PYROTECHNICS – FIREWORKS
Pyrotechnics is the science of using materials capable of undergoing self-contained and self-sustained exothermic chemical reactions for the production of heat, light, gas, smoke and/or sound. Its etymology stems from the Greek words pyro (“fire”) and tekhnikos (“made by art”). Pyrotechnics include not only the manufacture of fireworks but items such as safety matches, oxygen candles, explosive bolts and fastners, components of the automotive airbag and gas pressure blasting in mining, quarrying and demolition.
Individuals responsible for the safe storage, handling, and functioning of pyrotechnic devices are referred to as pyrotechnicians.
Explosions, flashes, smoke, flames, fireworks or other pyrotechnic driven effects used in the entertainment industry are referred to as theatrical special effects, special effects, or proximate pyrotechnics. Proximate refers to the pyrotechnic device’s location relative to an audience. In the majority of jurisdictions, special training and licensing must be obtained from local authorities to legally prepare and use proximate pyrotechnics.
Many musical groups use pyrotechnics to enhance their live shows. Pink Floyd were without a doubt the innovators of pyrotechnic use in concerts. For instance, at the climax of their song Careful With That Axe. Bands such as The Who, KISS and Queen, soon followed use of pyrotechnics in their shows. Michael Jackson attempted using pyrotechnics in a 1984 Pepsi advertisement, where a stray spark caused a small fire in his hair. German industrial metal band Rammstein are renowned for their large variety of pyrotechnics, which range from flaming costumes to face-mounted flamethrowers. Night wish, Lordi and Green Day have all become known for their vivid pyrotechnics in concert. Many professional wrestlers have also used pyrotechnics as part of their entrances to the ring.
Modern pyrotechnics are, in general, divided into categories based upon the type of effect produced or manufacturing method. The most common categories are: (1) Airburst – Hanging charges designed to burst into spheres of sparks; (2) Binary powders – Kits divided into separate oxidizer and fuel, intended to be mixed on site; (3) Comet (meteor) – Brightly colored burning pellets resembling shooting stars; (4) Mine – Tubes containing a lift charge intended to project stars, sparks, confetti or streamers; (5) Preloaded Smoke Pot – Cartridges designed to release a mushroom cloud of smoke; (6) Concussion (cannon simulator, concussion tube) – Device designed to create a loud report; (7) Falls – Propellant with titanium burning in an open ended tube creating a falling spark effect; (8) Fireballs / Mortar Hits – Short barreled device projecting smoky rolling ball of flame; (9) Flame Projector – Tube containing nitrocellulose granules that burn in pillars of colored flame; (10) Flare (Torch) – Short, high intensity flames or various colours; (11) Flash Cotton (Sparkle String) – Nitrated cotton string(nitrocellulose); (12) Flashpaper – Sheets of nitrated paper (nitrocellulose) resembling tissue paper; (13) Flash Pot – Short metal pot used with binary powders creating flash, smoke or sparks; (14) Flash Tray (split mine) – A long tube slit down one side to project a sheet of flash; (15) Gerb (including fountain, whistle and waterfall) – A fountain of sparks; (16) Lance – Small colored flare tube used in making points of light lance work or pictures in fire; (17) Line Rockets – Whistling or colored rocket devices that travel along guide cables; (18) Multi-Tube Article (multi-shot plate, multiple shot repeater boards and bombardo boards; designed to function in sequence) – Multiple effects chained together; (19) Pre-Mixed Powder – Powders intended to create various effects. (Concussions, flashes, etc.); (20) Squib – A small electrically initiated device replicating bullet hits; (21) Strobe – A brightly colored magnesium fueled flare blinking with repetitive flashes; and (22) Wheel (Saxon) – Tubes that create a spinning wheel of sparks.
