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By Charles E. Joachim, Christo V. Lunderman, Charles R. Wdch

The U.S. Army Engineer Waterways Experiment Station (WES) recently conducted a series of precision-scale water shock experiments which consisted of the detonation of several 8-gram, 10-gram, and 12-gram spherical explosive charges. The charges were fabricated from NAX 2000 Primasheet explosive and were center-detonated. Commercial tourmaline crystal water shock sensors were used to measure the induced pressure fields in the water. The measured water shock waveforms and related parameters from the precision-scale experiments were in general agreement with data from larger-scale experiments.

Jan 1, 1998

By Alan Tordoir, Mark Roberts

The drill and blast process is a critical function within the production cycle which significantly impacts the ability of an operation to effectively meet its safety and production targets. Acknowledging that D&B design and reconciliation practices were conducted inconsistently across operations, a Group wide initiative was launched to embed a standardized design and reconciliation platform in line with the company’s Operating Model principles. A technical system was selected to deliver the digitalization of critical D&B information and enable ‘analyze and improve’ routines for design compliance monitoring and downstream productivity optimization.

Jan 1, 2019

The following situation was submitted as an ethics case study for inclusion in the Journal. To the best of our knowledge, they are based on actual circumstances encountered in the field. Blowing the Whistle Protecting Confidentiality or Doing the Right Thing? This case centers around a construction job and involves a contractor, subcontractor/blaster, and a farmer/homeowner who lives near the job site. It is essentially a study of professional ethics versus morality, our professional code of conduct versus what is right or wrong.

Jan 1, 2007

By Mark Bosse

This is a paper demonstrating the use of a fixed wire and trolley system to deliver 2 or 5 lb cast primers (with 2 meter cap/fuse assemblies) deep into avalanche terrain. This avalanche terrain is mitigated using explosives prior to being opened to guests.

Feb 1, 2020

By Richard J. Mainiero, T S. Bajpayee

The U.S. Bureau of Mines (Bureau) has conducted research to evaluate the firing accuracy of electric delay detonators used in surface blasting operations. Over four billion pounds of explosives and blasting agents are used every year in surface blasting in coal, metal and non-metal mines. In a typical large-scale surface blast, several thousand pounds of explosives are fired in a timed sequence using delay detonators. The delayed firing of explosive charges allows time for the fragmented rock to move out before the next charge is fired.

Jan 1, 1990

By Gregg R. Gitschlag

There are more than 4,000 oil and gas structures present in the U. S. Gulf of Mexico. Approximately 100 structure removals occur each year and 66% of these are removed with explosives. From 1993-1995 an intensive study was conducted on the fish kill resulting from the explosive removal of 6 platforms off the Louisiana coast in water depths from 14-28 m (45-92 ft). After explosives were detonated, all floating fish and a sample of the dead fish which sank to the sea floor were collected.

Jan 1, 1997

By Michael S. Wieland

This report discusses the U.S. Bureau of Mines research regarding the desensitization and malfunction of cap-sensitive explosives deployed in underground coal mines. Delay blasting in underground coal generates severe shock waves and rifting forces that fracture and heave coal. These dynamic interactions can damage other charges still remaining in the delay pattern. The debilitating impacts precipitate degrees of reduced charge performance ranging from misfires to weak detonations or out-of-sequence firings. Damaged charges react poorly, perform less useful work, and/or generate atypical fumes with higher toxicity.

Jan 1, 1993

By John W. Kopp

The U. S. Bureau of Mines investigated flyrock and burden movement from blasting at several limestone and basalt quarries in the upper midwest. Blasts have been studied at 14 different sites using high-speed cinematography. Blasting was accomplished in 75- and 150-mmdiameter holes using a variety of explosives. Films from each blast were analyzed to show burden velocities, observed flyrock distance, and direction of throw in relation to the shot layout. This technique, in some cases, allowed determining point of origin and cause of the flyrock as well as the flyrock range.

Jan 1, 1994

By Steve Dillingham

A blast site incident has just occurred. Tensions are high, and, as the blaster, you’re in charge of the crisis at hand. Your mind is reeling, your thoughts frantic. The main areas of concern for you at the scene are to deal with immediate problems...aid the injured, take a head count, assess the damage, call emergency response, contact company headquarters, calm the neighbors, update your customer, and respond to the press on site. You feel as if all the bases have been covered...but, then again, have they? One of the biggest mistakes blasters and their companies can make is not including their Insurance carrier in the critical on-site accident procedures and emergency call list. Unfortunately, many companies believe that they are immune to the perils that can often, within a matter of minutes, create chaos that only happens to someone else.

