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By Jeff Hiedeman, Clint Sestrich, Christopher Hyle

Westslope Cutthroat trout have declined in distribution and abundance across their range and currently occupy about 59% of their historic habitat. Due to hybridization with non-native species such as rainbow trout, genetically pure populations persist in only 10% of that range. A westslope cutthroat trout population with relatively high genetic purity (97%) and conservation importance persists in less than two linear stream miles in the headwaters of the South Fork Madison River in southwest Montana. The relative purity of this population has been maintained through the presence of a downstream intermittent reach. However, spring flows fill the intermittent reach, creating a connection between occupied westslope cutthroat trout habitat in the headwaters and the habitat of competing trout species downstream.

Jan 1, 2011

Explosive manufacture, handling and transportation is hazardous and special precautions should be taken while manufacture, handling and transportation. Various regulations and rules defined in explosive act and factories act of India are discussed in this communication. General process control measures during the manufacturing of different types of explosives are also dealt in detail. Various processes hazardous in manufacture of various explosives like slurry explosives, PETN, detonators, styphnic acid, lead azide and lead styphnate and special precautions to be taken during the manufacture of the above explosives are also discussed.

Jan 1, 2007

By John Brown

Let’s talk about things that you, the driIl boss, the pit boss and the driller can do to eliminate the trend in drilling related accidents that have come to plague our industry in recent years. My paper will focus on reaI issues, problems and solutions that will affect our everyday outlook and attitudes about our jobs and lives. There are some real hard facts we must address if we are going to reverse this terrible killing trend.

Jan 1, 2000

By Charles R. Barnhart

The Nitrogen Dioxide Cloud: After one year of testing it can be stated that we do know and understand a great deal about why the nitrogen dioxide formation is exacerbated in cast blasting. Picture 1 is an example of how concentrated the NOx can be from a cast blast. It has long been felt that 300 or more milliseconds of timing needs to be put between each row of detonations to allow the rock a maximum time of flight so the cast percentage is high. Our experiments have found that higher cast percentages can make with timing between 150 to 200 milliseconds between rows. Picture 2 show a definite improvement in nitrogen dioxide concentration and most of that was the result of shooting a previously shot end of the cast pattern that had not been dug, thus no confinement of the powder columns.

Jan 1, 2004

By Peter Moser, Frank Chiapetta, Sacha Diaj, Florian Bauer

Good toe breakage and a flat working bench after blasting are important parameters to achieve a high productivity during material loading and reduce the necessity for secondary blasting. Good toe breakage requires a proper burden – side spacing design and a suitable sub-drilling. With unfavourable jointed rock mass conditions the use of horizontal bottom holes still can be found as common work practice even that this is associated to high risks.

Jan 1, 2009

By Phillip R. Mulligan, Catherine Johnson, Edward Kinzel, Cody Lough, Jason Ho

A shaped charge is an explosive device used to focus detonation energy in a desired direction. Shaped charges have numerous applications in several industries such as oil extraction, weaponry and demolition. The focusing of the detonation energy is the result of the Munroe Effect, which greatly increases the penetration properties of the explosive due to a void in the explosive’s volume. The void in the explosive is lined with a metal substrate that becomes a super-heated projectile when the explosive is detonated. Additive Manufacturing (AM) can allow greater design freedom and geometric complexity for the liner portion of the shaped charge. Specifically, hierarchical structuring and functional grading can potentially provide greater velocity, directionality, and efficiency. By utilizing AM, the conventional use of shaped charges can be greatly expanded upon and may open new possibilities. In this work, selective laser melting (SLM) was used to explore different conical shaped charge (CSC) liners made out of stainless steel 304L. A series of liners were tested that had varying densities and were compared to conventional liners. The CSCs were filled with the high explosive Composition C-4 and detonated to evaluate performance. The blast events were recorded using break wire screens to calculate the velocity of the jet through steel target plates over a standoff of 6 times the charge diameter. A high-speed camera recorded the blast event to calculate the velocity of the jet through the air. The depth of penetration into the steel target plates was also used as a measurement of the effectiveness of the CSCs. The aim of this work is to show the potential for advanced shaped charges produced using SLM.

Jan 1, 2019

By Michael Twomey, Alastair Torrance, Alan Twomey

Low density explosives have been available in various forms for nearly 20 years. These initially consisted of various diluted forms of ANFO formulated to slow the rate of reaction. One such product that was developed was a blend of ammonium nitrate and rubber. This product uses a coarse fuel provided by granulated rubber to slow the reaction rate of the explosive rather than being a diluted form of ANFO. There has always been a technical difficulty in blending two dissimilar materials without subsequent segregation.

Jan 1, 2011

By Ethan Steward, Kyle Perry

To test the effects of impact on mine seals, a projectile generator and two seals have been constructed. The projectile generator is a 12-inch (30.5 cm) inner diameter steel pipe with a 4-inch (10 cm) wall, is 8.5 feet (2.6 m) in length, and sealed on one end. Projectiles are propelled by a charge of black powder with a wooden wad and are held in place by foam sabots in the bore. This system, combined with the large bore, allows firing of many different potential projectiles that may be found in an underground mine at a high velocity into the seals.

