Photo/IllutrationA crack is seen in the outer frame of an undercarriage of the Nozomi No. 34 Shinkansen on Dec. 12. (Provided by West Japan Railway Co.)

  • Photo/Illustraion

The outer frame of the undercarriage of a Shinkansen on which a crack was found on Dec. 11 was on the verge of fracturing, which could have caused the bullet train to derail, the train operator said Dec. 19.

West Japan Railway Co. (JR West) said its command center in Tokyo ignored a warning by maintenance workers to have the Shinkansen checked at a station after an odor and unusual noises were confirmed aboard.

“(The fact that the train continued to run despite the crack) betrayed people’s trust in the safety of the Shinkansen," Norihiko Yoshie, vice president of JR West, said in a news conference. "We deeply apologize (for the fact).”

The crack measured 16 centimeters in length, almost the same width as the steel-made frame, and 14 cm in height, most of the 17 cm-high frame. The width of the crack was 1.3 cm at the maximum, JR West said.

According to JR West, the N700-series, 16-car Shinkansen, Nozomi No. 34, bound for Tokyo, departed Hakata Station in Fukuoka at 1:33 p.m. on Dec. 11. A staff member noticed an unusual smell aboard at around 1:50 p.m., soon after it left the next station, Kokura.

Three maintenance workers boarded the train at Okayama Station at around 3:15 p.m. and confirmed the unusual odor along with abnormal sounds such as a groaning noise around the fourth car from the front of the train.

They recommended that the operation of the train be suspended at the next station for checking. However, JR West’s command center in Tokyo ordered the train to continue operating, saying, “There will be no hindrance to its running.”

JR West staff members were replaced by those of Central Japan Railway Co. (JR Tokai) at Shin-Osaka Station at around 4 p.m. JR Tokai’s command center then ordered the train staff to investigate the strange odor to confirm its origin.

A conductor reported an unusual smell at around 4:20 p.m., soon after the train left the next station, Kyoto. Maintenance workers checked the Shinkansen at Nagoya Station, and found a crack and oil leakage in the underfloor section at around 5 p.m.

The bullet train's operation was suspended, and about 1,000 passengers were transferred to other trains.

“There was a possibility that the crack could have led to an extremely major accident such as a derailment,” a JR West official said in the news conference.

“We should have suspended the operation earlier for checking,” the official added.

Meanwhile, JR Tokai officials said that when their staff members replaced those of JR West at Shin-Osaka Station, they were told that the Shinkansen had no abnormalities.

According to the officials, a JR West staff member told the JR Tokai staffers, “Though there were unusual odors, maintenance workers got on the train at Okayama Station and confirmed whether there were abnormalities.”

The staff member then told them, “There are no abnormalities.”

The government's Transport Safety Board, which is investigating the crack, strongly rebuked JR West for continuing to run the train after the staff members noticed the abnormalities.

“At the very least, it should have suspended operations when they noticed abnormal sounds or unusual odors,” said the board’s chairman, Kazuhiro Nakahashi. “It is extremely rare for a crack to be found in the undercarriage."