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By Detnet Solutions

1. “Daisy-Chain” concept The term “daisy-chain” stems from the fact that when the HotShot? detonators are connected there is a chain or electrical path for electrical current to flow from detonator A to detonator B, detonator B to detonator C etc until the path is terminated by an electrical means. The “daisy-chain” concept has long been used in electronic detonator systems, historically used in Expert Explosives’ ExEx 1000 5/6 wire system and currently in use in African Explosives Limited (AEL’s) Electrodet? electronic detonator system and has been adopted as the basis upon which the “auto-programmability” of the HotShot? electronic detonator system functions. HotShot? Detonators are connected to each other in a string, completing a “daisy chain”, and during the auto-detection mode of the control equipment, it is possible for the equipment to determine the order of hookup of the detonators as well as map the entire blast layout. The auxiliary components (Row Controllers & Branch Controllers) assist the control equipment in mapping the entire blast by indicating different points on the blast, i.e. The inflection point of a row of blast holes on a closed chevron timing pattern, the beginning of row of blast holes on open chevron timing pattern and extra blast holes or extra blast rows.

Jan 1, 2004

By D. Pickering, R. Wharton

The deadline for meeting legal requirements relating to the sale of explosives in the European Union was 1 January 2003. The paper examines the range of materials that have already been certified by the different Explosives Notified Bodies as well as recent national and European Commission decisions relating to this work. The implications of enlargement of the European Union are also discussed as is the future role of the Great Britain Explosives Notified Body in certification and assessment.

Jan 1, 2003

By Robert Morgan

The mind-set that only blasters and their helpers need training in explosives can result in risk to other employees working at mine or construction sites where blasting is conducted. Misfires are not always immediately obvious during postblast examinations performed by the certified blaster in charge; the presence of undetonated explosives may not appear until well within the muckpile as was the case in the photo, right. To avoid accidents involving misfires, follow safety procedures specified in mine safety regulations, and the ISEE Blaster’s Handbook that include the following:

Jan 1, 2004

By P J. Hommert, D S. Preece

"Commercial development of the United States Oil Shale reserve will require substantial amounts of mining. In fact, even a modest 500,000 barrels per day industry requires a mining effort equivalent to nearly half of the current U.S. coal mining industry. Obviously, mining efforts on this scale will benefit from technological advances. There are a number of areas where advanced technology could impact mining. These include continuous miners, shale transport systems, and blasting. This paperexamines recent developments in computer modeling of blasting and assesses the likelihood of these advances being applied to practical oil shale mining problems."

Jan 1, 1989

By Ray Jambakhsh, Gabrielle Bourget

In the summer of 1998, Ontario Hydro awarded a contract to demolish an obsolete and inefficient chimney by blasting. The Ontario Hydro Thunder Bay Thermal Generating Station (T.G.S.), is a fully operational hydro thermal generating station located in Thunder Bay, Ontario, Canada. The Chimney was a 356 ft (108 m) high freestanding structure constructed of reinforced concrete with a brick liner. Falling the chimney required careful planning due to the highly sensitive structures and equipment which surrounded it. Damage either sustained to the existing systems through ground vibrations or direct contact would have resulted in expensive power outage and/or lost production. The role of Explotech Engineering Ltd. on this project was to provide and evaluation of the proposed demolition procedure, defme the predicted and maximum seismic vibrations at sensitive structures including underground services, conduct pre-blast / post-blast inspections and recommend various safety precautions. The general contractor for the project, LeBrun Northern Contracting Ltd., of Thunder Bay, Ontario was responsible for all site preparations and post-blast clean up. All demolition blasting calculations and operations were conducted by Dykon demolition experts from Tulsa, Oklahoma. On September 13, 1999, the chimney was successfully demolished. Extensive analysis of the vibration records and visual post-blast inspections of the surrounding structures concluded that the demolition event induced no damage to any of the Ontario Hydro facilities.

