HOW FIREWORKS WORK

AERIAL SHELLS 

Aerial shells are the most well known types of fireworks.  These are what rise into the air and create the magnificent colorful bursts of light seen at public fireworks displays.  A shell consists of a spherical ball or cylinder and a lift charge.  These are placed in large tubes sticking out of the ground, known as mortars or guns.  When ignited by the pyrotechnician, the lift charge on the bottom of the shell - no more than a bag or cup full of black powder - explodes, shooting the shell into the air like a bullet from a gun.  As the shell is rising upwards, a time fuse inside of it is burning towards the burst charge.  At the precise altitude, the shell explodes, blasting it apart and igniting the color pellets (stars) on the inside.  Display shells (for professional use only) can range anywhere from 3 to 24 inches in diameter!  Shells generally go 100 feet up for every inch in diameter they are.  Thus, an 8-inch shell (shown here) will go approximately 800 feet into the air before bursting.  

Smaller shells are available for consumer use, which are usually 1.75 inches in diameter.  Consumer aerial shell kits contain 1 or 2 mortars (tubes) and anywhere from 6 to nearly 40 shells.  To fire a shell, unwind the long fuse wrapped around it and carefully lower it flat end first into the mortar.  NEVER STAND OVER OR LOOK INTO THE TUBE.  Shells shoot up at several hundred feet per second - not something you want to get hit in the face with should it accidentally ignite.  Now here comes the classic line: Light the fuse and get away.  Before firing another one, turn the tube upside down and kick it or hit it against the ground to empty out any burning debris.  The shell should fit into the tube with no more than 1/8 inch or so between it and the tubing.  If there is too much space, the gas will escape and the shell will not go as high.  When a shell bursts, everything inside burns up.  The only "fallout" that comes back to earth are harmless little strips of the paper casing.

 FIRECRACKERS 

Do not light and throw firecrackers from your hand.  The fuse sometimes burns more quickly than usual, which can turn into a real nasty experience when it burns your finger or blows it off.    A great deal of fireworks related injuries result from this.  Don't risk it.

GROUND SPINNERS

Ground spinners spin around randomly at ground level, shooting out colored sparks and flames.  It works on the same principal as a rocket engine. When the powder inside ignites, it creates a large amount of gas, but rather than exploding, the gas and flames escape through the hole in the side (called a choke).  The thrust causes the device to move and bounce around crazily on the ground.  They must be used on hard, flat surfaces to work correctly.

FLYING SPINNERS 

NOVELTIES 

Novelties are small fireworks that usually look like some real life object (such as a frog, race car, ship, or tank) and often scoot across the ground.  They are one of the most harmless types of fireworks.  You don't need to get as far away as you would a typical firework, but then again, don't get too close - some will unexpectedly shoot out little flaming balls or emit a shrill, ear-splitting whistle.  Children really like these because they can use what's left over as a toy (or something to stomp on).

Novelties move by using tiny rocket engines.  When ignited, they expel hot gas out of a tube, thus moving the device in the opposite direction.  Whistling sounds, from novelties such as Piccolo Petes, are created by gas rushing through small, partly hollow tubes.  The length of the tube determines the pitch of the whistle.  A Piccolo Pete's whistle gradually changes as the powder burns farther and farther down the tube.

MINES 

Not to be confused with military weapons (i.e. land mines and naval mines), pyrotechnic mines produce upward, fan-shaped blasts of color and effects.  They are placed into mortar tubes, just like aerial shells.  Mines are usually only seen in professional displays.  There are very few mine products on the consumer firework market.   

Mines are relatively easy to make.  Click here to learn how to create your own mines. 

REPEATING AERIAL DISPLAYS

For safety, always place tall repeaters within a concrete cinder block or surround it with bricks so there's no chance of it tipping over.  Shorter, fat repeaters are pretty stable themselves, and don't need to have surrounding reinforcements, but it wouldn't hurt to have them.

REPEATING FOUNTAIN

Repeating fountains consist of multiple tubes, fused to go off in sequence.  As mentioned before, they can easily be confused with repeaters by their shape, but your clue that they are fountains is that the fuse is on the top, not the side.  These usually provide even longer lasting displays than regular single tube fountains, and can greatly improve your show.  Some pyros think fountains are childish and weak, but they can greatly enhance a show, especially when used in combination with shells or other aerial items.

ROCKETS & MISSILES

ROMAN CANDLES

Roman candles are a single tubes that fire many shots, unlike repeaters and shells that only fire one shot per tube.  They fire one at a time out of a tube.  The shots are like miniature aerial shells: they can be anything from a color star to a small comet or a whistle.  The construction is complex, and consists of many layers.  When the fuse is lit, it ignites the lift charge below the shot, thus firing it into the air.  A delay charge burns around the next shot before igniting it's lift charge and shooting it out of the tube.  This process repeats itself over and over again.

Only place roman candles in the ground or in a secure support, such as a pipe.  DO NOT hold them.  They seem like they're pretty harmless to hold, but if one of the shots were to get stuck in the tube, the whole thing could explode, scattering pieces of paper and fingers everywhere.  

SINGLE TUBE FOUNTAINS

SPARKLERS, SMOKES, SNAKES & STROBES

Smoke and snake items are generally for daytime use.  When snakes burn, they emit a long, brittle carbon ash, which looks like a snake coming out of the ground.  They can be a real pain to ignite, unless you use some sort of torch.  They also leave a burn mark on the ground that takes a long time to go away.  Smoke items are a good daytime item that are fun to play around with.  Strobes make bright, disorienting flashing of light.  Some are supposedly colored, but they all look white to me.  Sparklers are tiny hand held fountains that give off colored sparks from the burning tip.  They are the only firework meant to be held.

DO NOT, I repeat, DO NOT, give sparklers to young children!  The tips burn at up to 2000º.  Two thousand.  They can cause horrible 3rd degree burns, and are one of the leading causes of fireworks injuries simply because parents often give their toddlers/little kids sparklers thinking that they are safe.  Small children have absolutely no common sense, and will try to cup their hand over the burning end.  

WHEELS AND SAXONS

 Firework photos courtesy of Phantom Fireworks.  Used with permission.