Pyrotechnics is the science of materials capable of undergoing self-contained and self-sustained exothermic chemical reactions for the production of heat, light, gas, smoke and/or sound. Pyrotechnics include not only the manufacture of fireworks, but items such as safety matches, oxygen candles, explosive bolts and fasteners, and components of the automobile safety airbag.
Pyrotechnic devices combine high reliability with very compact and efficient energy storage, in the form chemical energy which is converted to expanding hot gases either through deflagration or detonation. The controlled action of a pyrotechnic device (initiated by any of several means, including an electrical signal, optical signal or mechanical impetus) makes possible a wide range of automated and/or remote mechanical actions; for example, deployment of safety equipment and services, precisely timed release sequences, etc. The majority of the technical pyrotechnic devices usepropellants in their function, a minority use materials that are classified as primary or secondary explosives to obtain very fast and powerful mechanical (mostly cutting) actions; for example cable cutters or exploding bolts.
Individuals responsible for the safe storage, handling, and functioning of pyrotechnic devices are referred to as pyrotechnicians.
Pyrotechnic Effects
Explosions, flashes, smoke, flames, fireworks or other propellant driven effects used in the entertainment industry are referred to as pyrotechnic special effects, theatrical effects, or proximate pyrotechnics. Proximate refers to the pyrotechnic device's location relative to an audience. Special training and licencing must be obtained from local authorities to legally prepare and use proximate pyrotechnics.
Many musical groups use pyrotechnics to enhance the quality of their live shows. Some of the earliest bands to use pyrotechnics were Queen, Pink Floyd, and KISS. The band Rammstein uses a large variety of pyrotechnics, from flaming costumes to face-mounted flamethrowers. Also Nightwish and Lordi are known for their vivid pyrotechnics. Many professional wrestlers have also used pyrotechnics as part of their entrances to the ring. One example would be Bill Goldberg, who used pyrotechnics during his in ring entrance in both World Championship Wrestling (WCW) and World Wrestling Entertainment (WWE).
Modern pyrotechnics are, in general, divided into categories based upon the type of effect produced or manufacturing method. The most common categories are:
- Airburst - Hanging charges designed to burst into spheres of sparks.
- Binary kits - Powders divided into oxidizer and fuel intended to be mixed before use.
- Comets (meteor) - Rising shots resembling shooting stars.
- Preloaded Comet
- Preloaded Mine - Tubes containing a lift charge intended to project stars, sparks, confetti or streamers.
- Preloaded Smoke Pot - Cartridges designed to release a mushroom cloud of smoke.
- Preloaded Report (concussion tube) - Tubes designed to create a loud report.
- Falls - Devices intended to drop like falling stars.
- Fireballs / Mortar Hits - Containers creating mushroom clouds of flame.
- Flame Projector - Columns shooting pillars of flame.
- Flare (Torch) - Short, high intensity flames or various colours.
- Flash Cotton (Sparkle String) - Cotton string impregnated with nitrocellulose.
- Flashpaper - Sheets of nitrocellulose resembling tissue paper.
- Flash Pot - A container for creating a bright flash and smoke.
- Flash Tray (split mine) - A long tube creating a wide, bright flash.
- Gerb (including fountain, whistle, and waterfall) - A fountain of sparks.
- Lance - A small brightly coloured fountain that produces few sparks.
- Line Rockets - Whistling gerbs travelling across wires.
- Multi-Tube Article (multi-shot plate, multiple shot repeater boards and bombardo boards; designed to function in sequence) - Multiple effects chained together.
- Pre-Mixed Powder - Powders intended to create various effects. (Concussions, flashes, etc.)
- Squib - A small, pre-matched device typically used to replicate bullet hits.
- Strobe - A device intended to create bright repetitive flashes.
- 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 blackpowder 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.
[edit]Display Pyrotechnics
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 setup a professional fireworks display. The size of these fireworks can range from 2.5" diameter to over 16" diameter depending on the available distance from the audience. Special fireworks training and licensing must be obtained from local authorities to legally prepare and use display pyrotechnics. NV
[edit]Consumer Pyrotechnics
Consumer pyrotechnics are devices readily available for purchase to the general public without 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, model rocket motors, highway flares, sparklers and caps for toy guns. Pyrotechnics are also indirectly involved in other consumer products such as powder actuatednail guns, ammunition for firearms, and modern fireplaces.
[edit]Safety
If not handled and/or used properly pyrotechnics can be dangerous. In 2003, improper use of pyrotechnic devices caused a fire in a Rhode Island nightclub called, The Station. The Station nightclub fire was started when the fireworks the band Great White was using accidentally ignited flammable soundproofing foam, which was not appropriate and/or not installed properly. The foam caused the fire to spread rapidly and the resulting fire led to 100 deaths, ostensibly because their quick escape was blocked by ineffective exit doors. A similar pyrotechnic-induced fire in 2004 destroyed the Republica Cromagnon nightclub in Buenos Aires, Argentina, killing 194 people.
Indoor and/or proximate pyrotechnics is a sub-specialty that requires additional training beyond that of other professional pyrotechnics areas and additionally requires the use of devices especially made for indoor and/or close proximity use. While the type of foam used and the lack of a required sprinkler system were important factors in the fire, the Great White fire could have been prevented had those involved paid even minimal attention to standard safety practices around the use of pyrotechnics[citation needed].
A common low-budget pyrotechnic electric flash pot is created using screw-in electric fuses in a porcelain light fixture. The viewing window is removed from the top of the fuse and flash powder poured into the hole around the fuse link. When plugged into line power, the fuse instantly blows, igniting the flash powder. Such flash pots are highly dangerous since they use exposed line current, the use of high amperage fuses can cause large main circuit breakers and building-wide fuses to trip, and there is usually no indication of whether the lamp socket is powered. Screwing a powder-loaded fuse into an unknowingly powered socket will result in immediate igniting in the face of the pyrotechnician and potentially severe burns. Proper commercial electric flash pots include safety features such as warning pilot lamps, preignition grounding and safing circuits, and keyed power connections to help prevent accidental ignition.
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