KOBE -- The mystery of a crack forming in the undercarriage of a Shinkansen bullet train has finally been solved, and improper handling by Japan's domestic leader in railway car production Kawasaki Heavy Industries Ltd. has been pinpointed as the cause of the first serious incident involving the trains.
According to a survey by Kawasaki Heavy, the problematic steel frame of the undercarriage was manufactured in February 2007, meaning that the defective part traveled with one of Japan's highest speed trains for some 10 years before discovery -- information sparking criticism that such negligent maintenance could have cost passengers their lives.
Roughly 100 members of the media rushed to an emergency press conference held by Kawasaki Heavy President Yoshinori Kanehana at the company's Kobe Head Office in Hyogo Prefecture on the evening of Feb. 28. There, Kanehana opened by lowering his head and apologizing.
The surface of the bottom of the 8-millimeter thick steel frame of the undercarriage was uneven in places, and Kawasaki Heavy needed to fix this. While company standards stipulate that filing down the steel frames of undercarriages is prohibited in principle, it was possible to scrape up to 0.5 millimeters of the steel where it would be welded.
Thus, the foreman at Kawasaki Heavy's rolling stock company Hyogo Works' factory permitted workers to scrape the parts, but did not explain the 0.5-millimeter limit to roughly 40 workers, who then repeatedly scrapped the bottom of the undercarriage components exceeding that thickness in order to flatten the surface of the part.
Additionally, the foreman did not inspect the finished products, and the manufacturing engineering division that set the handling standards did not check the finished parts either. The department left the production steps and the safety checks to the factory floor, and similar sloppy production management was reportedly conducted during the manufacturing of other undercarriage frames during that time.
"There was not enough attention paid to safety and strength (of the steel)," said senior vice president of the rolling stock company Makoto Ogawara at the press conference. Scraping down the steel frames can weaken the metal, and creating a serious situation where the safety of the train car is significantly decreased. "Basic company training was severely lacking," he added. Kawasaki Heavy has begun an emergency inspection to deduce if company regulations are properly understood.
While tough questions about improving Kawasaki Heavy's corporate culture rained down on the executives for close to one hour and 50 minutes, president Kanehana stated, "Our corporate group as a whole will thoroughly examine our quality control system so a problem like this never occurs again."