HOW FIREWORKS WORK - Innovations of ridiculous fireworks displays

Like a moth to a patterned explosive flame, everyone likes watching fireworks. How are they made and what crazy innovations are used to make these perfectly timed color-splosions work? DfS investigates...

Basic over the counter fireworks are fun to explode things with (minus your hand) but not that interesting to read about. Its the dangerous, complicated and expensive firework rigs that you want to read about. So lets start with figuring out how to get the firework off the ground and into the sky so that they can explode in time to Katy Perry's conveniently named 'Firework' song...

Traditional firework launching systems rely on a series of tubes and a control box. The tubes contain an explosive charge which, when detonated, shoots the firework into the sky. The control box determines when and what explosive charge is detonated. This allows the pyrotechnicians to launch specific fireworks at specific times. Most control boxes are dependant on a series of manually activated switches which send an electrical charge to the fireworks. It can be more practical to use a remotely detonated charge system such as when detonating fireworks at sea/ river on a floating barge. This allows the control box to be safely operated from a boat or land.

A typical detonation control box.

Tubes loaded and ready.

When you want your fireworks to explode in time with a song, a computer controlled detonation system is used. Pyrotechnitians will pre-program certain sized/ shaped fireworks to explode in time with the musics beat. Fancy. Its worth noting that the most prestigious firework displays, such as that of the NYE Sydney Harbor Bridge costs in excess of seven million dollars.

A recent firework launching innovation substitutes a detonating charge for compressed air, essentially using the same gun-like principles as the explosive charge technique (expanding gasses propelling the firework out of the tubes). This launch technique results in less smoke during the display, and we're guessing there will be less chance of catastrophic firework failures...

NOTE: the objective is to not explode everything at once in a ball of white pyrotechnic failure.

Once the firework is up in the night sky. Were going to want to see a vast array of colours, shapes, sizes and noises. Firework colour is determined by what type of colourant is mixed with the explosive. Different chemical compounds will produce specific light when set on fire, for example lithium carbonate (Li2CO3) burns red and thus will be used in red fireworks.

Making fireworks explode in specific shapes (see: smiley face) is actually quite simple. If you were to cut open a firework which explodes to form a smiley face, you would find a bunch of 'stars' (stars are what pyrotechnics call the individual explosive balls) that are literally in the shape of a smiley face. A black powder charge in the center of the firework propels the stars outward and then simultaneously explodes them. All this is contained in a spherical outer shell.

This firework half-cut shows the smiley face pattern with a central black powder detonating charge. Almost too easy.

That is everything you need to know about how fireworks work. Did you enjoy reading about fireworks? If so, then like, comment or share this article to support DfS. It takes time and effort to run this blog, so any support is greatly appreciated. Thanks!