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PURVEYORS OF
PYROTECHNICAL EXCELLENCE.

 

  Firework Glossary.

Battery      A battery is a collection of fireworks, often of different types, assembled             together and fused in sequence. Usually as an opener or a finale.

Black Match      A fuse consisting of a loosely woven string impregnated with black         powder. Match is often supplied wrapped in paper or plastic tube.   Piped Match or Quickmatch. A line of powder on a sellotape type  material is known as tape match. A variant of tape match called sticky match has been patented in Australia in which the line of powder is covered by a second piece of tape.

Black powder     Black Powder is the mainstay of Pyrotechnics. At a basic level it is the mixture of potassium nitrate, charcoal and sulphur. However, simply mixing these ingredients together will not produce proper black powder. It merely produces a much milder version, which itself is used extensively in pyrotechnics, and is commonly called meal powder. True black powder takes advantage of the extreme solubility of potassium nitrate by mixing the very fine milled ingredients into a dough with water, then using strong compression to force the water out of the mixture, so that tiny crystals of potassium nitrate form in and around the particles of the other ingredients. This produces a product that is far fiercer than the simple meal powder. The discovery or development of black powder is generally attributed to the Chinese, probably around 1000 AD.

Blue Touchpaper     A common fuse for garden fireworks, the expression " light the blue touchpaper and retire" has entered the English language as a colloquiaism. It is never used in display fireworks having no accuracy of timing.

Break     The break is the explosion of an ariel shell some shells are multi break, up to 4 is common. A 4 break shell effectively consists of four heads on one lifting charge. It is very important to have a good fit in the mortar to ensure plenty of height, and to allow plenty of clearance from the audience as multiple breaks are often quite low by the time of the final break.

Burst      Many of the best shells and rockets have a single break which changes colour or effect. This a double, or multiple burst.

Bursting Charge     The charge in a shell or rocket which is ignited by the lifting charge at the top of its ascent, exploding the firework and igniting the stars or other effects.

Catherine Wheel     As a garden firework this usually consists of a tube wound into a flat spiral, nailed to a post, which spins rapidly after being lit. Larger wheels consist of one or more drivers on a radial spoke, often with Gerbs for added effect.

Case     In general terms the case is the tube containing a compound. It usually refers to more specifically to a component of a Waterfall thus a Waterfall will be quantified for instance as a 24 case fall. Each case designated according to its weight e.g. " a 1lb case "

Category 1, 2, 3, 4.      Since the publication in 1988 of the Health and Safety Executive's Standard for outdoor fireworks, all fireworks in the UK have been divided into categories which govern their supply, handling, storage, transport and use. These, Very Briefly are:

CAT 1.     Indoor Fireworks

CAT 2.     Generally, shop goods.

CAT 3.      Requires a safety distance of 25 Meters to be observed, and a manufacturing                       specification which ensures that no burning material will fall within this distance.

CAT 4.      Only to be used by Explosive factory, or Explosive magazine licence holders and                       their employees.

Cakes.         A relative newcomer to the Fireworks scene, cakes are named after their appearance. The first to appear were circular and flat but now square and octagonal are common. A cake is a series of tubes with a fuse running through the base of each tube so they fire in sequence. Cakes can add enormous variety because they can consist of Roman Candles, Fountains, Mines or other types of Firework. Some Cakes are as big as a packing case, one of the most popular at the moment being the Poisonous Spider.

Choke.      The narrowed part of a rocket case. It forces gasses formed by combustion to be expelled at speed thereby generating the motive force to lift the Rocket.

Chrysanthemum.     The favourite shell of many pyrotechnic enthusiasts, and a speciality of the Japanese manufactures. The chrysanthemum shell emits its stars in a perfect circle and the brightness intensifies as the circle grows in size creating a magnificent simulation of the eponymous flower.

Dark Fire.     A composition giving off hardly and light when it burns. It is used in stars to give a winking effect, or to separate colour changes.

Daylight Fireworks.      Daylight Fireworks concentrate less on light and more on noise, coloured smoke and novelty effects such as parachutes and flags. There is not the degree of variety available for a long display but Daylight Fireworks can be used to great effect as a brief but spectacular flourish to announce special occasions.

Delay.     A tube of slow burning compound inserted into a fuse run to give a timed delay.

Driver.     Also called a motor this provides the motive power for a wheel, either singly or in multiples.

Flight Rocket.      A Rocket, usually only small, with a fast fuse. They are packed loosely in a metal cone and just one is ignited. The trail from this ignites thoes adjacent, which then do likewise so that all ascend in a few seconds. Although each individual rocket is small, forty or fifty make a real sky-filler.

Fuse.      The fuse transfers combustion from the source - a portfire or pyrotechnic igniter to the compound inside the Firework. Shop goods, use Blue Touchpaper but display fireworks often have match, or the touchparer is removed and another fuse inserted. Individual Fireworks are then connected together in sequences with timing created by the use of fast or slow fuses and delays. Another common fuse is igniter cord, especially green or slow, which is used for leaders. A Pyrotectnic fuse, also known as a Pyrotechinic igniter or electric match, is a fuse ignited by an electric current. Sometimes incorrectly referred to as a " detonator ", and known in the US as a squib.

