B
LASTING SYSTEMS AND SERVICES
Nitro Bickford, headquartered in Paris, France supplies a complete range of civils explosives produced by EPC including dynamite, ammonium nitrate, cartridge emulsions and pumpable emulsions. Also on offer are blasting systems produced in the French factory of Davey Bickford. Nitro Bickford has developed a range of monitoring equipment to optimise blasting techniques. These include: the Mini Seis range of vibration monitors; Diademe III hole deviation sondes; Microtir software covering all types of detonators including electric, sequential, nonel and electronic; and Expertir software for drilling and blasting planning covering hole diameters and depths and explosives loading for maximum efficiency.
Nitro Bickford offers blasting services in France from 12 distribution depots manned by a total of 20 blasting experts and with 80 specialists in a fleet of 60 vehicles. Outside France, four dedicated engineers advise on explosives products and the handling of dangerous substances, while a group of eight affiliate companies handles distribution on the four principal continents.
Nitro Bickford engineers will advise on any project involving explosives, designing blasting patterns, specifying explosives and detonators, and controlling velocity of detonation, vibration and blast quality. They will conduct and supervise vibration monitoring and seismic studies, always with an eye to reducing or eliminating blasting nuisance, and will train blasters at seminars by arrangement.
MORSE SYSTEM FROM NITRO BICKFORD
MORSE stands for Module for Repumping and Sensitization of Emulsion, used for on-site production and pumping of explosives at the blasthole. MORSE improves security because of the reduction in handling and transport of explosives. It also contributes to better productivity because of the ease of charging and the reduction in time required. Cost savings result from the reduction in storage and stocking of explosives.
The MORSE system was developed by EPC more than a decade ago in response to problems with the more traditional methods of charging in mines and tunnels. At this time, some 23 units are at work around the world, 80% of which are in use underground and the remainder in quarries and open pits.
The MORSE system comprises a self-contained stainless steel unit with: 980 litre bulk container for emulsion; three 115 litre tanks for reagents and water; one pump for emulsion and three for reagents; pump hydraulics and electrics; explosives charging regulator; and two 25 m-long flexible charging hoses.
Production capacity of the unit is 1.2 t, rate of production is 30-50 kg/min, and total weight including emulsion is 2.8 t.
The standard unit is 2.4 m-long, 1.7 m-wide, and 1.7 m-high, but more compact versions are available to special order. A 400 V three-phase electricity
supply is normally required.
DAVEYTRONIC® II SYSTEM FROM NITRO BICKFORD
In tunnels and mines, Daveytronic II electronic detonators offer the best performance in terms of control and reduction of blasting vibration; ground stability; fragmentation; reduction in overbreak; dilution of minerals; and consumption of explosives. Each detonator is programmable between 1 and 4,000 milliseconds.Security results from: the separation of the test and initiation circuits in the detonator by using two independent condensers; retention of the delay number in a permanent memory; and discharge of the energy in each detonator to ensure safe loading.
DIGITAL TUNNEL BLASTING
The N1 Porto tunnel project in Portugal is a 650 m-long segment of a large-scale civil engineering plan to improve traffic flow between the downtown district, the Santo Antonio hospital
district, and the highway access. The tunnel was
excavated in a massive granite structure, 4 – 20m below a highly urbanized
environment. The project was originally designed for mechanical excavation. When this method failed, traditional drilling and blasting techniques were introduced to complete the project. Digital blasting helped comply with the environmental and safety requirements concerning blast charging, firing and vibration control.
Tunnelling operations restarted in January, 2004 with 1.0 m-deep blasts using 50 kg of explosives some 4.5m below building foundations in Porto. The Daveytronic digital blasting system trebled the rate of tunnel advance in sound granite. This resulted in an overall reduction of 60 operating days in the duration of the excavation of the upper section of the project.
Nitro Bickford, 21 rue Vernet, 75 008 Paris, France, tel +33 (0)6 30 09 68 81.
Contact pmontagneux@nitrobickford.fr or visit www.nitrobickford.fr
© tunnelbuilder ltd