The last two trains in the "platypus" (kamonohashi) Shinkansen series known for its plump face and energy-saving features will be retiring in March.

Fans of the trains can take comfort in the fact that carriages of the beloved 700 series will be given a second life as aluminum building material to decorate a new shopping mall in the hub station in Tokyo.

The trains were designed on the theme of "harmony with the environment" and a focus on energy saving and ride quality rather than speed. The final run on the Tokaido Shinkansen Line section between Tokyo and Shin-Osaka will be March 8.

Central Japan Railway Co. (JR Tokai) and West Japan Railway Co. (JR West) manufactured a total of 91 trains for the 700 series. However, only two trains are currently in operation under JR Tokai.

The trains stopped regular runs on the Tokaido Line in December and have since served as a special Nozomi train.

As the only remaining Shinkansen with smoking cars in Japan, the 700 series also attracted tobacco fans. 

The 700 series made its debut in March 1999, replacing the first Nozomi 300 series.

While previous Tokaido Shinkansen trains broke speed records, the 700 series runs at a speed of 270 kph, the same as the 300 series.

JR West introduced its 500 series in 1997, which operated on the Sanyo section between Shin-Osaka and Hakata, reaching speeds of 300 kph.

The 700 series runs at a speed of about 285 kph on the same section.

"The 300 series that suddenly increased the maximum speed for 50 kilometers had several problems, such as in-car train noise and malfunctions," said Masayuki Ueno, a deputy general manager of JR Tokai’s Shinkansen railway business division.

"The 700 series possessed high reliability and was well-balanced with ride quality,” recalled Ueno, who took part in the development of the series.

To reduce noise inside the cars, the structure of the train's body was double-layered, with sound-insulating materials tucked in, and equipped with a device that changes the sound produced by a motor into a frequency that is difficult for humans to hear.

The 500 series has a cylindrical body to make it more aerodynamic, while the 700 series has a boxy body to emphasize spaciousness. 

The width of the aisles is 3 centimeters wider and the ceiling height 6.5 cm higher than those of the 300 series. In keeping with the "harmony with the environment" concept, the head is shaped like the beak of a platypus.

The unique shape not only helped reduce air resistance, one of the causes of noise, but also promoted energy-saving. The 700 series consumed 8 percent less power compared to the 300 series. 

Owing to such features, the train's operator has promoted the 700 series as "earth-friendly transportation," as it emits less carbon dioxide than typical passenger airplanes. 

TRAIN OF MANY FACES

The Tokaido Shinkansen first started operating in 1964, with the inaugural 0 series featuring a pug-nosed face, while the face of the 300 series was described as an "iron mask."

Since the 700 series was introduced, however, most Shinkansen have had faces resembling a "platypus."

Dogleg-shaped pantographs for collecting electricity and underfloor equipment layouts particular to the 700 series have also been incorporated into the latest bullet trains. 

"The basic design of the 700 series has continued to live on in the latest N700S series model," Ueno said.

The 700 series train cars will be dismantled and recycled after retirement. 

The aluminum bodies are expected to be used as building materials, a first in the history of recycling Shinkansen cars. The materials will be used for interior decorations and showcases for a shopping mall scheduled to open in early summer at Tokyo Station's Yaesu North Gate.

Retired Shinkansen bodies have mostly been recycled and reused as an additive in the steelmaking process, as it had been difficult to separate the layers of paint and sound insulation materials, according to Tokyo Station Development Co., a group business of JR Tokai.

However, the company developed a novel method to separate such materials in March 2019.

The shopping mall, called “Tokyo gifuto paretto,” will open just ahead of the 2020 Tokyo Olympic and Paralympic Games.

“At the 1964 Tokyo Olympics, the newly running Tokaido Shinkansen promoted Japan’s latest technology to the world,” said Akihiko Kusakabe, who heads the designing department of the company. “In 2020, the recycled 700 series will surely promote Japan's eco-friendliness.”