FX.     A shorthand term for " effects ". Any given effect might be fired from a mortar by a mine, projected intermittently by a roman candle, or seen in the sky bursting from a shell.

Gerbs.      These are pyrotechnic sprays, often referred to as fountains or flower pots. They consist of a tube full of composition, sealed at the one end and with a nozzle at the other, similar to a rocket. Unlike a rocket, they are not designed to move anywhere, so the emphasis is on making the nozzle exhaust as long and pretty as possible, with large amounts of sparks, and nice colours etc. The sparks are produced by metal powders or coarse charcoal in the gerb composition, with coarse titanium powder being the chemical of choice. Gerb compositions in a thin tube set up in a spiral arrangement are used as wheel drivers, fore spinning fireworks e.g.Catherine wheels.

Igniter cord.     A fuse consisting of a wire core ( usually ) with the pyrotechnic compound covered by a plastic outer layer. This gives excellent protection from damp, and igniter cord is very reliable in wet weather. Green igniter is slow - about 1 second per inch or 25mm, brown is fast - about 1 second per foot or 300mm.

Lance.      A lance is a thin paper tube containing a pyrotechnic composition. These are most commonly used in large numbers to make writing and pictures at firework shows - this is referred to as lancework. the tube is thin so it burns completely away as the lance burns, so as not to restrict light emission from the burning section.

Maroon.     A firework which produces a single loud report, often used to announce the start or the end of a display. An ariel maroon is a shell, and a signal maroon a rocket.

Mine.      Like a shell the mine is fired from a mortar, but emits directly from the tube. The lift charge sends up a bag full of stars and a bursting charge, with a short fuse set to spread the stars relatively close to the ground. Because the bag has much less strength than a shell, the stars are not spread as far, and the final effect is that of a shower of stars moving upwards in an inverted cone formation.

Mortar.      A tube, sealed at the one end for firing shells and mines. In the US they like to call mortars " guns " and to " shoot " displays.

Portfire.      A long thin tube which burns with a bright flame, used to ignite other fireworks.

Roman Candle.     A mainstay of many a display the candle projects a variety of stars, comets or other effects. often fired in batteries with mixed and matched effects.

Salute.     An effect produced, usually with flash powder - a single loud report and flash.

Serpents.      An effect consisting of erratic streaks, often humming or whistling.

Set Piece.      An assembly of components, usually fountains, wheels and lances. Set pieces are often pictorial or graphic.

Shell.      The shell is a sphere or cylinder of paper mache or plastic which contains stars and a bursting charge, together with a fuse. It is fired into the air from a tube using a lifting charge, usually black powder. The time the fuse takes determines the height above the ground at which the shell will burst, igniting and spreading the stars.

Stars.      A star is the bright burning objects you see ejected from Roman   Candles, shells, mines etc. consisting of a pyrotechnic composition fashioned into pellets. The pyrotechnic composition is mixed with a binder and a small amount of solvent to make a doughy mass which is then fashioned into stars. The usual methods are to make the composition into a flat pancake of sausage and cut it up into stars ( " cut stars " ), pushing it through a tube with a dowel, cutting it of at regular intervals ( " pumped stars " ), or rolling cores of lead shot coated in fire clay in a bowl of the composition ( " rolled stars " ). Cutting and pumping produce cubic or cylindrical stars, while rolling produces spherical stars. Pumped stars are the most suitable for Roman Candles, because it is easy to get the correct width. The stars are often dusted with a primer, usually meal black powder, to ensure ignition. Pressed stars involve the composition being pressed extremely hard into a mould with a hydraulic press or similar.

Strobe.      One of the latest aerial effects consisting of a cluster of slowly descending bright silvery lights, twinkling on and off.

Rocket.     A rocket consists of a tube of rocket fuel, sealed at one end, with a choke at the other end. The burning fuel produces exhaust gases, which, when forced out of the choke, produce thrust, propelling the rocket in the other direction. At the top of its flight most rockets burst. A rocket is not a projected body but a powered one. Not only will it not be describe a parabola, but a wind will catch the stick causing the climb to become flatter and, unlike the rest of the display the rocket will ascend into, not with the wind. Once the motor is spent the remains of the rocket will then descend with the wind, returning to the ground, sometimes, exactly, at the firing point. Solid fuel rockets can be one of two types - end burning, where the fuel is solidly packed into the tube, so that the fuel can only burn at the one end - and core - burning, where there is a central core longitudinally through the fuel, so the fuel can burn down its full length. At the top of the rocket can be a smoke composition, so it is possible to determine the maximum height ( "apogee") of the rocket, or a burst charge and stars.

Trajectory.     The path of a projected object. Under normal conditions the trajectory of a projectile is a parabola. The major effects which causes this to vary is the wind.

Waterfall.      These are similar to Gerbs, but usually do not spray as far. They usually mounted horizontally in banks of several tubes, placed some distance above the ground. when ignited, the effect is like a brilliant waterfall of sparks.

Willow.     A beautiful aerial effect created by excess charcoal in the composition of the star. This gives the star an extra long burn time which creates bright amber falling streaks, simulating the form of a weeping willow tree.

 

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