Laser diode initiated detonators for space applications

Ensign Bickford Aerospace Company (EBAC) has over ten years of experience in the design and development of laser ordnance systems. Recent efforts have focused on the development of laser diode ordnance systems for space applications. Because the laser initiated detonators contain only insensitive secondary explosives, a high degree of system safety is achieved. Typical performance characteristics of a laser diode initiated detonator are described in this paper, including all-fire level, function time, and output. A finite difference model used at EBAC to predict detonator performance, is described and calculated results are compared to experimental data. Finally, the use of statistically designed experiments to evaluate performance of laser initiated detonators is discussed

Optimization of blasting parameters in open cast quarries of El Hassa-Bouira (Northern Algeria)

In recent years, Algeria has known a rapid growth in the construction projects, such as: buildings, roads, and infrastructure, which increased the demand for aggregates production in quarries. However, vibrations and noises generated by blasting operations have a negative impact on the residents living nearby. For this reason, blast tests were performed in the open cast quarries of the company Sarl El Hassa-Bouira (Northern Algeria) using instantaneous electric detonators (IED), micro delays (MDD) and delays (EDD) to minimize the instantaneous load. We also minimized noise and vibration during the blasting. A seismograph allowed us to take further measurements

Saturn i launch vehicle sa-10 and launch complex 37b functional systems description. volume x- separation and flight termination systems functional description, index of finding numbers, and mechanical schematics

Inflight stage separation and flight termination system for Saturn I /SA-10/ launch vehicl

Research into the effect of gallery size on blast pull in underground coal mines

Purpose. To investigate the effect of gallery size on blast pull in underground colliery by drilling and blasting techniques. Methods. The study conducted in three different underground collieries namely A, B and C located in eastern part of India has been accomplished by solid blasting using milli-second short delay detonators and wedge cut pattern. The trial blasts were conducted in underground mines to investigate the effect of gallery size on blast pull. Findings. From the study it was found that the pull is related to the cross sectional area of the drive. It increases as the face size increases. This relation is obtained considering width of the gallery in the range of 3.0 – 4.8 m and height of the gallery in the range of 2.2 – 3 m. It is assumed that the angle of the hole and the length of the hole are optimum, charging and connections being appropriate. Advancement per blast round was found to vary from 0.8 to 1.5 m whereas average advancement per blast round was 0.98 m. Originality. This is a field study and the results are based on the data collected and analyzed on site. Although similar studies have been done by various researchers to improve the productivity of the mine for different conditions, the obtained results are condition, machinery, method and mine specific. Practical implications. This study is applicable for underground coal mine but can be extended in underground metal and tunneling projects for improving the blast pull.Мета. Дослідження впливу розмірів виробки на посування вибою у вугільній шахті при веденні буропідривних робіт. Методика. Дослідження проводилися на трьох шахтах A, B і C, розташованих у східній частині Індії. Підривання цілика здійснювалось методом клинового врубу із використанням детонаторів з мілісекундним уповільненням. Вибухова речовина, що використовувалась – Senatel 5000, Pentadyne Solar Coal 5. Випробувальні вибухи були проведені в шахтах для вивчення впливу розмірів виробки на посування вибою. Результати. Експериментальними шахтними дослідженнями встановлено, що посування вибою залежить від поперечного перерізу штреку та зростає зі збільшенням площі поверхні забою за поліноміальною залежністю, отриманою для виробок шириною 3.0 – 4.8 м і висотою 2.2 – 3.0 м. Визначено, що кути встановлення шпурів та їх довжина були оптимальні, а забійка заряду і з’єднання відповідають чинним нормативам. Встановлено, що посування вибою за один вибух склало 0.8 – 1.5 м при середній величині посування забою 0.98 м. Наукова новизна. Отримані результати впливу розмірів виробки на посування її вибою при проведенні є новими для певних умов шахт східної Індії, механізмів і методів видобутку. Практична значимість. Збільшення поперечного перерізу поверхні вибою дозволяє визначити оптимальний кут клину при бурінні шпурів. Отримані результати мають практичне значення не лише для вугільних шахт, а й для поліпшення посування вибою при будівництві тунелів і видобутку металевої руди.Цель. Исследование влияния размеров выработки на подвигание забоя в угольной шахте при ведении буровзрывных работ. Методика. Исследования проводились на трех шахтах A, B и C, расположенных в восточной части Индии. Взрывание целика производилось методом клинового вруба с использованием детонаторов с миллисекундным замедлением. Используемое взрывчатое вещество – Senatel 5000, Pentadyne Solar Coal 5. Испытательные взрывы были проведены в шахтах для изучения влияния размеров выработки на подвигание забоя. Результаты. Экспериментальными шахтными исследованиями установлено, что подвигание забоя зависит от поперечного сечения штрека и растет с увеличением площади поверхности забоя по полиномиальной зависимости, полученной для выработок шириной 3.0 – 4.8 м и высотой 2.2 – 3.0 м. Определено, что что углы установки шпуров и их длина были оптимальны, а забойка заряда и соединения соответствуют действующим нормативам. Установлено, что подвигание забоя за один взрыв составило 0.8 – 1.5 м, при средней величине подвигания забоя 0.98 м. Научная новизна. Полученные результаты влияния размеров выработки на подвигание ее забоя при проведении являются новыми для определенных условий шахт восточной Индии, механизмов и методов добычи. Практическая значимость. Увеличение поперечного сечения поверхности забоя позволяет определить оптимальный угол клина при бурении шпуров. Полученные результаты имеют значение не только для подземных угольных шахт, но и для улучшения подвигания забоя при строительстве туннелей и добычи металлической руды.The author is indebted towards the excellent cooperation and support provided by the entire operational crew, staff and management of the BCCL during collection of data for this study