Feb 1, 2020

By C. Pelley, S. Kelebek, S. Gregersen, P. Katsabanis

A series of small scale tests have been conducted to evaluate the effect of micro-fracture development, imposed by blasting, on the physical properties of the rock as well as its resistance to crushing and grinding. The uniaxial compressive strength, tensile strength, Young’s modulus, Poisson’s ratio, P-wave, S-wave velocity, point load strength index and grinding work index were evaluated for samples without any blasting load and for samples which had received a variety of blast loads, such as a simple side impact from a detonating cord, or combined impacts without any delays and with very short delays. The investigation covered two types of rock, granodiorite and limestone. The effect of blasting load on the physical and rock mechanics parameters of the rock was clearly shown and damage was quantified and related to loading. However the work index did not show significant differences between blasted and not blasted samples, probably due to the relatively low level of impact. Numerical modelling using the AutodynTM code was used to demonstrate damage development in the various configurations tested.

Jan 1, 2003

I had the opportunity recently to visit a magazine site of a major explosives company. It was fun to see the storage areas again and it was really interesting to see one of the old magazines that probably dated back before my time. Now that’s an old one. As son Tom says, “When Dad was young the Dead Sea was just sick.” While the magazine has been upgraded with a modern lock to match today’s standards it still has the old tumbler lock that is opened with the large bronze key. Those old tumbler locks were just about standard on magazines years ago. Those bronze keys were heavy and would make a good display item today or maybe a substitute for a blackjack. I don’t think the old locks would stop the modern criminal but then in those days we were all less sophisticated. And maybe I shouldn’t say this but honesty was a bit more prevalent then. Maybe ‘cause old fashioned police brutality still prevailed.

Jan 1, 2004

By Kate Satish

M/s Konkan Railways Corporation are constructing 760 kms long rail road in the Western Coastal Region of India. The rail road encounters 75 tunnels through the Western Ghats of India with a total length of 78.35 kms, the longest tunnel being 6.5 kms long. The tunnels are of horse shoes shape having a cross section of about 37 Sq.meters

Jan 1, 1996

By Matt Brandon

This case study demonstrates how integrating drone and GPS surveying with 3D modeling software creates more effective blast designs that address specific geotechnical challenges while improving safety and blast performance. In this case study an 80ft (25m) highwall experienced recurring slip plane failures exacerbated by a previously mined 40ft (12m) bench that removed back support, creating an unstable triangular rock mass. Previous blasting along this wall displaced the upper 40ft (12m) of material, opening geological discontinuities and causing progressive slope failures that compromised crew safety and blast effectiveness. High-resolution drone photogrammetry, GPS surveying, and laser measurements were employed to precisely map slip planes, bedding planes, and fault structures within the bench geometry. These geological features were imported into 3D design software to develop a shot pattern that strategically utilizes natural rock discontinuities rather than working against them. GPS-guided hole placement ensured accurate field implementation, while marking geological features on the surface of the bench provided visual references for the blast crew. The final blast design positioned the last row of holes to break preferentially along an existing slip plane while avoiding intersecting the next slip plane behind the blast. Explosive loading and timing sequences were adjusted based on the hole location relative to the 3D geological model to optimize fragmentation while maintaining wall stability. The optimized design improved highwall stability significantly, by reducing the slip plane failure mechanism that had previously compromised operations. Measurable improvements included enhanced highwall stability, reduced back-break, improved blast performance, and reduced safety risks for equipment operators and blast crews. Two subsequent shots using identical methodology were able to remove the rest of this problem area, confirming the repeatability and effectiveness of this integrated approach. This methodology demonstrates practical integration of surveying technologies with geological understanding to solve complex blasting challenges. Accurate 3D modeling of geological features enables blast designers to work with natural rock structures rather than against them, resulting in safer, more effective blasting practices. This case study shows the value of understanding the precise locations of geological features for optimizing blast design and provides a replicable process for addressing geotechnical challenges in blasting operations.

Jan 26, 2026

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

We had a cold, gray winter here in Kansas City and I spent a lot of time watching out my den window at the squirrels and birds trying to get by in the lousy weather. I remember too well working in the cold, loading shots. I was frostbitten several times since I couldn’t tie in MS connectors with gloves on. Those old connectors had a piece of detonating cord on either end of a metal tube that held the delay and you tied them to the trunk lines with square knots. Doing this on a “warm” day in Alaska or Montana shooting ditch for a pipeline could be a frosty experience. Also remember how hard it was to connect up electric caps (detonators to you new guys) in the cold. Now I don’t want you to feel sorry for me ‘cause I suspect most of you younger fellows have also paid your dues in the cold and for that matter in the heat too. Wowee, the heat at the bottom of a Chicago dolomite quarry in August was enough to fry the brains of all that were there. Maybe that’s why the third deck of my brains doesn’t exist.