Jan 1, 2002

By William Reisz

Managing the blast site at almost any operation can be a daunting task. There are so many details that must be observed, understood, and acted upon. It goes without saying that there are no two locations that have the exact same challenges and concerns. The level and the extent of these challenges can vary widely.

Jan 1, 2014

By William Reisz

The explosives and blasting industry has a commendable safety and security record, especially over the last several decades. This is due in large part to our newer technologies, better training and education, engineering practices, corporate initiatives, our professional organizations, and whether we like to admit it or not - our regulatory agencies.

Jan 1, 2012

By Garfiansyah Rayes

In 2023, an Indonesian coal mine experienced significant contamination of an emulsion blend explosive by dynamic mud and water flow, triggered by flooding due to exceptionally high rainfall. This intrusion into explosive columns compromised the stability and efficiency of blasting operations, thereby impacting overall mining productivity. The extent and impact of these contaminants on the stability and performance of the emulsion blend explosive were rigorously analyzed through a robust assessment methodology that included comprehensive field measurements and controlled laboratory experiments designed to replicate the challenging site conditions. Utilizing a combination of theoretical calculations and Computational Fluid Dynamics (CFD) simulations, this study evaluates the kinetic interactions between dynamic mud flows and emulsion explosives within drill holes. The methodology integrates Torricelli’s theorem for velocity assessments and Darcy’s Law for understanding the penetration mechanics of mud into the emulsion blend. CFD simulations are further correlated with actual blast data to assess discrepancies between theoretical predictions and real-world outcomes. Results demonstrate a significant reduction in the velocity of detonation (VOD) of the explo-sives, traced directly to mud contamination levels, which align with the quantified penetration rates in the study. Practical measures for mitigating such contamination are proposed, including the reinforcement of water-ways, culverts, and bund walls at drilling locations based on validated simulation data. Additionally, rec-ommendations for operational adjustments during high rainfall events are discussed, aiming to enhance blasting safety and efficiency. The paper concludes by suggesting future research directions towards the development of more resilient emulsion formulations and enhanced predictive modeling techniques to better forecast the impacts of en-vironmental variables on explosive performance in mining operations

Jan 21, 2025

By Andrew Ritter, Victor I. Montenyohl, Stephen R. Winzer

Thirty-seven open pit production blasting operations have been monitored using high-speed cameras running between 500 and 7000 frames per second. Analysis of the resulting films reveals irregularities in timing including sequencing errors and crowding (holes firing less than 8 ms apart), confirming results of laboratory testing of ms delay blasting caps (Winzer, 1978). Where blasting parameters are otherwise constant and within recommended guidelines (stemming, spacing, burden, etc.), timing problems dominate the overall performance of the blasting operation. Model tests in layered Homalite 100, designed to simulate joint or bedding planes in rock, indicate the importance of the stress waves generated by the explosive in developing the crack network which is ultimately responsible for the fragmentation seen in the resulting muckpile. These mechanisms are strongly supported by high-speed film studies at Pinesburg, Maryland. Experiments in controlling relief in deep shots (where depth approaches the lateral extent of the bench blasted) using borehole geometry and hybrid initiation systems (electronic timer and pyrotechnic delays) were carried out. The results suggest that the 1 me/ft. of burden guideline developed by Bergmann et aI., 1974 is too short, and that much longer times are necessary to optimize fragmentation and muck digability. Longer times are found to reduce noise, vibration, and flyrock.

Jan 1, 1979

By Bob de Raadt

After a review of the general principles for blasting stacks, the stagnations of two stack demolitions are investigated. The author concludes and demonstrates that MS-delay blasting can be risky under certain circumstances. How this initiation device can still be applied safely to the demolition of stacks is shown in an account of a blasting operation, in which two 106-m (350 ft) -high concrete stacks were involved. The recent discovery of a possible hazard of MS initiation in this field of blasting is an essential contribution to increased safety in blasting tall structures.