Explosive component acceptance tester using laser interferometer technology

Acceptance testing of explosive components requires a reliable and simple to use testing method that can discern less than optimal performance. For hot-wire detonators, traditional techniques use dent blocks or photographic diagnostic methods. More complicated approaches are avoided because of their inherent problems with setup and maintenance. A recently developed tester is based on using a laser interferometer to measure the velocity of flying plates accelerated by explosively actuated detonators. Unlike ordinary interferometers that monitor displacement of the test article, this device measures velocity directly and is commonly used with non-spectral surfaces. Most often referred to as the VISAR technique (Velocity Interferometer System for Any Reflecting Surface), it has become the most widely-accepted choice for accurate measurement of velocity in the range greater than 1 mm/micro-s. Traditional VISAR devices require extensive setup and adjustment and therefore are unacceptable in a production-testing environment. This paper describes a new VISAR approach which requires virtually no adjustments, yet provides data with accuracy comparable to the more complicated systems. The device, termed the Fixed-Cavity VISAR, is currently being developed to serve as a product verification tool for hot-wire detonators and slappers. An extensive data acquisition and analysis computer code was also created to automate the manipulation of raw data into final results

Clay-kickers of Flanders Fields: Canadian Tunnellers at Messines Ridge 1916-1917

This article explores the Canadian tunnelling companies’ military mining organisation and accomplishments in underground galleries during the Great War. This comprehensive study explains the crucial role played by the Canadian engineers, in conjunction with British and Australian engineers, in the successful detonation of nineteen deep mines at Messines Ridge, Belgium on 7 June 1917. The tunnellers’ perseverance and skill were evident that morning when they slammed home plungers and threw switches igniting the largest planned explosion up to that time. However, daily hardships and dangers of underground warfare from the claustrophobic environment to the stress from the eavesdropping enemy led to disciplinary action including Field Punishment No. 1

Portable fiber optic coupled Doppler interferometer system for detonation and shock wave diagnostics

Testing and analysis of shock wave characteristics such as detonators and ground shock propagation frequently require a method of measuring velocity and displacement of the surface of interest. One method of measurement is Doppler interferometry. The VISAR (Velocity Interferometer System for Any Reflector) uses Doppler interferometry and has gained wide acceptance as the preferred tool for shock measurement. An important asset of VISAR is that it measures velocity and displacement nonintrusively