Nagpur: The explosion that claimed 18 lives on Sunday occurred in the section of the explosives factory where detonators are crimped. Regular operations had not yet begun for the day and the workers were only making preparations ahead of the morning shift when the blast took place, say company sources.A detonator is a device used to trigger a much larger explosion. Although it contains only milligram quantities of explosive material, it is filled with highly energetic substances such as HMX (high-melting explosive) or pentaerythritol tetranitrate (PETN). These materials set off a powerful reaction in the main explosive charge, an industry source explained.
Crimping — commonly referred to as packing — involves sealing the top of a detonator after it has been filled with explosive material. This is done by applying pressure using a machine and is the final stage in the manufacturing process.Company officials said the detonators being produced were intended for industrial applications, including mining, and were not meant for military use. There are three main types of detonators: electric, non-electric, and electronic. Electric detonators were banned last year to prevent misuse by subversive elements such as the Maoists. In these, blast could be triggered by passing electric current from a distance, and this made them handy for Maoists for triggering explosions from their hideouts. The electric detonators also had certain safety issues too, said a source in the explosives industry.Non-electric detonators operate through a shock mechanism. The section where the accident occurred was making non-electric detonators. These detonators contain a shock tube — a small duct through which the initial detonation travels in wave form to ignite the main charge. Sources describe this system as relatively safer.The third category is electronic detonators, which function using a handheld device known as a logger. The logger must be compatible with the specific detonator, meaning it can only trigger devices produced by the same manufacturer. This feature is designed to prevent misuse. Industry experts consider electronic detonators the safest option, though the transition to them is still underway.It has been learnt that the company where the accident took place makes both non-electric and electronic detonators. The process of shifting to electronic detonators has already begun in the industry. It is learnt that industry players were supposed to make a presentation on electronic detonators before the govt in the coming month.However, the explosive industry needs to prepare before it entirely shifted to electronic detonators, sources said. Among industrial users, the coal mining industry is one of the biggest users of explosives.