Jan 1, 2000

By Nobel Insurance Service

[Executive Director’s note: ISEE is committed to continuing its efforts to ensure that blasters be made aware of the issue of migration of carbon monoxide resulting from blasting operations. In the July/August 2001 issue of the J o u rnal we printed excerpts from “Carbon Monoxide - The Silent Hazard,” an article from the Safety Update, published by Nobel Insurance Services. We also re minded readers of the text from the 17th edition of the ISEE Blasters Handbook in its section on trench blasting as follows: “...consideration must be given to the proper venting of gases generated from the blasting. Should those gases spread laterally rather than vent directly to the surface, the gases may travel underg round and finally vent well outside of the planned area. Such events may be caused by the strata, soil conditions or root systems, or existing and/or abandoned utilities or other man-made structures. In the worst situation, gases resulting from the detonation such as CO2, CO, and/or N Ox may travel through the strata and find their way into basements of nearby homes or businesses.” While incidents are rare, a number of cases in re c e n t years have resulted from outdoor blasting operations p roducing carbon monoxide gas that has migrated t h rough the earth and accumulated in nearby enclosed spaces. T h e re are steps that a blaster can take to be proactive in preventing incidents. These steps and studies of the occurrence have been expertly presented in several papers presented at ISEE conferences and included in the ISEE Conference Proceedings, available th rough the Blasters Library. In addition, Material Safety Data Sheets provided with explosives used in surf a c e blasting should provide additional information on gases p roduced by detonation. Below, we have reprinted the IME white paper, entitled “Fumes from Blasting Operations.” The paper underscores the unique set of circumstances that combine to contribute to high concentrations of CO measurements in underground, enclosed spaces following the detonation of explosive materials and provides recommendations to blasters

Jan 1, 2004

By R. Reed Skaggs, William Gault, Douglas Kooker

Both armored personnel carriers and light combat vehicles are increasingly vulnerable to a variety of highly lethal antitank land mines. As a result, there is a need for modeling and understanding the interaction of mine blast products with respect to the resulting loading and damage mechanisms inflicted by explosive blast and impact on vehicle structures. However, the mechanics of blast soil interactions are still poorly understood. The objective of this investigation is to computationally simulate a series of experimental buried mine explosions in saturated sand soil -- over a wide range of scale – and compare the predictions of blast loading to data. Small scale tests have recently been conducted at the University of Maryland with a few grams of RDX acting against an aluminum plate, while recent full-scale tests at ARL involve several kilograms of TNT against 12,500 kg of RHA. The ARL measurements reported here are based on the Vertical Impulse Measurement Fixture (VIMF) facility, a structural mechanical device that responds to blast loading by measuring the vertical displacement of a fixed mass vertical guide rail, which is a direct measure of the imparted impulse. CTH predictions for vertical momentum of the target plate are within 60 – 80 % of the reported impulse data for this wide ranging set of tests. One of the comparisons, however, suggests that the TNT charge in a particular VIMF test may not have fully reacted.

Jan 1, 2005

By Richard Curtis

Optimum Colliery is presently experiencing a shortfall of stripping capacity in order to meet its production requirements. Due to the long dragline procurement times, several alternative stripping methods were evaluated in order to alleviate this shortfall in the interim period. Based on the experience gained at the mine. The writer will discuss some of the important factors which influence dragline performance and show how these factors may by used in a theoretical approach to analyse various dragline applications.

Jan 1, 1990

Blast vibration analysis under relatively near-field conditions has been carried out in a narrow-vein underground operation. The objective was to characterize the vibration signal (particle acceleration and velocity) from carefully controlled stope blasts. The limitations of such analysis in deriving design guidelines for reducing dilution has been elucidated. It has been shown that identification of each individual hole with specific explosive types can yield explosive-specific predictive equations for particle velocity. This has been coupled with measurement of actual overbreak to arrive at a limiting vibration level to generate a realistic design tool for controlling dilution in narrow-vein mines.

