Breathtakingly large, the “Deka-yama,” or “huge mountain” floats, live up to their name as the largest in all of Japan. Try to picture something so large squeezing through a small city block.
The parade floats of the Seihaku Festival were recognized by UNESCO as an Intangible Cultural Heritage thanks to the Deka-yama. They stand about 12 meters tall. The V-shaped displays are called “hiraki”, and the largest ones are about 13 meters wide. The whole float weighs in at a whopping 20 or so tons, with the diameter of each wheel reaching about 2 meters. If you look closely you will see the intricate construction, like a puzzle of many wooden pieces. Such craftsmanship is a result of employing shipbuilding techniques.
The Seihaku Festival is regularly held by the Ōtokonushi Shrine, or Sannōmachi Shrine as it is colloquially known. It lasts for three days starting on May 3rd every year. The name “Seihaku,” or “green oak,” originates from the practice of offering food, drink, as well as green oak leaves to the gods. There are no accurate records detailing why the Deka-yama floats are offered up in this way at the Seihaku Festival. However, one can draw connections to Edo Period festival floats.
The Deka-yama cruise through three neighborhoods at the heart of Nanao city - Kajimachi, Fuchūmachi, and Uomachi - which are collectively called the Yamachō district. The three huge floats lined up side by side make for a truly breathtaking sight. The Deka-yama on display here was based on the Uomachi Deka-yama. In old times, wheels measuring two meters in diameter made from Japanese zelkova wood were used, but because it is difficult to process zelkova domestically, modern Deka-yama floats came to use bubinga wood processed in Africa. If you look closely you will see the intricate construction, like a puzzle of many wooden pieces. Such craftsmanship is a result of employing shipbuilding techniques.
When the festival is over, the Deka-yama floats are carefully dismantled piece by piece. Each year the floats are erected anew one month before the festival. Deka-yama floats are built without using a single nail because nails cannot fully bear the heavy swaying and weight without wearing down. The framework is held together by ropes made from mountain wisteria vines. However, recent years have seen complications in procuring wisteria vines, so instead, they are replaced with nylon ropes. But that doesn’t mean any material will work. Hemp rope, for instance, is too stiff to absorb the sways and bumps. The floats demand rope that’s flexible and allows plenty of slack. In addition, the Deka-yama here uses nylon ropes instead of wisteria vines for long exhibits and parades.
Did you notice the smaller wheels inside? These meter-wide wheels are called “jiguruma” and are installed in between and perpendicular to the gigantic outer cartwheels, to be used for course correction and cornering. Let’s get a closer look at how the Deka-yama changes direction.
Now let’s stand back a bit and have a look. According to one theory, the V-shaped “hiraki” display is modeled after Edo Period cargo vessels. The lavish display is usually decorated with three dolls depicting famous scenes from a Kabuki play about the Warring States period.
Movement is guided via a sharp triangular piece that is decorated with a red curtain. Viewing it from the front, you can see that the right and left sides are decorated with up to six smaller curtains in which are dyed with the symbol of each Yamachō neighborhood. The many crests distinguish the floats as Yamachō Deka-yama, even from a distance.
The enemy of the Deka-yama floats is, naturally, the wind. On gusty days, the woven mats catch the wind like a ship’s sails. In 2016, a spring storm caused gales strong enough to lift the wheels off one side of a Deka-yama float. This year, the mats had holes cut in them ahead of time so as to not catch the wind and avert the risk of overturning the float.
Now, then, what’s it's like to pull one of these enormous floats? Let’s find out
