Prioritizing safety over speed / New Shinkansen has shorter braking distance to respond to quakes
The operator of Tokaido Shinkansen bullet trains will shift its long-running innovation priority from higher speeds to a shorter braking distance so that trains can better respond to major earthquakes.
Central Japan Railway Co. (JR Tokai)'s new model, called the N700A, features a braking system with a shorter stopping distance.
The N700A, which will be introduced in February, is the sixth series in JR Tokai's Shinkansen designs. The Tokaido Shinkansen will soon mark its 50th anniversary.
Until now, each new series has brought greater train speeds and shortened riding times. With the latest model, however, these factors will remain unchanged.
From Tokyo to Shin-Osaka stations, the new model's maximum speed will be 270 kph, the same as now, and traveling time will also not change, currently at two hours 25 minutes.
One company official said: "We pursued faster stopping times for the new train. We prioritized improved safety over higher speed."
Shinkansen trains have systems in place that apply emergency braking if strong earthquake tremors are detected.
According to JR Tokai, the N700A's braking distance is about 10 percent shorter than conventional models.
With its improved speed control device, the new model can also automatically maintain speeds close to the limits on each section of a line.
Even if service is disrupted, a delay in the bullet train's arrival can be minimized.
The Tokaido Shinkansen Line started operations in October 1964, just before the Tokyo Olympics. At the time, their bullet trains connected Tokyo and Osaka in four hours, compared with the 6-1/2 hours required on conventional train lines.
In 1965, bullet trains became full-fledged high-speed services, and travel time was reduced to three hours 10 minutes.
Later, technological upgrades, such as lighter train bodies, raised the maximum possible speed, which resulted in even shorter travel times.
The speed limit on the Tokaido Shinkansen Line is currently 270 kph. The 300 series introduced in 1992 shortened the journey to 2-1/2 hours.
Since then, the travel time has been reduced by only five minutes.
Because the line has many curves, it is difficult to increase the train's speed. The company must also consider noise pollution as the trains run through densely populated areas.
The plan to build the Linear Chuo Shinkansen Line, whose maximum speed will be 500 kph, has caused the company to end its half-century-long tradition of raising trains' maximum speeds.
Under JR Tokai's plan, the linear line will start services from Tokyo to Nagoya in 2027, and in 2045, it will connect Tokyo and Osaka in one hour seven minutes.
Nobuyuki Sato, a traffic affairs commentator, said, "On the Tokaido Shinkansen Line, higher speeds and shorter travel times are no longer necessary."
On the Tohoku Shinkansen Line, which has many straight sections, the practice of raising trains' maximum speeds will continue.
East Japan Railway Co. (JR East) plans to run its trains at a maximum speed of 320 kph, which will be a record in the nation, to connect Tokyo and Shin-Aomori stations in two hours 59 minutes--11 minutes shorter than now.
JR East aims to raise the maximum speed on the Shinkansen lines to 360 kph in the future.
(Jan. 14, 2013)
