Sumida River Fireworks Festival
Date: Sat. July 25, 2015
The festival will be cancelled in case of rain.
Time: 7:05 PM - 8:30 PM
Location: Sumida River (at two sites. For details, see the map).
Origins of the Kawabiraki (Opening of the River) and Fireworks Displays
(from a Shinto rite to a pleasant pastime)
Rather than a type of firework, the word Starmine refers to technical aspects of launching fireworks. At the same time, it expresses how several varieties of fireworks are launched to create a harmony of colors and shapes.
* The sense and skills of fireworks pyrotechnicians.
This has the basic structure of a firework. On the inner side of the shell many smaller fireworks known as stars are lined up evenly. These individual fireworks give forth light and open up in the shape of a ball. The closer they are in shape to a perfect circle, the better they are said to be.
* There are a large number of papers for the shell and a large amount of breaking powder.
The shell rises up in the sky and breaks in two, after which the casings and the mechanisms (including parachutes or flags) descend to the ground. When casings are contained, the element of color is added in irregular movements.
* Both the number of papers for the shell and the amount of breaking powder is small.
This is a firework containing the characteristics of both the warimono and the pokamono. When it opens up in the air, it is characterized by a delicate coloring and configuration that differs from larger fireworks.
* Fireworks: The product of ideas and technology.
This is a firework that displays some structure or form when it opens up in the air. Development has continued in the hands of skilled fireworks artisans since the early years of the Meiji Period. Nowadays rather complex forms are possible. Here is a firework that you are almost certain to see at a fireworks festival. The photograph at right shows a "Snail" firework.
* The photographs of fireworks on the left side were all taken at the Sumida River Fireworks Festival in 2006.
●Gimmick Fireworks (Shikake-Hanabi)
Bamboo or other materials are used to create a model, after which fireworks are attached to the structure and caused to ignite in a dynamic firework in which the shape is shown in bold relief and brilliant color in the night sky.
●Large Shell Firework (Oodama)
As the name indicates, this is a firework that boasts one of the largest sizes among fireworks. Generally those fireworks measuring 5 sun (6.5 inches) (No. 15 Shell) or larger are known as Oodama. The largest such firework, registered in the Guinness Book of Records, was a 4 shaku (approx.11.8 inches) Shell. The locations where such fireworks can be launched are also limited, so they are naturally not found at the Sumida River Fireworks Festival.
■The colors of fireworks
Fireworks are pure chemistry! They use the night sky as their canvas for painting beautiful and colorful pictures. But where do those colors come from? Did you ever perform an experiment in chemistry class in school where you made a fine powder of metals and burned the powder to produce colors? The metal makes a crackling sound and emits color when it burns. This is known as the flame reaction. Fireworks are a form of technology that makes use of this chemical reaction. Nowadays modern chemistry has come to a certain understanding of the color reactions of compounds. Nevertheless, we are not yet at the stage where we can prepare colors at will.
A mixture of flame color agent (metallic chemicals), a combustion agent (combustion improver), and oxidizer (oxygenization agent) is used to create the basis for the firework. Even with the same composition, the color will vary depending on who makes the firework. And even in the case of red, it changes to dark red and to bright red, for example. Here is a field, then, where the skilled firework artisan can really show his skills. The composition tables for the toy fireworks used in the Edo Period still exist as precious documents and materials.
●Modern Colors, Edo Period Colors ("wabi" or Japanese-style flame)
Modern fireworks are extremely colorful and gorgeous, including red, yellow, green, white, purples, crimson and silver, to name just a few. In the Edo Period, however, there were no chemicals like those available today, which meant artisans had to make mixtures of sulfur, saltpeter and carbon to create changes in the color combination. This was the production technology for fireworks, which showed advances in technology with the passage of time. There are some colors which were only created quite recently.
Aqua: Completed in 1998
Emerald green: Completed in 1998
Orange: Completed in 2000
A traditional technology that is even used today is known as "ken" (exposure). By causing the firework to give off black, it appears for a moment as if the firework has extinguished. By causing it to give off color again, a deep impression is created in adding the element of "voidness."
■Dimensions of Fireworks
Number / Finished Size / Number of Papers for Shell / Weight / Launch Height /Diameter at time of opening
No. 3 8.5cm 9-12 0.2kg 120m 30m
No. 4 11.5cm 12-15 0.5kg 160m 65m
No. 5 14.2cm 18-21 1.3kg 190m 85m
No. 6 16.7cm 23-25 2.0kg 220m 110m
No. 7 20.5cm 27-30 3.0kg 250m 120m
No. 8 23.5cm 32-40 4.8kg 280m 140m
No. 10 29.5cm 43-50 8.5kg 330m 160m
No. 20 58.5cm 180 70.0kg 500m 240m
No. 30 88.5cm 450 280.0kg 600m 275m
* Reference works: Hanabi-Taikai Ni Ikou ("Let's go to a fireworks festival"), Shinchosha Publishing Co., Ltd.
Hanabi No Hon ("The book of fireworks"), Tankosha Publishing Co., Ltd.
* Photographs: Logical Think Co.