• Chunichi Shimbun


The Miyashiro No. 1 power plant, which houses the country’s oldest working hydraulic generator, is attracting public attention after it started offering guided tours last spring.

In operation for 111 years, the plant, in Azumino, Nagano Prefecture, has contributed to the nation’s industrial progress but has only begun gaining recognition — some 30 years after it was confirmed as the oldest such generator in Japan.

In a small building near a prefectural road that leads to the hiking trail of Mount Tsubakuro in the Northern Alps, one can hear the water wheel and generator churning furiously.

Plates with the year of manufacture, 1903, printed in German can be seen on the equipment.

The usual operating life of a water wheel is said to be about 80 years as it is worn down by sand and gravel in the river.

“But this one is thick and durable like a German car. The casting is also well-made,” said Takeshi Yajima, 52, manager of the Hydro Power & Substations Maintenance Department at Chubu Electric Power Co.’s Oomachi Local Maintenance Office.

The plant was built over 100 years ago after the machinery was transported from Germany by sea and then carried to the site using the now-defunct Shinonoi Railway Line and oxcarts.

The plant started operating in September 1904. At the time, it was considered to be one of the leading generators in Japan, with an output capacity of up to 250 kilowatts.

However, according to Hotaka town records, local residents were suspicious about whether it was possible to generate electricity from water. They worried that the electricity might deplete the nutrients in the water and thus damage rice crops.

It was Susumu Kitano, 85, a former teacher at an industrial high school, who discovered the year of manufacture written on the nameplates and realized it was the oldest existing generator in Japan.

Kitano was conducting research on the technological history of the prefecture and presented his discovery to the Japan Industrial Archaeology Society in 1982.

In 2007, the Ministry of Economy, Trade and Industry added the generator to the list of Heritage of Industrial Modernization.

The generator is not only valuable for its long use, but also because it “played an important role in Japan’s industrial history,” Kitano said.

It was designed and constructed by Shitagau Noguchi (1873-1944), who founded Chisso Corp. (formerly Japan Nitrogenous Fertilizer Co.) and Asahi Kasei Corp.

It was his first assignment after being hired by the Tokyo branch of Siemens K.K., which was manufacturing generators.

The plant enabled a local firm to operate the electronic furnace it invented to melt steel but could not put to use due to lack of electricity, thus greatly contributing to the development of steelmaking technology in Japan.

The generator currently produces 3 million kilowatt-hours annually, providing power to 900 households.

It was previously closed to the public because it is unmanned, but last year a small group of educators asked to visit the facility and their request was granted.

This year, the city’s tourism association organized tours to promote the site, which attracted 108 visitors in total.

“When we say ‘heritage,’ we usually refer to estates and facilities that are no longer in use, but this is a living heritage,” said Yasuhiro Hayashi, 45, a plant worker who guides the tours.

The facility only accepts reservations for group tours. For more information, call Chubu Electric Power Co.’s Shiojiri power station at 0263 (52) 2330.

This section, appearing Tuesdays, features topics and issues from the Chubu region covered by the Chunichi Shimbun. The original article was published on Nov. 7.

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