Jan 1, 2003

By Paul Downing

When was the last time the documents and paperwork were cleaned out of the glove boxes, door pockets, under the seats and above the visors in your company vehicles? Insurance cards that expired three years ago and vehicle registrations from 1999 through 2003, for instance, don’t do any good and just take up space

Jan 1, 2008

By James McGough, Lawrence Mirabelli, Ran Tamir

The paper will demonstrate how automated fragmentation photo analysis is being used at the Lafarge North America, Ravena NY quarry as part of an ongoing drill, blast and primary crushing continuous improvement process. Using on-line fragmentation photo analysis systems at both the primary crusher feed point and crusher discharge belt, data is collected to: benchmark the drill/blast process; monitor the work being done by the primary crusher; measure gradation changes in the crusher feed resulting from changes in drill/blast and measure the subsequent changes in further size reduction done by the primary crusher.

Jan 1, 2012

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 ATF Publications

The following is a summary of the changes that were incorporated into the new Federal Explosives Regulations, 27 CFR Part 55, dated 9/2000. However, in light of the recent events of September 2001, additional changes in the Federal Explosives Laws and Regulations may be forthcoming. The nature and extent of any such potential changes are impossible to gauge at this time. However, this synopsis of the changes contained in the September 2000 Orange Book, ATF P 5400.7 was current at the time of this writing. Any questions regarding this paper should be directed to the Public Safety Branch in ATF Headquarters in Washington, D.C.

Jan 1, 2002

Blasthole deviation is a frequent, well documented and undesirable occurrence in mining operations. It is caused by the drill string mechanics, operating variables and the interaction between the drill bit and the rock mass characteristics. It is composed of three distinct components: collaring or marking error, alignment error and trajectory deviation. This study has focussed on the dependence of trajectory or natural deviation on the geological features of the rock mass being drilled.

Jan 1, 1996

By John Haviland, Richard E. Danell

"BHP Australia Coat Pty Ltd (BHPAC) operates seven large open pit coal mines in the Bowen Basin ofCentral Queensland, Australia. These mines have operated for periods ranging from 16 to 37 years. All of these mines have dipping seams to varying degrees and are facing increasing overburden removal in an effort to maintain production. To ensure the economic viability of the operations, this increased level of overburden removal must ah.0 be conducted at lower unit costs."

Jan 1, 1995

By Felix Torres

CVRD is one of the largest mining companies in the world. Adoption of new technology and improving operational efficiency are top company priorities. Initiatives in these areas have driven continuous company growth and an increased share price. During the first half of 2001, the company had a net profit of nearly US$ 500 M.

Jan 1, 2003

By Brent Blanchard

Dallas/Fort Worth Airport recently took a major step in its fiveyear expansion project with the explosive demolition of the Hyatt Regency Hotel West. Built in 1965, the Hyatt Regency held the distinction of hosting five U.S. Presidents over the years and was reportedly one of the first hotels in the world to be built within an airport’s boundaries.

Jan 1, 2003

By Mark Svinkin

The purpose of this paper is to present an overview of recommended existing criteria of ground vibrations generated by blasting. It is shown that these criteria have limited liability because they were found for specific categories of structures. A new approach based on measurement of structure vibrations is suggested for assessment of damage in structures subjected to blasting vibrations. This approach provides the flexibility of implicitly considering a variety of soil-structure interaction and structure conditions. It is explained a new frequency-independent safe-level criterion of 51 mm/s (2 in/s) for the PPV of structural vibrations. Attention is brought to use seismographs properly calibrated for the required frequency range. Positive flexibility is demonstrated in assessment of structure and component of concern vibrations from blasting.

Jan 1, 2003

By Frank Chiappetta, Karl Zipf, Robert Hopler, Brian Stump, Francois Heuze, Bob Martin, Vindell Hsu, William Walter, Craig Pearson

The Comprehensive Test Ban Treaty (CTBT) was accepted for signature at the United ,Nations in September of 1996. It ‘now awaits ratification by its signatories, ~including the United States. After the Treaty is in force, the main concern of the international community twill be to verify that no nuclear test is performed.

Jan 1, 1998

By Frank Sames

Ground vibration levels are generally predicted using equations such as the USBM equation implementing the scaled distance concept and describing geological and blast design parameters in a ground transmission constant.

Jan 1, 1995