SAPPORO – Hokkaido Railway Co. continues to face a host of challenges to ensure the safety of its Hokkaido Shinkansen Line a year after the bullet train line went into service.
The 149-km-long high-speed train line connects Shin-Hakodate-Hokuto Station in the city of Hokuto in Hokkaido and Shin-Aomori Station in the city of Aomori.
Linked seamlessly to the East Japan Railway Co. Tohoku Shinkansen Line at Shin-Aomori, passengers can travel by shinkansen between Tokyo and Hokkaido without changing trains.
However, posing a challenge for the operator are the unique conditions under which the Hokkaido Shinkansen Line operates. Specifically, trains on the line travel in very cold areas, share part of the tracks with nonshinkansen trains and run through an undersea tunnel.
Since the Hokkaido Shinkansen Line was launched on March 26 last year, four trains have made emergency stops inside the Seikan Tunnel, which links Honshu and Hokkaido.
“Sharing the tracks with freight trains is a major challenge in the history of the shinkansen,” JR Hokkaido said in a train safety report last August.
Of the total length of the line, Hokkaido shinkansen trains share some 82 km, including the 53.85-km undersea tunnel, with freight trains from Japan Freight Railway Co. As freight trains have a narrower gauge than shinkansen trains, the shared section uses a dual-gauge system, in which an extra rail for freight trains is laid between the two rails for shinkansen trains.
In addition, maintenance work on the dual-gauge railway is difficult, with only two hours a day spent on late-night maintenance work — about a third of the time available for other shinkansen lines — as a result of freight trains using the line at night.
On April 1 last year, a Tokyo-bound Hayabusa bullet train from Shin-Hakodate-Hokuto made an emergency stop as it was traveling about 140 kph on a section near the Yoshioka emergency station inside the Seikan Tunnel.
The incident was blamed on an electric current along a metal segment between the extra rail for freight trains and one of the two rails for the shinkansen, which led the automatic train control system to falsely recognize that a freight train was traveling in the area.
Following the incident, JR Hokkaido cleaned the inside of the tunnel, but it happened three more times, in June, because of similar false recognitions by the ATC system.
The railway operator later raised the height of insulators between the rails to prevent the electric current from erroneously flowing between them.
Still, concerns linger, because of the unique structure of the dual-gauge railway system.
If a shinkansen is forced to stop inside the Seikan Tunnel and cannot be restarted, passengers and crew have to walk up to 10 km to the Yoshioka emergency station or the Tappi emergency station, which is also in the tunnel, where they can take a cable car to exit the tunnel or take a substitute train.
In April 2015, before the launch of the Hokkaido Shinkansen Line, 129 passengers and crew on a limited express train evacuated from Tappi using the cable car after the train stopped about 1 km from the emergency station due to smoke coming from the train.
On the shared section, shinkansen trains are allowed to travel at up to only 140 kph to prevent freight trains from derailing due to wind pressure when they pass each other.
The fastest shinkansen train currently links Tokyo and Shin-Hakodate-Hokuto in four hours and two minutes.
However, to reduce this to under four hours, JR Hokkaido is aiming to raise the maximum operating speed to 160 kph on the shared section as it competes with airlines for customers.
Sufficient safety measures will have to be installed, though, to realize the speed hike.
And JR Hokkaido is talking with JR Freight about the possibility of adjusting the timetable for freight trains in a bid to increase maintenance on the shared track to four hours daily.
Commenting on the first anniversary of the Hokkaido Shinkansen Line, JR Hokkaido President Osamu Shimada said, “We’ve had complex problems — operations in snowy areas and special equipment for the shared tracks. In more than 50 years of shinkansen history, this is the challenge facing only the Hokkaido Shinkansen Line.”
“We’ll accumulate experience and overcome our challenges,” he said.