, Renato Mancini, Daniele Castano

Tunneling by explosive blasting in civil works isn't merely intended to break somehow a way through the rock, rather to drive a permanent, constant cross section, lined way. The current mechanical excavation v/explosive blasting debate is mainly centered on the concept of the tunnel wall quality; and consequently explosive blasting strategy is founded on contour blasting.

Jan 1, 1992

By William D. Hissem

The purpose of this paper is to advise people about the methods, use, and possible applications of current "personal computer" hardware and software with regard to the economic cost analysis of percussion drilling equipment. The material content and orientation of this paper is toward those people who have just begun "PC" (personal computer) operations, and (or) those who are considering their use.

Jan 1, 1986

By Cathy McGinley, John Mullay, Clark Stancavage

The use of crater studies to evaluate explosive performance is a well-established practice in the Blasting Industry. Normally, this work utilizes larger charge sizes (>75mm) in order to minimize the influence of geological factors adjacent to the borehole. This can impose unwanted restrictions in the experimental factors accessible to investigation. Thus, for example, systematic studies of non-ideal performance in a somewhat practical setting is rendered quite difficult.

Jan 1, 1995

By Bruce B. Redpath

This paper reviews empirical and analytical information about window breakage due to airblast. As is the case with damage to structures caused by ground vibrations, a fixed break/no break threshold is inapplicable and window damage must be expressed in terms of a statistical probability. The information is summarized in a graph showing the probability of windows being broken by a given level of overpressure.

Jan 1, 1976

By Clifton W. Livingston

This paper is the first of a series in which evidence suggesting a quantum mechanical behavior of materials in blasting and high energy impact loading is presented. Such evidence relates the mechanical behavior of materials to their electro-magnetic behavior at successive stages in the development of the electric and magnetic fields as the disturbance proceeds outward from the borehole in blasting.

Jan 1, 1981

By Fumihiko Sumiya, Koichi Kurokawa, Yukio Kato, Tetsuya Sawada

In some metal mines, it is a serious problem the decomposition of explosives which occurs suddenly by contact with ore containing pyrites under high temperature conditions. In the present paper, we investigated heat resistant properties of emulsion explosives and other industrial explosives by contact with ore containing pyrites under high temperature conditions.

Jan 1, 1992

By Deane Boddorff

A 440 Volt AC power line is a typical power source for energizing electric blasting cap circuits in driving hard rock tunnels. A common misconception exists that the caps actually see 440 Volts. This paper describes an analysis of the entire blasting circuit determining the current flowing and the voltage drops through each component. If, from such an analysis, one determines that the current to the caps is too low or too high, the components that require changing are easily recognized.

Jan 1, 1975

By Tom Short

The contract to drive twin 4,100 foot (1250.5m) long tunnels under the existing Cumberland Gap highway was awarded to a Joint Venture of S.A. Healy of Chicago, Illinois and Lodigiani USA of Fairfax, Virginia in January of 1991 under a $51.8 million bid. Due to very complex geological conditions, there were six distinct categories of excavation, the New Austrian Method of ground support was utilized throughout.

Jan 1, 1993