A basic theatrical effect, designed to create a jet or fountain of sparks, is referred to as a gerb. A gerb consists of a sufficiently strong and non-flammable container to hold the pyrotechnic compound. Typical pyrotechnic formulations consist either of flammable materials such as nitrocellulose and/or black powder or a mixture of a fuel and oxidizer blended in situ. A plug placed at one end of the container with a small orifice, called a choke, constricts the expulsion of the ignited pyrotechnic compound, increasing the size and aggressiveness of the jet.
Various ingredients may be added to pyrotechnic devices to provide colour, smoke, noise or sparks. Special additives and construction methods are used to modify the character of the effect produced, either to enhance or subdue the effect; for example, sandwiching layers of pyrotechnic compounds containing potassium perchlorate, sodium salicylate or sodium benzoate with layers that do not creates a fountain of sparks with an undulating whistle.
In general, such pyrotechnic devices are initiated by a remotely controlled electrical signal that causes an electric match, or e-match, to produce ignition. The remote control may be manual, via a switch console, or computer controlled according to a pre-programmed sequence and/or a sequence that tracks the live performance via stage cues.
Display pyrotechnics, also known as commercial fireworks, are pyrotechnic devices intended for use outdoors, where the audience can be further away, and smoke and fallout is less of a concern. Generally the effects, though often similar to proximate pyrotechnics, are of a larger size and more vigorous in nature. It will typically take an entire day to set up a professional fireworks display. The size of these fireworks can range from 50 mm (2″) to over 600 mm (24″) diameter depending on the type of effect and available distance from the audience. In most jurisdictions, special fireworks training and licensing must be obtained from local authorities to legally prepare and use display pyrotechnics.
Consumer pyrotechnics are devices readily available for purchase to the general public with little or no special licensing or training. These items are considered relatively low hazard devices but, like all pyrotechnics, can still be hazardous and should be stored, handled and used appropriately. Some of the most common examples of consumer pyrotechnics encountered include recreational fireworks (including whistling and sparking types), model rocket motors, highway and marine distress flares, sparklers and caps for toy guns. Pyrotechnics are also indirectly involved in other consumer products such as powder actuated nail guns, ammunition for firearms, and modern fireplaces. Some types, including bird scarers, shell crackers, whistle crackers and flares, may be designed to be fired from a 12-gauge pistol or rifle.
Pyrotechnics are dangerous and must be handled and used properly. Recently, several high profile incidents involving pyrotechnics have re-enforced the need to respect these explosives at all times. Proximate pyrotechnics is an area of expertise that requires additional training beyond that of other professional pyrotechnics areas and the use of devices specifically manufactured for indoor, close proximity use.
A common low-budget pyrotechnic flash pot is built using modified screw-in electric fuses in a common light fixture. The fuses are intentionally blown, acting as ignitors for a pyrotechnic material.
Homemade devices may fail to include safety features and can provide numerous hazards, including: (a) A firing circuit using high-power, non-isolated AC line voltage can be a shock hazard to the operator and bystanders; (b) The use of high-current fuses as ignitors can cause main circuit breakers and fuses to trip, due to the sudden inrush of hundreds of amperes through a dead-shorted circuit. Switches used to control ignition may be damaged from the high-current surges; and (c) There may not be indicators or interlocks preventing premature ignition of the pyrotechnic material. Screwing a powder-loaded fuse into an unknowingly powered socket will result in immediate ignition, injuring the operator.
Commercial flash pots include safety features such as warning pilot lamps, pre-ignition grounding, and safing circuits. They also use isolated and low-voltage power sources, and have keyed power connections to help prevent accidental ignition. Pyrotechnics can be dangerous substances that must always be treated with the utmost respect and with the proper training. Due to the hazardous nature of these materials, precautions must always be taken to ensure the safety of all individuals in the vicinity of pyrotechnics. Despite all precautions, accidents and errors occur from time to time, which may result in property damage, injury and in severe cases loss of life. These incidents may be the result of poorly manufactured product, unexpected or unforeseen events, or in many cases, the result of operator error.
Fireworks/Pyrotechnics, while widely used to celebrate the 4th of July here in the United States, are also used for other celebrations as well such as the Inauguration of a President, concerts and much more.