Jan 1, 2004

By Roger Holmberg, Donald Jonson

The Swedish Standard SS 460 48 66, “Vibration and shock - guidance levels for blasting induced vibration limits”, is based on more than 50 years of experience from blasting close to structures and tunnels. The Swedish Standard gives a method for calculation of guidance values for different types of buildings and ground condition under the building. This is done for every building and structure within a predetermined zone. The guidance levels are for the peak particle velocity monitored in vertical direction. The standard is valid for all kinds of blasting project (tunnelling, quarrying, mining etc.) The guidance levels neither take in to consideration discomfort for people inside the building or structure nor vibration sensitive equipment inside the structure. The paper also presents the Swedish Standard SS 02521 “Vibration and shock - Blast induced airborne shock wave - Guidance levels for buildings”.

Jan 1, 2005

By Nikolaos Petropoulos, Changping Yi, Daniel Johansson, Håkan Schunnesson

The effect of jointing on fragmentation by blasting was investigated experimentally and numerically. Firstly the experimental results were presented. Then the numerical modelling based on the experiments was performed. The same conclusions can be obtained based on both experiments and numerical modelling.

Feb 1, 2020

By Dale Ramsey

Emulsion explosives have become the product of choice for many blasting applications and are not limited to just extreme wet hole conditions or special application environments as in the past. Today’s novel emulsion technology has evolved over many decades, allowing a great diversity of formulations, Emulsion explosives can be effectively designed to produce very high energies, cap sensitive high explosive cartridges to bulk blasting agents, with varying viscosities, stable VOD’s, excellent water resistance, long shelf life and sleep time. They are also conducive to the mixture of emulsion, An/F0 blends in varying proportions and are amenable to any type of sensitizer. The key to a stable, reliable and consistent emulsion formulation is the careful mixing of the internal phase, which consists of a solution of oxidizer salts suspended as microscopically fine droplets, with the surrounding continuous fuel phase. There are few blasting applications today where some form of an emulsion explosive cannot fit the application. In massive, hard rock, dense, tightly jointed and fine grained rock types, the emulsion explosives are the best choices in creating new fracture networks for good fragmentation with a few alternatives. In such environments, emulsions with expanded drill patterns often result in better economics than the use of straight AnLFo. This paper will cover emulsion formulations, sensitizing options, product testing, material handling, and blast optimization, Emulsion explosives characteristics have also proven to reduce adverse environmental effects such as noxious fumes, ground vibration, and airblast while still remaining cost effective.

Jan 1, 2000

By Douglas A. Anderson

It is quite common for people exposed to blast vibrations to ask questions such as "How big was that blast on the Richter Scale?" Although it is tempting to dismiss such questions out of hand, for the lay person it is understandable that something which shakes their house should have some sort of measure attached to it. Since a layman doesn't usually know about particle velocity, frequency or the other terms used in describing and regulating blast vibration, the Richter Scale is usually the only measure they can relate to.

Jan 1, 1994

By Enver Alan

This Research & Development (R&D) study was conducted in the field of applied blasting engineering in Ethiopia, within the AKH Railway Project, which was built in Girena, within the boundaries of the province of Mersa, in the Basalt Quarry at km 346, Ashangi Formation, occured in Eocene geological time in the aphanitic trachibasalt.

Feb 1, 2020

By Ethan Steward, Kyle Perry

Blast resistant structural design continues to be a research area of major concern for governments around the world due to explosive threats from both state and non-state actors. Glass and aluminum curtain wall systems are commonly used to clad the exterior of government and commercial structures, allowing light into the building, regulating the interior environment, and providing an aesthetically pleasing exterior. These systems are likely to fail when exposed to sudden, high-pressure events such as the purposeful or accidental detonation of explosives. Engineers have designed blast resistant curtain walls and structural elements to reduce the likelihood and severity of failure, but the design tools and testing mechanisms commonly used in the process may not accurately model or simulate actual blast conditions at all ranges. In blast resistant structural design, the origin of a shock wave is typically assumed to be in the far-field, creating a wave that is nearly planar and parallel to at least one face of the target. Shock is applied evenly and immediately across the entire impacted surface. However, the source of real-life blasts is often very close to the target structure, and the assumption of far-field planar shock does not always apply. Mid-field blasts exhibit qualities different from those assumed about far-field shocks, specifically a hemispherical shock that produces different peak pressures, impulse curves, oblique reflections, and Mach stems across a target. This paper will examine mid-field shock effects from scaled distances of 2.5 to 4 13 (6.3 to 10.1 13) on a tall, scaled target by measuring reflected and incident pressure, impulse, and shock velocity across the target. Results will be compared to theoretical blast parameter equations and empirical data used by the industry. Possible effects of mid-field blasts on structures and further research ideas will be suggested.

Jan 21, 2025