Jan 1, 1982

By U Nyberg

Peak particle velocity (PPV) and distance measurements from a single-charge blast test conducted by Swedish researchers in iron ore at the Kiruna Mine in northern Sweden are presented. They are used along with theoretical PPVs calculated using an equation based on hydrodynamics to determine a damage distance range caused by a single charge. This equation, which relates PPV to explosive properties, charge geometry, and distance from a charge, was then applied to a charge of different geometry that was used in drift rounds. A comparison between calculated and measured PPVs suggests that the stoping holes likely damage the easer hole locations, and the easer holes produce damage to the perimeter hole locations. The practical effect is that typical damage limit predictions based on measurements conducted in fresh or undamaged rock are conservative. This suggests that even when perimeter control is not exercised in drifting (i.e., the perimeter holes are fully loaded), the resulting damage may be less than normally expected due to the wave damping effect of the pre-damaged rock. Due to the damping effect, poor perimeter blasting practices are somewhat self correcting. However, it must be strongly emphasized that well-engineered blast designs with perimeter control are highly beneficial in relation to both economic and safety aspects.

Jan 1, 2011

By Park Yun-Seok, Jung Seung-Won, Hwang Nam-Sun, Song Jin-hyuk, Kim Young-ho

This study proposes a new blasting vibration estimation formula that reflects the vibration reduction characteristics of electronic detonators, which are not considered in the current MOLIT blasting vibration estimation formula. Test blasts were conducted across six types of Korean open-pit blasting designs. The results of the test blasts showed that the K value for electronic detonators decreased by approximately 30% compared to electric detonators. Predicted Peak Particle Velocity (PPV) analysis indicated a reduction effect ranging from 30% to 31% across various types. By incorporating this reduction in the K value into the MOLIT blasting vibration estimation formula (K=200), a new electronic detonator blasting vibration estimation formula (K=140) was proposed. Using this new formula, the blasting damage range (R) was calculated under various vibration limits to evaluate constructability improvement. On average, the R value for electronic detonators decreased by about 17%, with significant reductions of around 41% observed for TYPE I under certain vibration limits. In conclusion, the adoption of electronic detonators in open-pit blasting operations improves blasting efficiency, reduces economic costs, and significantly enhances constructability. Electronic detonators have demonstrated superior performance in minimizing damage to safety facilities compared to traditional electric detonators, thereby proving their practicality and effectiveness in blasting operations.

Jan 21, 2025

By Rob Farnfield, Ben Williams

The A5 road in the United Kingdom forms an ancient and well-used route through the hills and mountains of North Wales. In the 1990?s a programme of work was conducted to upgrade the road to modern standards. As part of this work a new cutting was constructed to bypass a portion of road routed through a gorge close to the village of Ty Nant. This new cutting was formed by drilling and blasting and included much pre-splitting and extensive rock bolting. This operation caused much concern to local residents relating to vibration, air overpressure and flyrock.

Jan 1, 2011

By Robert B. Hopler

"The story of packaged explosives begins with the use of black powder (also called gunpowder) in mining. Although discovered in the 13th century, it was not until 1627 that the first records of use in mining is recorded. It took until the early 1800's before its use began in underground coal. Althougha free-running, granular material, its recommended (and safest) manner of use was for the miner to pour it into ready-made or onsite formed paper bags prior to insertion into the borehole. This was absolutely necessary in horizontal or upward-slanting holes."

Jan 1, 1991

By William Everett, Jack Eloranta

United Taconite is an iron ore mine operated by Cleveland-Cliffs Inc (Cliffs) located near Eveleth, Minnesota. The mine, originally known as Eveleth Taconite Mines, was purchased in December 2003 by Cliffs (70%) and Laiwu Steel (30%). The mine site, known as the Thunderbird Mine, produces taconite ore for delivery by rail to the company’s Fairlane plant, located approximately 10 miles to the south near Forbes, Minnesota. At the plant, the crude ore is ground, concentrated and processed into pellets for steel industry customers. Total pellet production capacity is about 5.4 million long tons (Ltons) per year.

Jan 1, 2006

Blastserve, ISEE’s Listserve is being replaced by our new Blasters Forum-online, an exclusive member benefit. Our goal is to provide an ISEE forum for you to network with your peers and exchange technical information and get answers to your technical questions. This forum is unique in the fact that only ISEE members are permitted to review or post on the site. Over time you will be able review the discussion history and use the archived discussion as a valuable resource for trends in the industry. The following are a sample of the discussions that too place recently on Blastserve

Jan 1, 2013