花火情報館
Structure of Japanese Hanabi?


People enjoy the excitement and spectacle of Japanese HANABI (fireworks), when they explode in the sky. Few spectators, however, understand the structure or construction methods used to make these special HANABI shells. They bloom quickly and are gone but there are many kinds of effects that people may not be aware of.

Structure of Japanese HANABI.
The diagram at the left shows the structure of a HANABI shell and shooting mortars (TUTU). The lighting fuse extends out of the mortar and is lit with a match or source of fire. This fuse burns down to the lift charge (shooting powder) under the shell which ignites and shoots the shell into the sky. The HANABI shell has a fuse (DOUKASEN), on its bottom which is ignited by The lift charge when the shell is fired . The shell will rise into the sky and when the fuse (DOUKASEN) burns into the middle of the shell, the burst charge (WARIYAKU) blows the shell apart and ignites the colored stars or effects. Stars (HOSHI) are scattered in all directions to create a large spherical " bloom" of burning colors.


WARIYAKU (burst charge) ----This is a "burst charge" in the center of the shell which explodes and causes the stars (HOSHI) to ignite and p ropels them outwards, we use chaff, or rice hulls, covered with flash powder to burst the shell apart.

Star(HOSHI) -----We control or change the color of a shell by altering the chemicals in the mixture of the stars. We can even build the stars in different layers of compressed powder which will change color as they burn from the outside layers into the central core.

Fuse(DOUKASEN) ----The HANABI shell is propelled from the mortar and shot up into the sky by a lift charge of black gunpowder under the sh ell. The flames from this lift charge will ignite a " time fuse" at the same time that it propels the shells into the sky. This time fuse is designed to burn a specific length of time so that the shell blows up in the sky. This time may vary with the design and size of the shell. This fuse burns from the outside of the shell to the center where it ignites the WARIYAKU (burst charge).

Case(TAMAGAWA) ----The case used in our HANABI shells is made of cardboard and f orms a sphere when assembled. A long time ago, we made our own cases but now there are many companies that manufacture and supply these to us.



Classification of HANABI shells
Hanabi shell have many classification method. We explain typical classification. HANABI are classified by the type of effects and explosions that they create.
"Wari-mono" "Poka-mono"

Classification of the type of effects and explosions

WARIMONO-----This is a very common shell at fireworks conventions. It has a large quantity of explosive powder in its burst charge and makes a very loud bang with a big flower in the sky.

POKAMONO-----This is not a spherical bloom but instead has several reports inside which are thrown into the sky and explode as separate loud bangs.

HANWARIMONO-----This shell is in between WARIMONO and POKAMONO in power. It explodes and many small flower bursts open across the sky. An American equivalent might be a "shell of shells".




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