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Types Of Fireworks;
MORTARS / SHELLS
Video Shows 6" Ariel Shell with Red Wave To Blue Stars To Green Strobe effect.
Aerials shells are always seen at professional displays where they are fused together and fired in barrages -usually as part of a finale- producing huge bursts of patterns and colour high in the sky. They are also very popular as consumer fireworks, generally available in kits containing one or two mortars with anywhere up to 100 shells. Most shells are single units although multiple shells attached to each other and bursting in quick succession are also available in double, quadruple and quintuples. View this Firework Bust Effects Table for an explanation of the different effect available.
The mortar from which the shells are fired are increasingly made out of High-Density Polyethylene (HDPE), although they also come in fiberglas or heavy cardboard. Kits range from small ones with a single 12" cardboard mortar and 6-18 single-break shells, to larger shell assortments containing one or more 18" long HDPE mortars and many shells with multiple breaks and effects.
How Fireworks Work - Shells
A shell consists of five main parts:
- Casing: the strong outer wall to protect the explosive contents.
- Lift Charge: The main propellant.
- Time Fuse: To ignite the shell at the correct time.
- Burst Charge: To ignite the effects packed inside it
- Stars / Effects: The visual display part of the shell.
A shell is lowered into the mortar with the fuse trailing up and out. When the fuse is lit and enters the shell it ignites the lift charge creating an explosion that fires the shell high into the air while at the same time igniting the time fuse. As the shell reaches the apex of its flight, the time fuse reaches and ignites the black powder burst charge causing the shell to explode. The powerful explosion blasts apart the shell casing and ignites the stars, scattering them in all directions across the sky. These stars burn brightly and give off sparks, creating the familiar spherical pattern in the sky.
The actual pattern that an aerial shell forms when it bursts depends on the arrangement of stars inside the shell. If the stars are equally spaced in a circle around the burst charge, the resulting display will be small star equally spaced around a central explosion.. To create a specific figure in the sky, an outline of a figure is created in star pellets, surrounded as a group with a layer of burst charge to separate them simultaneously from the rest of the contents of the shell, and explosive charges placed inside the pellets to blow them outward into a large figure.
Consumer Shells (Display Tubes)
Display tubes come in two types - single and multiple. Single tubes are basically a pre-loaded aerial shell with an exotic effect not found in most shells - for example, a purple comet, and green palm tree, a thick gold comet, or a giant red chrysanthemum burst. Multiple-tube types contain several tubes with a single shell each, and are fused to fire a few seconds apart.
How Fireworks Work - Display Tubes
Display tube devices consist of little more than several aerial shells fused together to go off in sequence, with a few seconds of delay between each shell. There are usually anywhere from 3 to 7 tubes which are glued down to a thick wooden base to stabilize the device. Each tube contains a typical aerial shell in the bottom, protected by a cardboard disk and a cap at the top of the tube. Holes are drilled in the bottom of each tube, and small chunks of fuse connect each shell to the tube adjacent to it. The tube on the end has a long fuse that runs outside for a few inches. When that fuse is lit, the first shell fires. The lift charge of that shell ignites the chunk of fuse leading into the next tube, which in turn ignites a shell about four seconds later, and so on.
The Fireworks Company Thailand accepts no responsibility whatsoever for any injuries or accidents that occur as a result of attempting any of the displays or projects mentioned in this site, or as a result of use or misuse of any pyrotechnic products purchased from us. We highly recommend the use of professional display service for anything other than consumer 1.4G Fireworks with shells 1.75" or less in diameter.