Safety concern over Metro's 4000-series railcars

A possible safety concern has resulted in Metro to reorganize all of its 4000-series railcars in its fleet.

On Thursday afternoon, Metro General Manager Paul Wiedefeld initially ordered the removal of all 4000-series railcars from service effective immediately after engineers found an potential issue with the railcar's automatic train control (ATC) system.

However, Metro later clarified its plan and said they will continue to use the 4000-series railcars as long as they are not operated as the lead car and are only used in the center of trains. Doing so would not pose as a safety threat, according to Metro.

In a news release from Metro, the ATC system "keeps trains properly spaced and a safe distance from other trains by displaying 'speed commands' on a control panel in the operator's cab." When operating in manual mode, train operators use the speed commands to help them determine what speed they should be going and when a train is authorized to move.

Metro said railcar engineers found concern of a possible undetectable failure that may occur on the 4000-series ATC system control board "that could result in improper speed commands being given to a train when a 4000-series car is in the lead position."

"A false speed command means the operator could be revving the train too quickly, therefore creating a collision risk," said FOX 5 contributor Martin Di Caro.

Because Metro lacks the specialized equipment to test these railcars, the transit system had been unable to follow through with the recommended annual testing of the 4000-series cars.

There are 82 Metro 4000-series railcars, which consists of about 7 percent of Metro's fleet. According to Di Caro, the 4000-series railcars are the worst in Metro's fleet in terms of reliability. Metro said it had been considering retiring all of its 4000-series railcars by the end of 2017.

"Today's action is being taken in an abundance of caution and, while we believe that the risk is small, it is a risk I am unwilling to take," Wiedefeld said. "Everything we do here is going to put safety first, no matter what."