Photo/IllutrationThe derailed Puyuma Express in Yilan, Taiwan, on Oct. 22 (Asahi Shimbun file photo)

Rolling stock manufacturer Nippon Sharyo Ltd. said it uncovered a design flaw for a safety device on a train it built that derailed in eastern Taiwan in October, killing 18 people.

“As the cause of the accident is currently under investigation by Taiwanese authorities, we cannot tell if our mistake is linked to the accident,” the Nagoya-based company said on Nov. 1.

The eight-car, high-speed Puyuma Express has a safety device that controls speed and other operations. If the driver switches this device off, that information is automatically transmitted to railway operation command.

However, the company found that a wiring connection in the crashed train was different from specifications due to a mistake in the design stage, and the automatic alert function didn’t work.

Two days after the Oct. 21 derailment, which injured more than 200 passengers, the Taiwan Railways Administration, the train’s operator, asked Nippon Sharyo to check the train’s automatic alert function.

The train driver has already told Taiwanese prosecutors that he switched off the speed control device about 30 minutes before the accident occurred.

He apparently turned off the device so that he could operate the train manually because there were problems with the train’s power system.

The driver also said railway operation command had given him permission to turn off the device.

The Taiwan Railways Administration, however, denied there was such a report from the driver.

An investigative team of Taiwan’s Executive Yuan said radio records and other evidence indicate that railway operation command, through communications with the driver, knew that the device had been turned off at least three minutes before the accident.

But if there had not been a design flaw, railway operation command could have learned the situation surrounding the train earlier.